Eco-epidemiology of visceral leishmaniasis in Ethiopia

Survival analysis of adult visceral leishmaniasis patients admitted to Metema Hospital, Metema, Ethiopia: a hospital-based cross-sectional study

BACKGROUND

Visceral leishmaniasis (VL) is a neglected tropical disease that mostly affects the working class and impoverished segments of society, having a significant negative effect on the economic development of the affected nation. While anti-leishmanial medications lower mortality among VL patients, patients may still die or require more time to recover while receiving treatment. In this regard, there are limited studies in Ethiopia. This study aims to determine the time to recovery and its associated predictors among adult VL patients at Metema Hospital, Metema, Ethiopia.

METHODS

A hospital-based cross-sectional study was employed and the data were collected from patient's charts from September 2017 to September 2021. Data were entered and analysed using EpiData version 3.1, Stata version 14.2 and R version 3.4.0 statistical software. Kaplan-Meier survival curves and logrank tests were used to compare the survival time. The Cox proportional hazards model assumption and model fitness were checked and used to identify statistical association predictors in VL patients.

RESULTS

The Cox proportional hazards model was fitted. The overall medium recovery time was 7 d (minimum 4, maximum 14). The variables of nasal bleeding (adjusted hazard ratio [aHR] 0.44 [95% confidence interval {CI} 0.19 to 0.89]), no comorbidity (aHR 2.29 [95% CI 1.27 to 4.11]), relapse of VL (aHR 0.33 [95% CI 0.15 to 0.75]), low parasite load (aHR 2.58 [95% CI 1.48 to 4.51]) and ambulatory (aHR 3.26 [95% CI 2.45 to 6.53]) were significantly associated with time to recovery in VL patients.

CONCLUSIONS

Patients with comorbidities, nasal bleeding, relapse of VL, bedridden and high parasite load should be treated and monitored carefully to recover quickly from their illness.

Demographic characteristics and prevalence of asymptomatic Leishmania donovani infection in migrant workers working in an endemic area in Northwest Ethiopia

Introduction

Visceral leishmaniasis (VL), a neglected tropical disease that causes substantial morbidity and mortality, is a serious health problem in Ethiopia. Infections are caused by Leishmania (L.) donovani parasites. Most individuals remain asymptomatic, but some develop VL, which is generally fatal if not treated. We identified the area of Metema-Humera in Northwest Ethiopia as a setting in which we could follow migrant workers when they arrived in an endemic area. The demographic characteristics of this population and factors associated with their risk of asymptomatic infection are poorly characterised.

Methods

We divided our cohort into individuals who visited this area for the first time (first comers, FC) and those who had already been in this area (repeat comers, RC). We followed them from the beginning (Time 1, T1) to the end of the agricultural season (Time 2, T2), performing tests for sand fly bite exposure (anti-sand fly saliva antibody ELISA) and serology for Leishmania infection (rK39 rapid diagnostic test and the direct agglutination test) at each time point and collecting information on risk factors for infection.

Results

Our results show that most migrant workers come from non-endemic areas, are male, young (median age of 20 years) and are farmers or students. At T1, >80% of them had been already exposed to sand fly bites, as shown by the presence of anti-saliva antibodies. However, due to seasonality of sand flies there was no difference in exposure between FC and RC, or between T1 and T2. The serology data showed that at T1, but not at T2, a significantly higher proportion of RC were asymptomatic. Furthermore, 28.6% of FC became asymptomatic between T1 and T2. Over the duration of this study, one FC and one RC developed VL. In multivariable logistic regression of asymptomatic infection at T1, only age and the number of visits to Metema/Humera were significantly associated with asymptomatic infection.

Conclusion

A better understanding of the dynamics of parasite transmission and the risk factors associated with the development of asymptomatic infections and potentially VL will be essential for the development of new strategies to prevent leishmaniasis.

Epidemiological survey, molecular profiling and phylogenetic analysis of cutaneous leishmaniasis in Khyber Pakhtunkhwa, Pakistan

BACKGROUND

Cutaneous leishmaniasis (CL), an emerging vector-borne ailment in Khyber Pakhtunkhwa (KPK), Pakistan, exhibits diverse spread patterns and outbreaks.

METHODS

To comprehend its epidemiology and identify parasite species, we conducted an active survey on suspected CL cases (n=8845) in KPK.

RESULTS

Microscopy and internal transcribed spacer-1 PCR-restriction fragment length polymorphism (RFLP) molecular techniques detected Leishmania spp. in blood samples. Phylogenetic analysis gauged genetic affinities with other areas. District Bannu displayed the highest CL impact (14.58%), while Swat had the lowest impact (4.33%) among cases. Annual blood examination rate, parasite incidence and slide positivity rate were 4.96 per 1000 people, 0.0233 and 0.047%, respectively. CL infections were prevalent in 1- to 20-y-olds, with males (57.17%) more vulnerable than females (42.82%). Single lesions occurred in 43.73% of patients, while 31.2% people had two lesions, 17.31% had three lesions and 7.74% had more than three lesions. Most had sand-fly exposure but lacked preventive measures like repellents and bed nets. Leishmania tropica was confirmed via RFLP analysis in amplified samples. Phylogenetic analysis unveiled genetic parallels between L. tropica of KPK and isolates from China, Iran, Afghanistan, India, Syria and Morocco.

CONCLUSIONS

Urgent comprehensive control measures are imperative. Early detection, targeted interventions and raising awareness of CL and sand-fly vectors are vital for reducing the disease's impact. International collaboration and monitoring are crucial to tackle Leishmania spp.'s genetic diversity and curtail its cross-border spread.

First report of cutaneous leishmaniasis caused by Leishmania donovani in Ethiopia

BACKGROUND

Leishmaniasis is a common neglected tropical disease in Ethiopia. Visceral leishmaniasis (VL) caused by Leishmania donovani presents in the lowlands, while cutaneous leishmaniasis (CL) affects people living in the highlands. Although CL is described as being caused by Leishmania aethiopica, there is also evidence of L. tropica and L. major isolated from a patient, sand flies and potential reservoirs. Information on species causing CL in Ethiopia is patchy, and no nation-wide study has ever been done. Understanding which species are causing CL in Ethiopia can have important implications for patient management and disease prevention.

METHODS

We analyzed stored routine samples and biobanked DNA isolates from previously conducted studies of CL patients from different centers in the north, center and south of Ethiopia. Species typing was performed using ITS-1 PCR with high-resolution melt (HRM) analysis, followed by HSP70 amplicon sequencing on a selection of the samples. Additionally, sociodemographic, clinical and laboratory data of patients were analyzed.

RESULTS

Of the 226 CL samples collected, the Leishmania species could be determined for 105 (45.5%). Leishmania aethiopica was identified in 101 (96.2%) samples from across the country. In four samples originating from Amhara region, northwestern Ethiopia, L. donovani was identified by ITS-1 HRM PCR, of which two were confirmed with HSP70 sequences. While none of these four patients had symptoms of VL, two originated from known VL endemic areas.

CONCLUSIONS

The majority of CL was caused by L. aethiopica, but CL due to L. tropica and L. major cannot be ruled out. Our study is the first to our knowledge to demonstrate CL patients caused by L. donovani in Ethiopia. This should spark future research to investigate where, how and to which extent such transmission takes place, how it differs genetically from L. donovani causing VL and whether such patients can be diagnosed and treated successfully with the currently available tools and drugs.

Time to death and its determinant factors of visceral leishmaniasis with HIV co-infected patients during treatment period admitted at Metema hospital, Metema, Ethiopia: a hospital-based cross-sectional study design

BACKGROUND

Visceral leishmaniasis is caused by the parasites Leishmania donovani spices complex that can spread to internal organs and the disease is fatal with a fatality rate of nearly 100% if left untreated. Visceral Leishmania-HIV (HIV1) coinfection disease is a new clinical form of leishmaniasis very serious disease in the endemic part of the world. It also served as the primary cause of death in the lowlands of Ethiopia with the endemic Humara and Metema that are located near the Sudanese border.

METHODS

A total of 153 visceral leishmaniases with HIV co-infection secondary data was taken from the medical chart of patients from January 2015 to January 2021 and a hospital-based cross-sectional study design was carried out to retrieve relevant information. The data entered by SPSS and analysed using STATA version 14 and R4.2.1 statistical software packages using a non-parametric Model, semi-parametric Cox proportional hazard survival models at 5% significance level.

RESULT

Among the total visceral leishmaniasis with HIV co-infected patients 3.27% were females and 96.73% were males, 19 (12.42%) patients died and 134(87.58%) patients were censored. The Cox proportional hazard model result indicates that severe acute malnutrition, baseline CD4+ cell count ≥100, and underweight significantly contributed to the survival time of a patient. Cox proportional hazard model shows that severe acute malnutrition (HR=4.40027, 95% CI= 2.455061 262.7934, P-value=0.007), baseline CD4+cell count ≥100 (HR=0.2714623, 95% CI= 0.0764089 0.9644395, P-value=0.044), and Underweight (HR=4.678169, 95% CI= 1.970097 11.10872, P-value=0.040) significantly contributed to a shorter survival time.

CONCLUSION

Visceral leishmaniases with HIV co-infected patients show a large number of deaths occurred in the earlier days of treatment this implies that Visceral leishmaniasis accelerates HIV replication and disease progression death. The researcher suggests that people be aware of the burden posed by those risk factors and knowledgeable about the diseases. So, the researcher recommended that to health workers implement primary health care in those patients and careful consideration of a neglected parasitic disease.

Sero-prevalence of visceral leishmaniasis and its associated factors among asymptomatic individuals visiting Denan health center, southeastern Ethiopia

BACKGROUND

In the Somali region of Ethiopia, visceral leishmaniasis (VL) is a public health concern. However, VL epidemiology and sand fly vectors have not been well studied in various areas of the regional state, including Denan district. Therefore, this study was conducted to determine the sero-prevalence, associated factors, and distribution of sand fly vectors of VL in Denan district, south-eastern Ethiopia.

METHODS

A facility-based cross-sectional study was conducted from April to September 2021 among VL patients with classic signs and symptoms visiting Denan Health Center in south-eastern Ethiopia. Using a convenience sampling method, 187 blood samples were collected from individuals who visited Denan Health Center during the study period. Blood samples were subjected to Direct Agglutination Test for the detection of antibodies to VL. A pre-tested structured questionnaire was also used to gather information on risk factors and other characteristics of knowledge and attitude assessment. Sand flies were also collected from indoor, peri-domestic, mixed forest, and termite mounds using light and sticky traps to determine the fauna and abundance.

RESULTS

The overall sero-prevalence rate was 9.63% (18/187). The sero-prevalence was significantly associated with outdoor sleeping (OR = 2.82), the presence of damp floors (OR = 7.76), and sleeping outdoor near animals (OR = 3.22). Around 53.48% of the study participants had previously heard about VL. Study participants practiced different VL control methods, including bed nets (42%), insecticide spraying (32%), smoking plant parts (14%), and environmental cleaning (8%). In total, 823 sand fly specimens, comprising 12 species in two genera (Phlebotomus and Sergentomyia), were trapped and identified. The most abundant species was Sergentomyia clydei (50.18%), followed by Phlebotomus orientalis (11.42%). Also, a higher proportion of P. orientalis was found in termite mounds (65.43%), followed by mixed forest (37.8%) and peri-domestic (20.83%) habitats.

CONCLUSION

The study demonstrated a 9.63% sero-positivity of VL and a remarkable gap in knowledge, attitude, and practices towards VL. P. orientalis was also detected, which could be a probable vector in this area. Thus, public education should be prioritized to improve the community's awareness of VL and its public health impact. In addition, detailed epidemiological and entomological studies are recommended.

Social determinants of visceral leishmaniasis elimination in Eastern Africa

Visceral leishmaniasis is a vector-borne, protozoan disease with severe public health implications. Following the successful implementation of an elimination programme in South Asia, there is now a concerted endeavour to replicate these efforts in Eastern Africa based on the five essential elimination pillars of case management, integrated vector management, effective surveillance, social mobilisation and operational research. This article highlights how key social determinants (SD) of health (poverty, sociocultural factors and gender, housing and clustering, migration and the healthcare system) operate at five different levels (socioeconomic context and position, differential exposure, differential vulnerability, differential outcomes and differential consequences). These SD should be considered within the context of increasing the success of the five-pillar elimination programme and reducing inequity in health.

Asymptomatic Leishmania donovani infection and associated factors among blood donors attending at Metema district Blood Bank, Northwest Ethiopia: a cross- sectional study

BACKGROUND

Ethiopia is one of the top 10 countries in the world where 90% visceral leishmaniasis cases are reported. Metema-Humera lowlands are the most important foci in Ethiopia. Blood transfusion in visceral leishmaniasis endemic foci in Ethiopia does not consider screening of visceral leishmaniasis during blood donation. The aim of this study is therefore, was to assess asymptomatic Leishmania donovani infection and associated factors among blood donors attending at Metema district Blood Bank, Northwest Ethiopia.

METHODS

A Health facility based cross-sectional study was conducted at Metema Blood Bank from February to March 2020. A total of 205 blood donors were eligible and participated in this study. Structured questionnaire were used to collect data on socio-demographic characteristics and perceived risk factors associated with asymptomatic visceral leishmaniasis among blood donors. Blood donors were screened using both rK39 and direct agglutination tests based on the manufactures' instructions. Data were analyzed using SPSS version 20.0. Chi-square test was used to assess associations of Leishmania donovani infection with predisposing factors. Associations were considered statstically significant on P-value < 0.05 at 95% confidence level.

RESULTS

Of the total 205 participants, 32(15.6%) were positive for asymptomatic Leishmania donovani infection at least by one of the diagnostic tests used. Eight (3.9%) and 30(14.6%) of the participants` were positive by the rK39 and direct agglutination tests, respectively. Six (2.9%) donors were tested positive by both diagnostic tests. Family history of visceral leishmaniasis (X²=11.334, P = 0.003) and having neighbors with history of visceral leishmaniasis (X²=5.923, P = 0.015) were significantly associated with asymptomatic Leishmania donovani infection among blood donors.

CONCLUSIONS

The prevalence of asymptomatic Leishmania donovani infection was 15.6%. Asymptomatic visceral leishmaniasis was significantly associated with donors' family and neighbors' history of infection. Therefore, laboratory screening of blood donors for visceral leishmaniasis in endemic areas will be mandatory. Moreover, this study will give base line information for future study in the country.

Hidden sources of bias in diagnostic studies: the example of visceral leishmaniasis in east Africa

A clear understanding of the accuracy of diagnostic tests is essential for the management of infections such as visceral leishmaniasis in endemic areas. Using both published and unpublished datasets from field diagnostic trials of visceral leishmaniasis in the past ten years, we show the potential effects of unrecognised sources of bias including work-up bias, referral bias, and reference test bias on the results. We outline why these biases, which can occur in diagnostic studies of any disease, can go unrecognised despite adherence to current STARD and QUADAS-2 guidelines. Using these examples and referring to others seen in studies of bacterial and viral infections, we make specific recommendations on how these biases might be avoided through specific steps in study design, study reporting, and the locations where studies are conducted.

Detection of asymptomatic Leishmania infection in blood donors at two blood banks in Ethiopia

Visceral leishmaniasis (VL) is a disease caused by Leishmania parasites. While predominantly transmitted by sandflies, cases of VL transmitted through blood transfusion have been reported, particularly in immunocompromised recipients. Although Leishmania parasites have been found in blood donors in some VL endemic areas, this has never been studied in East-Africa, where HIV prevalence is relatively high. We established the prevalence of asymptomatic Leishmania infection and associated socio-demographic factors among blood donors presenting at two blood bank sites (Metema and Gondar) in northwest Ethiopia between June and December 2020. Metema is located in a VL-endemic area; Gondar has historically been considered VL non-endemic but as an outbreak of VL has occurred around Gondar, it was defined as previously VL non-endemic. Blood samples were tested by the rK39 rapid diagnostic test (RDT), rK39 ELISA, direct agglutination test (DAT) and qPCR targeting kinetoplast DNA (kDNA). Asymptomatic infection was defined as positive by any of these tests in a healthy person. A total of 426 voluntary blood donors were included. The median age was 22 years (IQR, 19-28 years); 59% were male and 81% resided in urban areas. Only one participant had a history of VL and three had a family history of VL. Asymptomatic infection was detected in 15.0% (n = 32/213) in Metema and 4.2% (n = 9/213) in Gondar. The rK39 ELISA was positive in 5.4% (n = 23/426), the rK39 RDT in 2.6% (11/426), PCR in 2.6% (11/420) and DAT in 0.5% (2/426). There were six individuals with two positive tests: one positive on rK39 RDT and PCR and five positive on rK39 RDT and ELISA. The prevalence of asymptomatic infection was higher in Metema (VL-endemic) and males but was not associated with age, a history of VL amongst family members or living in a rural area. Antibodies against Leishmania and parasite DNA was detected in a substantial number of blood donors. Future research should be directed at better defining the risk to recipients, including parasite viability studies and longitudinal studies amongst recipients.

Recurrent visceral leishmaniasis relapses in HIV co-infected patients are characterized by less efficient immune responses and higher parasite load

Visceral leishmaniasis (VL) and HIV co-infection (VL/HIV) has emerged as a significant public health problem in Ethiopia, with up to 30% of patients with VL co-infected with HIV. These patients suffer from recurrent VL relapses and increased mortality. Those with a previous history of VL relapses (recurrent VL/HIV) experience increased VL relapses as compared to patients with HIV presenting with their first episode of VL (primary VL/HIV). Our aim was to identify drivers that account for the higher rate of VL relapses in patients with recurrent VL/HIV (n = 28) as compared to primary VL/HIV (n = 21). Our results show that the relapse-free survival in patients with recurrent VL/HIV was shorter, that they had higher parasite load, lower weight gain, and lower recovery of all blood cell lineages. Their poorer prognosis was characterized by lower production of IFN-gamma, lower CD4+ T cell counts, and higher expression of programmed cell death protein 1 (PD1) on T cells.

PCR for detection of Leishmania donovani from microscopically negative tissue smears of suspected patients in Gondar, Ethiopia

BACKGROUND

As untreated visceral leishmaniasis (VL) is fatal, reliable diagnostics are pivotal for accurate treatment allocation. The current diagnostic algorithm for VL in Ethiopia, which is based on the rK39 rapid diagnostic test and microscopy of tissue smears, lacks sensitivity. This probably leads to missed cases and patients not receiving treatment.

METHODOLOGY

We conducted a retrospective study on stored microscopically negative spleen and bone marrow smears from suspected VL patients collected at the Leishmaniasis Research and Treatment Center (LRTC) in Gondar, northern Ethiopia between June 2019 and November 2020. Sociodemographic, clinical and treatment data were collected and samples were tested by real-time PCR targeting kinetoplast DNA.

PRINCIPLE FINDINGS

Among the 191 eligible samples (135 spleen and 56 bone marrow) with a microscopically negative and valid PCR result, 119 (62.3%) were positive by PCR, although Ct values for some were high (median 33.0). Approximately three quarters of these undiagnosed primary VL (77.3%) and relapse (69.6%) patients did not receive antileishmanial treatment. Of the 56 microscopically negative bone marrow samples, 46 (82.1%) were PCR positive, which is considerably higher compared to the microscopically negative spleen samples, for which 73 out of 135 (54.1%) were PCR positive. The odds of being PCR positive were significantly higher for bone marrow aspirates and higher when white blood cell values were lower and splenomegaly (in cm) was more pronounced.

CONCLUSIONS

This study demonstrates that a lot of suspected VL patients remain undiagnosed and untreated. This indicates the urgent need for better diagnostics for VL in the East-African region. The outcomes of PCR positive should be closely monitored and treatment should be provided if the patient deteriorates. In resource limited settings, implementation of PCR on bone marrow aspirate smears of patients with low WBC values and splenomegaly could lead to considerable improvements in patient management.

Epidemiological, clinical and hematological profiles of visceral leishmaniasis among patients visiting Tefera Hailu Memorial Hospital, Northeast Ethiopia: a 4 year retrospective study

Visceral leishmaniasis is a major, life-threatening parasitic disease that still remains a serious public health problem in Ethiopia. Understanding the epidemiological, clinical, and hematological profiles of visceral leishmaniasis patients is important for implementing evidence-based control strategies. It is also important for early treatment and to decrease the mortality rate from the disease. Therefore, this study was aimed at assessing the epidemiological, clinical, and hematological profiles of visceral leishmaniasis among patients visiting Tefera Hailu Memorial Hospital, Northeast Ethiopia. A retrospective study was conducted at Tefera Hailu Memorial Hospital from September 2017 to August 2021. Data were collected from the medical records of suspected patients who were tested by the rK39 rapid diagnostic by strictly following standard operating procedures. The data was summarized using Microsoft Excel and analyzed using SPSS 26 version software. Descriptive statistics were used to describe the epidemiological, clinical, and hematological profiles of visceral leishmaniasis patients. A p-value < 0.05 was considered statistically significant. The overall positivity rate for visceral leishmaniasis was 23.4% (132/564). The result of this study indicated a fluctuating yet declining trend in VL over the past 4 years. From a total of 132 VL confirmed cases, the numbers of cases were highest among males (78.0%), those 15-29 years of age (37.1%), and urban residents (89.4%). Furthermore, Abergele (11.0%), Sehala (6.0%), and Ziquala (5.0%) districts had the highest number of VL cases. The major clinical presentations of patients were fever (96.2%), splenomegaly (94.7%), and general weakness (80.3%). With regard to hematological profiles, the most common findings were anemia (86.4%), thrombocytopenia (81.8%), leucopenia (78.8%), neutropenia (74.2%), and pancytopenia (71.2%). In the study area, the VL positivity rate was high. Our findings also concluded that VL causes significant alterations in clinical and hematological parameters. Therefore, the zone health office and other concerned stakeholders should strengthen evidence-based control programs for VL.

Detection of Leishmania donovani using ITS1-RFLP from positive and negative smear samples among clinically reported patients visiting University of Gondar Comprehensive Specialized Hospital

BACKGROUND

Visceral leishmaniasis is caused by the Leishmania donovani species complex that can spread to internal organs and leading to death if not treated on time. Diagnosis of leishmaniasis is based on clinical signs and symptoms, microscopy, serological and molecular techniques. Because of a broad spectrum of diverse clinical manifestations and similarities of the responses to different species, identification to the species level is often difficult for the proper patient treatment and management. Therefore, the objective of this study was to evaluate the PCR- RFLP assay of the ITS1 region for identification of L. donovani species from clinical smear slide patient samples.

METHOD

DNA extraction was performed on a total of 90 smear slide samples using phenol-chloroform method. The PCR detection limit was determined by L. donovani reference strain DNA. The ITS1 region was amplified at 320 bp using LITSR/L5.8S genus specific primers and then the ITS1-PCR products were subjected to RFLP assay for confirmation of L. donovani species using HaeIII restriction enzyme.

RESULTS

Of the total samples ITS1-PCR revealed the true positive, false positive, true negative, and false negative results of 42 (46.7%), 6 (6.7%), 37 (41.1%) and 5 (5.6%), respectively. Considering microscopy as the gold standard, the sensitivity, specificity, positive predictive values, and negative predictive values of the ITS1- PCR technique was 89.4%, 86.0%, 87.5%, and 88.1% respectively. All ITS1-PCR positive clinical samples were confirmed as L. donovani species by PCR-RFLP patterns.

CONCLUSION

In conclusion, the ITS1- RFLP method is highly sensitive and more specific for identification of L. donovani species in the smear negative clinical samples of visceral leishmaniasis patients. There is also significant association and degree of agreement between the two methods. For direct identification of L. donovani species from clinical samples, irrespective of genus and species level, PCR-RFLP is more recommendable than a microscope.

Molecular Characterization of Leishmania Species among Patients with Cutaneous Leishmaniasis in Asir Province, Saudi Arabia

Anthroponotic cutaneous leishmaniais (ACL) and zoonotic cutaneous leishmaniasis (ZCL) caused by Leishmania tropica and Leishmania major, respectively, are endemic vector-borne diseases in southern Saudi Arabia. In 2021, an outbreak of cutaneous leishmaniasis occurred in the province of Asir. The main objective of our investigation was to analyze the epidemiological features of CL in southern Saudi Arabia. The ministry of health recorded 194 CL patients between January and December 2021 from the Asir province. Our findings showed that the majority of CL patients (87.1%) originated from the governorates of Khamis-Mushait and Abha. Most of the patients were males (62.3%). While CL affected all age groups, those under 13 years old were the most affected (38.1%). For both genders, CL patients were mostly Saudi citizens (90.7%) compared to non-Saudi expatriates. The majority of CL patients (75.2%) suffered from a single lesion, and the majority of lesions (61.3%) were located on the face. The seasonal prevalence of CL showed two peaks, a small one in July-August and a larger one in March. Of a total of 194 Giemsa slides samples, 188 showed positive amplification of Leishmania ITS1 gene. Based on PCR-RFLP and PCR-HMR, 183 patients showed positive amplification of L. tropica and five patients showed positive amplification of L. major. Phylogenetic analysis revealed a clear distinct separation between L. major and L. tropica sequences. Our results provided strong evidence of the pre-domination of L. tropica, the main etiological agent of ACL in Asir province. We reported for the first time the presence of L. major, an etiological agent of ZCL in the study areas. The co-circulation of ACL and ZCL highlighted the complexity of the epidemiology of CL in southern Saudi Arabia, and subsequently, further studies to identify competent vectors and reservoir hosts for the establishment of control strategies are needed.

Seroprevalence of visceral leishmaniasis and its associated factors among asymptomatic pastoral community of Dire District, Borena zone, Oromia Region, Ethiopia

Visceral leishmaniasis (VL) is a vector-borne protozoan neglected tropical disease. In some parts of Ethiopia, it is a public health problem and its main causative agent is the Leishmania donovani complex. The objective of the study was to determine the seroprevalence of VL and factors associated among the asymptomatic pastoral community of Dire District, Borena Zone, Oromia Region, Ethiopia. A community-based study was conducted among 432 pastoralist communities from June to July 2021. A systematic random sampling method was used to select households. Pretested structured questionnaires and face-to-face interviews were used to collect data. A single finger-prick blood sample was collected and tested for Leishmania donovani complex using an immune-chromatographic test (rk39-ICT). A logistic regression model was used to assess factors associated with VL infection and a p-value of < 0.05 was considered statistically significant. A total of 432 study participants were included (their mean age was 26.69) and 218 (50.5%) were females. The overall seroprevalence of VL was 33/432(7.6%) (95%CI: 5.32-15.60). Sero-prevalence was significantly associated with high family size (>5) (adjusted odds ratios (AOR) = 5.134; 95% CI: 2.032-9.748), sleeping or/and staying under acacia tree (AOR = 2.984; 95%CI = 1.074-8.288), presence of cracked house walls (AOR = 1.801; 95%CI: 1.026-4.926), presence of termite hills (AOR = 1.938; 95%CL: 1.002-7.050), availability of water points (AOR = 3.893; 95%CI: 1.034-7.426) and presence of domestic animals (AOR = 2.124; 95% CI: 2.341-5.108). It is recommended that community awareness on the transmission and prevention methods of Leishmania donovani complex and taking appropriate interventions on the identified factors play a greater role to prevent and control infection in the area. Further investigation is also needed to characterize the pathogens and risk factors and tackle the problem.

Climate Change and Environmental Influence on Prevalence of Visceral Leishmaniasis in West Pokot County, Kenya

Kala-azar is a parasitic disease caused by Leishmania species transmitted by sand fly. In Kenya, kala-azar is endemic in thirty subcounties spread over in eleven counties in the arid zones. Climate change-influenced seasonal weather variability and environmental alterations remain important determinants of many vector-borne diseases. The present study focused on climate change and environmental influence on kala-azar in West Pokot. A descriptive cross-sectional and retrospective research design was adapted. Study area was purposively selected. Locations were randomly selected, and households were systematically selected. Three hundred sixty-three household questionnaires, eleven key informant interviews, and five focus group discussions were undertaken. Secondary data were obtained from Kacheliba subcounty hospital records. Statistical Package for the Social Sciences version 24 was used to analyze quantitative data while qualitative data were analyzed to establish connection for interpretation. Kala-azar cases have been on the rise on aggregate and surge towards the end of dry season and just after the rains. Significant environmental factors included the presence of seasonal rain water pathways and rock piles around houses (AOR = 4.7; 95% CI = (2.3-9.6), $p<0.05$ ), presence of acacia trees in and around homesteads (AOR = 8.5; 95% CI = (2.5-28.6), $p<0.05$ ), presence of anthills around the homesteads (AOR = 5.2; 95% CI = (1.2-23.4), $p<0.05$ ), and presence of animal shed within compound (AOR = 2.8; 95% CI = (0.96-8), $p<0.05$ ). Climate change-induced seasonal weather variability, increased temperature and reduced precipitation as well as environmental alterations influence kala-azar occurrence in West Pokot. Community sensitization on disease prevalence, clearing of vector predilection sites, and improving community environmental risk perception are imperative to promote prevention.

Following successful anti-leishmanial treatment, neutrophil counts, CD10 expression and phagocytic capacity remain reduced in visceral leishmaniasis patients co-infected with HIV

Visceral leishmaniasis (VL) patients co-infected with HIV (VL/HIV patients) experience frequent treatment failures, VL relapses, opportunistic infections, and higher mortality. Their immune system remains profoundly suppressed after clinical cure and they maintain higher parasite load. This is in contrast with patients with VL alone (VL patients). Since neutrophils play a critical role in the control of Leishmania replication and the regulation of immune responses, we tested the hypothesis that neutrophil activation status and effector functions are fully restored in VL, but not in VL/HIV patients. Our results show the neutrophil counts and all activation markers and effector functions tested in our study were reduced at the time of diagnosis in VL and VL/HIV patients as compared to controls. CD62L, CD63, arginase 1 expression levels and reactive oxygen species production were restored at the end of treatment in both groups. However, neutrophil counts, CD10 expression and phagocytosis remained significantly lower throughout follow-up in VL/HIV patients; suggesting that dysregulated neutrophils contribute to the impaired host defence against pathogens in VL/HIV patients.

Impaired in vitro Interferon-γ production in patients with visceral leishmaniasis is improved by inhibition of PD1/PDL-1 ligation

Visceral leishmaniasis (VL) is a neglected tropical disease that causes substantial morbidity and mortality and is a growing health problem in Ethiopia, where this study took place. Most individuals infected with Leishmania donovani parasites will stay asymptomatic, but some develop VL that, if left untreated, is almost always fatal. This stage of the disease is associated with a profound immunosuppression, characterised by impaired production of Interferonγ (IFNγ), a cytokine that plays a key role in the control of Leishmania parasites, and high expression levels of an inhibitory receptor, programmed cell death 1 (PD1) on CD4+ T cells. Here, we tested the contribution of the interaction between the immune checkpoint PD1 and its ligand PDL-1 on the impaired production of IFNγ in VL patients. Our results show that in the blood of VL patients, not only CD4+, but also CD8+ T cells express high levels of PD1 at the time of VL diagnosis. Next, we identified PDL-1 expression on different monocyte subsets and neutrophils and show that PDL-1 levels were significantly increased in VL patients. PD1/PDL-1 inhibition resulted in significantly increased production of IFNγ, suggesting that therapy using immune checkpoint inhibitors might improve disease control in these patients.

Immunological factors, but not clinical features, predict visceral leishmaniasis relapse in patients co-infected with HIV

Visceral leishmaniasis (VL) has emerged as a clinically important opportunistic infection in HIV patients, as VL/HIV co-infected patients suffer from frequent VL relapse. Here, we follow cohorts of VL patients with or without HIV in Ethiopia. By the end of the study, 78.1% of VL/HIV-but none of the VL patients-experience VL relapse. Despite a clinically defined cure, VL/HIV patients maintain higher parasite loads, lower BMI, hepatosplenomegaly, and pancytopenia. We identify three immunological markers associated with VL relapse in VL/HIV patients: (1) failure to restore antigen-specific production of IFN-γ, (2) persistently lower CD4+ T cell counts, and (3) higher expression of PD1 on CD4+ and CD8+ T cells. We show that these three markers, which can be measured in primary hospital settings in Ethiopia, combine well in predicting VL relapse. The use of our prediction model has the potential to improve disease management and patient care.

In Vitro Antileishmanial and Antischistosomal Activities of Anemonin Isolated from the Fresh Leaves of Ranunculus multifidus Forsk

Leishmaniasis and schistosomiasis are neglected tropical diseases (NTDs) infecting the world’s poorest populations. Effectiveness of the current antileishmanial and antischistosomal therapies are significantly declining, which calls for an urgent need of new effective and safe drugs. In Ethiopia fresh leaves of Ranunculus multifidus Forsk. are traditionally used for the treatment of various ailments including leishmaniasis and eradication of intestinal worms. In the current study, anemonin isolated from the fresh leaves of R. multifidus was assessed for its in vitro antileishmanial and antischistosomal activities. Anemonin was isolated from the hydro-distilled extract of the leaves of R. multifidus. Antileishmanial activity was assessed on clinical isolates of the promastigote and amastigote forms of Leishmania aethiopica and L. donovani clinical isolates. Resazurin reduction assay was used to determine antipromastigote activity, while macrophages were employed for antiamastigote and cytotoxicity assays. Antischistosomal assays were performed against adult Schistosoma mansoni and newly transformed schistosomules (NTS). Anemonin displayed significant antileishmanial activity with IC₅₀ values of 1.33 nM and 1.58 nM against promastigotes and 1.24 nM and 1.91 nM against amastigotes of L. aethiopica and L. donovani, respectively. It also showed moderate activity against adult S. mansoni and NTS (49% activity against adult S. mansoni at 10 µM and 41% activity against NTS at 1 µM). The results obtained in this investigation indicate that anemonin has the potential to be used as a template for designing novel antileishmanial and antischistosomal pharmacophores.

Assessment of liver function test and associated factors among visceral leishmaniasis patients attending university of gondar leishmaniasis research and treatment center, Northwest Ethiopia

BACKGROUND

Visceral leishmaniasis (VL) is one of the major public health burden, mainly distributed throughout tropical and subtropical regions of the world. Among the Sub-Saharan African countries, Ethiopia is the second most affected country with VL. An Alteration of liver function is a typical manifestation of the disease.

OBJECTIVE

The purpose of conducting this study was to assess liver function tests and associated risk factors among VL patients at Leishmaniasis Research and Treatment Center of University of Gondar Comprehensive Specialized Hospital, North West Ethiopia.

METHOD

Hospital based comparative cross-sectional study design was conducted. A total of 102 study participants were involved in this study. Newly diagnosed VL patients who were attended at Leishmaniasis Research and Treatment Center of University of Gondar Comprehensive Specialized Hospital from 21st February 2020 to 30th September 2020 were included under case group category. On the other hand, age-sex matched apparently healthy study subjects were categorized as control group. Written consent was obtained willingness of patients to participate after ethical clearance was obtained from the Institutional Review Board of School of Medicine, University of Gondar. After overnight fasting, 5ml venous blood was drawn from both VL patients and controls to evaluate liver function tests, including AST, ALT, total bilirubin, albumin, and total protein. Thus, senior health professionals (laboratory technologist) investigate the results using Cobas Integra 400 Plus clinical chemistry analyzer. Data was entered into Epi-data version 4.6 and exported to STATA 14 for analysis of liver function tests and associated risk factors.

RESULT

The result of this study showed that significant mean difference was exhibited in aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin, serum albumin, and total protein level among VL patients and controls. It showed that there was a statistically significant elevation in the level of AST, ALT, and total bilirubin among cases as compared to control. The serum AST level was significantly (p<0.001) elevated among cases as compared to controls. Serum ALT was significantly (p<0.001) elevated among cases compared to controls. Additionally, the total serum bilirubin level was significantly increased (P<0.001) among cases as compared to controls. There was a statistically significant (P<0.001) reduction of serum albumin level among VL patients as compared to controls. Similarly, serum total protein was significantly (P<0.001) reduced in VL patients than control groups.

CONCLUSION

There were significantly higher mean levels of serum AST, ALT, and total bilirubin among VL patients as compared to controls. On the other hand, VL patients showed significantly lowered level of albumin and total protein as compared to controls.

Assessment of serum amylase, lipase and associated factors among patients with visceral leishmaniasis treated with sodium stibogluconate/paromomycin at University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia

BACKGROUND

Visceral leishmaniasis (VL) is a life-threatening parasitic disease next to malaria, which is responsible for the death of 50,000 patients annually. It has three major clinical stages, including visceral, cutaneous, and mucocutaneous leishmaniasis. Ethiopia is one of the east African countries commonly affected with leishmanisis disease. There are many drugs for leishmaniasis, including sodium stibogluconate and paromomycin combined therapy. However, the adverse effect of those combined drugs is not well-defined. Therefore, the purpose of this study was to assess serum amylase, lipase, and associated factors among patients with VL treatment with those combined drugs.

METHODS

Hospital-based cross-sectional study was conducted at the University of Gondar Comprehensive Specialized Hospital Leishmaniasis Research and Treatment Center from February to September 2020 G.C. Simple random sampling technique was utilized to select study participants. The study participants who fulfill the inclusion criteria were included in the study with written informed consent. 5 ml of blood was withdrawn by an experienced health professional to analyze serum amylase and lipase level. Descriptive data was presented by tables, charts and graphs. Data was cleared, entered by Epi-data version 3.1 then transfer to STATA 14.1 SE version and for analysis paired t-test was used, for factors correlation and regression was used. Those factor variable who have p-value <0.25 was filtered and goes to multivariate regression and p-value <0.05 was considered as significant variables.

RESULTS

The result of this study showed that there was a significant mean difference between serum pancreatic amylase and lipase before and after treatment. The mean ± SD level of serum amylase after treatment showed a statistically significant elevation (P<0.001) as compared to its level before treatment. Similarly, the mean ± SD level of serum lipase after treatment showed a statistically significant elevation (P<0.001) as compared to its level before treatment. There was also significant association between age and baseline serum amylase as compared to serum amylase after treatment. Similarly, there was also significant relation of age and serum lipase with serum lipase after treatment.

CONCLUSION

In this study, the level of serum amylase and lipase at treatment of cure was higher and there was an increase in mean serum amylase and lipase after a patient taking sodium stibogluconate and paromomycin combined drugs. Consequently, the elevated result of these biochemical profiles mainly associated with drug induced adverse effect and associated risk factors in VL patients.

From infection to vaccination: reviewing the global burden, history of vaccine development, and recurring challenges in global leishmaniasis protection

INTRODUCTION

Leishmaniasis is a major public health problem and the second most lethal parasitic disease in the world due to the lack of effective treatments and vaccines. Even when not lethal, leishmaniasis significantly affects individuals and communities through life-long disabilities, psycho-sociological trauma, poverty, and gender disparity in treatment.

AREAS COVERED

This review discusses the most relevant and recent research available on Pubmed and GoogleScholar highlighting leishmaniasis' global impact, pathogenesis, treatment options, and lack of effective control strategies. An effective vaccine is necessary to prevent morbidity and mortality, lower health care costs, and reduce the economic burden of leishmaniasis for endemic low- and middle-income countries. Since there are several forms of leishmaniasis, a pan-Leishmania vaccine without geographical restrictions is needed. This review also focuses on recent advances and common challenges in developing prophylactic strategies against leishmaniasis.

EXPERT OPINION

Despite advances in pre-clinical vaccine research, approval of a human leishmaniasis vaccine still faces major challenges - including manufacturing of candidate vaccines under Good Manufacturing Practices, developing well-designed clinical trials suitable in endemic countries, and defined correlates of protection. In addition, there is a need to explore Challenge Human Infection Model to avoid large trials because of fluctuating incidence and prevalence of leishmanasis.

Diversity and Within-Host Evolution of Leishmania donovani from Visceral Leishmaniasis Patients with and without HIV Coinfection in Northern Ethiopia

Visceral leishmaniasis (VL) is a fatal disease and a growing public health problem in East Africa, where Ethiopia has one of the highest VL burdens. The largest focus of VL in Ethiopia is driven by high prevalence in migrant agricultural workers and associated with a high rate of coinfection with HIV. This coinfection makes VL more difficult to treat successfully and is associated with a high rate of relapse, with VL/HIV patients frequently experiencing many relapses of VL before succumbing to this infection. We present genome-wide data on Leishmania donovani isolates from a longitudinal study of cohorts of VL and VL/HIV patients reporting to a single clinic in Ethiopia. Extensive clinical data allow us to investigate the influence of coinfection and relapse on the populations of parasites infecting these patients. We find that the same parasite population is responsible for both VL and VL/HIV infections and that, in most cases, disease relapse is caused by recrudescence of the population of parasites that caused primary VL. Complex, multiclonal infections are present in both primary and relapse cases, but the infrapopulation of parasites within a patient loses genetic diversity between primary disease presentation and subsequent relapses, presumably due to a population bottleneck induced by treatment. These data suggest that VL/HIV relapses are not caused by genetically distinct parasite infections or by reinfection. Treatment of VL does not lead to sterile cure, and in VL/HIV, the infecting parasites are able to reestablish after clinically successful treatment, leading to repeated relapse of VL. IMPORTANCE Visceral leishmaniasis (VL) is the second largest cause of deaths due to parasite infections and a growing problem in East Africa. In Ethiopia, it is particularly associated with migrant workers moving from regions of nonendemicity for seasonal agricultural work and is frequently found as a coinfection with HIV, which leads to frequent VL relapse following treatment. Insight into the process of relapse in these patients is thus key to controlling the VL epidemic in Ethiopia. We show that there is little genetic differentiation between the parasites infecting HIV-positive and HIV-negative VL patients. Moreover, we provide evidence that relapses are caused by the initially infecting parasite population and that treatment induces a loss of genetic diversity in this population. We propose that restoring functioning immunity and improving antiparasitic treatment may be key in breaking the cycle of relapsing VL in VL/HIV patients.

Acute kidney injury in patients with Visceral Leishmaniasis in Northwest Ethiopia

BACKGROUND

Visceral Leishmaniasis (VL) is a neglected tropical disease endemic to several countries including Ethiopia. Outside of Africa, kidney involvement in VL is frequent and associated with increased mortality. There is however limited data on acute kidney injury (AKI) in VL patients in East-Africa, particularly in areas with high rates of HIV co-infection. This study aims to determine the prevalence, characteristics and associated factors of AKI in VL patients in Northwest Ethiopia.

METHODS

A hospital based retrospective patient record analysis was conducted including patients treated for VL from January 2019 to December 2019 at the Leishmaniasis Research and Treatment Center (LRTC), Gondar, Ethiopia. Patients that were enrolled in ongoing clinical trials at the study site and those with significant incomplete data were excluded. Data was analyzed using SPSS version 20. P values were considered significant if < 0.05.

RESULTS

Among 352 VL patients treated at LRTC during the study period, 298 were included in the study. All were male patients except two; the median age was 23 years (IQR: 20-27). The overall prevalence of AKI among VL patients was 17.4% (confidence interval (CI): 13.6%-22.2%). Pre-renal azotemia (57%) and drug-induced AKI (50%) were the main etiologies of AKI at admission and post-admission respectively. Proteinuria and hematuria occurred in 85% and 42% of AKI patients respectively. Multivariate logistic regression revealed HIV co-infection (adjusted odds ratio (AOR): 6.01 95% CI: 1.99-18.27, p = 0.001) and other concomitant infections (AOR: 3.44 95% CI: 1.37-8.65, p = 0.009) to be independently associated with AKI.

CONCLUSION

AKI is a frequent complication in Ethiopian VL patients. Other renal manifestations included proteinuria, hematuria, and pyuria. HIV co-infection and other concomitant infections were significantly associated with AKI. Further studies are needed to quantify proteinuria and evaluate the influence of AKI on the treatment course, morbidity and mortality in VL patients.

Epidemiological and pathological characteristics of Cutaneous Leishmaniasis from Baluchistan Province of Pakistan

Cutaneous Leishmaniasis (CL) is considered a neglected tropical disease which in Pakistan can now be considered as a growing public health problem. The exact figures on the magnitude of the disease are lacking both at the national and regional level and only a few health centres are available for diagnosis of CL. The present study was designed to identify the epidemiology of CL infection from August 2018 to December 2019 and to assess clinical aspects of CL in Baluchistan Province of Pakistan. A total of 4072 clinically suspected CL cases were analysed statistically. The highest number of CL cases were reported in May, followed by April, January and then July, February and June and the lowest number of cases were observed in March and November. The highest prevalence rate was found in males where 38% of reported cases were aged 0-9 years. The majority (24.4%) of lesions were found on the hands followed by the face in which cheeks, ears and nose were the effected organs. About 50% of the participants have single lesion while 14% of the participants had two and nearly 3% of the participants have six lesions. The atypical clinical presentations were observed in Baluchistan and common unusual presentations were lupus erythematosus. The study findings suggest that more epidemiological studies and health education campaigns are needed for the population awareness regarding CL in Baluchistan. It is recommended that risk factors should be evaluated to establish control and management strategies to prevent disease at the individual and community level.

Leishmaniasis Beyond East Africa

Climate change is having a substantial impact on our environment and ecosystems and has altered the way humans live, access, and utilize resources with increased risk of zoonotic infectious disease encounters. As global temperatures continue to increase, they impact on public health, migration, food security and land conflict, and as new environments become favorable, exposure to disease carrying vectors. Increased forests or natural habitat clearance for land repurposing, urbanization, road building, and water management are related to an increase in emerging vector borne parasitic diseases. The East African region remains one of the most impacted regions globally for leishmaniasis, a vector borne disease that impacts significantly on the health, wellbeing and livelihoods of affected communities and for which a lack of reporting and control interventions hinder progress toward elimination of this neglected tropical disease. As our world continues to transform, both politically and climatically, it is essential that measures are put in place to improve surveillance and disease management with implementation of control measures, including vector control, especially in low- and middle-income countries that are expected to be most impacted by changes in climate. Only through effective management, now, can we be sufficiently resilient to preventing the inevitable spread of vectors into suitable habitat and expansion of the geographical range of leishmaniasis. This review offers a current perspective on Leishmaniasis as an endemic disease in East Africa and examines the potential of the recent emergence of Leishmania infection in hitherto unaffected regions to become a public health concern if no disease management is achieved.

Prevalence of asymptomatic visceral leishmaniasis in human and dog, Benishangul Gumuz regional state, Western Ethiopia

BACKGROUND

The Benishangul-Gumuz region is an important development corridor in Ethiopia. Large-scale projects such as the Great Renaissance Dam, mining and agriculture have entailed huge environmental modifications and settlement pattern changes. There is no detailed epidemiological information on visceral leishmaniasis (VL) in the region.

MATERIALS AND METHODS

A cross-sectional study was carried out to assess the epidemiology and risk factors associated with Leishmania infection. A leishmanin skin test (LST) was done for 1342 participants, and for 253 of them rK39 and DAT were carried out. Thirty-six dogs owned by households with LST-positive member(s) were rK39 and DAT tested. A pretested questionnaire was used to capture individual and household characteristics.

RESULTS

Of the 89.2% (1197/1342) who availed themselves of the LST reading, 6.0% were positive. The rk39 and DAT positivity among the 253 tested were 3.2% and 5.9%, respectively. In dogs, positivity rates by rK39 and DAT were 13.9% and 5.6%, respectively. Of the household and individual risk factors, presence of a dog in the household (P = 0.005), male sex (0.003), residence woreda (0.000) and occupation (0.023) showed a strong positive association with LST positivity. Individuals who lived in households that had dogs were 2.6 times more likely to be LST positive (AOR = 2.6; 95% CI = 1.54, 4.40). Being female decreased the probability of being LST positive by 0.38 times (AOR = 0.38; 95% CI = 0.20, 0.72). People living in Guba and Kurmuk had 4.7 (AOR = 4.74, 95% CI 1.83, 12.31) and 5.9 (AOR = 5.85, 95% CI 2.27, 15.09) times more risk of being infected.

CONCLUSIONS

We demonstrated the presence of active VL transmission in the areas. Thus, we underline the need to establish the responsible vector(s) and reservoir(s) for comprehensive early containment plans to prevent potentially harmful public health and economic consequences.

Prevalence and Risk Factors of Human Leishmaniasis in Ethiopia: A Systematic Review and Meta-Analysis

Introduction

Tropical diseases are public health problems affecting hundreds of millions of people globally. However, the development of adequate, affordable, and accessible treatments is mostly neglected, resulting in significant morbidity and mortality that could otherwise be averted. Leishmaniasis is one of the neglected tropical diseases caused by the obligate intracellular protozoan Leishmania parasite and transmitted by the bite of infected phlebotomine sandflies. No systematic review and meta-analysis has been done to identify the prevalence and risk factors of leishmaniasis to the authors’ knowledge. Therefore, the objective was to determine the prevalence and risk factors of human leishmaniasis in Ethiopia.

Methods

Eleven studies conducted in all regions of Ethiopia, which were fully accessible, written in any language, and original articles done on prevalence and risk factors of leishmaniasis, were included. STATA™ version 11.1 was used for statistical analysis. Chi-square, I², and p values were assessed to check heterogeneity. A random effects model with heterogeneity taken from an inverse-variance model was employed to estimate the pooled effect. Subgroup meta-analysis was computed to reduce random variations among each article’s point prevalence, and Egger and funnel plots were used to check for publication bias.

Results

The highest proportion of human leishmaniasis was reported from a study done in Amhara region (39.1%), and the lowest was reported from a survey done in Tigray (2.3%). The overall pooled prevalence of leishmaniasis was 9.13% (95% CI 5–13.27). Subgroup analysis by region revealed moderate heterogeneity (I² = 51.8%) in studies conducted in the Southern Nations Nationalities and Peoples Region (SNNPR). The presence of hyraxes and being male were associated with an increased risk of human leishmaniasis.

Conclusion

The prevalence of leishmaniasis in Ethiopia remains high (9.13%), with significant risk factors being male and the presence of hyraxes within a 300-m radius of the sleeping area.

Molecular epidemiological survey of cutaneous leishmaniasis from Azad Jammu and Kashmir, Pakistan

Cutaneous leishmaniasis (CL) is an emerging neglected tropical disease in Azad Jammu and Kashmir which is an underdeveloped area. Prevalence and parasite species identification are the key factors to control disease in a particular population, which were the objectives of the present study. Due to a lack of previous data, we performed a district-based active CL surveillance in 2018. The data of CL, suspected (n = 20,000) cases were analyzed statistically and identified the parasite species in microscopic positive cases by ITS1-PCR RFLP and also obtained accession numbers MN891719-28 from gene Bank. The phylogenetic tree was constructed using MEGA6 software. Out of 20,000 CL, suspected cases the highest rate of 4.02% (135/3360) of CL in Mirpur and the lowest 1.58% (8/505) in Neelum was reported. The slide positivity rate, annual parasite incidence rate and annual blood examination rate were 2.27 per 1000 population, 0.08 and 0.34%. The males were more infected 58.12% (297/511) than females 41.88% (214/511) and the age group of 1-20 years were found highly infected 82.78% (423/511) than 21-40 years 13.89% (71/511) and 41-60 years 3.33% (17/511) in the studied population. The patients 56.36% (288/511) had a single lesion whereas 29.35% (150/511) had two, only 10.76% (31/288) and 8% (12/150) were using bed nets. The patients 14.29% (73/511) had three or more lesions were not using bed nets. Only 27.98% (143/511) patients had received treatment, while 72.02% (368/511) didn't. Microscopically positive cases were found to be 2.56% (511/20,000) and ITS1-PCR positive cases were found to be 91.39% (467/511). The RFLP assay confirmed the presence of Leishmania tropica in 467 samples.

Incidence of Mortality and Its Predictors Among Adult Visceral Leishmaniasis Patients at the University of Gondar Hospital: A Retrospective Cohort Study

Background

Visceral leishmaniasis (VL) is a neglected tropical disease, affecting the poor and productive age group of a country, resulting in a huge impact on its economic development. Even though anti-leishmanial drugs reduce the incidence of mortality among VL patients, there is still death of these patients while on treatment. In this aspect, there are limited studies in Ethiopia; therefore, this study aimed to determine the incidence of mortality and its predictors among adult VL patients at the University of Gondar Hospital.

Methods

Institution-based retrospective cohort study was conducted among 586 adult visceral leishmaniasis patients who were admitted to the University of Gondar Hospital from 2013 to 2018. Data were collected from the patients’ charts and registration books, and analyzed using Stata 14 software. Kaplan–Meier failure curve and Log rank test was used to compare the survival probability of patients with independent variables. A multivariable stratified Cox regression model was used to identify predictors of mortality among VL patients. P≤ 0.05 was employed to declare statistically significant factors. Adjusted hazard ratio (AHR) and 95% confidence interval (95% CI) were estimated for potential risk factors included in the multivariable model.

Results

A total of 586 VL patients were included in the study. The age of patients ranged from 18 to 55 years with a median age of 27 years. The incidence of mortality was 6.6 (95% CI: 5.2–8.4) per 1000 person-days of observation. Independent predictors of mortality were presence of comorbidity (AHR=2.29 (95% CI: 1.27–4.11)), relapse VL (AHR=3.03 (95% CI: 1.25–7.35)), treatment toxicity (AHR=5.87 (95% CI: 3.30–10.44)), nasal bleeding (AHR=2.58 (95% CI: 1.48–4.51)), jaundice (AHR=2.84 (95% CI: 1.57–5.16)) and being bedridden at admission (AHR=3.26 (95% CI: 1.86–5.73)).

Conclusion

The incidence of mortality among VL patients was high. Mortality was higher among VL patients with concomitant disease, relapse VL, treatment toxicity, nasal bleeding, jaundice, and those who were bedridden at admission, which implies that great care should be taken for these risky groups through strict follow-up and treatments.

Knowledge, attitude and practices of the resident community about visceral leishmaniasis in West Armachiho district, Northwest Ethiopia

Visceral leishmaniasis (VL) or kala-azar is a tropical disease, which is caused by an obligate intracellular parasite of the genus Leishmania. It is transmitted by the bite of an infected phlebotomine sand fly. The disease is endemic in northwest part of Ethiopia particularly in areas bordering Sudan. Assessing the knowledge, attitude and practices (KAP) of the community is helpful to design and implement appropriate control and prevention strategies. A cross-sectional study was conducted to assess the KAP of the resident community on VL in West Armachiho district, northwest Ethiopia. Data were collected by using pretested and well-structured questionnaire. Two villages (Abderafi and Abrehajira) were selected randomly. Households engaged in the study were selected by systematic random sampling method and then finally, simple random sampling was used to engage a maximum of two individuals per household. A total of 422 participants were engaged in the study. Almost all participants heard about VL. The source of information was mainly from friends (80.8%). The highest proportion (88.2%) of participants thought that persistent enlargement of liver and spleen (enlargement of the abdomen) was the main symptom of VL. Of all participants, only 52.1% knew sand fly as the vector of the disease. The overall assessment of participants indicated that 21.1% were knowledgeable, 53.6% had positive attitudes and 14.9% had optimal practices on VL. In conclusion, the survey indicated that participants had better attitude about VL. However, there were a large gap in knowledge and practices. The misunderstanding and incorrect practices may remain serious concerns in the control and prevention of the disease. It is recommended that health education program should be strengthened to increase peoples’ awareness and improve their practices on VL in the district and further studies are strongly suggested for better understanding of the dynamics of the disease in the area.

An epidemiological study of visceral leishmaniasis in North East Ethiopia using serological and leishmanin skin tests

Background

In Ethiopia, visceral leishmaniasis (VL) is caused by Leishmania donovani. The estimated country-wide incidence of VL in Ethiopia is 3700–7400 cases/year. The balance between anthroponotic and zoonotic transmission is still unknown even though most authors believe that visceral leishmaniasis in East Africa is anthroponotic. Asymptomatic leishmania infections occur more frequently than clinically apparent visceral leishmaniasis cases. The aim of this study was to determine the prevalence of asymptomatic VL infection and assess the degree of exposure among residents in Raya Azebo Woreda villages where cases of VL were recently reported.

Methods

A community based cross-sectional survey was conducted in 2013 between 1^st of May and 25^th of July. A total of 1099 individuals living in 314 households were included in the study. Socio-demographic and clinical data were collected from each of the participants and venous blood was also collected for the detection of antibodies to visceral leishmaniasis using Direct Agglutination Test. Leishmanin skin test was performed to detect the exposure to the parasite. Data was entered into excel and exported to SPSS version 17 for statistical analysis. Chi-square and the corresponding p-values were used to determine the statistical significance of the proportions/ratios obtained from the cross tabulated data. A p-value < 0.05 was considered statistically significant.

Result

A total of 1099 study subjects comprising 401 males and 698 females were included in the study. The overall positive leishmanian skin test and sero-prevalence rates respectively were 9.08% and 0.87%. The difference in LST positivity by age group and sero-prevalence by sex were statistically significant (P <0.01 and P<0.05 respectively). Out of the 9 sero-positive individuals, 7 had no history of travel to visceral leishmaniasis endemic areas out of Raya Azebo.

Conclusion

In general our results suggest occurrence of VL in the study area is, very low. Our survey also indicates that due to the low incidence of the disease, and lack of awareness, some patients remain under diagnosed.

Longitudinal evaluation of asymptomatic Leishmania infection in HIV-infected individuals in North-West Ethiopia: A pilot study

Background

In endemic regions, asymptomatic Leishmania infection is common. In HIV patients, detection of asymptomatic Leishmania infection could potentially identify those at risk of visceral leishmaniasis (VL). However, data on the prevalence, incidence, and determinants of asymptomatic infection, and the risk of VL are lacking.

Methods

We conducted a cross-sectional survey at a single ART centre, followed by a prospective cohort study amongst HIV-infected adults in HIV care in a district hospital in a VL-endemic area in North-West Ethiopia (9/2015-8/2016). Asymptomatic Leishmania infection was detected using the direct agglutination test (DAT), rK39-rapid diagnostic test (RDT)), PCR on peripheral blood and the KAtex urine antigen test, and defined as positivity on any Leishmania marker. All individuals were followed longitudinally (irrespective of the Leishmania test results). Risk factors for asymptomatic Leishmania infection were determined using logistic regression.

Results

A total of 534 HIV-infected individuals enrolled in HIV care were included in the study. After excluding 13 patients with a history of VL and an 10 patients with incomplete baseline Leishmania tests, 511 were included in analysis. The median age was 38 years (interquartile range (IQR) 30–45), 62.6% were male. The median follow-up time was 12 months (IQR 9–12). No deaths were reported during the study period. Most (95.5%) were on antiretroviral treatment at enrolment, for a median of 52 months (IQR 27–79). The median CD4 count at enrolment was 377 cells/mm3 (IQR 250–518). The baseline prevalence of Leishmania infection was 12.8% in males and 4.2% in females. Overall, 7.4% tested positive for rK39, 4.3% for DAT, 0.2% for PCR and 0.2% for KAtex. Independent risk factors for a prevalent infection were male sex (odds ratio (OR) 3.2; 95% confidence intervals (CI) 14–7.0) and concurrent malaria infection (OR 6.1; 95% CI 1.9–18.9). Amongst the 49 prevalent (baseline) infections with further follow-up, the cumulative incidence of losing the Leishmania markers by one year was 40.1%. There were 36 incident infections during the course of the study, with a cumulative one-year risk of 9.5%. Only one case of VL was detected during follow-up.

Conclusions

We found a high prevalence of asymptomatic Leishmania infection, persisting in most cases. The incidence was more modest and overt VL was rare. Larger and longer studies with more complete follow-up may help to decide whether a test and treat strategy would be justified in this context.

Trial registration

ClinicalTrials.gov NCT02839603

As visceral leishmaniasis (VL) in HIV patients is difficult to treat and associated with high mortality, strategies to detect and treat asymptomatic Leishmania infection in HIV patients should be explored. However, data on the prevalence, incidence, determinants of asymptomatic infection and risk of VL are lacking. We conducted a longitudinal study, including HIV-infected adult patients in HIV care in a district hospital in a VL-endemic area in North-West Ethiopia. Asymptomatic Leishmania infection was evaluated by Leishmania antibody tests (DAT and rK39), urine antigen tests (KAtex) and PCR, and was defined as positivity on any Leishmania marker. We also looked for independent risk factors for asymptomatic Leishmania infection at study recruitment. A total of 511 patients were included in the analysis. The median age was 38 years, 62.6% were male. The median time of residence in a VL-endemic area was 18 years. Most (95.5%) were on antiretroviral treatment at enrolment, for a median of 52 months. The median CD4 count at enrolment was 377 cells/mm³. The baseline prevalence of Leishmania infection was 12.8% in males and 4.2% in females. Overall, 7.4% tested positive for rK39, 4.3% for DAT, 0.2% for PCR and 0.2% for KAtex. Independent risk factors for a prevalent infection were male sex and concurrent malaria infection. Amongst the 49 prevalent infections that were present upon enrolment in the study, the probability of losing the Leishmania markers by one year was 40.1%. There were 36 new infections during the course of the study, with an overall risk of 9.5% by one year of follow-up. One case of VL was detected during follow-up. In conclusion, we found a high prevalence of asymptomatic Leishmania infection, which persisted in most cases. The incidence was more modest. Larger and longer studies would be needed to decide whether a test and treat strategy would be justified in this context.

In vitro activity of Erythrophleum ivorense extract against the promastigote stage of cutaneous Leishmania parasite, a member of Leishmania (Mundinia) enriettii complex isolates from Ghana

BACKGROUND

Cutaneous leishmaniasis causes physical disfigurement and impairment on affected individuals, however, little attention has been paid to it eradication. The situation of this neglected disease is complicated with the expansion of the non-human pathogenic Leishmania enriettii complex causing infection in humans. We have previously shown that the extract from Erythrophleum ivorense has leishmanicidal activity against promastigote stages of the L. enriettii complex isolate from Ghana and L eishmania donovani. The extract of E. ivorense has shown to have anti-inflammatory, wound-healing ability, antiallergic, antimalarial and antischistosomal activity. However, the concentration threshold of E. ivorense extract required for leishmanicidal activity against the emerging human pathogenic L. enriettii complex isolates is not clear.

AIM

To test for the concentration threshold of E. ivorense extract required to obtain ideal leishmanicidal activity against the promastigote stage of human pathogenic L. enriettii complex isolates from Ghana.

METHOD

The ethanolic leaf extract of E. ivorense was serially diluted and tested against the promastigote stage of the L. enriettii complex. Parasite inhibition was measured at 590 nm using a spectrophotometer after staining parasites with trypan blue. To select the threshold concentration for maximum inhibition of the promastigote stage of the L. enriettii complex, the concentration cut-off statistic was used.

RESULTS

The MIC of E. ivorense extract for L. enriettii promastigote inhibition was 62.3 μg ml-1. The highest promastigote inhibition was observed at 72 h.

CONCLUSION

We show that a MIC of 62.3 μg ml-1 of E. ivorense leaf extract exhibits an ideal leishmanicidal activity against the promastigote stage of L. enriettii complex isolates.

Dynamic spatiotemporal modeling of the infected rate of visceral leishmaniasis in human in an endemic area of Amhara regional state, Ethiopia

Visceral Leishmaniasis is a very dangerous form of leishmaniasis and, shorn of appropriate diagnosis and handling, it leads to death and physical disability. Depicting the spatiotemporal pattern of disease is important for disease regulator and deterrence strategies. Spatiotemporal modeling has distended broad veneration in recent years. Spatial and spatiotemporal disease modeling is extensively used for the analysis of registry data and usually articulated in a hierarchical Bayesian framework. In this study, we have developed the hierarchical spatiotemporal Bayesian modeling of the infected rate of Visceral leishmaniasis in Human (VLH). We applied the Stochastics Partial Differential Equation (SPDE) approach for a spatiotemporal hierarchical model for Visceral leishmaniasis in human (VLH) that involves a GF and a state process is associated with an autoregressive order one temporal dynamics and the spatially correlated error term, along with the effect of land shield, metrological, demographic, socio-demographic and geographical covariates in an endemic area of Amhara regional state, Ethiopia. The model encompasses a Gaussian Field (GF), affected by an error term, and a state process described by a first-order autoregressive dynamic model and spatially correlated innovations. A hierarchical model including spatially and temporally correlated errors was fit to the infected rate of Visceral leishmaniasis in human (VLH) weekly data from January 2015 to December 2017 using the R package R-INLA, which allows for Bayesian modeling using the stochastic partial differential equation (SPDE) approach. We found that the mean weekly temperature had a significant positive association with infected rate of VLH. Moreover, net migration rate, clean water coverage, average number of households, population density per square kilometer, average number of persons per household unit, education coverage, health facility coverage, mortality rate, and sex ratio had a significant association with the infected rate of visceral leishmaniasis (VLH) in the region. In this study, we investigated the dynamic spatiotemporal modeling of Visceral leishmaniasis in Human (VLH) through a stochastic partial differential equation approach (SPDE) using integrated nested Laplace approximation (INLA). Our study had confirmed both metrological, demographic, sociodemographic and geographic covariates had a significant association with the infected rate of visceral leishmaniasis (VLH) in the region.

Zoonotic impact and epidemiological changes of leishmaniasis in Ethiopia

Leishmaniasis is one of the growing public health challenges in Ethiopia and estimated over 7,000 and 50,000 new cases of visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL) per year, respectively. The aim of the review is to address zoonotic impact and epidemiological changes of leishmaniasis in Ethiopia. VL is caused by L. donovani and it is endemic in many parts of the country with one third of the country’s landmass is highly suitable for VL. CL is principally caused by L. aethiopica. CL is endemic and widespread in the highland of Ethiopia. Northern lowland foci are Humera and Metema plains in the Tigray and Amhara regional states constitute the main VL endemic areas in the country, contributing over 60% of the total burden. The southern foci are the south-western savannah, and the south-eastern semi-arid lowlands which account for approximately 20 % of the total VL burden in Ethiopia. Leishmaniasis is a serious zoonotic disease in Ethiopia with more reservoir hosts maintaining the disease. Dogs and hyraxes are the main reservoir hosts for visceral and cutaneous leishmaniasis in the country, respectively. Epidemiological changes of leishmaniasis may relate to environmental changes and expansion of mega projects such as irrigations and sugar cane factories, knowledge and socio-economic factors, development of new settlements, migration of peoples and HIV/AIDS co-infection. Expansions of mega projects such as sugar factories and irrigations are suitable for reproduction of stray dogs, rodents, wild canids and vectors. VL is one of the major challenges to prevent and control in the endemic areas of the country. Therefore, new research should be imperative, especially in the mega projects to design strategic control and prevention methods.

Barriers to access to visceral leishmaniasis diagnosis and care among seasonal mobile workers in Western Tigray, Northern Ethiopia: A qualitative study

Background

Ethiopia bears a high burden of visceral leishmaniasis (VL). Early access to VL diagnosis and care improves clinical prognosis and reduces transmission from infected humans; however, significant obstacles exist. The approximate 250,000 seasonal mobile workers (MW) employed annually in northwestern Ethiopia may be particularly disadvantaged and at risk of VL acquisition and death. Our study aimed to assess barriers, and recommend interventions to increase access, to VL diagnosis and care among MWs.

Methodology/Principal findings

In 2017, 50 interviews and 11 focus group discussions were conducted with MWs, mobile residents, VL patients and caretakers, community leaders and healthcare workers in Kafta Humera District, Tigray. Participants reported high vulnerability to VL among MWs and residents engaged in transitory work. Multiple visits to health facilities were consistently needed to access VL diagnosis. Inadequate healthcare worker training, diagnostic test kit unavailability at the primary healthcare level, lack of VL awareness, insufficient finances for care-seeking and prioritization of income-generating activities were significant barriers to diagnosis and care. Social (decision-making and financial) support strongly and positively influenced care-seeking; workers unable to receive salary advances, compensation for partial work, or peer assistance for contract completion were particularly disadvantaged. Participants recommended the government/stakeholders intervene to ensure: MWs access to bed-nets, food, shelter, water, and healthcare at farms or sick leave; decentralization of diagnostic tests to primary healthcare facilities; surplus medications/staff during the peak season; improved referral/feedback/reporting/training within the health system; free comprehensive healthcare for all VL-related services; and community health education.

Conclusions/Significance

Contrary to what health policy for VL dictates in this endemic setting, study participants reported very poor access to diagnosis and, consequently, significantly delayed access to treatment. Interventions tailored to the socio-economic and health needs of MWs (and other persons suffering from VL) are urgently needed to reduce health disparities and the VL burden.

Ethiopia bears a high burden of visceral leishmaniasis (VL)—a neglected tropical disease transmitted through the bite of a sand fly that disproportionately affects vulnerable populations. Without treatment, VL progresses, causing increasingly severe symptoms and ultimately death within two years, in most cases. Early access to VL diagnosis and care improves clinical prognosis and reduces transmission from infected humans; however, significant obstacles exist. To our knowledge, our study is the first in Ethiopia to use qualitative methods to assess barriers to VL diagnosis and care among seasonal mobile workers. Strikingly, we found that contrary to what health policy for VL dictates in this endemic setting, study participants reported very poor access to diagnosis and, consequently, significantly delayed access to treatment. Our findings have important public health and policy implications. Specifically, our results offer strategies that may increase access to VL diagnosis and care, allowing for earlier treatment and better prognoses for VL patients, and reducing the potential health disparities and the overall burden of VL.

Effect of iron-folic acid supplementation on change of hemoglobin among visceral Leishmaniasis patients in northwest Ethiopia: a retrospective follow up study

Background

An individual with visceral Leishmaniasis (VL) commonly present with anemia and one of the VL treatment center in northwest Ethiopia has been recommended iron-folic acid supplementation to these patients. But there is no documented evidence whether iron-folic acid supplementation improves the hematological profile of patients. Therefore, the study aimed to assess change in hemoglobin (Hb) and its determinant factors among VL patients with and without iron-folic acid supplementation in northwest Ethiopia.

Methods

A retrospective cohort study was conducted from January 2015 to December 2016. Data were entered into Epi-Data version 3.1 and transferred to Statistical Package for Social Science (SPSS) version 20 for analysis. Independent sample T-test and linear regression were used to compare the change in Hb and identify factors associated with a change in Hb, respectively. A 95% confidence level and p-values less than 0.05 were used determine statistically significant.

Results

From a total of 602 VL patients, 299 (49.7%) were from University of Gondar hospital. The mean (±SD) change of Hb from baseline to end of treatment was 0.99(±1.64) and 1.61(±1.88) g/dl with and without iron-folate supplementation, respectively, with mean difference 0.62, 95% CI (0.34, 0.90) and a p-value of < 0.0001. In multiple linear regressions, combination therapy of sodium stibogluconate-paramomycin (SSG-PM) was positively associated with a change of Hb (β [SE, p]: 0.710/0.15, < 0.0001). Whereas age (- 0.030/0.009, 0.001), nasal bleeding (- 0.261/0.123, 0.035), baseline white blood cell (- 0.139/0.044, 0.002) and hemoglobin (- 0.513/0.031, < 0.0001), end of treatment spleen size (- 0.059/0.015, < 0.0001) and iron-folic acid supplementation (- 0.574/0.163, < 0.0001) were negatively associated with change of Hb.

Conclusion

Iron-folic acid supplementation had a negative effect on the change of Hb. A combination therapy of SSG-PM, age, nasal bleeding, baseline white blood cells and Hb, and iron-folic acid supplementation were the determinants of change of Hb. Therefore, avoiding iron-folic acid supplementation and strengthening VL treatment with a combination of SSG-PM and, and early identification of complications is recommended for a better outcome.

Recent Development of Visceral Leishmaniasis Treatments: Successes, Pitfalls, and Perspectives

Research in visceral leishmaniasis in the last decade has been focused on how better to use the existing medicines as monotherapy or in combination. Systematic research by geographical regions has shown that a universal treatment is far from today's reality. Substantial progress has been made in the elimination of kala-azar in South Asia, with a clear strategy on first- and second-line therapy options of single-dose liposomal amphotericin B and a combination of paromomycin and miltefosine, respectively, among other interventions. In Eastern Africa, sodium stibogluconate (SSG) and paromomycin in combination offer an advantage compared to the previous SSG monotherapy, although not exempted of limitations, as this therapy requires 17 days of painful double injections and bears the risk of SSG-related cardiotoxicity. In this region, attempts to improve the combination therapy have been unsuccessful. However, pharmacokinetic studies have led to a better understanding of underlying mechanisms, like the underexposure of children to miltefosine treatment, and an improved regimen using an allometric dosage. Given this global scenario of progress and pitfalls, we here review what steps need to be taken with existing medicines and highlight the urgent need for oral drugs. Furthermore, it should be noted that six candidates belonging to five new chemical classes are reaching phase I, ensuring an optimistic near future.

Leishmaniasis in Ethiopia: A systematic review and meta-analysis of prevalence in animals and humans

Leishmaniasis is a neglected tropical disease caused by obligate intracellular protozoa of the genus Leishmania. Ethiopia does not have an overall estimation of prevalence of leishmaniasis infection at a country level. The objective of this systematic review and meta-analysis was to summarize and pool estimates of studies that report the prevalence of leishmaniasis in Ethiopia. The literature search was conducted to identify all published studies reporting the prevalence of leishmaniasis with clearly designed inclusion and exclusion criteria. From all screened articles, 30 studies were eligible for final meta-analysis and systematic review. Because substantial heterogeneity was expected, random-effects meta-analyses were carried out using the total sample size and number of positives to estimate the prevalence of the disease at a country level. Between-study variability was high (τ² = 0.02; heterogeneity I² = 99.72% with Heterogeneity chi-square = 11985.41, a degree of freedom = 33 and P = 0.001). The overall random pooled prevalence of leishmaniasis was 19% (95% CI 14%-24%). Meta-regression analysis showed that diagnosis method used have contributed to the heterogeneity of studies. Molecular diagnosis has significantly lower prevalence than microscopic examination with a coefficient of -0.32, a p-value of 0.024, and CI (-0.6-0.05). The result of effect estimates against its standard error showed there was no publication bias with a P value of 0.084. This review indicated that there is still a higher prevalence of Leishmaniasis in the country. Reporting on risk factors like sex and age affected, species of Leishmania involved and many more other risk factors reviewing was not possible in this study due to lack of completeness in articles included. However, this report is an indication that the country needs nationally coordinated extensive prevention and control plan to reduce public health and socio-economic impact of the disease.

Visceral leishmaniasis in selected communities of Hamar and Banna-Tsamai districts in Lower Omo Valley, South West Ethiopia: Sero-epidemological and Leishmanin Skin Test Surveys

Background

Visceral leishmaniasis [VL] is a debilitating parasitic disease which invariably kills untreated patients. The disease is caused by Leishmania (L.) donovani or L. infantum, and transmitted by the bite of female phlebotomine sandflies. VL often remains subclinical but can become symptomatic with an acute/subacute or chronic course. Globally, the Eastern Africa region is one of the main VL endemic areas. The disease is prevalent in numerous foci within Eritrea, Ethiopia, Kenya, Somalia, Sudan South Sudan, and Uganda. In Ethiopia, the Lower Omo plain is one of the many VL endemic regions.

Objectives

The objective of this study was to determine the prevalence of asymptomatic visceral leishmaniasisin Hamar and Banna-Tsamai districts of the South Omo plains where VL is becoming an emerging health problem of neglected communities.

Methods

A community based cross-sectional survey was conducted in 2013 between 25th of July and 14^th of August. A total of 1682 individuals living in 404 households were included in the study. Socio-demographic and clinical data were collected from each of the participants and venous blood was also collected for the detection of antibodies to visceral leishmaniasis using Direct Agglutination Test. Leishmanin Skin Test was performed to detect the exposure to the parasite.

Results

The surveys included 14 villages located in areas where VL had been reported. In a study population of 1682 individuals, the overall positive leishmanian skin test and sero-prevalence rates respectively were 8.6% and 1.8%. A statistically significant variation in the rate of positive LST response was observed in different study sites and age groups. Positive LST response showed an increasing trend with age. The sero-prevalence rate also showed a statistically significant variation among different study sites. Higher rates of sero-prevalence were observed in children and adolescents. The LST and sero-prevalence rates in Hamar District exceeded significantly that of Banna-Tsamai District (10.7% versus 5.8% for LST; and 2.6% versus 0.7% for sero-prevalence).

Conclusion

The prevalence of asymptomatic VL infection in Hamar and Banna-Tsamai districts during the study period in 2013 was low compared to rates previously reported in other endemic areas of Ethiopia. This could be due to the fact that the disease is emerging in Hamar and Banna-Tsamai districts. Based on records of a nearby Hospital, increasing numbers of active VL cases have been reported in these districts through the years 2006–2012, especially in Hamar District. Both districts are important destinations of tourism, and thus the importance of surveillance should be emphasized. Detailed epidemiological and entomological studies are recommended.

Some aspects of entomological determinants of Phlebotomus orientalis in highland and lowland visceral leishmaniasis foci in northwestern Ethiopia

Visceral leishmaniasis (VL) is one of the major public health problems in northwest Ethiopia, mainly in Libo-Kemkem and Metema districts, where Phlebotomus orientalis is the most probable vector of the disease. The aim of this study was to determine the physiological age, host preference and vectorial potential of P. orientalis in the highland and lowland foci of the region. Sand flies were collected using CDC light traps between May 2011 and April 2012 in Libo-Kemkem and October 2012 and September 2013 in Metema from household compounds, farm field and mixed forest. Females belonging to Phlebotomus were dissected for physiological age determination and Leishmania detection and isolation. Leishmania infections in sand flies were investigated using molecular methods. Freshly fed Phlebotomus females were tested to identify blood meal sources using PCR-RLB and ELISA. A total of 1149 (936 from Libo-Kemkem and 213 from Metema) blood unfed female P. orientalis were dissected for age determination. The parity rate was 45.6% and 66.2% in Libo-Kemkem and Metema, respectively. None of 798 female P. orientalis dissected (578 from Libo-Kemkem and 220 from Metema) was infected with Leishmania parasites. A total of 347 P. orientalis specimens collected from Libo-Kemkem were processed using PCR, of which 10 (2.8%) specimens were found with DNA of Leishmania spp. Of a total 491 freshly fed female P. orientalis analyzed for blood meal origins by RLB-PCR and ELISA, 57.6% (67.8% from Libo-Kemkem and 49.8% from Metema) were found to contain bovine blood while 4.9% (3.7% from Libo-Kemkem and 5.7% from Metema) were of human blood. In conclusion, the present study showed parity difference between the two populations of P. orientalis and that both populations have strong zoophilic behavior. Based on the presented evidences, the species is strongly implicated as a vector of kala-azar in both areas. Therefore, vector control should be a component of a strategy to manage visceral leishmaniasis in both study areas.

Comparative study on the antileishmanial activities of chemically and biologically synthesized silver nanoparticles (AgNPs)

The present study was conducted to investigate the antileishmanial activity of biogenic silver nanoparticles (AgNPs) compared to chemically synthesized AgNPs. A nano dimension size (10-15 nm) biogenic AgNPs was produced and characterized by UV-Vis spectroscopy and X-rays diffraction. The chemically synthesized AgNPs was recovering from our previous study with a nanoparticle (NP) size in the range of 10-40 nm. The antileishmanial activities were investigated through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell viability assay. The infectivity was determined by Giemsa staining of the infected macrophages cells. Nitric oxide (NO) accumulation was measured by Griess reagent using NaNO₂ as a positive control. After 24 h of exposure with nanoparticles (NPs), a concentration-dependent growth inhibition was observed. The IC₅₀ values were determined against promastigotes of L. infantum as 19.42 ± 2.76 µg/ml for leaves aqueous extract mediated AgNPs, 30.71 ± 1.91 µg/ml for stem mediated AgNPs and 51.23 ± 2.20 µg/ml for chemically synthesized AgNPs. It was also detected that all types of NPs produced NO at a significant level. However, the production of a high-level of NO in the biologically synthesized NPs activated macrophage cells, infected with L. infantum promastigotes indicates that NO radicals are mainly responsible for induced cell death and a decrease in the pathogenicity of the parasites. Since, biogenic nanoparticles are cost-effective, eco-friendly, simple to synthesize, and more effective than chemically synthesized silver nanoparticles, therefore, it could be used as a potential alternative for the development of antileishmanial drugs.

Minimally invasive microbiopsies: a novel sampling method for identifying asymptomatic, potentially infectious carriers of Leishmania donovani

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Microbiopsy devices were designed to assess the infectiousness of asymptomatic Leishmania donovani carriers.

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The microbiopsy devices sample both skin tissues and blood, as do pool-feeding phlebotomine sand flies.

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Devices were tested on human volunteers in Ethiopia and proven effective, surpassing the sensitivity of finger-pricks.

Visceral leishmaniasis (VL) is a potentially lethal, sand fly-borne disease caused by protozoan parasites belonging to the Leishmania donovani species complex. There are several adequate methods for diagnosing VL, but the majority of infected individuals remain asymptomatic, comprising potential parasite reservoirs for transmission of the disease. The gold standard for assessing host infectiousness to biting vector insects is xenodiagnosis (i.e. scoring infection rates among insectary-reared insects that had fed on humans suspected of being infected). However, when it comes to sand flies and leishmaniasis, xenodiagnosis is an intricate operation burdened by logistical hurdles and ethical concerns that prevent its effective application for mass screening of widely dispersed communities, particularly in rural regions of underdeveloped countries. Minimally invasive microbiopsy (MB) devices were designed to penetrate the skin to a depth of ∼200 µm and absorb blood as well as skin cell lysates, mimicking the mode by which phlebotomine sand flies acquire blood meals, as well as their composition. MBs taken from 137 of 262 volunteers, living in endemic VL foci in Ethiopia, detected Leishmania parasites that could potentially be imbibed by feeding sand flies. Although the volume of MBs was 10-fold smaller than finger-prick blood samples, Leishmania DNA detection rates from MBs were significantly higher, implying that skin, more often than blood, was the source of parasites. Volunteers with histories of VL were almost as likely as healthy volunteers to test positive by MBs (southern Ethiopian focus: 95% CI: 0.35–2.59, P = 1.0. northern Ethiopian focus 0.87: 95% CI: 0.22–3.76, P = 1), suggesting the importance of asymptomatic patients as reservoirs of L. donovani. Minimally invasive, painless MBs should be considered for reliably and efficiently evaluating both L. donovani infection rates among large numbers of asymptomatic carriers and their infectiousness to blood-feeding sand flies.

Perceived quality of life among Visceral Leishmaniasis and HIV coinfected migrant male-workers in Northwest Ethiopia: a qualitative study

Background

There is paucity of data on quality of life as a dimension of treatment outcome among Visceral Leishmaniasis and HIV coinfected patients. This study sought to explore perceived quality of life among Visceral Leishmaniasis and HIV coinfected male migrant workers in Northwest Ethiopia.

Methods

Twenty Visceral Leishmaniasis and HIV coinfected study participants took part in the in-depth interviews at Visceral Leishmaniasis and HIV treatment centers. Ten participants were on antiretroviral treatment (ART) and the remaining 10 have not yet started ART. All interviews were recorded, transcribed and translated for analysis. Data were analyzed by qualitative content analysis using Open Code software version 3.4.

Result

Participants reported on four aspects of quality of life: liveability of the environment, utility of life, life ability of a person and appreciation of life. Respondents living environment, therapeutic side effects of Visceral Leishmaniasis drugs, poverty and stigma negatively affected their quality of life. On the contrary, good treatment response and financial security were reported to positively affect their quality of life.

Conclusion

Challenges related to the living environment, financial limitations and sub-optimal response of Visceral Leishmaniasis drug and relapse of Visceral Leishmaniasis disease are factors most negatively affecting the quality of life of Visceral Leishmaniasis and HIV coinfected patients. Micro-financing and other socio-economical support programs should be launched to assist the unemployed males migrating to Visceral Leishmaniasis endemic and relatively higher HIV prevalent areas to work as daily laborers. HIV prevention programs in HIV positive-living counseling programs should target such high risk migrant workers in the endemic areas.

Chemotherapy of leishmaniasis: present challenges

Cutaneous and visceral leishmaniasis are amongst the most devastating infectious diseases of our time, affecting millions of people worldwide. The treatment of these serious diseases rely on a few chemotherapeutic agents, most of which are of parenteral use and induce severe side-effects. Furthermore, rates of treatment failure are high and have been linked to drug resistance in some areas. Here, we reviewed data on current chemotherapy practice in leishmaniasis. Drug resistance and mechanisms of resistance are described as well as the prospects for applying drug combinations for leishmaniasis chemotherapy. It is clear that efforts for discovering new drugs applicable to leishmaniasis chemotherapy are essential. The main aspects on the various steps of drug discovery in the field are discussed.