The effect of single low-dose primaquine treatment for uncomplicated Plasmodium falciparum malaria on hemoglobin levels in Ethiopia: a longitudinal cohort study

Background

To interrupt residual malaria transmission and achieve successful elimination of P. falciparum in low-transmission settings, the World Health Organization (WHO) recommends the administration of a single dose of 0.25 mg/kg (or 15 mg/kg for adults) primaquine (PQ) combined with artemisinin-based combination therapy (ACT) without glucose-6-phosphate dehydrogenase (G6PD) testing. However, due to the risk of hemolysis in patients with G6PD deficiency (G6PDd), PQ use is not as common. Thus, this study aimed to assess the safety of a single low dose of PQ administered to patients with G6PD deficiency.

Methods

An observational cohort study was conducted with patients treated for uncomplicated P. falciparum malaria with either single-dose PQ (0.25 mg/kg) (SLD PQ) + ACT or ACT alone. Microscopy-confirmed uncomplicated P. falciparum malaria patients visiting public health facilities in Arjo Didessa, Southwest Ethiopia, were enrolled in the study from September 2019 to November 2022. Patients with uncomplicated P. falciparum malaria were followed up for 28 days through clinical and laboratory diagnosis, such as measurements of G6PD levels and hemoglobin (Hb) concentrations. G6PD levels were masured by a quantiative biosensor machine. Patient interviews were also conducted, and the type and frequency of clinical complaints were recorded. Hb data were taken on days (D) 7, 14, 21, and 28 following treatment with SLD-PQ + ACT or ACT alone.

Results

A total of 249 patients with uncomplicated P. falciparum malaria were enrolled in this study. Of these, 83 (33.3%) patients received ACT alone, and 166 (66.7%) received ACT combined with SLD-PQ treatment. The median age of the patients was 20 (IQR 14) years. G6PD deficiency was found in 17 (6.8%) patients, 14 males and 3 females. There were 6 (7.2%) and 11 (6.6%) phenotypic G6PD-deficient patients in the ACT alone and ACT + SLD-PQ arms, respectively. The mean Hb levels in patients treated with ACT + SLD-PQ were reduced by an average of 0.45 g/dl (95% CI = 0.39 to 0.52) in the posttreatment phase (D7) compared to a reduction of 0.30 g/dl (95% CI = 0.14 to -0.47) in patients treated with ACT alone (P = 0.157). A greater mean Hb reduction was observed on day 7 in the G6PD deficiency group (-0.56 g/dL) than in the G6PD normal group (-0.39 g/dL); however, there was no statistically significant difference (P = 0.359). Overall, D14 losses were 0.10 g/dl (95% CI = -0.00 to 0.20) and 0.05 g/dl (95% CI = -0.123 to 0.22) in patients with and without SLD-PQ, respectively (P = 0.412).

Conclusions

Our findings showed that single low-dose primaquine (SLD-PQ) treatment for uncomplicated P. falciparum malaria is safe and does not increase the risk of hemolysis in G6PDd patients. This evidence suggests that the wider deployment of SLD-PQ for P. falciparum is part of a global strategy for eliminating P. falciparum malaria.

Higher outdoor mosquito density and Plasmodium infection rates in and around malaria index case households in low transmission settings of Ethiopia: Implications for vector control

BACKGROUND

Understanding the clustering of infections for persistent malaria transmission is critical to determining how and where to target specific interventions. This study aimed to determine the density, blood meal sources and malaria transmission risk of anopheline vectors by targeting malaria index cases, their neighboring households and control villages in Arjo-Didessa, southwestern Ethiopia.

METHODS

An entomological study was conducted concurrently with a reactive case detection (RCD) study from November 2019 to October 2021 in Arjo Didessa and the surrounding vicinity, southwestern Ethiopia. Anopheline mosquitoes were collected indoors and outdoors in index case households and their surrounding households (neighboring households), as well as in control households, using pyrethrum spray cache (PSC) and U.S. Centers for Disease Control and Prevention (CDC) light traps. Adult mosquitoes were morphologically identified, and speciation in the Anopheles gambiae complex was done by PCR. Mosquito Plasmodium infections and host blood meal sources were detected by circumsporozoite protein enzyme-linked immunosorbent assay (CSP-ELISA) and cytochrome b-based blood meal PCR, respectively.

RESULTS

Among the 770 anopheline mosquitoes collected, An. gambiae sensu lato (A. gambiae s.l.) was the predominant species, accounting for 87.1% (n = 671/770) of the catch, followed by the Anopheles coustani complex and Anopheles pharoensis, which accounted for 12.6% (n = 97/770) and 0.26% (n = 2/770) of the catch, respectively. From the sub-samples of An. gambiae s.l.analyzed with PCR, An. arabiensis and Anopheles amharicus were identified. The overall mean density of mosquitoes was 1.26 mosquitoes per trap per night using the CDC light traps. Outdoor mosquito density was significantly higher than indoor mosquito density in the index and neighboring households (P = 0.0001). The human blood index (HBI) and bovine blood index (BBI) of An. arabiensis were 20.8% (n = 34/168) and 24.0% (n = 41/168), respectively. The overall Plasmodium sporozoite infection rate of anophelines (An. arabiensis and An. coustani complex) was 4.4% (n = 34/770). Sporozoites were detected indoors and outdoors in captured anopheline mosquitoes. Of these CSP-positive species for Pv-210, Pv-247 and Pf, 41.1% (n = 14/34) were captured outdoors. A significantly higher proportion of sporozoite-infected mosquitoes were caught in index case households (5.6%, n = 8/141) compared to control households (1.1%, n = 2/181) (P = 0.02), and in neighboring households (5.3%, n = 24/448) compared to control households (P = 0.01).

CONCLUSIONS

The findings of this study indicated that malaria index cases and their neighboring households had higher outdoor mosquito densities and Plasmodium infection rates. The study also highlighted a relatively higher outdoor mosquito density, which could increase the potential risk of outdoor malaria transmission and may play a role in residual malaria transmission. Thus, it is important to strengthen the implementation of vector control interventions, such as targeted indoor residual spraying, long-lasting insecticidal nets and other supplementary vector control measures such as larval source management and community engagement approaches. Furthermore, in low transmission settings, such as the Arjo Didessa Sugarcane Plantation, providing health education to local communities, enhanced environmental management and entomological surveillance, along with case detection and management by targeting of malaria index cases and their immediate neighboring households, could be important measures to control residual malaria transmission and achieve the targeted elimination goals.

Anopheles larval habitats seasonality and environmental factors affecting larval abundance and distribution in Arjo-Didessa sugar cane plantation, Ethiopia

BACKGROUND

Water resource development projects are essential for increasing agricultural productivity and ensuring food security. However, these activities require the modification of pre-existing environmental settings, which may alter mosquito larval habitat availability and seasonality. The intensive utilization of current adult vector control tools results in insecticide resistance among the main vectors. When coupled with behavioural resistances, a shift in malaria vector feeding and resting behaviours could compromise the effectiveness of the current adult vector control strategies. Thus, it is important to look for new or alternative vector control interventions for immatures to complement adult control by focusing on different larval habitats and their seasonal availability. Thus, this study investigated larval habitat seasonality and seasonal larval abundance and distribution in irrigated sugar cane plantation settings in Ethiopia.

METHODS

Anopheles mosquito larval habitats were surveyed and visited twice a month for a period of 14 months. Anopheline larvae and pupae were collected, reared, and fed finely ground fish food. Adults were provided with sucrose solution and kept under standard conditions. Female Anopheles mosquitoes were identified morphologically and using a species-specific PCR assay. Environmental parameters, which include habitats' physico-chemical characteristics, were assessed. Larval habitat diversity and larval abundance and distribution were determined across different seasons.

RESULTS

The study revealed that Anopheles gambiae sensu lato (s.l.) was the most predominant 4197(57%) vector species, followed by Anopheles coustani complex 2388 (32.8%). Molecular analysis of sub-samples of An. gambiae s.l. resulted in Anopheles arabiensis (77.9%) and Anopheles amharicus (21.5%), and the remaining 1.1% (n = 7) sub-samples were not amplified. Physico-chemical parameters such as temperature (t = 2.22, p = 0.028), conductivity (t = 3.21, p = 0.002), dissolved oxygen (t = 7.96, p = 0.001), nitrate ion (t = 2.51, p = 0.013), and ammonium ion (t = 2.26, p = 0.025) showed a significant and direct association with mosquito larval abundance. Furthermore, mosquito larval abundance was correlated with distance to the nearest houses (r = - 0.42, p = 0.001), exposure to sunlight (r = 0.34, p = 0.001), during long and short rainy season animal hoof prints, truck tires/road puddles and rain pools were negatively correlated (r = - 0.22, p = 0.01) and types of habitat (r = - 0.20, p = 0.01). Significant habitat type productivity were observed in man-made pools (t = 3.881, P = 0.01163), rain pools, animal hoof prints, (t = - 4.332, P = 0.00749 in both short and long rainy season, whereas, during dry seasons habitat type productivity almost similar and have no significance difference.

CONCLUSION

The study found that different larval habitats had variable productivity in different seasons, and that physical and physicochemical features like ammonium and nitrate, as well as the distance between larval habitats and households, are related to larval production. As a result, vector control should take into account the seasonality of Anopheles larval habitat as well as the impact of pesticide application on larval source management.

Asymptomatic and submicroscopic malaria infections in sugar cane and rice development areas of Ethiopia

BACKGROUND

Water resource development projects, such as dams and irrigation schemes, have a positive impact on food security and poverty reduction. However, such projects could increase prevalence of vector borne disease, such as malaria. This study investigate the impact of different agroecosystems and prevalence of malaria infection in Southwest Ethiopia.

METHODS

Two cross-sectional surveys were conducted in the dry and wet seasons in irrigated and non-irrigated clusters of Arjo sugarcane and Gambella rice development areas of Ethiopia in 2019. A total of 4464 and 2176 study participants from 1449 households in Arjo and 546 households in Gambella enrolled in the study and blood samples were collected, respectively. All blood samples were microscopically examined and a subset of microscopy negative blood samples (n = 2244) were analysed by qPCR. Mixed effect logistic regression and generalized estimating equation were used to determine microscopic and submicroscopic malaria infection and the associated risk factors, respectively.

RESULTS

Prevalence by microscopy was 2.0% (88/4464) in Arjo and 6.1% (133/2176) in Gambella. In Gambella, prevalence was significantly higher in irrigated clusters (10.4% vs 3.6%) than in non-irrigated clusters (p < 0.001), but no difference was found in Arjo (2.0% vs 2.0%; p = 0.993). On the other hand, of the 1713 and 531 samples analysed by qPCR from Arjo and Gambella the presence of submicroscopic infection was 1.2% and 12.8%, respectively. Plasmodium falciparum, Plasmodium vivax, and Plasmodium ovale were identified by qPCR in both sites. Irrigation was a risk factor for submicroscopic infection in both Arjo and Gambella. Irrigation, being a migrant worker, outdoor job, < 6 months length of stay in the area were risk factors for microscopic infection in Gambella. Moreover, school-age children and length of stay in the area for 1-3 years were significant predictors for submicroscopic malaria in Gambella. However, no ITN utilization was a predictor for both submicroscopic and microscopic infection in Arjo. Season was also a risk factor for microscopic infection in Arjo.

CONCLUSION

The study highlighted the potential importance of different irrigation practices impacting on submicroscopic malaria transmission. Moreover, microscopic and submicroscopic infections coupled with population movement may contribute to residual malaria transmission and could hinder malaria control and elimination programmes in the country. Therefore, strengthening malaria surveillance and control by using highly sensitive diagnostic tools to detect low-density parasites, screening migrant workers upon arrival and departure, ensuring adequate coverage and proper utilization of vector control tools, and health education for at-risk groups residing or working in such development corridors is needed.

Asymptomatic and submicroscopic malaria infections in sugar cane and rice development areas of Ethiopia

Background

Water resource development projects such as dams and irrigation schemes have a positive impact on food security and poverty reduction but might result in increased prevalence of malaria.

Methods

Two cross-sectional surveys were conducted in the dry and wet seasons in irrigated and non-irrigated clusters of Arjo sugarcane and Gambella rice development areas of Ethiopia in 2019. A total of 4464 and 2176 blood samples were collected from Arjo and Gambella. A subset of 2244 microscopy negative blood samples were analyzed by PCR.

Results

Prevalence by microscopy was 2.0% (88/4464) in Arjo and 6.1% (133/2176) in Gambella. In Gambella, prevalence was significantly higher in irrigated clusters (10.4% vs 3.6%) than in non-irrigated clusters (p < 0.001), but no difference was found in Arjo (2.0% vs 2.0%; p = 0.993). Level of education was an individual risk factors associated with infection in Arjo [AOR: 3.2; 95%CI (1.27-8.16)] and in Gambella [AOR: 1.7; 95%CI (1.06-2.82)]. While duration of stay in the area for < 6 months [AOR: 4.7; 95%CI (1.84-12.15)] and being a migrant worker [AOR: 4.7; 95%CI (3.01-7.17)] were risk factors in Gambella. Season [AOR: 15.9; 95%CI (6.01-42.04)], no ITN utilization [AOR: 22.3; 95%CI (7.74-64.34)] were risk factors in Arjo, and irrigation [AOR: 2.4; 95%CI (1.45-4.07)] and family size [AOR: 2.3; 95%CI (1.30-4.09)] risk factors in Gambella. Of the 1713 and 531 randomly selected smear negative samples from Arjo and Gambella and analyzed by PCR the presence of Plasmodium infection was 1.2% and 12.8%, respectively. P. falciparum, P. vivax, and P. ovale were identified by PCR in both sites.

Conclusion

Strengthening malaria surveillance and control in project development areas and proper health education for at-risk groups residing or working in such development corridors is needed.

Prevalence of Malaria and Associated Risk Factors Among Febrile Children Under Five Years: A Cross-Sectional Study in Arba Minch Zuria District, South Ethiopia

Background

Malaria is a major public health problem affecting humans, particularly in the tropics and subtropics. Children under 5 years old are the group most vulnerable to malaria infection because of less developed immune system. Countries have set targets that led to control and eliminate malaria with interventions of the at-risk groups, however malaria infection remained a major public health challenge in endemic areas.

Objective

This study aimed at determining the magnitude of malaria and associated factors among febrile children under 5 years old in Arba Minch “Zuria” district.

Methods

The study was conducted from April to May 2017. Blood samples were collected from 271 systematically selected febrile children under 5 years old. Thin and thick blood smears were prepared, stained with 10% Giemsa and examined under light microscope. Data of sociodemographic data, determinant factors, and knowledge and prevention practices of malaria were collected using a pretested structured questionnaire. Data were analyzed using binomial and multinomial regression model in SPSS^® Statistics program, version 25.

Results

Among those febrile children, 22.1% (60/271) were positive for malaria; 50.0%, 48.33% and 1.66% of them were positive for Plasmodium falciparum, Plasmodium vivax and mixed infections of both parasites, respectively. Malaria infection was associated with nearby presence of stagnant water to resident areas (AOR=8.19; 95%CI: 3.62-18.5, P<0.0001). Children who slept under insecticide-treated mosquito nets (ITNs) were more likely to be protected from malaria infection than those did not sleep under an ITNs (AOR=9.65; 95%CI: 4.623-20.15, P<0.0001).

Conclusion

Malaria infection is highly prevalent in children aged between 37 and 59 months old, in Arba Minch “Zuria” district. The proximity of residence to stagnant water and the use of ITNs are the most dominant risk factor for malaria infection. Improved access to all malaria interventions is needed to interrupt the transmission at the community level with a special focus on the risk groups.

Current status of intestinal parasitic infections and associated factors among primary school children in Birbir town, Southern Ethiopia

Background

Intestinal parasites still pose major public health problems in developing countries like Ethiopia. Local epidemiological data is indispensable in order to design and monitor prevention and control strategies. Therefore the present study aimed to assess the prevalence of intestinal parasitic infections and associated factors among students at Birbir town, Southern Ethiopia.

Methods

A school-based cross-sectional study was conducted from March to May 2018. Three hundred fifty-one students, who were selected by stratified followed by systematic random sampling, participated in the study. Socio-demographic information was collected using a structured questionnaire. Anthropometric measurements of height and weight were taken at the time of interview. Stool samples were collected and processed by direct wet mount and formol-ether concentration techniques for microscopic detection of intestinal parasites. Data was analyzed using SPSS version 20.

Results

Among 351 (180 male and 171 female) children participated, 135 (38.5%) and 216 (61.5%) were within the age groups of 5–9 and 10–14 respectively. Ninety five (27.1%; 95%CI: 22.2–31.9) of them were tested positive for intestinal parasites. Helminths and protozoa account 21.1 and 7.1% prevalences respectively. Seventy eight children were infected with a single parasite species while 17 were positive for double or triple infections. A. lumbricoides (31, 8.8%) was the most frequently detected parasite followed by T. trichiura (20, 5.7%) and hookworms (19, 5.4%). Age group of 10–14 years (AOR = 2.51; 95%CI: 1.41–4.45, p = 0.002) and absence of hand washing habit after toilet (AOR = 4.49; 95%CI: 2.00–10.1, p = 0.001) were significantly associated with intestinal parasitic infection.

Conclusions

The prevalence of intestinal parasitic infection among school age children is still unacceptably high. Age group of 10–14 year old and not having habit of hand washing after toilet were significantly associated with intestinal parasitic infection. The ongoing school based deworming should be strengthened and be integrated with school health programs.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-3879-5) contains supplementary material, which is available to authorized users.

Prevalence of Opportunistic Intestinal Parasites and Associated Factors among HIV Patients while Receiving ART at Arba Minch Hospital in Southern Ethiopia: A Cross-sectional Study

BACKGROUND

Opportunistic Intestinal Parasites (OIPs) commonly cause morbidity in HIV/AIDS patients due to the decline of CD4+T-cells. The burden of Opportunistic Intestinal Parasitic Infections (OIPIs) in Ethiopia is expected to be high due to poor sanitation and co-pandemicity of HIV/AIDs. Therefore, frequent assessment of the magnitude and associated factors for intestinal parasitosis is essential for the management of HIV/AIDS patients.

METHODS

A hospital based cross-sectional study was conducted among patients attending Arba Minch Hospital Antiretroviral Therapy (ART) Clinic from March to June 2016. Stool specimens were processed for parasitological examination using direct wet mount, formol-ether sedimentation and modified Ziehl-Neelsen staining techniques. CD4+ T-cell count data were taken from patients' medical records. A structured questionnaire was used to collect data on socio-demographic characteristics and possible associated factors for OIPIs. All the data were analyzed using SPSS version 20.

RESULTS

Two hundred and twenty ART patients participated in the study. The overall prevalence of intestinal parasitic infections was 28.18% while that of OIPIs alone was 17.72%. Among identified intestinal parasites, Cryptosporidium species accounts for the highest frequency (19/220, 8.63%), followed by Cyclospora species (13/220, 5.90%). Presence of domestic animals (AOR=2.07, 95%CI:1.07-8.40, P= 0.032) and CD4+ T-cell count <500cell/µl (AOR=4.66, 95%CI:1.17-5.35, P= 0.001) were significantly associated with OIPIs.

CONCLUSION

The study indicated that co-infection rate of OIPs is high among ART patients. It also found that contact with domestic animals and having CD4+ count <500 cell/µl predict for the presence of OIPs.

Assessment of isoniazid preventive therapy in the reduction of tuberculosis among ART patients in Arba Minch Hospital, Ethiopia

Background

Tuberculosis (TB) is the most frequent life-threatening opportunistic disease among people living with HIV and remains a leading cause of mortality, even among persons receiving antiretroviral therapy (ART). Isoniazid preventive therapy (IPT) and cotrimoxazole prophylaxis have been recommended for the benefit of HIV/AIDS-infected individuals to prevent opportunistic infections. The aim of this study was to assess IPT prophylaxis in the reduction of TB among ART patients.

Methods

The study was a hospital-based retrospective study. A total of 271 study participants’ available information such as demographic data, the type of prophylaxis used, and TB/HIV coinfection status as well as other variables were collected from clinical laboratory and HIV care/ART follow-up clinic. Data analysis was performed using Statistical Package for the Social Sciences (SPSS) version 20.0.

Results

TB-infected ART patients were higher among non-IPT group (37 [27.8%]) compared to IPT group (12 [8.7%]). The finding showed that IPT prophylaxis significantly reduces acquiring TB with the relative risk =0.31 (95% confidence interval =0.122, 0.49) in ART patients of this study site where the tuberculosis prevalence is prominent. ART had significant contribution for CD4⁺ T-cell lymphocyte count improvement in both IPT and non-IPT groups (P<0.05) in this study.

Conclusion

IPT had significant contributions to reduce the burden of TB in ART patients than non-IPT group. This result highlights the use of IPT for the prevention of TB, especially for all ART patients. Other longitudinal studies are needed to observe the benefits and side effects of IPT prophylaxis in tuberculin skin test-positive individuals.

Deworming and the immune status of HIV positive pre-antiretroviral therapy individuals in Arba Minch, Chencha and Gidole hospitals, Southern Ethiopia

Background

Helminths/HIV co-infections are very common in developing countries, especially in Africa. The effect of overlapping distribution of HIV and helminths becomes important because concomitant infection may exacerbate disease outcome of HIV infection. The study aimed at determining the effect of deworming on the immune status of helminth/HIV coinfected Pre-ART HIV patients attending three health institutions in Southern Ethiopia.

Methods

97 HIV-positive Pre-ART individuals were observed into 2 groups on the basis of helminth co-infection and no infection. Out of these, 66 study participants were helminths/HIV co-infected and the remaining 31 study participants were helminths (−)/HIV (+) control. Helminth/HIV co-infected participants CD4+ T-cell count was done at baseline, after 15 weeks and 6 months after antihelminthics treatment. Data were analyzed using SPSS version 16.

Results

Ascaris lumbricoides was the highest prevalent soil transmitted helminths in Pre-ART individuals in this study. CD4+ T-cell count in the Ascaris lumricoides/HIV co-infected was significantly higher (P = 0.05) and (P < 0.05) after 15 weeks and 6 months post-antihelminthics treatment respectively. Also, after antihelminthic therapy, the CD4+ T-cell count significantly increased (P < 0.005) in all treated helminth infections.

Conclusions

The study showed that treatment of ascariasis had a significant effect on CD4+ T-cell count increase in the treated Pre-ART Ascaris lumbricoides/HIV co-infected individuals; whereas the same positive effect was not evident for other intestinal helminth parasites detected in the study. In conclusion, this finding on Ascaris lumbricoides-specific nature of immune interaction in helminth/HIV co-infection may partly explain the inconsistent reports on the role of intestinal helminths on progression of HIV infection to AIDS. Therefore, a well-designed longitudinal study on helminth species-specific HIV/helminth co-infection will be needed to fully establish the possible benefits of deworming in intestinal helminth/HIV co-infection.

Assessment of the prevalence of intestinal parasitosis and associated risk factors among primary school children in Chencha town, Southern Ethiopia

BACKGROUND

Parasitic infection is the most prevalent among rural communities in warm and humid regions and where water, hygiene and sanitation facilities are inadequate. Such infection occurs in rural areas where water supplies are not enough to drink and use, and in the absence of environmental sanitation, when the rubbish and other wastes increased, and sewage and waste water are not properly treated. Hence the aim of the study was to assess the prevalence of intestinal parasitosis and associated risk factors.

METHODS

This cross sectional study was conducted on children of the selected primary schools in Chencha town from March to May, 2012. Children were selected within age group 5-15 years. The socio-demographic, environmental and behavioral variables data were collected using structured questionnaire from the guardians of children and school teachers to assess the risk factors. Prevalence of intestinal parasitosis was determined using direct method and formol-ether concentration method. Participants' data were analyzed using SPSS version 16.0.

RESULTS

Of 422 selected school children, 400 participated in the study with full information for analysis. The overall prevalence of intestinal parasitosis was high (81.0%). Soil-transmitted helminths (STHs) infections (63.0%) were more prevalent than protozoa infections (23.5%). The predominant parasites were A. lumbricoides (60.5%), E. histolytica/dispar (16.25%), Giardia lamblia (11.7%) and T. trichuria (9.7%). The presence of Intestinal Parasitic Infections (IPIs) have statistically significant association with the educational status of the household heads, absence of washing facility, home cleanness condition and type of latrine used with (p < 0.05).

CONCLUSIONS

The prevalence of intestinal parasitic infections, especially soil-transmitted helminths (STHs) is very high in the school children. The high prevalence of parasitic infections in these children indicates that the protozoa and helminths concerned are very common in the environment of these villages and the results of the risk factors analysis suggests that the transmission is from several routes. Therefore, multiple intervention strategies should be implemented for the school children, households and the environment to reduce the disease burden.