Profils épidémiologique, clinique et biologique de la leishmaniose viscérale infantile à l’hôpital de Kairouan (Tunisie) : à propos de 240 cas

Canine Leishmania spp. infection in two distinct foci of visceral and cutaneous leishmaniasis in Tunisia

Visceral leishmaniasis (VL) and zoonotic cutaneous leishmaniasis (ZCL) caused by Leishmania (L.) infantum and L. major, respectively, are endemic in Tunisia. The aim of the study was to assess canine Leishmania spp. infection prevalence as well as to identify the Leishmania species involved in two well-documented and geographically distinct VL and ZCL foci. One hundred seventy-six dogs were randomly recruited in the VL focus of Sbikha-Zaghouan (n = 100) and the ZCL focus of Echrarda-Nasrallah (n = 76). Physical examination and blood collection were systemically performed. Needle aspiration was done in case of lymph node (LN) enlargement. All sera were tested by ELISA. kDNA RT-PCR was performed on DNA extracts from (i) buffy coats of seropositive dogs and (ii) LN aspirates. Leishmania species identification was done by ITS1 PCR-sequencing. Thirty-three dogs (18.8%) were infected by Leishmania; 30 having anti-Leishmania antibodies and 3 were seronegative dogs with Leishmania DNA in LN aspirates. Prevalence of infection was significantly higher in VL foci than in ZCL foci (27% versus 7.9%, p = 0.002). Leishmania species was identified in 11 dogs and corresponded to L. infantum. Combination of serology and qPCR on LN aspirates seems to be the best option for canine leishmaniasis diagnosis. Infection is more frequent in VL foci and L. infantum is the only identified species.

Mediterranean visceral leishmaniasis : update on biological diagnosis

Visceral leishmaniasis (VL) is a severe life threatening parasitosis requiring early management of cases. It is an emerging disease in the Mediterranean region with a spread of endemic areas and an increase in case incidence. The patient profile has also evolved with more affected adults, presenting generally non-specific symptoms. Hence the interest of a systematic biological confirmation. The microscopic detection of Leishmania amastigotes in bone marrow aspirates (BMA) smears is the gold standard diagnostic technique. However, it requires invasive sampling. Serological tests searching for specific antibodies remain highly contributory, but their interpretation must always take into account the epidemiological context and the patient's clinical and biological features. Currently, the Western-Blot represents the most specific serological technique for diagnostic confirmation. VL diagnosis has greatly improved by the introduction of both rapid diagnostic tests (RDTs) and molecular biological techniques. RDTs using recombinant rk39 antigen are easy to perform and deliver results in less than 30 minutes. Real-time PCR (Polymerase Chain Reaction) is currently retained as the best technique for VL diagnosis. It is efficient on simple blood samples, allowing to avoid invasive BMA needed for microscopy. In addition, real time PCR estimates parasite load which is helpful for the post-treatment follow-up. In any case, the choice of techniques to be used should be strategic and adapted to the local epidemiology as well as to the means available.

Investigation of natural infection of Phlebotomine (Diptera: Psychodidae) by Leishmania in Tunisian endemic regions

Leishmaniases are caused by protozoan parasites of the genus Leishmania transmitted by females blood-feeding phlebotomine insects (Diptera: Psychodidae). In Tunisia, cutaneous and visceral leishmaniases are of public health concern. In Tunisia, 17 species of phlebotomine sand flies are described. Here we investigate natural infection in Tunisian mixed foci regions of leishmaniases. We trap female sandflies during the Leishmania transmission season in the country's central-eastern and northern parts. We investigate Leishmania infection using PCR-RFLP targeting the ITS1 ribosomal DNA, followed by enzymatic digestion with HaeIII; then, we identify sand flies using molecular methodologies. We confirm the presence of Phlebotomus papatasi and Phlebotomus perniciosus infected by L. major and L. infantum parasites in Tunisia.

Male predominance in reported Visceral Leishmaniasis cases: Nature or nurture? A comparison of population-based with health facility-reported data

Background

Bangladesh, India, and Nepal aim for the elimination of Visceral Leishmaniasis (VL), a systemic parasitic infectious disease, as a public health problem by 2020. For decades, male patients have comprised the majority of reported VL cases in this region. By comparing this reported VL sex ratio to the one observed in population-based studies conducted in the Indian subcontinent, we tested the working hypothesis that mainly socio-cultural gender differences in healthcare-seeking behavior explain this gender imbalance.

Methodology/Principal findings

We compared the observed sex ratio of male versus female among all VL cases reported by the health system in Nepal and in the two most endemic states in India with that observed in population-based cohort studies in India and Nepal. Also, we assessed male sex as a potential risk factor for seroprevalence at baseline, seroconversion, and VL incidence in the same population-based data. The male/female ratio among VL cases reported by the health systems was 1.40 (95% CI 1.37–1.43). In the population cohort data, the age- and study site-adjusted male to female risk ratio was 1.27 (95% CI 1.08–1.51). Also, males had a 19% higher chance of being seropositive at baseline in the population surveys (RR 1.19; 95% CI 1.11–1.27), while we observed no significant difference in seroconversion rate between both sexes at the DAT cut-off titer defined as the primary endpoint.

Conclusions/Significance

Our population-based data show that male sex is a risk factor for VL, and not only as a socio-cultural determinant. Biological sex-related differences likely play an important role in the pathogenesis of this disease.

Visceral Leishmaniasis (VL) is a parasitic disease that is lethal if not treated timely and mainly affects impoverished populations. Bangladesh, India, and Nepal have targeted the elimination of this disease as a public health problem by 2020. The majority of VL patients attending the health services are male, and this is usually attributed to unequal access to health care for men and women in this sociocultural context. We analyzed two large datasets obtained in population surveillance projects, including regular door-to-door screening for VL, in India and Nepal. Thereby we minimized any potential differences in access to health care between both sexes, as every suspect VL case occurring in the community received a full diagnostic work-up, and the research project facilitated transport to treatment centers if needed. By comparing the observed sex ratio in the health services records with those of the population surveillance records, we aimed to reach meaningful conclusions about the pathway through which male gender exerts its leverage for increasing VL risk: socio-cultural determinants blocking women from accessing care (nurture) or biological factors (nature) making men more vulnerable to VL. Because in the population-based age adjusted-data, male VL cases were significantly more frequent than female, our findings strongly suggest that in the Indian subcontinent, biological differences between men and women play a more critical role in the pathogenesis of VL than previously assumed, and the observed male predominance in VL cases in health services cannot be explained by socio-cultural factors only. Moreover, data show that above the age of 14 years, males are seropositive more often than females and are at higher risk to develop VL disease.

Epidemiology and spatiotemporal analysis of visceral leishmaniasis in Palestine from 1990 to 2017

OBJECTIVES

Visceral leishmaniasis (VL) is a deadly disease endemic in all countries around the Mediterranean Sea. In Palestine, VL is transmitted to humans from infected dogs by a sandfly bite. The aim of this study was to investigate the epidemiology and spatiotemporal pattern of VL in Palestine within a period of 27 years (1990-2017).

METHODS

A long-term descriptive epidemiological study on human VL was conducted based on patient's profiles to calculated disease prevalence, geographical, spatiotemporal and seasonal distribution, distribution by age and gender, diagnosis, treatment, and treatment outcome.

RESULTS

A total of 343 patients were reported, the average annual incidence rate was 0.73 case/100000 population. Most cases came from the western parts of the West Bank. The number of reported males was 162 (51%), and patient's age ranged from 4 months to 16 years (average 2.5 years), of which 93.3% were ≤5 years old. The annual incidence rate increased between 1993-1999, peaked in 1995, and dropped as from 2002. The future projections of VL indicate that the endemic foci in most governorates are projected to disappear in the future and only the very northwest of the West Bank will be at risk of VL.

CONCLUSIONS

Visceral leishmaniasis continues to be endemic in the West Bank but not the Gaza Strip. Pentavalent antimonial sodium stibogluconate continues to be the first line treatment and physicians are recommended to consider liposomal Amphotericin B (AmBisome) for refractory patients only. Geographical, spatiotemporal and seasonal trends of VL were identified.

The epidemiology of cutaneous leishmaniasis in Golestan Province, Iran: A cross-sectional study of 8-years

Background

Leishmaniasis occurs with an incidence of 0.5-1.5 million new cases annually, and is also endemic in 88 countries across the world.

Aim

Presently, we aimed to investigate the status of Cutaneous Leishmaniasis (CL) in Golestan Province in North of Iran.

Methods

A retrospective survey was conducted on existed data of 6873 patients with CL who attended to Health Centers in Golestan Province during 2010 to 2017 years. Data were collected using patient sheets and online registry form of CL. Descriptive statistical methods such as mean and standard deviation, and Chi-square test were employed to report and analyze results. p-Value <0.05 was considered significant.

Results

CL cases were more common in men 3885 (56.7%) than women 2965 (43.3%) (p = 0.001). The most and least cases was reported in 2017 and 2104 as 18 and 3 CL cases, accordingly. CL was mainly happen in the November (3816 cases), December (2832 cases) months. Presently, CL gradually increases in the last three years from 2014 to 2017 years.

Conclusion

Decrease of exposurement, improve the nutrition and child's immunity can be more beneficial.

Paediatric visceral leishmaniasis: a retrospective study on clinical manifestations, demographic features and laboratory findings of hospitalised cases in Iran between 2006 and 2016

Visceral leishmaniasis (VL) is a neglected disease. Our retrospective study describes 38 clinical and epidemiological characteristics of VL in patients admitted to a paediatric hospital in Tehran, Iran, who came from different geographical regions, indicating that the disease has spread to most parts of the country. Some 76.3% of the children documented suffered with symptoms of the disease for two months before admission.

Human visceral leishmaniasis: factors associated with deaths in Belo Horizonte, Minas Gerais state, Brazil from 2006 to 2013

The aim of this study was to evaluate the distribution of cases and the social determinants associated with death from human visceral leishmaniasis (HVL) and VL-HIV co-infection in Belo Horizonte, Minas Gerais state, Brazil, between 2006 and 2013. Descriptive statistics and analysis of associations were performed using chi-square of the raised variables, such as sex, age, skin colour and schooling of cases of HVL. During the study period, there were 866 cases of HVL with 111 deaths in Belo Horizonte. Morbidity and lethality rates (LR) of HVL in Belo Horizonte remained high over almost all the years evaluated, with an average incidence rate of 4.18 cases/100 000 inhabitants and a LR of 11.16%. With respect to skin colour, it was found that people characterised as black or mulatto had higher morbidity, followed by white. Regarding schooling, LR was more prevalent among individuals with lower education. One of the social risk factors was co-infection with HIV, which was present in many cases of HVL. Furthermore, it was found that older age and the male sex were also risk factors for death from HVL in Belo Horizonte.

Epidemiology of Infantile Visceral Leishmaniasis in Western Algerian And The Convenience of Serum For The Disease Diagnosis by PCR and Immunochromatography

Epidemiological situation of infantile visceral leishmaniasis (IVL), which is a public health problem in Algeria, is almost unknown in the cities of Western part of the country. The aim of this study was to analyze the epidemiological, clinical, biological, therapeutic, and evolutionary aspects of IVL in Western Algeria, to evaluate the performance of the immunochromatography as a rapid diagnostic test of the disease, and to propose a diagnosis approach by real-time polymerase chain reaction (RT-PCR) assay from the serum. This prospective study was performed on 63 suspicious cases of visceral leishmaniasis collected from the infectious diseases department at the Pediatric Hospital of Oran from January 2012 to July 2017. For each patient, the epidemiological parameters, and the clinical and biological data were collected. Bone marrow and blood samples were drawn from all cases. Bone marrow was performed to research amastigote forms of Leishmania and to identify the species by PCR-sequencing. Blood samples were used to detect anti-Leishmania antibodies as well as parasite DNA. Patients from the Western regions were mostly from rural areas. Sensitivity of RT-PCR from the bone marrow and from serum was 95.45% and 94.44%, respectively. The immunochromatography allowed the disease's diagnosis for 11 cases whose myelogram did not confirm the presence of the amastigote forms of Leishmania. Immunochromatography was revealed to be a good technique for disease diagnosis regarding the strongly evocative clinical signs. The results also suggest the interest of the RT-PCR assay from patient serum as a non-invasive sample, in the detection of parasite DNA.

Intraspecific genetic variability in a population of Moroccan Leishmania infantum revealed by PCR-RFLP of kDNA minicircles

In Morocco, Leishmania infantum is the main etiologic agent of human and canine visceral leishmaniasis (VL). This species has been proven to be an opportunistic agent in HIV+ patients and is also responsible of sporadic cutaneous leishmaniasis (CL).This work aims to evaluate the genetic variability of Moroccan L. infantum strains based on PCR-RFLP analysis of the kinetoplastid DNA (kDNA) minicircles. A total of 75 DNA samples extracted from positive Giemsa-stained smears (n=32) and from L. infantum cultures (n=43) was studied. The samples have been taken from VL patients infected (n=7) or not (n=56) by HIV, patients with CL (n=2) and finally from infected dogs (n=10). An hypervariable region of kDNA was amplified using the primers MC1 and MC2; the PCR products were digested separately by a panel of nine restriction enzymes. The presence or absence of restriction fragments was scored in a binary matrix and the SplitsTree4 software was used for the construction of a Neighbor-Net network. Moroccan L. infantum population showed an important level of variability with the identification of 6 genotypes. For each genotype a PCR product was sequenced, confirming the presence of all the expected restriction sites. The predominant profile was the genotype B. A new genotype, named Q was detected for the first time, whereas the four other genotypes (G, K, N and O) were reported sporadically in the Mediterranean basin. The Neighbor-Net network segregates our L. infantum population into 3 clusters: Cluster I includes genotype B, cluster II grouping the genotypes O, Q and G and finally the cluster III contains the genotype N. The kDNA-PCR-RFLP assay is suitable for use directly on biological samples; it reveals an important degree of genetic variability among L. infantum strains even those belonging to the same zymodeme what is of great epidemiological interest.

Visceral leishmaniasis: a forgotten epidemic

Visceral leishmaniasis (VL or kala-azar) is most endemic in Asia and Africa and commonly affects young children. It is usually caused by Leishmania donovani or Leishmania infantum that are transmitted by Phlebotomine sand flies. Transmission may be anthroponotic or zoonotic or both, depending on the endemic area. Clinical features include fever, hepatosplenomegaly, weight loss and pancytopenia. Younger age, malnutrition and immunosuppression (HIV infection, use of immunosuppressive drugs) are risk factors. Many infections remain asymptomatic. Diagnosis is made by demonstration of the Leishmania parasite in aspirates of lymph node, bone marrow or spleen. Serological tests such as rK39 strip test are widely used but the sensitivity varies. qPCR is useful to detect low numbers of parasites and to monitor treatment. Treatment is with AmBisome monotherapy in most areas but with drug combinations elsewhere. HIV co-infected patients are most difficult to treat and often relapse. Control efforts focus on case finding, availability of diagnostic tools, reservoir control and protection from sand flies (insecticides, bed nets). There is no human vaccine.