The usefulness of trained field workers in diagnosis of post-kala-azar dermal leishmaniasis (PKDL) and clinico-epidemiological profile in highly endemic areas of Bihar.

BACKGROUND: Surveillance of post-kala-azar dermal leishmaniasis (PKDL) is critical to the elimination of visceral leishmaniasis (VL). In this study we assessed the feasibility of using trained field workers for detecting suspected PKDL cases. METHODS: A cross-sectional study using a multistage sampling technique was conducted in the Araria district of Bihar. Trained field workers were utilized for identification of suspected PKDL case. RESULTS: We investigated 57 099 individuals from 11 300 households. The trained field workers were useful in identifying 107 (18%) probable PKDL cases. The calculated PKDL prevalences were 18.7/10 000 and 9.7/10 000 for probable and confirmed PKDL cases, respectively. The median duration of onset of PKDL was 23 months (interquartile range 16.5-56.5). The younger age group developed PKDL significantly more often compared with the older age group (p=0.007). Of the 107 patients, 25 (55.5%) were positive by microscopy of slit skin smear and 42 (93.3%) by polymerase chain reaction. Of 45 patients, 33 (73%) PKDL cases were cured after full treatment. The risk of not being cured with incomplete treatment was three times higher than with complete treatment (relative risk 3.12 [95% confidence interval 1.23 to 8.67], p=0.004). CONCLUSIONS: We conclude that the prevalence of PKDL is high and the use of trained field workers may be feasible to actively detect PKDL cases in VL-endemic areas of Bihar, India.

Cytokines and chemokines differentially regulate innate immune cell trafficking during post kala-azar dermal leishmaniasis.

Post kala-azar dermal leishmaniasis (PKDL) is often considered to be the anthroponotic reservoir of visceral leishmaniasis (VL) in India. A better understanding of the host immune-response in dermal lesions of PKDL patients is therefore of utmost significance to minimize such patients and to restrict VL transmission. Although the innate immune response is known to play an important role in parasite clearance from dermal lesions, the actual contribution of innate cells to the pathogenicity of PKDL is poorly understood. The present study explored the immune-pathogenesis of PKDL patients to understand the expression of CD62L, CD11b, CXCL8/IL-8, and MIP1-α and their contribution in signaling during innate cell trafficking. Twenty-five individuals were enrolled, who comprised eight active and untreated macular cases, seven active and untreated cases with papulo-nodular PKDL manifestations, five successfully treated post PKDL cases and five healthy individuals from a non-endemic region of Bihar, India. The immunological investigation was performed on biopsy specimens prepared with a disaggregation technique and blood samples. We observed that the PMNs in nodular patients displayed decreased L-selectin (CD62L) levels and increased integrin (CD11b) expression compared with those in macular patients. Further analysis showed that lower PMN extravasation in macular patients occurred because of inadequate CXCL8/ IL-8 release. In summary, Leishmania donovani (L. donovani) infection in macular PKDL patients decreased leucocyte rolling (L-selectin shedding) and induced up-regulation of the cellular signaling factors involved in pathogenesis (ERK1/2) as well as down regulated the signaling elements (p38 MAPK) involved in the Th1 response, especially in PMNs.

Asymptomatic infection with visceral leishmaniasis in a disease-endemic area in bihar, India.

A prospective study was carried out in a cohort of 355 persons in a leishmaniasis-endemic village of the Patna District in Bihar, India, to determine the prevalence of asymptomatic persons and rate of progression to symptomatic visceral leishmaniasis (VL) cases. At baseline screening, 50 persons were positive for leishmaniasis by any of the three tests (rK39 strip test, direct agglutination test, and polymerase chain reaction) used. Point prevalence of asymptomatic VL was 110 per 1,000 persons and the rate of progression to symptomatic cases was 17.85 per 1,000 person-months. The incidence rate ratio of progression to symptomatic case was 3.36 (95% confidence interval [CI] = 0.75-15.01, P = 0.09) among case-contacts of VL compared with neighbors. High prevalence of asymptomatic persons and clinical VL cases and high density of Phlebotomus argentipes sand flies can lead to transmission of VL in VL-endemic areas.