Dendritic cell engineered cTXN as new vaccine prospect against L. donovani

Dendritic cells (DCs), as antigen-presenting cells, can reportedly be infected withLeishmaniaparasites and hence provide a better option to trigger T-cell primary immune responses and immunological memory. We consistently primed DCs during culture with purified recombinant cytosolic tryparedoxin (rcTXN) and then evaluated the vaccine prospect of presentation of rcTXN against VL in BALB/c mice. We reported earlier the immunogenic properties of cTXN antigen derived fromL. donovani when anti-cTXN antibody was detected in the sera of kala-azar patients. It was observed that cTXN antigen, when used as an immunogen with murine DCs acting as a vehicle, was able to induce complete protection against VL in an infected group of immunized mice. This vaccination triggered splenic macrophages to produce more IL-12 and GM-CSF, and restricted IL-10 release to a minimum in an immunized group of infected animals. Concomitant changes in T-cell responses against cTXN antigen were also noticed, which increased the release of protective cytokine-like IFN-γ under the influence of NF-κβ in the indicated vaccinated group of animals. All cTXN-DCs-vaccinated BALB/c mice survived during the experimental period of 120 days. The results obtained in our study suggest that DCs primed with cTXN can be used as a vaccine prospect for the control of visceral leishmaniasis.

Magnitude of unreported kala-azar cases in a highly endemic district of Bihar, India: A positive impact of Indian elimination programme

BACKGROUND & OBJECTIVES

In India, kala-azar surveillance is weak and no public-private partnership exists for disease containment. Estimate of disease burden is not reliably available and still cases are going to private providers for the treatment. The present study aimed to assess the magnitude of kala-azar cases actually detected and managed at private set-up and unreported to existing health management information system.

METHODS

Institution based cross-sectional prospective pilot study was conducted. List of facilities was created with the help of key informants. The information about incidence of kala-azar cases were captured on monthly basis from July 2010 to June 2011. Rapid diagnostic strip test (rk-39) or bone marrow/splenic puncture were applied as laboratory methods for the diagnosis of kala-azar. Descriptive statistics as well as chi-square test for comparison between proportions was conducted.

RESULTS

Overall availability of private practitioners (PPs) was 4.59/1,00,000 population and maximum PPs (46; 93.9%) were from qualified category. The median years of medical practice was 25 yr (inter quartile-range [18, 28]). Interestingly, only a small proportion (240; 19%) of cases was managed by PPs. Amongst the PPs, only low proportion (32; 18.2%) managed >2 cases per month. The mean number of kala-azar suspects and cases identified varied significantly between different PPs' professions with p <0.048 and p <0.032, respectively. A highly significant difference (p <0.0001) was observed for kala-azar case load between qualified and unqualified practitioners. A small proportion (38; 15.8%) of kala-azar cases was not present in the public health system record.

INTERPRETATION & CONCLUSION

Still sizeable proportions of cases are going to PPs and unrecorded into government surveillance system. A mechanism need to be devised to involve at least qualified PPs in order to reduce treatment delay and increase case detection in the region.

Asymptomatic infection of visceral leishmaniasis in hyperendemic areas of Vaishali district, Bihar, India: a challenge to kala-azar elimination programmes

A cohort of 91 asymptomatic individuals with visceral leishmaniasis (VL) were identified during base line screening using recombinant 39-aminoacid antigen (rk-39) and polymerase chain reaction (PCR) conducted from December 2005 to June 2006 involving 997 individuals of two highly endemic villages of Vaishali district, Bihar. The point prevalence of asymptomatic infection was 98 per 1000 persons at baseline. There was no statistically significant difference between rk-39 and PCR positivity rate (P>0.05), even though PCR positivity alone was found significantly higher (4.2%) than rk-39 positivity alone (2.6%). The monthly follow-up of the asymptomatic cohort revealed a disease conversion rate of 23.1 per 100 persons within a year. There was a statistically significant difference in conversion of disease when individuals were positive by both tests as compared to single tests by rk-39 and PCR (P<0.01). Disease conversion rate in the subjects residing in households with a history of VL (62%, 13/21) was higher than those residing in the households without a history of VL (38%, 8/21). Most of the identified asymptomatic individuals were from low socio-economic strata similar to that of VL cases in general. Apart from rk-39, PCR may be considered for screening of asymptomatic Leishmania donovani infection in large-scale epidemiological studies. Screening of asymptomatic cases and their close follow-up to ascertain early detection and treatment of VL may be considered in addition to the existing VL control strategies.

Wilson disease with visceral leishmaniasis: an extremely uncommon presentation

Visceral leishmaniasis (VL), which is caused by the protozoa Leishmania donovani and transmitted by the bite of the female sand fly Phlebotomus argentipes, is common in Bihar, India. Wilson disease is an autosomal recessive disorder of copper metabolism in which copper is deposited in the brain and liver. We report a case of an extremely uncommon combination of these diseases in a patient. Treatment options for such a combination of diseases are limited and difficult.