Low serum zinc levels in an endemic area of visceral leishmaniasis in Bihar, India

Background & objectives: India carries approximately 50 percent of the global burden of visceral leishmaniasis and majority of patients from the poor, rural communities of Bihar State. Zinc is an essential trace element and its relevance for proper functioning of the entire immune system is already well documented. Though low serum zinc levels have been reported in many parasitic diseases, limited information is available regarding zinc status in human leishmaniasis. We investigated to define the relationship between zinc level in visceral leishmaniasis (VL) patients in endemic and non-endemic regions. Methods: Venous blood was collected from 88 patients, 16 parasitologically confirmed VL, 35 healthy controls from endemic area (Bihar) and 37 healthy urban controls from non-endemic area, Delhi. In all the three groups, levels of serum albumin, total protein (markers of nutritional status) and zinc were estimated by colorimetric methods. Results: Serum zinc levels were found to be significantly lower (P<0.001) in VL patients than non-endemic controls. The serum zinc levels in VL endemic controls were also significantly lower (P<0.001) than non-endemic controls, but these values were not statistically significantly different from VL patients. However, all samples from Bihar (VL patients and controls) had lower serum zinc levels than non-endemic controls from Delhi. Interpretation & conclusion: Low serum Zn levels, in healthy subjects from Bihar and more significantly in VL patients of this region, are possibly associated with vulnerability and endemicity of visceral leishmaniasis in the region. Further studies need to be done to assess the role of oral zinc supplementation in better management and prevention of VL, particularly in endemic areas.