4.2. Study Design

A cross-sectional study was designed to study the prevalence of human symptomatic and asymptomatic L. (L.) infantum-infection using clinical and parasitological diagnostics as well as humoral (ELISA-IgG/IgM) and cellular (DTH skin test) immune responses, respectively, which also were used to clarify the clinical-immunological profiles of the infection spectrum. In all cases, we used L. (L.) infantum-specific antigens [19,20,43]. To calculate the sample size, we used WinEpiscope statistical program [44], which estimated that the population involved in the study should consist of a cohort of approximately 586 subjects aged 1 year or older, assuming an infection rate of 50%, since there are no previous studies carried out in Central America. We were able to 576 individuals from 15 locations in the municipality of Amapala, Department of Valle, Honduras (Figure 2).

Study area, municipality of Amapala, Honduras. For details about the symbols, please refer to the inset legend.