Differential malaria prevalence among villages of the Gidra in lowland Papua New Guinea.

Antibody titres against Plasmodium falciparum and P. vivax were examined using the indirect fluorescent antibody test (IFAT) for 183 Gidra-speaking adults and adolescents in four ecologically different villages of lowland Papua New Guinea. The findings highlight that 1) in Gidraland P. falciparum was more prevalent than P. vivax, 2) the proportion of antibody titres of 1:64 or higher markedly differed among the villages, ranging from 35.3% to 100% for males and from 31.6% to 100% for females, and 3) in the two villages with high prevalences, these were higher among males than females. The inter-village and sex differences can be largely explained by microenvironmental conditions and behavioural patterns of the population. The population-based analyses of this study intend to contribute to a better understanding of the prevalence of malaria in human-environment settings and thus to the planning of malaria prevention.