Me. Dearruda et al., A SEROPREVALENCE AND DESCRIPTIVE EPIDEMIOLOGIC-STUDY OF MALARIA AMONGINDIAN TRIBES OF THE AMAZON BASIN OF BRAZIL, Annals of tropical medicine and parasitology, 90(2), 1996, pp. 135-143
Data on the seroprevalences of Plasmodium falciparum, P. vivax, and P.
malariae in four isolated Indian tribes of the Amazon basin in Brazil
, as determined by IFAT, were re-analysed. Age-, sex- and tribe-specif
ic geometric mean antibody titres and externally standardized prevalen
ce ratios were calculated for each parasite species. Correlation coeff
icients and prevalence odds ratios were also calculated for multiple i
nfections with different combinations of the three Plasmodium species.
Titres of all but one of the antibodies studied were similar in males
and females; titres of antibodies to the blood stages of P. malariae
were slightly higher in females than in males. Titres of antibodies to
all three Plasmodium species increased with subject age, and this age
effect was not confounded by sex or tribal differences. There were st
riking differences between tribes, with the Parakana tribe having rela
tively low titres of antibodies against P. falciparum and P. malariae;
these tribal effects were not confounded by sex or age differences be
tween tribes. The results indicate that conditions conducive to the tr
ansmission of P. malariae exist in this region of the Amazon. The pote
ntial for zoonotic transmission of P. brasilianum, a parasite of monke
ys which is morphologically similar to P. malarie, and the generally h
igh rates of seropositivity to all three species of Plasmodium indicat
e that control measures which are adequate and applicable to the regio
n studied need to be developed.