A seroprevalence and descriptive epidemiological study of malaria among Indian tribes of the Amazon basin of Brazil.
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-specific geometric mean antibody titres and externally standardized prevalence ratios were calculated for each parasite species. Correlation coefficients and prevalence odds ratios were also calculated for multiple infections 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 striking differences between tribes, with the Parakana tribe having relatively low titres of antibodies against P. falciparum and P. malariae; these tribal effects were not confounded by sex or age differences between tribes. The results indicate that conditions conductive to the transmission of P. malariae exist in this region of the Amazon. The potential for zoonotic transmission of P. brasilianum, a parasite of monkeys which is morphologically similar to P. malarie, and the generally high rates of seropositivity to all three species of Plasmodium indicate that control measures which are adequate and applicable to the region studied need to be developed.
de Arruda
M E
ME
Department of Immunology, Centro de Pesquisas Aggeu Magalhaes, Recife, Brazil.
Aragaki
C
C
Gagliardi
F
F
Haile
R W
RW
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000818:Animals; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007199:Indians, South American; D007223:Infant; D008288:Malaria / Q000453:epidemiology / Q000208:ethnology*; D008297:Male; D018512:Parasitemia / Q000453:epidemiology; D010963:Plasmodium falciparum / Q000302:isolation & purification; D010965:Plasmodium malariae / Q000302:isolation & purification; D010966:Plasmodium vivax / Q000302:isolation & purification; D015995:Prevalence; D017678:Sex Distribution