Schistosomiasis Mansoni in Bananal (State of São Paulo, Brazil). III. Seroepidemiological Studies in the Palha District|
Fabiana Zacharias; Maria Esther de Carvalho; Cybele Gargioni; Horacio M Santana Teles; Cláudio S Ferreira & Valquíria R de Lima
The Palha district, municipality of Bananal, State of São
Paulo, Brazil, had 10.3% cases of Schistosoma mansoni diagnosed from 1994
to 2000 by coproscopy: about three times the municipality average. The immunofluorescent
antibody test was used to assess gut-associated IgM antibody titers of samples
from 452 inhabitants. It disclosed 129 (28.5%) positive cases. Subjects
were classified according to age, sex, birthplace, and period of residence.
Titers varied from 8 to 4,096 (geometric mean: 170.2). Seropositives were
aged from 6 to 69 years (average: 24.5), 75% of them aged 34 or less, predominantly
males (78 or 60.5%). Of all subjects, 65.7% were born and had been living
in Bananal since; 24.2% came from neighboring municipalities and are residing
in Bananal from two months to 89 years (average: 22.7 years). Further Kato-Katz
coproscopy from 97 seropositives (geometric mean titer, 619) revealed S.
mansoni eggs in 11 subjects (11.3%). Serology was deemed useful in screening
subjects to be further investigated by coproscopy, considering that blood
collection had better acceptance than supplying fecal samples. Higher than
average serological titers may indicate new cases in endemic areas. Longitudinal
studies associated with epidemiological investigation, including titer evolution
are advised, as isolated data are difficult to interpret.
schistosomiasis mansoni - seroepidemiology - low transmission area - São Paulo - Brazil