Urban schistosomiasis: morbidity, sociodemographic characteristics and water contact patterns predictive of infection.
BACKGROUND
Schistosomiasis (Schistosoma mansoni) is classically described as a rural disease that occurs in areas with poor sanitary conditions. This cross-sectional study was undertaken in a suburban area of a large industrialized city in Brazil (Belo Horizonte), aiming at examining epidemiological characteristics of schistosomiasis in an urban setting.


METHODS
A simple random sample of 658/1896 dwellings was selected and 3049/3290 (92.7%) residents were submitted to stool examination. Of 518 eligible infected cases and 518 uninfected controls, 87.1% and 89.9% participated in the study, respectively.


RESULTS
The prevalence of S. mansoni infection was 20%, predominantly low egg counts in stools; no cases of splenomegaly were found. Signs and symptoms associated with infection were bloody stools (odds ratio [OR] = 8.0) and hardened palpable liver at the middle clavicular and at the middle sternal life (OR = 5.5 and 8.0 respectively). Sociodemographic variables and water contacts predictive of infection were age (10-19 and > or = 20 yrs; OR = 7.1 and 3.3, respectively), gender (male; OR = 3.1), contacts for swimming and/or playing (twice a month or less and more than twice a month; OR = 2.2 and 3.0, respectively) and residence in Belo Horizonte (born in the City; OR = 2.5). Ninety per cent of dwellings had a piped water supply; no association between water supply and infection was found.


CONCLUSIONS
Our results emphasize the need for schistosomiasis control measures focusing on water contacts for leisure purposes in this industrialized urban area.
Firmo
J O
JO
Laboratory of Epidemiology and Medical Anthropology, René Rachou Research Institute, Oswaldo Cruz Foundation, Belo Horizonte, Minas Gerais, Brazil.
Lima Costa
M F
MF
Guerra
H L
HL
Rocha
R S
RS
D000293:Adolescent; D000328:Adult; D000818:Animals; D017164:Ascaris lumbricoides / Q000302:isolation & purification; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003710:Demography; D005243:Feces / Q000469:parasitology; D005260:Female; D006801:Humans; D008297:Male; D009017:Morbidity; D010270:Parasite Egg Count; D015995:Prevalence; D012307:Risk Factors; D012550:Schistosoma mansoni / Q000302:isolation & purification*; D012555:Schistosomiasis mansoni / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D012919:Social Behavior; D014258:Trichuris / Q000302:isolation & purification; D014505:Urban Population; D014867:Water / Q000469:parasitology
D014867:Water