Epidemiology of Schistosoma mansoni infection in a low-endemic area in Brazil: clinical and nutritional characteristics

Abstract

A cross-sectional case-control study designed to evaluate the role of malnutrition in the association between the intensity of Schistosoma mansoni infection and clinical schistosomiasis, was conducted in an area with both low frequency of infection and low morbidity of schistosomiasis in Brazil. Cases (256) were patients with a positive stool examination for S. mansoni; their geometrical mean number of eggs/gram of feces was 90. Controls (256) were a random sample of the negative participants paired to the cases by age, sex and length of residence in the area. The clinical signs and symptoms found to be associated with S. mansoni infection, comparing cases and controls, were blood in stools and presence of a palpable liver. A linear trend in the relative odds of these signs and symptoms with increasing levels of infection was detected. Adjusting by the level of egg excretion, the existence of an interaction between palpable liver and ethnic group (white) was suggested. No differences in the nutritional status of infected and non-infected participants were found.

Childhood stunting in Northeast Brazil: the role of Schistosoma mansoni infection and inadequate dietary intake

“…Lima e Costa et al (1988) also observed that heavy egg burdens (Z500 eggs/gram) as much as clinical signs of morbidity are associated with weight-for-height deficit in children 4.5-14.4 y of age. This relationship is not always observed (Proietti et al, 1992) in areas of low endemicity. However, from the review by Ferreira and Coutinho (1999), it can be concluded that there is a relationship between infection with S. mansoni and nutritional compromise in the parasitized population.…”

Factors Involved in Schistosoma mansoni Infection, in Rural Areas of Northeast Brazil

“…Several studies have tried to correlate the nutritional status of the host with prevalence/intensity of infection (Coutinho 1976, 1980, Stephenson 1986, Coutinho et al 1992, Ferreira et al 1993 or severity of clinical manisfestations in schistosomiasis (De Witt et al 1964, Coutinho et al 1972, Akpon & Warren 1975, Akpom 1982, Stephenson 1993. Conflicting results may be due to differences in local epidemiological features and in part, to different methodologies (Costa et al 1988, Proietti et al 1992. The prevalence of moderate or severe undernutrition in patients under 18 years old was 21.9% in Itapinassu and 24.1% in São Joaquim, much higher than the expected 3% (WHO 1983).…”

“…The association between the host nutritional status with susceptibility to infection and clinical manifestations of the disease is not completely established (Lima e Costa et al 1987, Proietti et al 1992. Thus, further evaluation on this issue is necessary.…”