The effect of Schistosoma mansoni infection on child morbidity in the State in Bahia, Brazil: II — Analysis at the individual level

Abstract

SUMMARYThe present investigation was carried out on a sample of 840 children (5 to 16 years old) from ten small towns of the State of Bahia in northeastern Brazil. The objetive was to study, by using a cross sectional methodology, the evolution of schistosomiasis morbidity (hepatic and splenic enlargement) in children, and the role of the intensity of S. mansoni infection in this process. The children were analised in three age groups (5 to 8, to 12 and 13 to 16 years old) and classified as uninfected, mildly infected, moderately infected and heavily infected according to the number of eggs in the stool. In children aged 5 to 8 years, increasing egg counts were not associated with increasing frequencies of hepatic or splenic enlargement. In the 9 to 12 years old group and association was observed with the prevalence of hepatic enlargement, but not with the prevalence of spleen enlargement. In the oldest group, 13 to 16 years old, an association was observed with the prevalence of enlargement of both organs. It was evident that in this population schistosomiasis morbidity develops in the early period of life as a gradual process starting with liver enlargement and followed by spleen enlargement some years later. It was found that the intensity of infection has a fundamental role in this process, although there is a latent period of some years before clinical splenomegaly appears in moderate-heavily infected children. The Authors suggest that the prevalence of splenomegaly in the 13 to 16 years old group is a good measure of the community level of schistosomiasis morbidity and could be used to measure the impact of control programs.

Adult population as potential reservoir of NTD infections in rural villages of Kwale district, Coastal Kenya: implications for preventive chemotherapy interventions policy

“…This study revealed that approximately 46% of adults with schistosomiasis also had hookworms. The additional parasites may aggravate morbidity due schistosomiasis infection, especially in young children [21]. Hookworm infection is a well-known cause of iron-deficiency anaemia because of intestinal blood loss.…”

Schistosomiasis mansoni in low transmission areas: abdominal ultrasound

“…Usually, hepatomegaly and intensity of infection are employed as the classic morbidity markers in schistosomiasis (Arap-Siongok et al 1976, Barreto & Loureiro 1984, Gryseels 1992). In our study, hepatomegaly below the costal margin was detected in similar percentages in in- fected and uninfected people.…”

Clinical and laboratory evaluation of schistosomiasis mansoni patients in Brazilian endemic areas

“…According to Barreto and Loureiro (1984), the intensity of the infection is a better indicator of morbidity than the prevalence.…”