Antibody response toActivation of the immune system has been demonstrated during acute schistosomiasis2 3 27 and, although modulation of both the cellular15" and humoral1819 immune responses occur later during the chronic phase of the disease, high levels of anti-Schistosom a m an son i antibodies are still detectable. However, the ability of infected individuals to mount an immune response to unrelated antigens has not yet been clearly established.It has been shown that some Schistosom ain fected individuals co-infected with salmonella p rod u ce less a n tib o d ies to both O and H antigens of this bacteria20 23, and antibodies present in their sera show an impaired ability to inhibit in vitro salmonella growth1'. However, serum from S chistosom a-infected hamsters can inhibit bacterial growth13. On the other hand, some human studies have indicated that schistosomiasis impairs the immune response to anti-salmonella vaccine5, while others do not seem to support this conclusion26.An altered ability of Schistosom a-infected individuals to produce antibodies to unrelated antigens may result in a con strain t to the elimination of some pathogens. For instance, it has been shown that antibodies help the clearance of salmonella from the blood stream11. Therefore, a deficient production of antibodies to salmonella in schistosomiasis may facilitate the development of the atypic form o f salm on ellosis w hich occu rs in Sch istosom a-infected individuals.This work aimed at evaluating the antibody response to S alm on ella typhi in Schistosom ain fected individuals before and after typhoid vaccine.
MATERIAL AND METHODSThe rules put forw ard by the H elsinki Declaration for experiments in human subjects630 w e re s t r ic t ly f o llo w e d th r o u g h o u t th is investigation.Twenty six patients of both sexes, 13 to 43 y ears old (m ean ± SD = 24 ± 10), m ostly. Caucasians (75%) were studied. The diagnosis of schistosomiasis was established on clinical and parasitological grounds. Our study group :441-445, set-out, 1996. comprised 16 individuals with die hepatointestinal, and 10 with the hepatosplenic schistosomiasis, characterized according to the criteria defined by Prata21. Their clinical and nutritional status were satisfatory. Eggs of Schistosom a m an son i in faeces were quantified by the Kato-Katz method8. The control group comprised nine healthy individuals of both sexes, 20 to 50 years old (m ean ± SD = 29 ± 9), 70% being Caucasians.
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M u n iz-Ju n qu eirã MI, Tavares-Neto J, P rata A, Tosta CE. A n tibody response toSalmonella typhi in h u m a n schistosom iasis m an son i. Revista d a S o cied a d e B rasileira d e M ed icin a T ropical 2 9The S alm on ella typhi vaccine, prepared with 10s formol-treated bacteria strain Ty2 by the Instituto Oswaldo Cruz, was intradermaliy administered in a single dose, as indicated by the manufacturer. Before vaccination and 30 days after serum antibodies to O and H a n tig e n s w e r e d e t e c t e d u s in g a W id al agglutination test29 provided by Laborclin. T...
