Nor Biomphalaria glabrata neither Schistosoma mansoni were reported
from Rio Grande do Sul, the southernmost Brazilian state before 1997.
Their detection next to the Sinos River, Esteio, confirmed ...predictions
of schistosomiasis expansion to the south. Parasitological examinations
both in snails and fecal samples from the human population were
performed from 1997 to 2000. The last 3 out of 5 surveys were performed
after a preliminar serological screening procedure in a risk group
identified at a population census. A total of 11 infected individuals
were found infected and snails from 2 different sites were positive for
S. mansoni. Samples from these 2 and other sites were identified as B.
glabrata. Egg counts in feces were below 1 per gram in 6 out of 11
patients. Some socio-cultural perceptions of water contact activities
next to the Sinos River may cause difficulties to control efforts, but
they also may be partially acting against a very rapid increase in
transmission intensity. The southernmost schistomiasis mansoni foci in
Americas rise the alert for its ongoing expansion.
Abdominal angiostrongyliasis is a zoonotic infection caused by Angiostrongylus costaricensis, a nematode with an intra-vascular location in the mesentery. Our objective was to address several aspects ...of the natural history of this parasitosis, in a longitudinal clinical and seroepidemiological study. A total of 179 individuals living in a rural area with active transmission in southern Brazil were followed for five years (1995-1999) resulting in yearly prevalence of 28.2%, 4.2%, 10%, 20.2% and 2.8% and incidences of 0%, 5.9%, 8% and 1.5%, respectively. Both men and woman were affected with higher frequencies at age 30-49 years. In 32 individuals serum samples were collected at all time points and IgG antibody reactivity detected by ELISA was variable and usually persisting not longer than one year. Some individual antibody patterns were suggestive of re-infection. There was no association with occurrence of abdominal pain or of other enteroparasites and there was no individual with a confirmed (histopathologic) diagnosis. Mollusks were found with infective third-stage larvae in some houses with an overall prevalence of 16% and a low parasitic burden. In conclusion, abdominal angiostrongyliasis in southern Brazil may be a frequent infection with low morbidity and a gradually decreasing serological reactivity.
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