Longitudinal Study on the Natural Infection of Biomphalaria straminea and B. glabrata by Schistosoma mansoni in an Endemic Area of Schistosomiasis in Pernambuco, Brazil
Mem. Inst. Oswaldo Cruz
;
97(4): 465-475, June 2002. mapas, tab, graf
Article
in English
| LILACS
| ID: lil-314514
ABSTRACT
The abundance of snail hosts and the rates of infection with Schistosoma mansoni were monitored monthly for four years in two representative localities subjected to repeated chemotherapy of infected persons. Snail abundance varied from 1.0 to 4.4 collected per person/minute/station for Biomphalaria straminea and from 0.1 to 7.0 for B. glabrata. Infection rates of snails in nature varied from 0 percent to 15 percent for the former and from 0 percent to 70 percent for the latter species. Human infection increased from 35.5 percent to 61.9 percent in the locality occupied by B. straminea, and decreased from 40.3 percent to 20.8 percent in that occupied by B. glabrata. No relationship could be detected between human infection and the snail variables. Despite seasonal variations, natural infection persisted throughout the monitoring period in both snail species. It reached remarkably high levels in B. straminea when compared to those obtained by other authors probably because of differences in methodology. It is recommended that longitudinal studies should be carried out focally and periodically to avoid underestimating the prevalence of schistosome infection in snails
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Schistosoma mansoni
/
Biomphalaria
Type of study:
Observational study
/
Risk factors
Limits:
Animals
/
Humans
Country/Region as subject:
South America
/
Brazil
Language:
English
Journal:
Mem. Inst. Oswaldo Cruz
Journal subject:
Tropical Medicine
/
Parasitology
Year:
2002
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Fiocruz/BR
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