The distribution of Biomphalaria spp. in different habitats in relation to physical, biological, water contact and cognitive factors in a rural area in Minas Gerais, Brazil

• Main Authors: Kloos Helmut, Souza Cecilia de, Gazzinelli Andrea, Soares Filho Britaldo Silveira, Temba Plinio da Costa, Bethony Jeffrey, Page Kristen, Grzywacz Claudia, Lewis Fred, Minchella Dennis, LoVerde Phillip, Oliveira Rodrigo Corrêa
• Format: Article
• Language: English
• Published: Instituto Oswaldo Cruz, Ministério da Saúde 2001-01-01
• Series: Memórias do Instituto Oswaldo Cruz.
• Subjects: Biomphalaria glabrata; Biomphalaria straminea; geographic distribution; environmental factors; local knowledge; Minas Gerais; Brazil
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0074-02762001000900008

A total of 256 sites in 11 habitats were surveyed for Biomphalaria in Melquiades rural area (State of Minas Gerais) in August and November 1999 and in March 2000. Of the 1,780 Biomphalaria collected, 1,721 (96.7%) were B. glabrata and 59 (3.3%) B. straminea. Snails were found in all habitats except in wells, with the largest mean numbers in tanks, seepage ponds and canals, and the smallest numbers in springs, rice fields and fishponds. People's knowledge of the occurrence of Biomphalaria at the collection sites and the presence of Biomphalaria ova were strongly correlated with the occurrence of snails, and distance between houses and collection sites, as well as water velocity were inversely correlated with Biomphalaria occurrence (p < 0.001). The strongest predictor o f Biomphalaria occurrence was the presence of tilapia fish in fishponds. Fourteen Biomphalaria (0.8% of all snails) found at 6 sites were infected with Schistosoma mansoni. Suggestions are made for the utilization of local people's knowledge in snail surveys and further studies are recommended on the possible use of tilapia for biological control of Biomphalaria in fishponds, as well as modeling of S. mansoni transmission and reinfection.