ABSTRACT
The Greater Metropolitan Area of Belo Horizonte currently contains 18 city parks (also known as "ecological parks") with various bodies of water (lakes, springs, streams, etc). Initial research in 17 of these parks showed the occurrence of intermediate mollusk hosts for Schistosoma mansoni in at least 4. Monthly captures done from August 1994 to February 1996 showed the following results for these planorbids: Julien Rien Park: 1,145 specimens of Biomphalaria glabrata (2 to 13 mm); Betânia Park: 149 specimens of B. glabrata (4 to 13 mm); Santa Lúcia Park: 2,431 specimens of B. straminea (3 to 9 mm); and Lagoa do Nado Park: 3 specimens of B. tenagophila (3 to 10 mm). Visits to the parks will continue, and after a diagnosis of each park's situation, control and/or eradication measures suitable for each one will be proposed to the municipal authorities.
ABSTRACT
In Belo Horizonte, Minas Gerais, Brazil, the snail Biomphalaria straminea was found in the Pampulha region. Recently the snail was found in ditches in the old Santa Lúcia Reservoir, a now-extinct focus of schistosomiasis transmission by B. glabrata. The snails were collected and examined to verify whether they were naturally infected with Schistosoma mansoni. Negative specimens were used for breeding or infection with the LE strain of S. mansoni from the laboratory and another strain obtained from eggs found in the feces of a schoolchild (VGS) from Belo Horizonte. Among the 1890 snails collected from 1994 to 1995, none were infected with S. mansoni. Among 87 snails collected and exposed to the LE strain, 9 (10.3%) shed cercariae; among 83 snails from F1, and exposed to LE, 10 (12.0%) shed cercariae. Among 88 snails exposed to VGS, 10 (11.3%) shed cercariae. In Belo Horizonte, schistosomiasis is transmitted by B. glabrata and B. tenagophila. However, currently there exists the risk of appearance of a focus in which B. straminea could be the host if prophylactic measures are not taken by the authorities responsible for the construction of a park and lake at that site.
ABSTRACT
Experimentos foram feitos no laboratorio e no campo nos anos de 1980 a 1984, objetivando detectar as causas do repovoamento de criadouros de Biomphalaria glabrata apos tratamento com niclosamida. Os bioensaios no laboratorio mostraram que a suscetibilidade a niclosamida emulsionavel de B. glabrata coletada mensalmente em um sistema de valas de irrigacao, variou durante o ano. As concentracoes letais 'CL IND. 90' foram 0,15 'mgl POT. -1' a 0,60 'mgl POT. -1', apresentando diferencas significantes estatisticamente (p<0,01) nos meses de maio/82 e janeiro/83 e dezembro/82 e janeiro/83, relacionadas a nutricao. No campo, foram tratados dois tipos de focos com solucao aquosa a 10 ppm de niclosamida. O primeiro era formado por reservatorio com cerca de 12.000 litros de agua e continha 14,5 por cento de moluscos infectados pelo Schistosoma mansoni. Uma unica aplicacao do produto, seguida de esvaziamento e limpeza do reservatorio, eliminou os moluscos. O segundo, era constituido por sistema de valas e poco com 5,6 por cento de moluscos infectados pos S. mansoni. Uma unica aplicacao do produto, sem limpeza das valas, reduziu a densidade planorbidica 98 por cento. As causas da sobrevivencia de 2 por cento dos moluscos do sistema de valas, sao discutidas, sendo relacionadas ao substrato do criadouro e a tecnica utilizada no tratamento.
