Pr. Rambo et al., ABDOMINAL ANGIOSTRONGYLOSIS IN SOUTHERN BRAZIL PREVALENCE AND PARASITIC BURDEN IN MOLLUSK INTERMEDIATE HOSTS FROM 18 ENDEMIC FOCI, Memorias do Instituto Oswaldo Cruz, 92(1), 1997, pp. 9-14
Angiostrongylus costaricensis is a parasitic nematode of rodents and m
olluscs are the intermediate hosts. Nocturnal collection of molluscs a
nd search for infective third stage larvae of A. costaricensis was car
ried out in 18 endemic foci identified by the notification of a confir
med diagnosis in human biopsies or surgical specimens. Molluscs were d
igested in acidic solution and isolation of larvae eventually present
was done in a Baermann funnel. Larvae identified by the presence of a
delicate groove in the tail were counted to assess the individual para
sitic burden. Four species were found infected, with ranges of prevale
nce in parenthesis: Phyllocaulis variegatus (7% to 33.3%); Bradybaena
similaris (11.7% to 24.1%); Belocaulus angustipes (8.3%) and Phyllocau
lis soleiformis (3.3% to 14.2%). Parasitic burden varied from 1 to 75
with P. variegatus, 1 to 98 with B. similaris, 1 to 13 with B. angusti
pes and 1 larvae in each of two specimens of P. soleiformis. P. varieg
atus was present in all sites and was found infected with the highest
prevalence figures and the highest individual parasitic but-dens. Thes
e data stress the importance of veronicellid slugs as intermediate hos
ts for A. costaricensis in the endemic areas in Rio Grande do Sul, Bra
zil.