Frequency of canine heartworm disease (D. immitis) in some regions of São Paulo State using a circulating antigen indicator test

Abstract

The frequency of canine heartworm disease was determined in 310 dogs (158 males and 152 females) from São Paulo city (154) and several towns along the São Paulo state coast (156). The survey was carried out through the Knott's technique (direct presence of microfilariae in the blood) and ELISA for soluble circulating antigen detection. Twenty five (8.0%) samples were positive to D. immitis using both methods being 6 dogs (3.9%) from the city and 19 (12.2%) from the coastal area. Nineteen dogs (6.1%) were positive to the Knott's technique (4 from the city and 15 from the coastal area) and 12 dogs (3.9%) to the ELISA (4 from the city and 8 from the coastal area); six dogs (1.9%) were positive for both methods being two from the city and four from the coastal area. The frequency of positive dogs by the Knott's technique in the coastal area was higher than that in São Paulo city (P<0.05), but equivalent frequency was found in dogs from both areas when the ELISA test was used. Higher number of dogs with a patent infection (microfilaremic) was found than those with occult infection (amicrofilaremic). This survey has shown that the dogs were not infected with high frequency probably because the studied areas were not hiperenzootic endemic (higher than 10% of frequency).

Microfilaruria by Dirofilaria immitis in a dog: a rare clinical pathological finding

“…From 1988 to 2001, the prevalence countrywide has decreased from 7.9 to 2%, probably due to effective prophylactic measures (Labarthe and Guerrero 2005). The reported dog lived in Sao Paulo, SP, where the prevalence is 3.89% (Souza and Larsson 2001). Therefore, the animal had never had prophylactic treatment for dirofilariasis.…”

Dirofilariosis in the Americas: a more virulent Dirofilaria immitis?

“…Remarkably, approximately 70% of the cases reported in South America originated from south-eastern Brazil, particularly, from São Paulo city [67], one of the biggest medical poles in Latin America. Because the prevalence of D. immitis in dogs in São Paulo is low [68], the apparently high number of human pulmonary dirofilariosis from this state is probably due to the high standards of health care services provided. Indeed, there is no eco-epidemiological factor that could explain a higher risk of infestation in São Paulo city as compared with other Brazilian cities where canine dirofilariosis is endemic [49].…”

Ectopic dirofilariosis in two dogs from Rio de Janeiro state, Brazil

“…The intermediate hosts are mosquitoes from several genera, such as Culex, Aedes and Anopheles. The parasite has a worldwide distribution, and several endemic areas have been described in Brazil 2,3,5,8,10,15,16,18,21,22,36,40 . Canids are the most adapted definitive hosts and are the primary reservoir for parasite transmission, but reports about feline and human infection are becoming more frequent, including in Brazil 4,6,24,33,39,42 .…”