Prevalence of Dirofilaria immitis in dogs from Barcelona: Validation of a geospatial prediction model.

BACKGROUND:

The metropolitan area of Barcelona is the most densely populated metropolitan area on the Mediterranean coast. Several studies have reported the presence of canine heartworm disease in this region; however, there are no published epidemiological data regarding feline heartworm in this region and the prevalence in this species remains unknown.

METHODS:

Serum samples from 758 cats living in the metropolitan area of Barcelona (Spain) were collected between 2012 and 2013. To establish the seroprevalence of heartworm infection in cats, serological techniques for anti-D.immitis and anti-Wolbachia antibody detection were used while a commercial ELISA test kit was used to detect circulating D.immitis antigens.

RESULTS:

Of these samples, 11.47% were positive to D.immitis and Wolbachia surface protein antibodies and 0.26% were positive to D.immitis antigens. The higher antibody seroprevalences were found in the areas that follow the courses of the rivers Llobregat and Anoia (Baix Llobregat 11.5%, Vallés Occidental 13.2%; Barcelonés 11.7%) where humidity and vegetation favour the development of the mosquito vectors. High antibody seroprevalences were also found in the urban areas (Barcelona city 13.1%; Sabadell 15.5%), which demonstrates that city cats are also at risk from D.immitis infection.

CONCLUSIONS:

Generally, in Spain cats do not receive prophylactic treatment and therefore the risk of infection is higher in this species than in dogs. Adequate prophylactic plans should be implemented in the feline population. This is the first epidemiologic study on feline heartworm infection to be carried out in continental Spain.