Current Situation of the Presence of Dirofilaria immitis in Dogs and Humans in Bucaramanga, Colombia

Background: The cardiopulmonary dirofilariasis caused by Dirofilaria immitis, is a vector-born infection, which can be transmitted to humans. The main host are both domestic and wild canids. It mainly occurs in tropical and subtropical climates, temperature and humidity are the main factors that favor the presence and proliferation of Culicidae mosquitoes. There are few reports of this disease in dogs and humans in Colombia, a region with favorable climatic conditions for the development of this disease. Therefore, this research aimed to study its current prevalence in dogs and the risk of human exposure to the disease in Bucaramanga, one of the most populated areas in Colombia located at the center of the country. Furthermore, its demographic and environmental characteristics could be useful as a study model for other similar locations and neighboring countries.Method: Serum samples from 351 dogs and 506 humans from the Bucaramanga metropolitan area were analyzed. All dog samples were tested with a commercial immunochromatographic test kit to detect the presence of circulating antigens of D. immitis. Human samples were analyzed using a non-commercial ELISA test kit to detect IgG against the somatic antigens of adult D. immitis and Wolbachia. Positive results were further confirmed using a Western blot analysis.Results: Dirofilaria immitis prevalence was 10.82% (95% CI) in dogs and 5.12% (95% CI) in microfilaremic dogs. Seroprevalence in humans was 6.71% (95% CI) and was significantly higher in individuals aged 16–34 years and in women than in men.Conclusions:This study describes seropositivity to D. immitis for the first time in a Colombian human population located in the same area as that of dogs infected with D. immitis, which represents a potential threat to public health. In humans, age and sex can be considered risk factors for exposure to D. immitis.