Background
Tick-borne diseases (TBD) and dirofilariasis are currently not under surveillance in most Latin American countries, and there is a significant lack of studies describing the current situation in most endemic areas, including Colombia. Seroprevalence studies are crucial for understanding the epidemiology of these vector-borne diseases.
Methods
A serosurvey for TBD and dirofilariasis amongst 100 dogs was carried out in the municipality of Pereira, located in the Coffee-Triangle region, Colombia. Samples were tested using a rapid assay test system (SNAP® 4Dx®); based on an enzyme immunoassay technique‚ screening for antibodies to Anaplasma phagocytophilum/platys (sensitivity 99.1%)‚ Borrelia burgdorferi s.l. (98.8%), and Ehrlichia canis/ewingii (96.2%) by using specific antigens, and checking for Dirofilaria immitis antigen based on specific antibodies (99.2%). Bivariate analyses were performed on Stata®14, significant p < 0.05.
Results
Global seroprevalence to the selected vector-borne pathogens was 74% (95%CI 65–83%). The highest seroprevalence was found for Ehrlichia canis/ewingii (74%), followed by Anaplasma phagocytophilum/platys (16%). Seropositivity for Borrelia spp. and Dirofilaria spp. was 0%. All Anaplasma spp. seropositive dogs showed co-detection of Ehrlichia spp. (16%). Seroprevalence was significantly higher among dogs from families of lower socioeconomic status / level (I, 86%), followed by level II (74%), and III (36%) (p = 0.001); no seropositive dogs were found in for levels IV and V (higher socioeconomic status). All dogs exhibiting anorexia (12%) were invariably seropositive (100%) (p = 0.029). Seroprevalence was higher amongst those showing mucocutaneous paleness (95%) compared to those without paleness (68%) (p = 0.013) (OR = 9.3; 95%CI 1.18–72.9). There was high variability in seroprevalence through the studied areas, ranging from 0% (La Libertad Park) up to Combia, Cesar Nader, Las Brisas and Saturno localities (100%) (p = 0.033).
Conclusions
Given the high seroprevalence obtained in an area with documented presence of ticks, there is a potential risk for zoonotic transmission to humans. Further seroprevalence studies in humans are needed to assess the prevalence of infections. Poverty is highly associated with these tick-borne pathogens in Pereira, as shown in the present study.