First report of Babesia gibsoni in Central America and survey for vector-borne infections in dogs from Nicaragua

Abstract

Background: Although many vector-borne diseases are important causes of morbidity and mortality in dogs in tropical areas and potential zoonoses, there is little information on these conditions in Central America.

Methods: Seven qPCRs for vector-borne pathogens were performed on a Roche LightCycler PCR Instrument to investigate their prevalence in a convenience sample of whole blood samples from apparently healthy dogs in Nicaragua. Also, a qPCR targeting the canine hydroxymethylbilane synthase (HMBS) gene was used as an endogenous internal control and verified the quality and quantity of DNA in the samples was appropriate for the study.

Results: We found DNA of Rickettsia felis (5%), Babesia spp. (26%), Hepatozoon canis (51%), Anaplasma platys (13%) and Ehrlichia canis (56%) in the 39 dogs studied. The qPCRs for Coxiella burnetii and Dirofilaria immitis were negative. Of the 30 (80%) dogs that were positive by qPCR, 12 (31%) were positive for one agent, 11 (28%) for two, 3 (8%) for three, and 4 (10%) for four agents.

Conclusions: This is the first report of B. gibsoni in dogs from Central America and the first recording of vector-borne agents in dogs from Nicaragua. Dogs in Nicaragua are commonly infected with a variety of vector-borne pathogens, some of which may also infect people.

Figure 1

Gene copy number of five vector-borne pathogens in canine whole blood samples. Quantitative FRET-PCRs determined the gene copy number of five tick-borne pathogens. The rRNA copy numbers for E. canis (84 ± 71 /per ml whole blood; range 50 ~ 313) were significantly lower than those for H. canis (72,120 ± 260,148), A. platys (370472 ± 659438; range 651 ~ 1534409), and B. canis (35161 ± 61,335; range 72 ~ 199,552). The gltA copy number for R. felis (204 ± 125; range 116 and 292) was not significantly different from the rRNA copy number of the other four tick-borne agents. The Y-axis is shown as logarithmic scale, and the data were shown as average gene copy number (-), mean ± SD (□) and mean ±1.96 × SD (Ι).