Ticks and tick-borne pathogens of dogs along an elevational and land-use gradient in Chiriquí province, Panamá

Abstract

Systematic acarological surveys are useful tools in assessing risk to tick-borne infections, especially in areas where consistent clinical surveillance for tick-borne disease is lacking. Our goal was to identify environmental predictors of tick burdens on dogs and tick-borne infectious agents in dog-derived ticks in the Chiriquí Province of western Panama to draw inferences about spatio-temporal variation in human risk to tick-borne diseases. We used a model-selection approach to test the relative importance of elevation, human population size, vegetative cover, and change in landuse on patterns of tick parasitism on dogs. We collected 2074 ticks, representing four species (Rhipicephalus sanguineus, R. microplus, Amblyomma ovale, and Ixodes boliviensis) from 355 dogs. Tick prevalence ranged from 0 to 74% among the sites we sampled, and abundance ranged from 0 to 20.4 ticks per dog with R. sanguineus s.l. being the most commonly detected tick species (97% of all ticks sampled). Whereas elevation was the best single determinant of tick prevalence and abundance on dogs, the top models also included predictor variables describing vegetation cover and landuse change. Specifically, low-elevation areas associated with decreasing vegetative cover were associated with highest tick occurrence on dogs, potentially because of the affinity of R. sanguineus for human dwellings. Although we found low prevalence of tick-borne pathogen genera (two Rickettsia-positive ticks, no R. rickettsia or Ehrlichia spp.) in our study, all of the tick species we collected from dogs are known vectors of zoonotic pathogens. In areas where epidemiological surveillance infrastructure is limited, field-based assessments of acarological risk can be useful and cost-effective tools in efforts to identify high-risk environments for tick-transmitted pathogens.

Seroprevalence and Current Infections of Canine Vector-Borne Diseases in Costa Rica

“…Both R. sanguineus s.l. and Amblyomma ovale may act as vectors for this apicomplexan parasite and both tick species occur in Central America (5, 6). Hepatozoon canis mostly causes moderate or asymptomatic infections with low parasitemia in dogs and is not considered a zoonotic pathogen (42).…”

A review on the occurrence of companion vector-borne diseases in pet animals in Latin America

“…Rickettsiosis has been reported in dogs at a seroprevalence of 55% for R. amblyommii , 20% for R. rickettsii , 5% for R. bellii , 25% for R. rhipicephali , 10% for R. parkeri and 15% for R. felis [614]. Similarly, R. felis and R. amblyommii /“ Candidatus R. amblyommii” have been detected in fleas and ticks, respectively, from dogs and cats [477, 614–617].…”

Species distribution models for the eastern blacklegged tick, Ixodes scapularis, and the Lyme disease pathogen, Borrelia burgdorferi, in Ontario, Canada

“…It is interesting that Algonquin Park and regions of northern Ontario have a lower predicted probability of blacklegged tick occurrence. This is probably a result of higher elevation, which has been shown to be a strong predictor of tick occurrence globally [ 21 , 22 , 53 ]. However, landscape structure and connectivity as well as host abundance and diversity may also play a role in the establishment of ticks in forest habitats.…”

“…which has been shown to be a strong predictor of tick occurrence globally [21,22,53]. However, landscape structure and connectivity as well as host abundance and diversity may also play a role in the establishment of ticks in forest habitats.…”