Parasitic burden of African squirrels captured in a Nigerian University community

Abstract

Most emerging diseases in humans have zoonotic reservoirs which are often wildlife species. In Nigeria, very few studies
have reported parasites of small mammals with observed variations in parasitic burden. The parasitic burden of African
squirrels captured in a University community was studied between November 2018 and February 2019. A total of 33 squirrels
belonging to two species (Funisciurus anerythrus (60.6%) and Heliosciurus gambianus (39.4%)) were trapped with
tomahawk live trap and examined for parasitic infections. The squirrels were examined for ectoparasites from skin scrapings.
Blood and gastrointestinal content were collected to assess haemoparasites and gastrointestinal parasites, respectively.
Haematological parameters were assessed. Six (18.2%) squirrels of 33 examined were positive for ectoparasite (mite)
identified as Ornithonyssus bacoti. Haemoparasites identified include Trypanosoma spp. (9.1%), Plasmodium spp. (3.0%)
and Microfilaria worm (3.0%), with overall prevalence of 15.2%. All the 33 squirrels captured were infected with helminth
parasites. The small intestine and stomach had the highest and lowest parasitic ova counts, respectively. The parasite with the
highest prevalence was Hymenolepis spp. (75.8%) and the lowest were Heligmosomoides spp. (3.0%), Oxyuroid ova (3.0%),
Aspicularis spp. (3.0%), Strongyloides spp. (3.0%) and Schistosoma spp. (3.0%). Blood parameters according to species
were not significant. However, animals with co-infection showed lower packed cell volume (PCV) and haemoglobin (Hb)
values compared to single infections. Helminth-only infected squirrel showed marked eosinopenia. Parasites of public health
importance were prevalent in squirrels trapped in the University community. Therefore, humans should avoid unprotected
contact with squirrels and their excreta.

Keywords: Squirrels, parasites, helminths, haemoparasites, ectoparasites