Filariae of Raccoons from Southeast Georgia

Abstract

The prevalence of filariae in wild raccoons trapped in southeast Georgia was determined. Examination of blood samples revealed that 74 of 113 raccoons (66%) trapped in 6 southeastern Georgia counties were infected. Seventy-three of these raccoons (65%) were infected with Mansonella llewellyni and this parasite was observed in raccoons from every location examined. Dirofilaria tenuis was found in 22 raccoons (20%) and was observed in only 3 of the 6 counties surveyed. An adult specimen of Acanthocheilonema procyonis was found in the subcutaneous tissues of 1 of 5 necropsied raccoons. This is the first record of filariae in raccoons from Georgia. In addition, Dirofilaria-like larvae were found in Aedes taeniorhyncus mosquitoes collected in Liberty County.

Dirofilaria tenuis Causing Neuritis

“…Microfilaremia is linked to an underlying immune compromise, and these rare cases should be pursued. 25,39 In the northern areas of the state 26 and in southeastern Georgia, prevalence falls by more than half. Most but not all subcutaneous filariases are benign, and even the more serious manifestations respond to excision.…”

“…D tenuis, D ursi, and perhaps Dirofilaria striata of wildcats 38 should be considered when presented with a small periorbital, subconjunctival, or subcutaneous mass, either quiescent or inflammatory. 39 Prevention is by avoiding the outdoors during hours of peak activity, applying N,N-Diethyl-meta-toluamide, and wearing protective clothing. Treatment of D tenuis is by removal of the nodule and surrounding inflammation without need for ivermectin.…”

Subcutaneous Dirofilariasis in the United States

“…16 Prevalence of D. tenuis microfilaremia in raccoons studied in Florida and Georgia has been reported as high as 45%. 17,18 In contrast, microfilaremia in black bears of North America have been studied, citing a prevalence of between 21% and 100% in various studies of D. ursi in the United States. 19 However, there is a paucity of studies comparing this microfilaremia with rates of human infection, likely because of the limited number of D. ursi cases reported.…”

Mosquito-borne parasites in the Great Plains: searching for vectors of nematodes and avian malaria parasites

“…which cause human morbidity in different parts of the world with Dirofilaria immitis causing heartworm in canines (Mullen and Durden 2018). While various filarioid nematodes are found in different animals (Rabinowitz et al, 1985;Pung et al, 1996;Netherlands et al, 2020), Setaria spp. are mainly found in bovids and cervids and can be transmitted by different species of mosquitoes (Cancrini et al, 1995(Cancrini et al, , 1997Ubleis et al, 2018).…”