Canine Dirofilaria Infections in Two Uninvestigated Areas of Serbia: Epidemiological and Genetic Aspects

Abstract

In 2009 canine filarial infections were investigated in two northern areas of Serbia (Pančevo and Veliko Gradište), applying morphometry, biochemical staining, and immunological kit to detect Dirofilaria immitis antigens, and two home-made ELISAs to detect antibodies to D. repens and D. immitis somatic/metabolic polyproteins. Moreover, molecular tools were applied to analyze the phylogenetic relationships of the isolates. The microfilariae detected in 21/122 dogs (17.2%) were identified as D. repens (n=21) and D. immitis (n=2). D. immitis antigens were found in another 13 animals with occult infection. All of the 15 heartworm-positive dogs also had antibodies to this parasite, which were detected in another 13 subjects, indicating an overall D. immitis seroprevalence rate of 22.9%. Serology for D. repens revealed evidence of antibodies in 42.6% of the dogs, but was negative for 4 microfilaremic dogs. As for the two different areas, the prevalence of microfilariae and/or D. immitis antigens, mainly due to D. repens microfilaremic animals, was not significantly higher in Veliko Gradište (33.3%) than in Pančevo (22%). However, serology showed a different epidemiological picture. Heartworm infection occurred more often in both areas, and antibodies to dirofilarial nematodes were detected in 72.9% of dogs living in Pančevo, a rate higher than in those living in Veliko Gradište (57.1%). No risk factors for infection were found, confirming the uselessness of prophylactic drugs against D. repens, and suggesting the presence in these areas of sunrise- or sunset-biting mosquitoes as important vectors. The results indicate the need for both appropriate entomological studies and further research on the intra-species variability shown by D. repens.

First records of Dirofilaria repens in wild canids from the region of Central Balkan

“…Besides, some researchers suggest that wild carnivores such as foxes may be significant wild reservoirs for zoonotic filarioids (Magi et al, 2008). With an exception of a few studies on the presence of microfilariae in the blood of domestic dogs (Tasić et al, 2008(Tasić et al, , 2012Kočevski et al, 2010) and human dirofilariosis case reports (Stefkov and Gjorgov, 1967;Cvetković et al, 2007;Džamić et al, 2009;Tasić et al, 2011;Jurhar Pavlova et al, 2012), no research has been conducted so far on wild animals, either in Serbia or in the Former Yugoslav Republic of Macedonia. The aim of this study was to present the first data on D. repens in wild canids from the Central Balkan and to help understand the importance of these species as hosts and potential reservoirs of dirofilariosis in nature.…”

Efficiency of modified therapeutic protocol in the treatment of some varieties of canine cardiovascular dirofilariasis

“…Destruction of the end symbiotic bacteria (Wolbachia) with antibiotic treatment (doxycycline, 10 mg/kg, twice a day for four weeks) is of great importance for a successful treatment (10,21). Better results have been obtained with a combination of doxycycline and ivermectin (15,26), but the true mechanism of synergism is still unknown. It is believed that doxycycline destroys the end symbiotic bacteria (AHS 2014) and ivermectin causes somatic degeneration of the parasite (10).…”

“…Death is mainly due to cachexia or respiratory distress after thromboembolism (10). Laboratory diagnosis of dirofilariasis involves the detection and identification of microfilaria in the peripheral blood (8,27), performance of immunological tests (13,20,23), and molecular diagnostic methods (5,9,26). If dogs manifest symptoms and the results of blood tests are negative, then radiography of the thorax should be performed (15).…”

“…In this study we have shown the effects of treatment of dogs with diagnosed cardiovascular dirofilariasis during a two-year period (2012)(2013). The aim of the present study was to evaluate efficacy of the modified therapeutic protocol reported by Grandi et al (10) in 2010, (involving a combination of ivermectin and doxycycline, modified with combination of imidoclopride and moxidectin) on the varieties D. immitis found on the territory of republic of Serbia (26). We decided to use this combination due to a lack of drug available in our country, despite the guidelines given by the American Heartworm Society (1).…”

Subconjunctival Infection due to Dirofilaria Repens ‐Case Report

“…This is the first case of the human ocular, subconjunctival dirofilariosis on the territory of the southeast Serbia and the city of Niš. Note that in this case there was no history of patient's trips or stay in other parts of Serbia, such as Vojvodina which is considered as a hyperendemic area for D. repens in dogs (16,(20)(21)(22)(23)(24).…”