First Serological Evidence of West Nile Virus Among Equines and Birds in Kosovo, 2018-2019
VECTOR-BORNE AND ZOONOTIC DISEASES
Authors: Rexhepi, Agim; Sherifi, Kurtesh; Berxholi, Kristaq; Xhekaj, Betim; Muja-Bajraktari, Nesade; Ozkul, Aykut; von Possel, Ronald; Emmerich, Petra
Abstract
This study was conducted to assess the presence of West Nile virus (WNV) in Kosovo by serological testing of apparently healthy local horses and free-range chicken, and it attempted to detect viral nucleic acid in birds and mosquitoes. Between January 2018 and June 2019, 260 equine serum samples were collected, additionally 580 adult mosquitoes (53 pools) were grouped in for genera, includingCulexspp. (226 individuals; 26 pools),Aedesspp. (136 individuals; 16 pools),Anophelesspp. (184 individuals; 7 pools), andCulisetaspp. (34 individuals; 4 pools). Fifty domestic birds and 51 wild birds were collected from different regions of Kosovo. Equine and domestic bird serum samples were tested by flavivirus IgG enzyme-linked immunosorbent assay (ELISA), while mosquitoes and bird viscera were tested for WNV RNA by RT-qPCR. All ELISA-positive results were confirmed by plaque reduction neutralization test (PRNT) and eight by virus neutralization test. WNV antibodies were present in 27 out of 260 equine sera (10.38%) and one out of 50 samples in domestic birds by ELISA and PRNT. Eight of 27 positive equine serum samples with high titer neutralized WNV, but not Usutu virus. No WNV RNA was detected in birds or mosquitoes. The occurrence of WNV antibodies in local equines from all regions of Kosovo indicates that the virus is circulating within the country. Public health authorities should therefore plan a risk assessment and disease control program.
A review on epidemiology and ecology of West Nile fever: An emerging arboviral disease
JOURNAL OF ACUTE DISEASE
Authors: Dehghani, Rouhullah; Kassiri, Hamid; Kasiri, Niusha; Dehghani, Mousa
Abstract
West Nile virus (WNV) is found in 26 provinces of Iran in humans, horses, and birds. Due to lack of vaccines, the only method to reduce the risk of the disease in communities is to increase people's awareness. Lack of killing and overhunting of animals does not alter the infected-blood transmission from animals to humans by mosquito bites, but can reduce disease transmission risks including the transmission of West Nile fever (WNF) to humans. WNV is an enveloped Flavivirus that in nature has an enzootic cycle between mosquitoes and birds. The virus has occasional epizootic spillover causing disease in humans and horses. WNV-transmitting mosquitoes are widespread around the world, and the geographical range of transmission and the disease has increased over the past seven decades. Most human infections with WNV are asymptomatic, but severe neurological disease may develop resulting in long-term complications or death. Given the increasing trend of reported human WNF cases, it is necessary to implement surveillance programs and increase awareness of people and health staff about the function of biological factors including carnivores in the hunting of infected animals and collecting their carcass from nature. Hunting and killing of birds and dogs living near humans increase both the risk of deviation of blood-feeding of the zoophilic mosquitoes to humans and the outbreak of the disease.