Poland - Occurrence of West Nile Virus Antibodies in Wild Birds, Horses, and Humans

[Gert van der Hoek]

Biomed Res Int. 2015; 2015: 234181.
Published online 2015 Mar 19. doi: 10.1155/2015/234181

Abstract

Serum samples of 474 wild birds, 378 horses, and 42 humans with meningitis and lymphocytic meningitis were collected between 2010 and 2014 from different areas of Poland. West Nile virus (WNV) antibodies were detected using competition enzyme linked immunosorbent assays: ELISA-1 ID Screen West Nile Competition, IDvet, ELISA-2 ID Screen West Nile IgM Capture, and ELISA-3 Ingezim West Nile Compac.

The antibodies were found in 63 (13.29%) out of 474 wild bird serum samples and in one (0.26%) out of 378 horse serum samples.

Fourteen (33.33%) out of 42 sera from patients were positive against WNV antigen and one serum was doubtful.

Positive samples obtained in birds were next retested with virus microneutralisation test to confirm positive results and cross-reactions with other antigens of the Japanese encephalitis complex.

We suspect that positive serological results in humans, birds, and horses indicate that WNV can be somehow closely related with the ecosystem in Poland.

[Gert van der Hoek]

A Survey on West Nile and Usutu Viruses in Horses and Birds in Poland.


Viruses. 2018 Feb 17;10(2). pii: E87. doi: 10.3390/v10020087.

Abstract


West Nile virus (WNV) and Usutu virus (USUV) are members of the family Flaviviridae which, natural life cycles involve mosquito-bird-mosquito transmission. Both represent emerging viruses in Europe with potential to cause neuroinvasive disease in humans. This study investigates the seroprevalence of serum neutralizing antibodies to WNV and to USUV in birds and in horses in Poland.

Antibodies against WNV and USUV were detected in 5 (35.7%) and in 1 (7.14%) of 14 birds and in 62 (15.08%) and in 115 (27.98%) of 411 horses, respectively. Twenty-one WNV serologically positive horses (33.87%) and 67 USUV serologically positive horses (58.26%) did not travel outside Polish borders.

Given the high abundance of potentially competent mosquito species in Poland, high populations of horses and different bird species, our findings highlight implementation of active control programs, including monitoring of geographic spread and dynamics of WNV and USUV transmission in both primary and accidental hosts. It is also important to improve public health awareness about the disease these viruses may cause.




Geographic distribution of WNV and USUV seropositive horses. Site and number of sera collected; USUV positive serum samples; WNV positive serum samples; USUV/WNV positive serum samples.