West Nile Fever in the Rostov Region: Ecological and Epidemiological Peculiarities of the Outbreak in 2010

This paper describes the outbreak of West Nile fever in the Rostov Region in 2010 and evaluates its ecological and epidemiological peculiarities. From 15^th of July till 22^nd of September 2010, detected were the 64 cases (1, 480_0/0000) of the disease, which were characterized by vector-born mechanism of transmission. Peak of morbidity coincided with mass breeding of Culicidae, increase in the number of Culex mosquitoes, and reoccurring growth of Aedes mosquito population. Diffuse type of the epidemiological process, higher rates of the cases among urbanites, infected in the country-side area, were the characteristic features of that outbreak. West Nile virus antigen was detected by means of IFA in samples taken from An. maculipennis and Cx. pipiens mosquitoes, wild and synanthropic birds, Rh. rossicus ticks, house and wood mice, which facilitates identification of the core factors for the agent circulation and West Nile fever natural focus formation.

environmental conditions, West Nile fever, outbreak, epidemiological analysis

1. Vinogradova E.B. [Mosquitoes Culex pipeins in Russia (taxonomy, dissemination, ecology, physiology, genetics, practical importance, and con- trol/surveillance)]. Trudy Zool. Inst. RAS. 1997; 271:308.

2. Gutsevich A.V., Monchadsky A.S., Shtakel’berg A.A. [Mosquitoes (Culicidae Family). Fauna of the USSR. Diptera]. L.: Nauka; 1970. 384 p.

3. Zabashta M.V., Moskvitina E.A., Lomov Yu.M., Minoransky V.A., Pichurina N.L., Orekhov I.V. et al. [Ecological and epidemiological aspects of West Nile fever in the Rostov region]. Probl. Osobo Opasn. Infek. 2006; 2(92):25–32.

4. Kolobukhina L.V., L’vov D.K. [West Nile fever]. In: [Guidelines for Medical Virology]. M.; 2008. P. 514–22.

5. L’vov D.K., Deryabin P.G., Aristova V.A., Butenko A.M., Galkina I.V., Gromashevsky V.L. et al. [Atlas of Dissemination of the Natural Focus Viral Infection Agents in the Territory of the Russian Federation]. M.; 2001. 193 p.

6. L’vov D.K., Il’ichev V.D. [Bird Migration and Infectious Agent Transfer (ecological and geographical connections of birds and infectious agents)]. M.; 1979. P. 54–8.

7. L’vov D.K., Savchenko S.T., Alekseev V.V., Lipnitsky A.V., Pashanina T.P. [Epidemiological situation and prognosis for the West Nile fever morbid- ity in the territory of the Russian Federation]. Probl. Osobo Opasn. Infek. 2008; 95:10–2.

8. Oblapenko G.P., Vershinsky B.V. [Spatial Aspect of Epidemiological Process]. Trudy Inst. Im. Pastera. 1976; 45:40–8.

9. Platonov A.E., Karan’ L.S., Shopenskaya T.A., Fedorova M.V., Kolyasnikova N.M., Rusakova N.M., et al. [Genetic typing of the West Nile fever strains, circulating in the South of Russia, as a means of epidemiological investigation: principles and results]. Zh. Microbiol. Epidemiol. Immunobiol. 2011; 2:29–37.

10. Putintseva E.V., Lipnitsky A.V., Alekseev V.V., Smelyansky V.P., Antonov V.A. et al [Dissemination of the West Nile Fever in the Russian Federation and in the World in 2010]. Probl. Osobo Opasn. Infek. 2011; 1(107):38–41.

11. Putintseva E.V., Smelyanskiy V.P., Antonov V.A., Lipnitskiy A.V., Alekseev V.V. [Prognosis of Epidemiologic Situation of West Nile Fever in the Territory of the Russian Federation for 2010]. Probl. Osobo Opasn. Infek. 2010; 104:14–7. 12. Flint V.E., Mosalov A.A., Lebedeva E.A., Bukreev S.A., Galushin V.M., Zubakin V.A. et al. [Birds of European Russia]. Polevoy Opredelitel’. M.; 2001. 224 p.

12. Cherkassky B.L. [Guidelines for General Epidemiology]. M.; 2001. P. 101–35.

13. Assessing capacity for surveillance, preservation and control of West Nile virus infection in United States, 1999 and 2004. Morb. Mortal. Wkly Rep. 2006; 17(6):150-3.

14. Deardorff E., Estrada-Franco J., Brault A.C., Navarro-Lopez R., Campomanes-Cortes A., Paz-Ramirez P. et al. Introductions of West Nile virus strains in Mexico. Emerg. Infect. Dis. 2006; 12(2):314-8.

15. Komar N., Clark G.G. West Nile virus activity in Latin America and the Caribbean. Rev. Panam. Salud Publica. 2006; 19(2):112-7.