Continued Transmission of West Nile Virus to Humans in Southeastern Romania, 1997–1998

Abstract

After an epidemic of West Nile (WN) virus neurologic infections in southeastern Romania in 1996, human and animal surveillance were established to monitor continued transmission of the virus. During 1997 and 1998, neurologic infections were diagnosed serologically as WN encephalitis in 12 of 322 patients in 19 southeastern districts and in 1 of 75 Bucharest patients. In addition, amid a countrywide epidemic of measles, the etiology of the febrile exanthem in 2 of 180 investigated cases was determined serologically to be WN fever; 1 case was complicated by hepatitis. Sentinel chickens placed in Bucharest seroconverted to WN virus during the summer months, indicating their potential value in monitoring transmission. The continued occurrence of sporadic WN infections in southeastern Romania in consecutive years after the 1996 epidemic is consistent with local enzootic transmission of the virus.

Evaluation of a West Nile virus surveillance and early warning system in Greece, based on domestic pigeons

“…This enabled the timely dissemination of information to public health authorities, in order to increase preparedness and implementation of adapted vector control measures and minimize the impact of the epidemic for humans and horses. The sensitivity of this WNV surveillance system based on pigeons is comparable to other surveillance systems applied for WNV surveillance in other countries [30][31][32][33][34][35], as well as in Greece [14,17,18]. In our case, and in order to increase the possibilities to detect seroconverted pigeons early in the epidemic seasons, we monitored mosquito populations and environmental temperatures, before the initiation of the pigeon samplings.…”

“…Moreover, pigeons have already been identified as potential sentinel birds [22]. Consequently, active surveillance of domestic birds has been used successfully in America and Europe for their early warning capacity [30][31][32][33][34][35].…”

West Nile Outbreak in Horses in Southern France, 2000: The Return after 35 Years

“…However, human transmission likely depends on several factors, including environmental factors, vectors, and amplifying host conditions. Usually in most countries where WN outbreaks have been documented, a few cases are reported during subsequent years (34).…”

Le virus West Nile: diagnostic, surveillance et évolution épidémiologique en Europe

“…Depuis, sa circulation a été observée plus largement en Europe de l'Est et du Sud (Koopmans et al 2007). Un pourcentage significatif de personnes ont présenté des anticorps contre le VWN en Roumanie, Espagne, Grèce et Russie (Lozano & Filipe, 1998;Cernescu et al 2000;Platonov et al 2001;Bofill et al 2006 ;. De plus, des anticorps ont été trouvés chez des chevaux (avec une séroprévalence pouvant varier d'un à 15%) en France, Espagne, Croatie, Roumanie et Russie (Murgue et al 2001;Vasil'ev et al 2005 ;Jimenez-Clavero et al 2007;Madic et al 2007).…”