West Nile Virus Surveillance in Romania: 1997–2000

Abstract

In response to the 1996 West Nile (WN) fever epidemic that occurred in Bucharest and southeastern Romania, a surveillance program was established. The surveillance system detected 39 clinical human WN fever cases during the period 1997-2000: 14 cases in 1997, 5 cases in 1998, 7 cases in 1999, and 13 cases in 2000. Thirty-eight of the 39 case-patients lived in the greater Danube Valley of southern Romania, and 1 case-patient resided in the district of Vaslui, located on the Moldavian plateau. The estimated annual case incidence rate for the surveillance area during the period 1997-2000 was 0.95 cases per million residents. Thirty-four cases were serologically confirmed, and 5 cases were classified as probable. Twenty-four case-patients presented with clinical symptoms of meningitis (62%), 12 with meningoencephalitis (31%), 1 with encephalitis (3%), and 2 with febrile exanthema (5%). Five of the 39 cases were fatal (13%). Fourteen case-patients resided in rural areas, and 25 in urban and suburban areas, including 7 case-patients who resided in Bucharest. The ages of case-patients ranged from 8 to 76 years with a median age of 45 years. Twenty-four case-patients were males and 15 were females. Dates of onset of illness occurred from May 24 through September 25, with 82% of onset dates occurring in August and September. Limited entomological surveillance failed to detect WN virus. Retrospective sampling of domestic fowl in the vicinity of case-patient residences during the years 1997-2000 demonstrated seroprevalence rates of 7.8%-29%. Limited wild bird surveillance demonstrated seroprevalence rates of 5%-8%. The surveillance data suggest that WN virus persists focally for several years in poorly understood transmission cycles after sporadic introductions or that WN virus is introduced into Romania at relatively high rates, and persists seasonally in small foci.

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“…Seventeen patients died [19]. After that first large epidemic further investigations in the following years confirmed the virus circulation in humans [20, 21] in birds and horses [22, 23]. In 1997, one year after the Romanian outbreak, five human cases were confirmed in Breclav area (South Moravia region) in Czech Republic from June to September 1997 [24].…”

High Prevalence of Rickettsia typhi and Bartonella Species in Rats and Fleas, Kisangani, Democratic Republic of the Congo

“…1 Endemic foci do usually refer to rural settings, but the focal distribution of pathogens may occur in urban areas offering a mosaic of habitats suitable to hosts, 2 vectors, 3 pathogens survival, 4 and exposed human population. 5 At different spatial and temporal scales, the anthropogenic modifications directly and indirectly play a role in the host and vector dynamics and act on the probability for (re)emergence of zoonotic diseases.…”

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

“…L'épidémie la plus sévère a touché la Roumanie en 1996-97 avec 352 formes neuro-invasives et 17 décès recensés (Ceianu et al 2001;Hubalek & Halouzka, 1999).…”