NEWS SCAN: West Nile mortality risk, new flaviviruses, zoonoses in developing nations

Oct 25, 2011

West Nile may double 3-year risk of death
West Nile virus (WNV) infection appears to more than double the mortality risk for up to 3 years after acute illness, according to a study by scientists from Colorado and the US Centers for Disease Control and Prevention (CDC). The team analyzed data from 221 WNV patients who were hospitalized in 2003 in northern Colorado, excluding 13 who died in the acute phase and 7 cases in children. Of the remaining 201 adults, 8 (4%) died within 1 year of illness onset and 24 (12%) had died within 4 years. They found that the overall age-standardized mortality ratio (SMR) 3 years after illness onset was 2.4 (95% confidence interval, 1.1-4.8). The researchers also found that age, autoimmune disease, tobacco use, encephalitis during acute illness, and endotracheal intubation during acute illness to be independently associated with death. They write that their finding of long-term increased risk of death "reinforces the need for prevention measures against WNV infection among at-risk groups to reduce acute as well as longer-term adverse outcomes."
Oct 24 Vector Borne Zoonotic Dis abstract

Three new flaviviruses identified in Spanish mosquitoes
Spanish and US researchers have identified three new flaviviruses—the family that also contains West Nile, yellow fever, and dengue viruses—isolated in Spain, according to a study yesterday in Vector-Borne and Zoonotic Diseases. The three viruses, first identified as possibly new flaviviruses by the researchers in 2009, were isolated from mosquitoes during surveillance conducted in four Spanish wetlands from 2001 through 2007. Two, called Marisma mosquito virus and Spanish Ochlerotatus flavivirus, were isolated from Ochlerotatus caspius mosquitoes. The third virus, which they named Spanish Culex flavivirus, was isolated from Culex pipiens mosquitoes. The researchers also developed a specialized polymerase chain reaction test useful for flavivirus characterization and surveillance, saying, "The method described here constitutes a valuable tool for the discovery, characterization, and phylogenetic analysis of classical and atypical flaviviruses."
Oct 24 Vector Borne Zoonotic Dis abstract

Zoonosis incidence underscores need for One Health programs in developing nations
A review of zoonosis incidence in India highlights the need for developing countries to undertake "One Health" initiatives (which emphasize the integration of human medicine, veterinary medicine, and environmental science), according to scientists from Bahrain and India writing in Infection Ecology & Epidemiology. The researchers' meta-analysis highlighted incidences from 1% (for cryptosporidiosis) to 40% (listeriosis) in humans for a wide variety of diseases, the vast majority of which had no corresponding national program in humans or animals. The authors point out that zoonoses constitute 75% of emerging infectious diseases and conclude that developing nations, especially, could benefit from One Health programs.
Oct 24 Infect Ecol Epidemiol study

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