Increasing West Nile virus antibody titres in central European plasma donors from 2006 to 2010

Abstract

We analysed by neutralisation assay 55 intravenous immunoglobulin preparations produced from human plasma collected in three central European countries, specifically Austria, Germany and the Czech Republic, from 2006 to 2010. The preparations from 2009 and 2010 contained increasing titres of neutralising antibodies against West Nile virus (WNV) in the absence of reported human WNV cases in these countries.

Retrospective identification of human cases of West Nile virus infection in Austria (2009 to 2010) by serological differentiation from Usutu and other flavivirus infections

“…Our data are consistent with recent findings of increasing WNV antibody titres in human plasma collected in Austria, Germany and the Czech Republic from 2006 to 2010 [26] and support activities to increase vigilance for this infection as a potential public health problem in central Europe [27]. In this context, it is also important to strengthen the awareness of clinicians for WNV infections, especially during the summer months, and to include tests for WNV into routine diagnostic practice of CNS diseases.…”

Household survey of container–breeding mosquitoes and climatic factors influencing the prevalence of Aedes aegypti (Diptera: Culicidae) in Makkah City, Saudi Arabia

“…Culex spp. mosquitoes are known to be the most important vectors of West Nile virus (WNV) [53] of which infections are increasingly occurring in many parts of the world [54,55] including the Arabian Peninsula [56] . In nature, this flavivirus is maintained by a bird-mosquito transmission cycle [57,58] .…”

Tick-Borne Encephalitis Virus-Neutralizing Antibodies in Different Immunoglobulin Preparations

“…When a virus or microbial agent is expanding its geographical range, exposure of the formerly naïve population to this novel agent is reflected in the Ab content of IVIG. This was demonstrated, e.g., for US-IVIG after the introduction of WNV into the United States in 1999 (4,25,31) and recently also for EU-IVIG, where increasing WNV-neutralizing Ab titers were detected in EU-IVIG lots manufactured after 2009, even though no human WNV infections have yet been reported from the countries in which the plasma was sourced (31).To further increase the understanding of the geographical difference in IVIG Ab content, we determined the neutralizing Ab titers of IVIG preparations for tick-borne encephalitis virus (TBEV). This member of the Flaviviridae, for which three subtypes (European, Siberian, and Far Eastern) are distinguished, may cause tick-borne encephalitis (TBE), a potentially serious neurological disease with high fever and encephalitis (33), while 70 to 95% of human infections in regions in which the virus is endemic are either subclinical or totally asymptomatic (12).…”

“…When a virus or microbial agent is expanding its geographical range, exposure of the formerly naïve population to this novel agent is reflected in the Ab content of IVIG. This was demonstrated, e.g., for US-IVIG after the introduction of WNV into the United States in 1999 (4,25,31) and recently also for EU-IVIG, where increasing WNV-neutralizing Ab titers were detected in EU-IVIG lots manufactured after 2009, even though no human WNV infections have yet been reported from the countries in which the plasma was sourced (31).…”