ARCHIVED - Infectious Diseases News Brief - November 16, 2012

Transmission of Hepatitis C virus among people who inject drugs: viral stability and association with drug preparation equipment

Background
HCV transmission among people who inject drugs remains a challenging public health problem. The researchers investigated the risk of HCV transmission by analyzing the direct association of HCV with filters, water to dilute drugs and water containers.

Methods
Experiments were designed to replicate practices and include equipment routinely used by injecting drug users. HCV stability in water was assessed by inoculation of bottled water with HCV. Viral association with containers was investigated by inoculation of water with subsequent emptying and refilling of containers. Transmission risk associated with drug preparation filters was analyzed by drawing virus through a filter following incubation to release infectivity.

Results
HCV can survive for up to three weeks in bottled water. Water containers present a risk for HCV transmission as infectious virions remained associated with water containers after washing. Physical properties of the water containers determined the degree of HCV contamination after re-filling with water. HCV also associated with filter material, with around 10% of the viral inoculum.

Conclusions
This study demonstrates the potential risk of HCV transmission among people who inject drugs who share water, filter and water containers and will help to define public health interventions to reduce HCV transmission.

Source: The Journal of Infectious Diseases (First published online: November 5, 2012)

Serological and molecular investigation into the role of wild birds in the epidemiology of West Nile virus in Greece

Background
A West Nile virus (WNV) disease outbreak occurred in 2010 in northern Greece with a total of 262 laboratory-confirmed human cases and 35 deaths. A serological and molecular surveillance was conducted on samples of wild birds hunter-harvested prior to and during the outbreak.

Findings
Serum and tissue samples from 295 resident and migratory wild birds, hunter-harvested during the 2009--2010 and 2010--2011 hunting seasons at the epicenter of the outbreak in northern Greece, were tested for the presence of WNV-specific antibodies by immunofluorescence assay and virus neutralization test. WNV neutralizing antibodies were detected in 53 avian samples. Fourteen positive sera were obtained from birds hunter-harvested up to 8 months prior to the human outbreak. Specific genetic determinants of virulence (His249Pro NS3 mutation, E-glycosylation motif) were recognized in a WNV lineage 2 strain isolated from a hunter-harvested Eurasian magpie and a nucleotide mismatch was revealed between this strain and a mosquito WNV strain isolated one month earlier in the same area.

Conclusions.
This is the first report regarding exposure of wild birds to WNV prior to the 2010 outbreak, in Greece. Results provide evidence of the implication of wild birds in a local enzootic cycle that could allow WNV maintenance and amplification of the virus before and during the outbreak. Findings of past exposure of migratory birds to WNV upon their arrival in Greece during autumn migration, suggest avian species with similar migration traits as candidates for the introduction of WNV into Greece. The possibility that an endemic circulation of WNV could have caused the outbreak, after an amplification cycle due to favorable conditions cannot be excluded.

Source: Virology Journal, (Published: 12 November 2012)