A ProMED-mail post
http://www.promedmail.org
ProMED-mail is a program of the
International Society for Infectious Diseases
http://www.isid.org
Date: Wed 8 Aug 2012 Source: Emerging Infectious Diseases journal [edited] http://wwwnc.cdc.gov/eid/article/18/9/12-0402_article.htm Ref: Gutierrez RA, Buchy P: Contaminated soil and transmission of influenza virus (H5N1) [letter]. Emerg Infect Dis [serial on the internet]. 2012 Sep [date cited] ---------------------------------------------------------------------- Highly pathogenic avian influenza (HPAI) virus (H5N1) has been responsible for 603 confirmed human cases worldwide, including 356 that resulted in death, and for over 7000 epizootic outbreaks (1,2). Direct contact between hosts is the main mechanism of transmission for avian influenza viruses, but the possible role of the environment as a source of HPAI virus (H5N1) infection has been rarely studied, particularly in the context of countries where the virus is enzootic or epizootic (3-7). To determine if contaminated soil contributes to the transmission cycle of HPAI virus (H5N1), we used experimental and simulated field conditions to assess possible transmission in chickens. All experiments were conducted by using HPAI virus (H5N1) strain A/chicken/Cambodia/LC1AL/2007 (GenBank accession nos. HQ200574-HQ200581). All animal experiments were conducted in the biosafety level 3 laboratory of Institut Pasteur in Cambodia (IPC), in compliance with the European Community 86/609/CEE directive and approved by the Animal Ethics Committee of IPC (permit: AEC/IPC/003/2010). Specific pathogen-free (SPF) chickens were provided by the National Veterinary Research Institute of Cambodia. We used 3 types of soil: 1) sandy topsoil collected from around rice fields in Phnom Penh Province, Cambodia; 2) building sand purchased from a local building company; and 3) soil-based compost purchased from a local tree nursery. Physicochemical and microbiologic parameters were measured for water extracts obtained for each type of soil (Technical Appendix Table [available at the source URL above]), and low- and high-dose contamination protocols (Technical Appendix Figure [available at the source URL above]) were used to experimentally contaminate each soil type. In brief, we seeded the soil samples with 1-56 infectious units of contaminated feces; one infectious unit was
