Web Exclusive: Human ‘sentinels’ for H5N1 in poultry
Since 2004 Cambodia has recorded just 20 outbreaks of H5N1 in poultry compared with over 2373 in neighbouring Vietnam.
Seven all-fatal cases (most recent 3 April 2007) have been identified in Cambodia. Vietnam has recorded 93 human cases (42 fatal), the last on 14 November 2005. Ratio of H5N1 disease outbreaks in poultry to identified human infections is 3:1 and 25:1 respectively for Cambodia and Vietnam.
The latest Cambodian case – a 13-year-old girl from Ponhea Kreak district Kampong Cham province, 124km east of Phnom Penh – was identified with H5N1 on 3 April 2007. Reports in a local newspaper (Rasmei Kampuchea) indicate that several hundred backyard birds (chickens and ducks) died in the vicinity before and after the girl fell ill. She had tended her family’s small flock of poultry and eaten infected chicken, claimed other reports.
There were no previous or accompanying official reports of H5N1 outbreaks in poultry in the district. An outbreak was confirmed at Laork Village, Ponhea Kreak district in Kampong Cham province on 10 April and logged with OIE (World Organisation for Animal Health) on 12 April. The outbreak affected 1086 backyard chickens and ducks killing 302 and causing 784 to be culled.
There appears to be no pro-active surveillance for H5N1 within Cambodian poultry, officials only investigating suspected outbreaks when a person in the area is infected and dies. In such situations, humans are essentially the ‘sentinels’ for outbreaks of avian influenza in poultry.
Current situation is even more disturbing in Indonesia and Egypt where 19 and 13 human cases, respectively, have occurred since 1 January 2007. Last reported outbreaks in poultry were in 9 August 2006 for Indonesia and 13 December 2006 for Egypt. In these countries, it appears that authorities in these countries are not even bothering to test local poultry flocks even when someone in the vicinity succumbs to H5N1.