H5 and H7 subtypes of the influenza A virus (avian influenza; AI) has affected poultry for years but the advent and advancement of the highly pathogenic strain, H5N1, is providing opportunity for bird flu to be used as a ‘big stick’ to unfairly beat intensive poultry production.
For instance, findings of the Worldwatch Institute’s report ‘Vital Signs 2007-2008’, released by research associate Danielle Nierenberg at the 2007 annual conference of the American Association for Advancement of Science (AAAS) in San Francisco appeared to do just that. Growth of factory farms, their proximity to congested cities in the developing world and the global poultry trade are all culprits behind the spread of avian influenza, according to the report.
Identified and notified outbreaks occurring on large poultry farms rather than in backyard flocks is cited as evidence. The perceived situation in Laos, previously used by others to make the same point, was prominent. The report claims 42 of the 45 outbreaks of AI occurring in Laos during 2004 were on intensive farms, with 38 in the capital, Vientiane. However, the World Organisation for Animal Health (OIE) lists only 9 outbreaks in Laos for the entire 2003-2007 period, and only one of these in 2004.
Could it be that commercial poultry farms protecting their birds against diseases like Newcastle disease and Marek’s disease by vaccination or administration of veterinary chemicals are sensitive to even low incidence of sickness and death? For instance, the normal mortality rate for broilers in Malaysia is just 0.1% and farmers inform authorities at 1%.
Arrival of AI in backyard flocks in countries like Laos can easily be lost in the high levels of sickness, morbidity and mortality already experienced at this level of poultry production. Various international organisations have been conducting education campaigns in rural Laos about bird flu. Going by the basic level at which these are pitched, it would appear that most communities to their detriment have no clue about the H5N1 virus, the disease or its implications.
OIE can only log reports that it receives. If there were 45 outbreaks of H5N1 on large poultry farms in Laos during 2004, how many outbreaks were there in backyard flocks that were not reported to OIE or more likely not even noticed and identified?
A more likely scenario for Laos is that bird flu first entering on smuggled poultry – Laos has common borders with China, Myanmar, Vietnam, Thailand and Cambodia – and getting into backyard flocks. From there, it could easily enter the industrial sector, perhaps via workers who keep poultry at home. Once inside the commercial poultry sector, which is sensitive to low levels of bird sickness and mortality, the disease would quickly be picked up, identified and notified.