birds flu H5N1 2

Flu pandemic: Back-to-basics is best option Dr Musa Mohd Nordin Nov 2, 05 3:15pm


Influenza or the flu is often erroneously equated with the common cold. Hence the myth that it is a relatively mild illness which would improve rapidly over 2-3 days. Lots of rest, fluids; vitamin C and aspirin is all that is required. On the contrary, they are strikingly different pathologies. Influenza is often associated with high grade fever lasting 3-4 days; severe muscle aches, chest discomfort; early and severe physical weakness and generalised fatigue which could last up to three weeks. Thirty-one pandemics have been documented, four in the last century. The 1918 Spanish flu killed 20 million people. The epidemic waves of Type A flu comes every 1-3 years whilst Type B flu strikes every 3-4 years. This is due to the to emergence of new influenza virus strains causing high rates of morbidity and mortality, affecting all ages and inflicting high costs to society. Quite evidently, the pandemic clock is ticking; we just do not know what time it is! The Avian flu is caused by Type A influenza virus that typically infect birds. The virus is genetically distinguishable from human flu. The global concern on the Avian flu is due to the following worrisome trends: - The number of affected countries with avian flu is increasing; - The number of avian and human cases are increasing; - The majority of human population have no immunity; - The high case fatality rate. Human flu viruses are circulating in Asian countries and incubating elsewhere. Across Asia, increased episodes of transmission of avian flu virus strains to humans has illustrated the remarkable ability of the virus to jump the species barrier. Hence the widespread efforts to stop transmission of avian flu to humans from poultry through the elimination of animal reservoirs of H5N1. The emergence of the “pandemic virus” is postulated to result from a genetic re-assortment of human and avian viruses within the human anatomy which acts as a “mixing vessel”. This new virus strain would be highly pathogenic with an extreme avidity for humans. And since humans have no immunity, a pandemic is the nightmarish scenario. A strategy to bar the meeting of the viruses in the human body would go a long way towards preventing the emergence of the deadly new virus. It would reduce the opportunities for simultaneous infection of humans with the avian and human flu viruses. Decreasing this dual infection would reduce opportunities for re-assortment and the eventual emergence of a novel and pandemic virus. This, I believe, can be achieved with higher immunisation rates with the influenza vaccine. Higher uptake of the influenza shots would decrease the risk for genetic re-assortment in humans by preventing human flu virus infections. The influenza preparedness strategy should, among others, actively sensitise the population on the importance of influenza immunisation. Mandatory influenza vaccination of all persons likely to be in contact with poultry; cullers and those living and working on poultry farms should be in place. And all health professionals and first-line essential and emergency servicemen (eg, military, firemen, disaster and relief workers, policemen, etc) should be immunised. The experience with the Sars epidemic should be a painful lesson in this respect. This investment in the expanded use of influenza vaccines would prove to be a cost-saving policy. It would undoubtedly decrease the health burden of annual flu epidemics and prevent influenza morbidities and mortalities. Too much attention has been focused on curative strategies namely the anti-viral, Tamiflu. Nations are rushing to stockpile this drug in preparation for the pandemic. My back-to-basics virology and vaccinology would suggest that during this inter-pandemic period, influenza immunisation would be the best option for protection against influenza and would help to mitigate the emergence of a pandemic virus. A protective “pandemic vaccine” would benchmark our pandemic preparedness but would probably not be available for the first pandemic wave. And even if available there would be insufficient stocks for universal usage due to limited manufacturing capacity – let alone to stockpile.