Tamiflu vs bird flu

The cure may, at times, be worse than the disease. That would now seem to be the case with tamiflu, the drug used more than any other for treating and preventing the dreaded bird flu "" caused by the pathogenic H5N1 virus. Going by the findings of a study by researchers of the Oxford-based Centre for Ecology and Hydrology, the consequences of large-scale consumption of tamiflu can be scarier than even those of a bird flu outbreak.

The main fear is that the many tonnes of this drug that are in stock in various countries for combating a possible pandemic would, on consumption, play havoc with wildlife besides increasing human health hazards. Specifically, the scientists have warned that the bulk of this drug would get excreted through urine and flushed down sewers into natural water bodies and rivers, devastating aquatic bio-life. The worst hit would most likely be micro-organisms, including all manner of useful bacteria, present in these waters. This is because oseltamivir carboxylate, the active anti-viral ingredient of tamiflu that also kills bacteria, is resistant to bio-degradation and cannot be eliminated through normal sewer water treatment. Its toxicity can, therefore, persist in water bodies for weeks, even if only treated water is released in them. As a result, fish, birds and other creatures that dwell in these tanks and rivers or feed on them could face ruin. Man, too, needs certain kinds of bacteria in the gut for the digestion of food. All these systems could go haywire if the need should arise to use tamiflu on a mass scale.

As if this scenario were not alarming enough, the scientists have also pointed out that widespread consumption of this drug can create conditions in which the H5N1 virus, which normally infects only birds and some animals and does not get transmitted to humans, can mutate into forms capable of being passed on to humans. Another likely fall-out could be the development of immunity against oseltamivir carboxylate in H5N1 virus itself, rendering tamiflu ineffective. This would further heighten the risk of a flu pandemic. And, what is worse, should this happen, mankind would find itself fighting a losing battle till an alternative vaccine targeted specifically at the new form of virus is developed, which might take months.

Of course, it can be argued that these dreadful implications are hypothetical even though they emanate from a scientific study carried out on rivers in the US and UK. In any case, the possible hazards are far too serious and indeed unnerving to be disregarded. The bird flu has not yet been eradicated and its incidence continues to be reported from the south-east Asian region. What needs to be remembered is that the flu outbreak of 1918, albeit of a different virus strain, had killed nearly 50 million people. Equally essential to bear in mind is the alarming decline in the population of vultures, which are nature's scavengers, owing to the indiscriminate use of diclofenac, an anti-inflammatory drug, for the treatment of animals. Its residual toxicity in animal carcasses is killing the vultures who feed on them.

It is, therefore, imperative to revisit the strategies devised to cope with the bird flu menace and to look for safer drugs. An anti-influenza vaccine developed at the Bhopal-based high security laboratory of the Indian Council of Agricultural Research is believed to be a less harmful alternative to tamiflu. If that is indeed the case, enough stocks of this vaccine, as also adequate production capacity, need to be built up. Simultaneously, research needs to be initiated to evolve suitable biological and chemical treatments for sewer water to minimise its residual toxicity before the discharge is put out into natural water bodies.