While unprecedented preparations are being made to prepare for the likely worsening of swine flu this fall and winter, it can be instructive to consider the infection from the virus point-of-view.
A virus does not have feelings, exactly. It infects without foresight, malice or mercy. But to understand a disease, it is important to look at things from the point of view of the organism – virus, bacteria or worm – that causes it. Take virulence, for example, the degree of damage a pathogen does to its host. The conventional wisdom used to be that a proper disease evolved to become relatively benign; why bite the hand that feeds you, not to mention the vital organs making that feeding possible?
The idea was that only new diseases would run rampant and have truly devastating effects. Once the disease organism settled down and learnt to behave, as it were, its excesses would be moderated and host and parasite would live together, if not in equanimity then at least without total ruin.
The problem with this notion is that it fails to take the pathogen’s-eye view. Pathogens are all about what’s-in-it-for-me. Biting off the hand that feeds you is just fine, as long as another hand can easily take its place. So being virulent works perfectly well, as long as it enhances the transmission of the pathogen. Diseases that are spread by vectors, such as malaria carried by mosquitoes, can afford to be virulent because incapacitating the victim does not slow the pathogen down – a fevered malarial patient is more likely to be bitten by a mosquito and transmit the disease once infected since she is less likely to swat the swarms of insects or have the derring-do to put screens over the windows and nets over the beds.
If, on the other hand, the disease is spread not by a mosquito but by direct contact between infected and uninfected individuals, a host who feels only mildly ill is more likely to go out and spread germs along with a handshake than one who is so debilitated that he can only lie in bed moaning gently and calling for ginger ale and magazines. In this case, a less virulent pathogen does better. [More]
If you know anyone involved in education, you may have discovered their summer was spent following official guidelines for swine flu arrival. Plans for isolation or school closure are replacing lesson plans at the top of the agenda.
While remarkably mild so far, the fact that swine flu has hung around all summer has many epidemiologists nervous, and anticipating widespread occurrence once the normal flu season begins.
Meanwhile, it is becoming slightly more possible, I think, that the result will just be a rotten flu season - not a devastating and deadly epidemic.
Don't panic, be careful. That's the advice from health experts who point out that the H1N1 influenza is milder than the seasonal flu and that 55 percent of the more than 1,000 cases in the country have already been cured and discharged from hospitals.India has so far has reported 1,079 swine flu cases and 12 deaths. While 589 have been discharged, the others are still undergoing treatment in various government hospitals in the country.'The swine flu virus is a mild strain and, in fact, is less virulent than the seasonal flu, which causes more deaths... We have treatment for it, which is Tamiflu. It is a curable disease, not an incurable one,' said Health Secretary Naresh Dayal.According to Randeep Guleria, head of medicine at the All India Institute of Medical Sciences in New Delhi, worldwide about 95 percent of those hospitalised have been discharged.
'Global data shows that less than six percent of those affected needed hospitalisation, while one third (of those in hospital) needed ICU care. However, those who have recovered from the flu are not immune to the infection and have to take care as others. But the next time they get the virus, it would be a mild one,' Guleria said. [More]
This is what passes for "good news" these days, BTW.