THE STRENGTH OF VIRUSES

An emailer makes an interesting point:

If HIV follows the same trend as other epidemic diseases, the outcome will be a little more subtle than a generalized weakening of the virus. In areas where practices to reduce the severity and transmission of HIV are broadly applied, the virus will indeed weaken. This is due to selection pressure on the virus to keep its host alive long enough to successfully pass the virus on to a new host. In areas where little is done to prevent the spread of the disease, it will remain virulent and selection pressure may even favor more-virulent strains. This is because, with hosts dying relatively quickly, aggressive viruses are more likely to make the jump to their next host. A well-studied analog is the cholera parasite. In countries with poor sanitation, periodic outbreaks are characterized by their virulence. In the US, the disease is mostly confined to travelers returning from overseas. However, an endemic strain has developed in Texas and Louisiana which is characterized by mild symptoms and the ability to survive outside the classical human host/contaminated water cycle. References here and here. This divergence of virulence might explain why different studies come to different conclusions on the matter. It also seems a strong argument for extension of first-world HIV prevention/treatment practices to the rest of the planet.

Meanwhile, we have a new U.N. avian flu czar.

EMAIL OF THE DAY: “I’m afraid that, no matter what comes to light in the Abu Ghraib materials, you’re still gonna be disappointed. There is far too much else going on right now domestically for the majority of average Americans (and sorry, but living in Provincetown, MA, you don’t have a clue what we are thinking) to get all excited over something that happened 12-18 months ago thousands of miles away in a country brimming with folks trying to kill American military personnel and innocent Iraqis.
Oh sure, the Dems, the Wa Post, NYT, MSM at large, various bloggers and those predisposed to an anti-military and/or GOP animus will wring their hands, but most Americans will greet it with a yawn.”

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