Let H1N1 infect Singaporeans

Let H1N1 infect Singaporeans

Let it in while benign to develop herd immunity



Fri, May 15, 2009
The Straits Times

THE Influenza A (H1N1) virus is rapidly sweeping over the United States, Europe and Asia. It will be impossible to prevent the virus from entering Singapore just by screening those entering here who are ill and/or febrile.

We know that of all the patients who carry H1N1, at least 30 per cent are asymptomatic, and even those who will become symptomatic are infectious for at least the first 24 hours before symptoms appear. However, we are still doing temperature screenings at our borders and other public sites and buildings. A false negative is highly likely and is worse than not screening at all as infectious individuals may then go around thinking that they are well.

World Health Organisation director-general Margaret Chan warns that the virus may well return in a more virulent form after lying dormant in the warm months of the northern hemisphere. Singapore needs to rethink its strategy in this respect while we still have time.

We should stop temperature screening, which is ineffective for picking up infected subjects. When the pandemic started, there was a concern that it could be a virulent disease which makes sense for countries to err on the side of over-cautiousness and adopt stringent measures to prevent its spread. The situation has since changed as we learn more about the H1N1 virus. It appears to be highly contagious, but with low morbidity and mortality.

One possibility suggested by some doctors, including specialists in infectious diseases, is to freely open our borders, allow the relatively benign H1N1 to come into Singapore and allow our people to develop herd immunity. This way, if or when the virus mutates and turns virulent, our herd immunity may better protect us from a serious epidemic. In my view, there is merit in this idea. Continuing with the present strategy may invite more risks.

Professor Lee Wei Ling

This article was first published in The Straits Times.
http://www.asiaone.com/Health/News/Story/A1Story20090513-141202.html