Don’t Cancel the Olympics

Since I wrote about Zika in February, genome sequencing has shown that the virus has three lineages: West African, East African and Asian. Analysis of a 1966 Malaysian strain and a 1968 Nigerian one point to an Asian origin for the Brazilian viruses; it is likely that Zika has been circulating in Brazil since 2013. The virus has been evolving in expected ways (its RNA genome has a high mutation rate); no change that could account for an enhanced ability to damage the brain has yet been found. None of these findings has hit the headlines.

But an open letter to Margaret Chan, the director general of the World Health Organisation, published on 27 May did. It recommended that the Rio Olympic Games be postponed, or transferred elsewhere. The signatories were worried that infected visitors would take the virus back to countries in Africa and Asia, helping it to become established there.

But it is already there. Zika was discovered in Uganda in 1947, antibodies against it were found years ago in people living in Nigeria, India and South East Asia, and it is currently circulating in Indonesia, Thailand, Cambodia and the Philippines. The signatories’ worries have been given short shrift by the WHO, the director of the CDC, and scientists who know about Zika. Consideration of the natural history of the virus and its transmission, together with information on the number of travellers to and from Brazil, has caused them to conclude that, at worst, the Olympic contribution to the worldwide spread of Zika will be trivial.

In theory athletes might be infected, but the risk is very low. They will be living in secure purpose-built villages, not the favelas where Aedes aegypti, the mosquito vector of Zika, breeds in small collections of water in discarded cans, bottles and car tyres. It does not fly far. And the Brazilian authorities have a strong incentive apart from Zika to protect Olympians from Aedes aegypti. It also transmits dengue, which is on the rampage in Brazil. Most cases are mild, but it can cause muscle and joint pain (an old name for it was ‘break bone fever’). If I were the manager of an Olympic team, dengue would worry me far more than Zika.

The open letter ends by suggesting that the WHO has a possible conflict of interest because of its official partnership with the International Olympic Committee. My guess is that, after receiving the letter, someone at the WHO would have been reminded of Wolfgang Wodarg. A German politician, ethicist and former ship’s doctor, Wodarg very publicly suggested in 2009 that the WHO response to the new H1N1 influenza virus was influenced by vaccine and antiviral manufacturers, and that the pandemic was a ‘fake’. He was wrong.