Holding Olympics in the time of Zika virus

img_0316The World Health Organisation has confirmed that the Olympic Games scheduled to be held in August in Rio de Janeiro will go ahead, the Zika virus notwithstanding. An Emergency Committee meeting convened by the WHO Director-General said there is “very low risk” of the virus spreading globally as a consequence of the Games being held in Brazil. The WHO’s position comes in the wake of opposition to holding the Games as scheduled. In an open letter to Dr. Margaret Chan, Director-General of  WHO, 150 scientists and doctors had cited several reasons why the Olympics, the world’s biggest sporting event to start from August 5, to has to be postponed and/or moved to another location. According to the WHO, the local mosquito population level is expected to drop sharply in August, the Brazilian mid-winter, the annual infection rate is expected to peak before that, and more number of people who have been infected and, therefore, immune to further infections will reduces the scope for the virus to circulate. Intensive vector-control measures at and around the venue will reduce transmission risks. It is possible that a few individuals may get infected and contribute to a global spread and start off a new chain of local transmission. But the risk will be the same as in any country where the local transmission of the Zika virus is ongoing; it does not get amplified even when thousands come together, as the committee has noted. The WHO, however, has stressed that pregnant women should refrain from travelling to Brazil and other countries where the virus is circulating. The onus is now on Brazil to ensure that mosquito-control measures are intensified, surveillance is enhanced, and as required by the WHO, to make all information public about the virus circulation, surveillance and vector-control measures.

Indians travelling to any country with a Zika transmission trail have to take precautionary measures during their stay and on return. The first case of Zika virus infection through needlestick injury suggests that it is likely to be as infectious as HIV. While the virus primarily spreads through infected Aedes mosquitoes, through blood, and from mother to foetus (vertical transmission), several studies have confirmed a sexual route. While the Zika virus has been detected in saliva, urine and breast milk, there is no evidence yet of its transmission through these body fluids. But in the case of semen, the viral load has been found to be 100,000 times more than in both blood and urine even two weeks after the onset of symptoms. The virus has been found in semen even 62 days after symptom onset. A June 2016 study in The Lancet has found evidence of late sexual transmission — 44 days after symptoms show up. It is for these reasons that the WHO recommends that men and women returning from countries with Zika transmission consider abstinence or adopt safe sex practices for two months, with these strategies extended for at least six months for men who exhibit symptoms. As the landscape of Zika transmission is evolving, there is a critical need to exercise caution. More so as the Aedes aegypti is widely prevalent in India and the chances of the virus becoming endemic are high.

Published in The Hindu on June 21, 2016