‘Olympic Fever’ has a new and unwanted meaning with the threat of exposure to Zika virus for over 500,000 athletes and spectators at this year’s Rio Olympics. More than 100 leading scientists have signed an open letter addressed to Margaret Chan, Director General of the World Health Organisation (WHO), requesting that WHO supports their call for the 2016 Olympics be postponed or moved to new venues in the interests of global health. Their claims are backed by WHO’s own declaration of Zika as a ‘Public Health Emergency of International Concern’ that coupled with new scientific findings underscore the seriousness of the problem.
The Zika outbreak that began in Brazil’s northeast has now reached Rio de Janeiro where it is flourishing. Evidence from numerous clinical studies are also revealing that Zika infection is associated not just with pediatric microcephaly and brain damage but also adult conditions such as Guillain-Barré syndrome and acute disseminated encephalomyelitis, which are debilitating and sometimes fatal.
Put simply, the Zika infection is more dangerous than first realised and Brazil’s outbreak is significantly more extensive than scientists and public health officials predicted only months ago.
Although WHO has responded with cautionary tones to the increased risks posed by the Zika virus, independent appeals to postpone the games are not moving Margaret Chan and her colleagues to advise on any amendments to the games’ schedules: ‘Based on the current assessment of Zika virus circulating in almost 60 countries globally and 39 countries in the Americas, there is no public health justification for postponing or cancelling the games. WHO will continue to monitor the situation and update our advice as necessary.’
Meanwhile Brazil has reacted by mobilising over half a million public officials and military personnel in the fight to control the tiny Aedes aegypti mosquito which has been identified as responsible for the spread of the Zika virus. Though programmes for wide area spraying of pesticide will kill the mosquito, it is an extremely hardy foe and only needs a drop of water in which to lay its larvae – up to 200 at a time can hatch within a very short space of time bringing new dangers even to areas that are frequently treated. Brazil has already spent more than a decade in trying to manage this same mosquito that is also responsible for transmitting dengue virus, without success.
Some reports have suggested that Zika may follow the pattern of other mosquito-borne diseases and decline during Rio’s winter months of July to September when the games will be held. Because cooler temperatures reduce the activity and prevalence of mosquitos in general this is plausible, although nobody actually knows because Rio has never experienced a winter with Zika before. If one assumes that Zika will behave like dengue fever, because they are caused by related viruses and transmitted by the same mosquito, then Zika transmission will ebb but not vanish in Rio’s winter, just as dengue did in past winters.
Although much is unknown about how Zika will develop during and after the Olympics, all sides on the debate of Zika’s impact on global health are adamant that practical steps to prevent infection should be made by all visitors and residents in risk areas. For the latest in practical guides in combating mosquitos, battleface recommends the CDC link below.