For a virus that has remained vastly quiet since its discovery 70 years ago in the Zika forest of Uganda, it has been the source of increasing concern over the past decade. The first major outbreak caused by the virus was on the Pacific island of Yap in the Federated States of Micronesia. Prior to this, there were no known outbreaks, and a total of 14 sporadic cases of human ZIKV infections that were reported in Africa and Asia. Until the Yap island outbreak, there were no reports of transmission of Zika virus outside of Africa and Asia. Since this outbreak on the Yap Island, there were outbreaks on four other groups of Pacific islands in 2013/14: French Polynesia, Easter Island, the Cook Islands, and New Caledonia. By far the most documented and studied is the French Polynesia outbreak, which generated thousands of suspected cases which were intensely investigated. It was during this outbreak that the association with increased risk for microcephaly in the instance of infection in the first trimester was established.
But now, Brazil’s problem is inconveniently not ending. Clinical studies are also mounting that Zika infection is associated not just with paediatric microcephaly and brain damage, but also adult conditions such as Guillain-Barré syndrome and acute disseminated encephalomyelitis, which are debilitating and sometimes fatal. Zika is much more dangerous, and the Brazilian outbreak much more extensive than previously expected.
In March, 2015, serum samples were collected from 24 patients at Santa Helena Hospital in Camaçari, Bahia, Brazil, as a consequence of an ongoing outbreak of an illness characterised by fever, maculopapular rash, muscle and joint pain, and conjunctivitis. Further analysis identified Zika virus in seven patients, and chikungunya virus in three, with no reported co- infection. Sequence analysis of regions of the Zika virus envelope protein showed 99% identity with sequences from a French Polynesian isolate. In a second study, done on serum samples from patients in the city of Natal, Rio Grande do Norte, Brazil, in March, 2015, also showed the presence of Zika virus at around the same time, with similar homology to the French Polynesian Zika virus sequences. The two collection sites are slightly over 1000 km apart, and as such are possibly separate introductions of Zika virus to Brazil.
Although there have been suggestions that the virus was introduced during the World Cup football tournament hosted by Brazil in 2014, no Zika endemic countries took part in the competition. Although it is possible that visitors from such a country may have been in attendance as spectators, there is also a possibility that the virus was introduced during the IVF Va’a World Elite and Club Sprint Championship held in August, 2014. This event included competitors from four Pacific countries with Zika circulation: French Polynesia, New Caledonia, Cook Islands, and Easter Island. However, it was held in Rio de Janeiro (as reported in), which is located about 1600 km from Camaçari and 2600 km from Natal.
But what does the outbreak mean for the Olympics? With an anticipated half a million extra international visitors to the Games, and athletes and their respective teams, what are the risks? Already we have seen some of the major athletes pull out of the games, citing Zika virus as their reason to do so. World number one Jason Day, Tejay van Garderen and Rory McIlroy, who have withdrawn from the games, many other competitors such as Jessica Ennis ad Greg Rutherford have shown their concerns. Rhianna recently cancelled one of shows in Colombia over the Zika virus scare.
Rio is more affected by Zika than previously expected, which means that the earlier expectations about safety are now obsolete. When in January, the International Olympic Committee declared Rio ‘safe’ for the Games, it was speculations. It was February before the Ministry of Health declared ZVD a notifiable disease and officially began counting cases. With data available, at this point in time, the situation does not seem so safe. Similar concerns were raised in 2013 about the risks of dengue infections for tourists and athletes travelling to the 2014 World Cup. At the time the estimates for individual risk for dengue infection were values varying from around 6 × 10−5 to around 4 × 10−4, which represented an expected number of infections among tourists between three and 59 cases. The reported number of dengue cases among tourists after the Games was three. The risk estimation provided for tourists and athletes who intend to visit the summer Olympics in August of this year to be between 9 × 10−6 and 3 × 10−5. The risk of Zika infection is 15 times less than that for dengue. Furthermore, with Rio being the epicentre with the some of the highest numbers of Zika cases, it is at the ‘heart’ of the outbreak.
Zika is transmitted by mosquitoes, mainly the Aedes aegypti mosquito, which is also one of the main carriers of the dengue virus. Though some have previously suggested that during the winter months in Rio (July to September) Zika will follow the pattern of other mosquito-borne diseases and decline, we do not have any reliable data to base this prediction on, as Rio has not experienced a winter with Zika before. Even if we do assume that Zika will behave as dengue fever, as they are so closely related, the transmission of the virus will merely decrease, but not disappear. Especially, when dengue transmission has been 6 fold higher in the first quarter of this year than last year, during one of the strongest and biggest movements towards mosquito killing measures in the country, the outlook for the Games is very worrisome.
Zika virus has had a devastating effect. Though it went unnoticed in many of its previous outbreaks, such as in French Polynesia, retrospective analyses now show that the risk of microcephaly increased by 23 to 53 fold. With an established causal relationship between microcephaly and the virus, a study shows that, in Rio, among women with confirmed Zika infections during pregnancy, fully 29% had foetal abnormalities on ultrasound. Exploration into the effects of the virus on the adult brain have only just begun, and the results so far look bleak. Studies show that exposure to the virus can increase the risk of Guillain-Barré by 60 fold. With no exact cure for any of these conditions, it seems that going to the Games is probably a bad idea.
While it is true that many of the cases of Zika found in countries outside of South America are imported cases – travellers to Zika endemic areas who have been infected – the Olympics will only aid to speed up this process of spreading the virus worldwide. With 500,000 additional foreign visitors, potentially becoming infected, returning to their homes, where it would be surprisingly easy for both local Aedes mosquitoes and sexual activity to help spread the virus and start off new outbreaks.
On top of all this, Brazil is in serious economic hardships. While reports of many of the Olympic venues still remain constructions sites (with those nooks and crannies and stagnant water – a perfect breeding ground for mosquitoes), will the Brazilian government be able to handle the surge in population during the Games and be able to protect these people against the virus? As the virus spreads faster and farther than predicted, can the government help support the health professionals and scientists to build defences against it? Would it be ethical to put other, lesser developed countries, who may not have the same resources and efforts as Brazil – which really aren’t helping anyways – under the risk of Zika by hosting the Olympics? But it is not money or government back up that we are running so fast. It is time. The Games could help propagate a fresh wave of cases and steal away the time we have to develop an efficient vaccine or barrier against it.
The Brazilian Health Ministry still remains adamant that it is safe to go ahead with the games, with precautions in mind. But there is still time to change this. Many countries have the infrastructure to hold the Olympics at short notice. The recent Pirates-Marlins baseball series was moved from Puerto Rico to Miami over Zika fears. In the past, the Olympics have moved too, for instance in 1976. So, there is room for flexibility. Though there is a big financial aspect to moving the games, this will undoubtedly be made up by the lower health risks. One can be in debt and repay as and when, but once you have devastating conditions like microcephaly, there is no way – at least one we know of – that you can give back a healthy life to that child.
The International Olympics Committee and the WHO have joined the Brazilian Health Ministry in their denial. The WHO has yet to release a statement regarding the Olympics and Zika. Both the Centre for Disease Control and the World Health Organization recommend partners of reproductive age to delay any plans on reproduction. While this may be a viable plan for many couples, but for those who may be at a later stage in their lives, who after 2, 3 or 5 years may not be in the best position to expand their family, it puts them in a very difficult position.
Many of the bigger questions about Zika are being answered, but many continually rise up. Over 200 cases reported in the USA and one death related to Zika, the virus is on the move The Olympics will help to speed up the process and put many in danger. But what kind of danger? What exactly are the consequences for each individual? Research