Zika and the Olympics

The Opening Ceremony of the 2016 Summer Olympics will be held today in Rio de Janeiro, Brazil. Unfortunately, Brazil is currently in the midst of a Zika virus outbreak and the “Zika infection is more dangerous, and Brazil’s outbreak more extensive” than originally thought.1

Although the Zika virus was discovered nearly seventy years ago, the viral strain that recently entered Brazil is new, different, and vastly more dangerous than “old” Zika.2 Lineage tracing and molecular analyses have determined that Brazil’s massive outbreak stems from a single viral introduction likely between May and December 2013.2

The Virus:

Zika is an arbovirus of the Flaviviridae family, which means it is similar to dengue, West Nile and yellow fever viruses.3 As a virus it cannot function outside of a living cell. While there is limited evidence that Zika can infect monkeys and apes, currently, all evidence suggests that the virus is passed from human to human via the Aedes aegypti mosquito. The map above shows where these mosquitos are found which also represents where Zika virus could spread.4

The Disease:

Zika infection is most notorious for the pediatric microcephaly (small head) it causes during fetal development.5 In Rio de Janeiro, a recent study shows that among women with confirmed Zika infections during pregnancy, 29% had fetal abnormalities on ultrasound.6 There’s increasing clinical evidence that Zika infection is also responsible for adult conditions such as Guillain-Barré syndrome7 and acute disseminated encephalomyelitis (brain swelling), which are debilitating and sometimes fatal.8

Zika and the Olympics:

Rio de Janeiro’s suspected Zika cases are the highest of any state in in Brazil (26,000), and its Zika incidence rate is the fourth worst of any state (157 per 100,000).9

An estimated 500,000 foreign tourists are expected to flock into Rio de Janeiro, Brazil for the Games, both from the 207 countries participating and others that are not. When these individuals return to their homes both local Aedes mosquitoes and sexual transmission could establish new outbreaks, if the visitors carry the virus with them.10, 11

In addition to that there are concerns for the safety of the athletes participating in the Games. Out of fear of contracting Zika, many of the top ranked male golfers have withdrawn from the Olympic entirely.12 Australia has provided its athletes with antiviral condoms.13 The American National Institutes of Health has recruited athletes into a study looking at the rates and effects of exposure.14

The International Olympic Committee (IOC) writes that the Olympics seek to create “social responsibility and respect for universal fundamental ethical principles”.  People have questioned if it is socially responsible or ethical to risk spreading Zika? Especially considering that, while the people who fly to Brazil to see the games have chosen to expose themselves the people they return to have not made that choice. There were viable alternatives. Historically, the 1976 Winter Olympics were moved, and the 1994 Winter Olympics broke with the regular schedule.  London, Beijing, Athens and Sydney still possess useable Olympic facilities to take over from Rio.  Since the IOC decided in 2014 that the Olympics could be shared between countries, sporting events could even be split between them making this the first transcontinental, truly Global Olympics.15


Zika can cause a lifelong devastating brain malformation in a developing fetus and debilitating Guillain-Barré syndrome in adults. The most recent figures show that there are 157 cases per 100,000 people in Rio de Jenairo.9 With at least 500,000 people expected to come for the Olympics that could equate to 785 cases of Zika which could be transmitted to areas that have not been infected.

It has been suggested that since the Olympics will be held during Brazil’s winter, there won’t be any of the Aedes aegypti mosquito to transmit the virus. However, this year cases of dengue virus (a closely related virus transmitted by the same mosquito) have been six-fold higher than a year ago (8,133 cases, compared to 1,285 cases).16, 17 While there is obviously a risk of infecting participants, spectators, and, through them, spreading the virus to other areas of the world, the World Health Organization (WHO) has released a statement that “cancelling or changing the location of the 2016 Olympics will not significantly alter the international spread of Zika virus” as Brazil is only “1 of almost 60 countries and territories which to date report continuing transmission of Zika by mosquitoes” but advises “pregnant women not to travel to areas with ongoing Zika virus transmission, including Rio de Janeiro”.18

Zika research is already on the fast track, and with time, the odds are excellent that scientists can develop, test, and prove an effective Zika vaccine, antiviral drug, insecticide, or genetically-engineered mosquito. Unfortunately, science needs time.

The Olympic village is already filling up with athletes and only time will tell if the games will be affected by this Zika epidemic.

The Science Aces would like to wish all of the athletes, supporters, spectators and citizens of the area a safe and exciting Olympic Games!


[1]Amir Attaran. Off the Podium: Why Public Health Concerns for Global Spread of Zika Virus Means That Rio de Janeiro’s 2016 Olympic Games Must Not Proceed. Harvard Public Health Review. Retrieved June 29, 2016.

[2] Faria NR, do Socorro da Silva Azebedo R, Kraemer MUG, et al. Zika virus in the Americas: Early epidemiological and genetic findings. Science. Published online March 24, 2016.  DOI: 10.1126/science.aaf5036

[3] Hamel R, Dejarnac O, Wichit S, Ekchariyawat P, Neyret A, Luplertlop N, Perera-Lecoin M, Surasombatpattana P, Talignani L, Thomas F, Cao-Lormeau V, Choumet V, Briant L, Desprès P, Amara A, Yssel H, Misséa D. Biology of Zika Virus Infection in Human Skin Cells. Journal of Virology 2015; doi:10.1128/JVI.00354-15

[4] Centers for Disease Control and Prevention. Zika and Animals. Available at: http://www.cdc.gov/zika/transmission/qa-animals.html.

[5] Rasmussen SA, Jamieson DJ, Honein MA, Petersen LR. Zika Virus and Birth Defects — Reviewing the Evidence for Causality. NEJM 2016; DOI: 10.1056/NEJMsr1604338.

[6] Brasil P, Pereira JP Jr, Raja Gabaglia C, et al. Zika virus infection in pregnant women in Rio de Janeiro — preliminary report. NEJM 2016; DOI: 10.1056/NEJMoa1602412

[7] Cao-Lormeau V-M, Blake A, Mons S, et al. Guillain-Barré Syndrome outbreak associated with Zika virus infection in French Polynesia: a case-control study. Lancet 2016; 387:1531-39.

[8] Brito Ferreira ML. Neurologic Manifestations of Arboviruses in the Epidemic in Pernambuco, Brazil. Abstract presented at the 68th Annual Meeting of the American Academy of Neurology, April 10, 2016. Available at: https://www.aan.com/PressRoom/home/GetDigitalAsset/12033.

[9] Ministério da Saúde, Secretaria de Vigilância em Saúde. Boletim Epidemiológico 2016;47(18). Available at: http://portalsaude.saude.gov.br/images/pdf/2016/abril/27/2016-014—Dengue-SE13-substitui—-o.pdf

[10] Oster AM, Russel K, Stryker JE, Friedman MS, et al. Update: Interim Guidance for Prevention of Sexual Transmission of Zika Virus — United States, 2016. MMWR 2016;65(12):323-5.

[11] Petersen LR, Jamieson DJ, Powers AM, Honein MA. Zika virus. NEJM 2016;374:1552-63.

[12] Kyle Porter. 2016 Rio Olympics: A list of all the golfers who will not compete this summer. CBSSports. July 11, 2016

[13] Australian Olympic Committee. Australian Team taking Dual Protect™ VivaGel® Condoms to Rio. Available at: http://rio2016.olympics.com.au/news/australian-team-taking-dual-protect-vivagel-condoms-to-rio. May 16, 2016

[14] National Institute of Child Health and Human Development. NIH funds Zika Virus study involving U.S. Olympic Team. Available at: https://www.nichd.nih.gov/news/releases/Pages/070516-zika-olympics.aspx. Published July 5, 2016.

[15] Associated Press. I.O.C. Approves Sweeping Reform Package. New York Times December 8, 2014. Available at: http://www.nytimes.com/2014/12/09/sports/olympics/ioc-approves-tv-channel-and-changes-in-bidding-process.html

[16] Prefeitura da Cidade do Rio de Janeiro, Superintendência de Vigilância em Saúde. Número de Casos de Dengue por mês, 2016.  Available at: http://www.rio.rj.gov.br/dlstatic/10112/6062171/4159109/denguenotificadosexcetodescartadosMes_2016_21_03_2016.htm

[17] Prefeitura da Cidade do Rio de Janeiro, Superintendência de Vigilância em Saúde. Número de Casos de Dengue por mês, 2015.  Available at: http://www.rio.rj.gov.br/dlstatic/10112/5880996/4153672/denguenotificadosexcetodescartadosMes2015_25_01_2016.htm

[18] World Health Organization. WHO public health advice regarding the Olympics and Zika. Available at: http://www.who.int/mediacentre/news/releases/2016/zika-health-advice-olympics/en/. Published May 28, 2016. Retrieved June 29, 2016.

Christina is a Ph.D. candidate studying the interactions between gut bacteria and the human intestine. She is pursuing a career teaching undergraduates.

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