Zika Virus: A Case Study in the Importance of Ntd Research

While you may have heard about it only recently, the infamous Zika virus was first discovered back in 1947. Scientists researching yellow fever in Uganda identified the new virus in a rhesus monkey in the Zika forest (hence the name "Zika" virus). The first human case was detected in Nigeria in 1954, followed by decades of relatively rare outbreaks in Africa and Southeast Asia. It wasn’t until 2007 that the first large Zika outbreak took place in the Pacific Island of Yap in Micronesia, which led to over 70 percent of the island residents being infected by the virus. Since then, there have been many outbreaks throughout different parts of the world.

Unlike many diseases which primarily rely on airborne transmission, Zika spreads from person to person via the bite of infected Aedes mosquitoes. Zika has also been shown to transmit through sexual contact as well as blood transfusions. Surprisingly, while symptoms of Zika include fevers, headaches, joint pain, and skin rashes, only 1 in 5 people infected actually develop these symptoms. As a result, many people may be infected without actually realizing it. Accurate diagnosis of Zika virus can be done via lab tests on body fluids (i.e. blood, saliva, urine). While there is currently no cure for Zika, the disease is usually mild enough to only require some rest, fluids, and pain/fever medicines as needed.

Given the relatively low likelihood of developing such mild symptoms, what is the big deal behind Zika? It turns out that Zika can be transmitted from a pregnant mother to her offspring, and this can lead to a number of devastating birth defects. Most prominently, Zika has been shown to cause offspring microcephaly – a brain abnormality that leads to intellectual disability, reduced head size, and in more severe cases, death. Currently, scientists are trying to understand the link between Zika and microcephaly. While a vaccine is still in development, preventative measures are already being put in place to reduce exposure to mosquitoes that could be spreading the virus.

It’s been over 60 years since Zika was first detected in humans, and yet extensive research into the virus started only recently. Why did it take so long? Just as with the Ebola virus, Zika only affected small populations in less developed regions around the world, which meant that there wasn’t a sufficient economic incentive to intervene at the time. It is only when these viruses started affecting more developed areas (i.e. North America and Europe) that governments decided to intervene. Moving forward, neglected diseases need to be researched when they are first discovered, as this is the only way to be able to successfully combat these diseases before it is too late.

BBC News: http://www.bbc.com/news/health-35370848

World Health Organization: http://www.who.int/mediacentre/factsheets/zika/en/

Centers for Disease Control and Prevention: https://www.cdc.gov/zika/