The Zika virus is a virus spread by mosquitoes, and when a pregnant woman is infected, complications to the unborn child can occur, such as microcephaly and other defects. The virus became prominent in the west following an outbreak in 2016, resulting in the spread of the virus being considered an epidemic by the CDC.
Signs and Symptoms
The most common signs and symptoms of the Zika virus would be evident of a mosquito bite, followed by fever, headache, rash, muscle pain, and joint pain. The effects of Zika are generally mild, and many people may not realize that they have become infected. The symptoms are most similar to dengue fever. Zika is not fatal, but the main risk is for pregnant women due to the complications it can cause (Honein et al., 2016).
Pathogen
The pathogen responsible for causing Zika is a single-stranded RNA virus from the Flaviviridae family. The pathogen exists within Aedes mosquitoes, where it is transmitted to humans via a mosquito bite (Honein et al., 2016).
Virulence Factors
The Zika virus attaches itself to the surface of protein E and AXL receptors when transmitted through a bite. Zika is easily transmittable, and does not require specific conditions for it to take root after a bite has occurred (Gubler et al., 2017).
Description
The Zika virus is spread most commonly from the bite of an infected mosquito. While the actual symptoms might be mild, the significance of the virus is that it can cause severe birth defects for unborn children of pregnant women. Non-pregnant women and men do not normally need to be concerned with any long-term repercussions of the disease, but because of the birth defects it can cause, and the difficulty in protecting against mosquito bites, the disease is considered dangerous (CDC, 2018).
Ecology
Zika virus is most present in areas where Aedes mosquitoes live, which would be tropical regions or equatorial regions. Mosquitos most commonly live near stagnant bodies of water. It is currently present in western Africa, Mexico, the Caribbean, Central America, and the northern half of South America. As of 2018, there have been no reports of Zika virus in the continental United States (CDC, 2018).
Host Response
The Zika virus is believed to enter the bloodstream following a mosquito bite, where it will then enter the lymph nodes. From here, the host response is to release white blood cells to fight the infection. The process is similar to other forms of mild fever, in that the host’s immune response will work to fight the virus internally (CDC, 2018).
Epidemiology
Zika was first identified in Uganda within monkeys in 1947, and later observed in humans in Tanzania in 1952. Not much else was observed until 2007, when an outbreak occurred in Micronesia, followed by an outbreak in the Pacific Islands in 2013. Zika was previously considered relatively harmless, but the 2013 outbreak saw a correlation with birth defects. In 2015, the virus was observed to have spread to Brazil and Latin America, with a few cases observed in southern U.S. states in 2016 (Gubler et al., 2017).
Diagnosis, Treatment and Prevention
Zika will be diagnosed following evidence of associated symptoms such as rash or fever, at which point a blood sample can reveal the presence of Zika. For those who are not pregnant, treatment generally involves rest until the body’s immune system is able to fend off the disease, similar to other fevers. There is currently no vaccine for Zika. Preventing Zika will involve avoiding areas where a known outbreak has occurred, and wearing protective clothing or using mosquito nets to avoid being bitten. Preventing Zika therefore involves avoiding bites from infected mosquitos, so it can be difficult to prevent if traveling in a region where an outbreak has occurred, as even one bite can cause infection.
- CDC. (2018). Zika Virus. Accessible online at http://www.cdc.gov/
- Gubler, D. J., Vasilakis, N., & Musso, D. (2017). History and emergence of Zika virus. The Journal of infectious diseases, 216, S860-S867.
- Honein, M. A., Dawson, A. L., Petersen, E. E., Jones, A. M., Lee, E. H., Yazdy, M. M., … & Ellington, S. R. (2017). Birth defects among fetuses and infants of US women with evidence of possible Zika virus infection during pregnancy. Jama, 317(1), 59-68.
