BY ANABEL STAROSTA

Aedes_aegypti_CDC-Gathany
A. aegypti feeding on a human. Source: Wikipedia

We are no strangers to viral outbreaks and the panic they often incite. As new infections emerge, understanding their trajectories and risks is crucial. Currently, most countries in South and Central America are facing outbreaks of the Zika virus. The pandemic does not appear to be life threatening, but it is spreading quickly. The most concerning aspect of the Zika virus is its side effects; it is thought to be causing birth defects and increases in rare conditions. In order to address any threats with the necessary degree of precaution, it is important to understand what is known about the Zika virus.

Zika virus is an arthropod-borne viral disease that is transmitted mostly by mosquitoes and ticks. It was first observed in Uganda in the 1950s but remained obscure until recently.[1] In comparison to its previously low profile, the current rise in prevalence of Zika is both surprising and concerning. Zika is currently present in countries such as Mexico, Guatemala, El Salvador, Brazil, Venezuela, Colombia, Ecuador and many more of the surrounding countries. While countries, Brazil specifically, are trying to contain Zika by educating populations about prevention and looking for stagnant water sources where mosquitoes might breed, there is no clear-cut solution to Zika [2]. As a result, it is expected to continue spreading to more countries in North, South and Central America. However, officials believe that Zika will not be as prevalent in the United States due to the weather, living conditions, and already-implemented mosquito control measures in tropical places [3].

Typically, the immediate illness caused by Zika is not particularly severe. Its symptoms include fever, rash, joint pain, muscle pain, headache, and conjunctivitis. Zika’s mild symptoms result in infrequent hospitalization or death, and it is usually treated and cured with fluids, rest, and acetaminophen [4].

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Comparison of a baby with and without microcephaly. Source: Wikipidea

While Zika is not usually dangerous, the majority of concern arises from its potential effects on newborn children. After Zika emerged in Brazil, a 20-fold annual increase in microcephaly cases was observed [5]. Microcephaly is when a child is born with an abnormally small brain, which can result in developmental defects [7]. The connection between these brain defects in newborn children and Zika requires further study, but there appears to be a definite link based on the birth outcomes in Brazil. It is unknown whether Zika is transmitted from mother to child during pregnancy or upon birth, so it is recommended that pregnant women avoid travel to areas with where Zika virus transmission is ongoing [4]. Additionally, Zika may be linked to the rise in Guillain-Barré syndrome, a typically rare autoimmune disease, which causes muscle weakness and occasional paralysis [8]. Before the Zika outbreak, this syndrome was so rare that Brazil’s Health Ministry did not even require that officials report it. Now, however, Zika appears to be increasing the diagnosis rate of Guillain-Barré by twenty times the previous amount [6].

These findings are worrisome, and further investigations are required regarding both fetal brain development and Guillain-Barré syndrome. Currently, the C.D.C. is helping Brazil set up studies on affected children. Additionally, Zika may signify that arboviruses, transmitted by mosquitoes, are spreading past their remote ecological niches (Fauci and Morens). This will require adapted public health strategies to contain and treat emerging infectious diseases. For now, avoiding travel to pandemic countries is suggested, and the course and direct results of Zika remain to be seen.

Anabel Starosta is a pre-med student majoring in History of Science, Medicine and Public Health. She can be contacted at anabel.starosta@yale.edu

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References

  1. Fauci, Anthony; Morens, David. “Zika Virus in the Americas – Yet Another Arbovirus Threat.” New England Journal of Medicine, 13 Jan. 2016. Web. 05 Jan. 2016
  2.  Johnson, Reed; Jelmayer, Rogerio. “Brazil Struggles To Contain Zika Virus.” The Wall Street Journal. 18 Jan. 2016. Web. 29 Jan. 2016.
  3. Cohen, Elizabeth. “Halting the spread of Zika into the United States.” CNN. 26 Jan. 2016. Web. 29 Jan. 2016.
  4. “Zika Virus.” Centers for Disease Control. 24 Jan. 2016. Web. 25 Jan. 2016.
  5. Ventura, Camila; Maia, Mauricio. “Zika virus in Brazil and macular atrophy in child with microephaly.” Correspondence. The Lancet. 07 Jan. 2016. Web. 25 Jan. 2016.
  6. Romero, Simon; McNeil, Donald. “Zika Virus May be Linked to Surge in Rare Syndrome in Brazil.” The New York Times. 21 Jan. 2016. Web. 25 Jan. 2016
  7. “Facts about microcephaly,” Birth Defects. Centers for Disease Control. 20 Jan. 2016.Web. 29 Jan. 2016.
  8. “Guillain-Barré Syndrome and Flu Vaccine,” Influenza. Centers for Disease Control. 16 Oct. 2015. Web. 29 Jan. 2016.
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