What Is Zika Virus?
It was identified in 1947, in the Zika forests in Uganda, in the blood of a rhesus monkey. For decades thereafter, it barely bothered humans. Between 2010 and 2014, there were an average of 160 cases per year.
By May 2015, the virus that had possibly arrived with a tourist during the World Cup in 2014 had quickly spread through Brazil. As of February 2016, health officials have already reported 3,530 cases: the first big outbreak erupted on Yap Island in Micronesia and brought 49 deaths. Currently, more than 23 countries are seized by Zika.
On Tuesday, the Centers for Disease Control and Prevention confirmed a case of sexual transmission of the disease in Texas: a person spread the virus to his sexual partner after contracting it abroad. The case confirmed the scientists’ assumptions that Zika could be sexually transmitted but they still do not know whether women can pass Zika to men through sex. However, they urge people to use condoms in order to protect themselves and their sexual partners as well.
The illness caused by the virus is usually mild. Fortunately, symptoms, if they appear at all—fever, joint pain, rash, and conjunctivitis—last for up to 7-10 days. Most infected do not even realize that they are ill. The CDC director Tom Frieden argues that for most people there is no reason to think that Zika presents a particular risk. However, researchers found that some infected people, particularly from Brazil and French Polynesia, were later diagnosed with Gullian-Barre Syndrome, a rare neurological disease in which an immune system takes its own nerve cells as foreign and aggressively attacks them. It leads to muscle weakness and paralysis in adults. Some epidemiologists think that Zika’s invisibility makes the pathogen more dangerous.
What has raised the alarm is its strong link to microcephaly, a rare and potentially deadly birth defect. If a pregnant woman is infected, her child could be born with an abnormally small head and an incompletely developed brain. Since Zika was found in Brazil in 2015, nearly 4,000 cases of microcephaly have been reported. However, the evidence linking Zika to microcephaly is circumstantial.