The Zika virus was first isolated from a Rhesus Macaque monkey in 1947 in the Zika Forest in Uganda (zika meaning “overgrown” in the Luganda language–gotta love useless trivia!); it was first isolated from a human in 1954 in Nigeria. It appeared sporadically along the equator in Africa and Asia for several decades until it spread to French Polynesia in 2013 and then to Latin America, Mexico, the Caribbean, and now the US.
Illness from Zika was rare until the pandemic began in 2007. The illness it caused was mild and self-limited until October 2015, when we began to see babies with microcephaly (very small brains) born to mothers who had been infected while pregnant. New evidence shows that these babies may also have eye abnormalities that will effect their vision.
There have now been more than 1500 cases of microcephaly in Brazil; in the most severe areas the incidence has been as high as 1:100 births. On August 15, 2016 a state of emergency was declared in Puerto Rico, where they now have 10,690 confirmed Zika cases, including 1,035 pregnant women. Currently, more than 500 pregnant women in the US have shown evidence of a possible Zika infection.
Zika is a flavivirus related to Dengue, Chikungunya, and West Nile encephalitis. It is transmitted by several species of Aedes mosquitos which can, after biting an infected human, infect another person. Transmission has also been reported through blood transfusions and sexual contact.
The newly infected person may not have any symptoms at all, or may develop symptoms of illness within 2 weeks: fever, a bumpy red rash, sore joints, and pink eye. Less common symptoms include aching muscles, headache, and vomiting. The illness itself is usually mild and self limited.
There is no preventative vaccine available yet and no treatment, other than pushing fluids, resting, and treating the symptoms with acetaminophen (Tylenol). The ill person should not take aspirin, ibuprofen (Motrin, Advil), or naproxen (Aleve) until Dengue fever is ruled out, to avoid the risk of bleeding.
Where is it?
As of now, local transmission has been reported in more than 50 countries and territories. Current recommendations are that women who are pregnant, especially in their first trimester, do not travel to any of these areas. If they have to travel, they should do what they can to protect themselves from mosquito bites: wear long pants and long sleeved shirts, preferably treated with permethrin insect repellant; sleep in air conditioned rooms, screened in areas or with permethrin treated mosquito nets; and wear insect repellant, because these mosquitos are active during the daytime.
If you do travel to these areas and develop the symptoms of Zika after returning home, pregnant or not, see your doctor. Avoid mosquitos for the first few days, so that you will not be the source of spreading infection.
Men who have had Zika should use barriers during sex for at least 6 months after the infection; women for 8 weeks. Use of a barrier is recommended for at least 8 weeks after travel to endemic areas even if you have no symptoms.
As of today, we have had 1962 confirmed cases of the infection in the US, with 413 in Florida. Twenty eight of those were caught from local mosquitos. We have the Aedes mosquito along our southern coast and in southern California.
In all likelihood the same measures we used to contain Denque in the US will contain Zika, but its spread is still possible. Taking precautions is certainly sensible.
- Get rid of standing, stagnant water.
- Clean up piles of garbage, because mosquitos love to breed in trash.
- Put up or repair your window screens.
Another possibility to limit spread of the infection is releasing GMO mosquitos with a lethal gene, to decrease the population of the bugs. When this was done in the Caman Islands the mosquito population decreased by 80%.
If you are pregnant, stay out of the endemic areas when possible. Take sensible precautions: clean up standing water and trash, put up or repair window screens, and wear insect repellant.
And keep an eye out for current recommendations from public health officials, because the places and numbers change daily.