Midland County News

Zika Virus Update

  • February 5 2016

Dr. Tammy Movsas, Medical Director
Midland County Health Department

I am alerting you to the recent CDC warning that pregnant women should avoid non-essential travel to any country with current Zika transmission (such South America, Central America, Caribbean, Puerto Rico and Mexico)  due to the  strongly suspected association of Zika-virus with microcephaly (fetal brain maldevelopment). Because of the seriousness of this rapidly emerging Zika epidemic, I will expand upon Zika in this newsletter. Please share this important information with patients, friends, family, colleagues and anyone else who who may benefit from it.

Though most of us had never heard of Zika virus before this year, Zika is not new and previous outbreaks of Zika have been reported in tropical Africa, Southeast Asia and the Pacific Island. It is transmitted to humans via the bite of an infected mosquito. In May 2015, The Pan American Health Organization issued an alert regarding the first confirmed Zika virus infection in Brazil.  Since that time the virus has been spreading like wildfire and has coincided with a tremendous increase in the number of babies born with microcephaly.  Currently, there are no known infected mosquitoes in the U.S. but the Aedes species of mosquito that can carry that Zika virus does lives in several U.S. states. Although >30 travelers have returned to the USA with Zika virus infections since 2015, the disease is not yet spreading locally in the continental USA.  Some infectious disease experts feel that the USA is less vulnerable to large mosquito-borne outbreaks than cities in Latin America, which are often more densely populated, with more trash on roads and in villages, less air conditioning and fewer window screens. Of note, the mosquito that carries the Zika virus is active all day long (unlike some of the other species of mosquitoes that are mostly active at dawn and dusk).    

Only  about 20% of those infected with Zika will develop any symptoms at all and those who do develop symptoms usually have only mild disease.  Typical symptoms include fever, rash, joint pain and conjunctivitis and symptoms usually begin 2-7 days after mosquito inoculation.  If a person has travelled to one of the Zika-infected countries and develops symptoms,  Tylenol can be given but NOT aspirin or other non-steroidal anti-inflammatories.  Aspirin and NSAIDs should be avoided until dengue (which can present with similar symptoms) is ruled out to reduce the risk of hemorrhaging.

Unlike West Nile Virus which is not usually transmitted to the fetus, Zika can be transmitted from mom to baby during any trimester. Thus, pregnant women should consider postponing travel to the areas where Zika virus transmission is ongoing.  If travel is essential, pregnant or nursing moms should choose an EPA registered insect repellent and use it according to the product label.  Zika virus usually remains in the blood of an infected person for only a few days to a week. The virus will not cause infections in an infant that is conceived after the virus is cleared from the blood. There is currently no evidence that Zika virus infection poses a risk of birth defects in future pregnancies.  At this time, Zika virus testing in asymptomatic pregnant women who have traveled to a country with Zika transmission is not recommended for the following reasons.  First, there can be false-positive results due to antibodies that are made against other related viruses. Second, we do not know if there is a risk to mothers who were infected with Zika but do not develop symptoms.

At the current time, there is no vaccine or antiviral treatment.  The best prevention is to use EPA-registered insect repellants and to follow the product label instructions.  If you are also using sunscreen, apply sunscreen before applying insect repellent.  Do not use insect repellant on babies younger than 2 months of age.  You should also treat clothing and gear with permethrin.  Keep in mind that treated clothing remains protective after multiple washings.  See product information to learn how long the protection will last.  Do not use permethrin products directly on skin;  permethrin products are only intended to treat clothing.  Also, sleep under a mosquito bed net if you are overseas or outside and are not able to protect yourself from mosquito bites.