The Zika Environment-What to Know Now

Today I am introducing a new column from author and infectious disease guru Dr. Wink Weinberg. I have known the good doctor for over 35 years and he is my go to guy when it comes to Travel and Infectious Disease. He will be addressing current travel topics on Green With Renvy and begins with the headline grabbing  zika environment.

The Zika Environment-What to Know Now

There is a lot of information to process about Zika virus. You know that it has caused an explosive epidemic in Latin America. There are some other thoughts about Zika that might be more nebulous in your mind. You might be muddled about insecticides, sexual transmission, complications from the infection if you are not pregnant, and whether Zika virus is going to spread to your home city. Let me try to clear some of that up for you, as far as we know right now.

There are two things about insecticides and insect repellants that you might have questions about. First, accusations were made in Brazil that certain insecticides might cause microcephaly. In fact, microcephaly after Zika virus infection is due to growth of the virus in the brain of the fetus; it is not due to the inhalation of toxic vapors. Second, many people do not like insect repellants containing DEET. (I don’t like applying DEET myself, and we all know it’s relationship to the environment.) But there is no good alternative.

There are no personal mosquito-deterring products that work half as well as DEET. To avoid that chemical smell, greasy feel and any toxicity, try the following. Never spray insect repellants near mouth and nose. Light, loose-fitting, covering clothing is a great strategy for avoiding mosquito bites, and then the repellant can be applied to the clothes. Lower concentrations applied more frequently may work better for you.

A 6% solution of DEET will need to be re-applied in 1-2 hours and a 28% containing product lasts 5-6 hours. Insect repellants go over sunscreens, and not the other way around.

Now, let’s discuss sex! Although 99.9% of Zika virus infections are acquired by the bite of an Aedes mosquito, Zika virus can also be spread during sex. In this case, a man infected with Zika virus may spread the infection to his sex partners. In this way, pregnant women can expose their developing child to the virus without entering a country where there is active transmission. If you are a man who was diagnosed with Zika (or just had an undiagnosed fever after traveling anywhere south of the 50 states) you should protect your sexual partners for 6 months. If your partner is pregnant, you should follow these precautions even if you were not sick when you were in an active transmission zone, because not every Zika infection causes symptoms.

A typical case of the virus infection is not so bad, not when you compare it to dengue, chikungunya, or yellow fever – some of the other viral infections transmitted by Aedes mosquitoes. Most people infected with Zika virus won’t even know they have the disease because they won’t have symptoms at all. The most common symptoms of Zika are fever, rash, joint pain, and red eyes. Other common symptoms include muscle pain and headache. The illness is usually mild with symptoms lasting for several days to a week.

However mild the infection is, two dreaded complications may follow. One, of course, is microcephaly or other fetal developmental abnormalities. The other has nothing to do with pregnancy; it is a form of weakness or paralysis called Guillain–Barré syndrome . GBS has already followed Zika virus infection in 100 Columbians and about 10 U.S. citizens in Puerto Rico. The numbers are sure to rise.

If there is any good news about the Zika virus epidemic, it is that it is not likely that you will ever catch Zika virus in your home town if you live in the 50 U.S. states. (This is not true for Puerto Rico and some other U.S. territories.) You may have heard from government announcements that the States should be prepared for a Zika epidemic, and there is nothing wrong with preparedness. However, chikungunya and dengue viruses are transmitted in a very similar manner to Zika and those epidemics have not marched northward through the U.S. (A rare case of dengue may have been acquired in South Texas and South Florida.)

The main reason most mosquito-borne diseases don’t get established in the U.S. is that we get less mosquito bites. We spend less time outdoors; we are more likely to have screens on open windows; and we spend more time in air-conditioned buildings than people do in Latin America. Global warming in the environment is not going to change this.

West Nile virus is a mosquito-borne disease that did spread around the States. The difference with West Nile is that it lives in birds, too, and birds carried the virus around the country and brought it into proximity to people who might be spending time out of doors. Birds are a “reservoir” of West Nile virus, but Zika (and chikungunya, dengue, and yellow fever) have no reservoir in the States.

Knowledge is power. I hope I have helped you gain some power over the Zika virus.

Dr. Weinberg and his wife, Lynn, hiking in Iceland.

Wink Weinberg has been a practicing Infectious Disease specialist for over 30 years. He is certified by the International Society of Travel Medicine and has written extensively about travelers health, including his information filled book “No Germs Allowed”. In his spare time he enjoys traveling, woodworking, raising bonsai, exercising and grand-parenting.

Would the current Zika environment change your travel plans?