In 2014, PediaBlog readers were introduced to a funny-sounding virus that was making people sick with high fevers, joint and muscle aches, headaches, and fever. Chikungunya — a mosquito-borne virus — appeared to have jumped from its known locations in sub-Saharan Africa, India, and Southeast Asia all the way to the islands of the Caribbean. Now, another mosquito-borne virus with an exotic name — Zika — has made its way across forests, deserts, and oceans to more adjacent locales, and into the news. Here are some basic facts about Zika virus:

  • It is spread by the same two species of mosquitos that also carry dengue virus, yellow fever virus, and Chikungunya.
  • The incubation period ranges from 3-12 days after the bite of an infected mosquito.
  • Infection with Zika virus usually results in no symptoms. (60-80% of infected people remain asymptomatic.)
  • Those who do get sick have mild symptoms — fever, rash, joint pain, headache, conjunctivitis — that quickly resolve with no treatment within a few days.
  • Complications, hospitalizations, and deaths have been extremely rare as a result of infection with Zika virus.
  • There is no specific treatment for Zika virus and no vaccine to prevent it.


Apparently, something happened to Zika virus when it spread from its tropical homes in Africa, India, and Asia to Central and South America. Maggie Fox says a recent outbreak in Brazil has been getting a lot of attention:

Zika’s strongly suspected of causing a severe birth defect called microcephaly, which causes underdevelopment of the head and brain. Babies with microcephaly often miscarry before they are born, or they die at birth. Those who survive are usually very disabled. Other viruses are known to cause microcephaly if a pregnant woman is infected – rubella is the most notorious. But Zika belongs to a family of viruses not known to cause birth defects and birth defects had not been noticed in countries that had Zika previously.


In recent months, Brazil has counted 3,500 new cases of microcephaly and public health investigators are pointing fingers at Zika virus. Last week, the CDC issued a travel alert for areas in Central and South America, and the Caribbean. Our “Travel-Ready M.D.” and Pediatric Alliance doctor Sarah Kohl agrees, advising her pediatric colleagues:

I for one, am specifically recommending that women of child bearing age avoid travel to 14 countries (Brazil, Colombia, El Salvador, French Guiana, Guatemala, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Suriname, Venezuela, and the Commonwealth of Puerto Rico) until more is known.

Especially if they are planning a pregnancy or are currently pregnant.

It’s just not worth the risk. There are plenty other places to visit while scientists get this Zika thing figured out. The stakes are just too high.

The problem is that travelers most likely to be affected are long-term travelers. People going ‘home’ to visit their friends and relatives. Or students studying abroad. They are in the age groups most likely to get pregnant.

They are also the group least likely to get pre-travel advice.


Dr. Kohl says the small and aggressive Aedis mosquitos need to be met with equally aggressive tactics like avoidance and the use of protective clothing and insect repellents. She has very practical advice for anyone wanting to avoid mosquito bites anywhere in the world:

Each morning as they are dressing for the day ask your patients to wear as much protective clothing as is comfortable. Long pants and sleeves can be a uncomfortable in the tropics, but encourage them to wear them anyway. Then apply effective repellent on all exposed skin. And reapply according to the instructions on the label.

Effective repellents in my opinion are ones proven to work with a minimum of applications ie apply once every 8-12 hours. I’ve never heard of a traveler able to apply a product successfully every 2-3 hours when traveling.

Suggest 20% Picardin or 30% DEET in a long-lasting formulation (ex. Sawyer or Ultrathon). Encourage your patients to treat their clothing with Permethrin for added protection. Fortunately Permethrin lasts 6 weeks or 6 washings, which is very convenient for extended travel.

Whenever possible, advise your patients to stay in air conditioning or in buildings with screens and doors.


Visit Dr. Sarah Kohl’s blog at and read more of her contributions to The PediaBlog here.


(Image: CDC — “Distribution map of Zika virus”)