The following article is a paid collaboration with ThermaCELL®, an effective mosquito repellent for the outdoors.
The Zika virus–spread by mosquitos and human sexual contact, and for which there is yet no cure–has spread to 55 countries, including 273 travel-associated cases in the United States, as reported by the CDC. Outbreaks could occur in as many as 50 U.S. cities, possibly bringing an increase in cases of a previously rare neurological disease and fatal birth defects, the latter characterized by underdevelopment of the brain.
That’s a truly scary prospect.
But it’s also true that 80 percent of those infected show no symptoms. Those that do may get a fever, bloodshot eyes, develop a rash, or feel joint pain for a few days after being bitten by an infected mosquito. Symptoms serious enough to require hospitalization are rare; death rarer still.
Nevertheless, infected people not showing symptoms remain carriers of the Zika virus. The spread of the Zika virus has proven especially devastating in Brazil, infecting as many as 1.3 million people, and is believed to have a causal role in more than 6,100 cases of microcephaly (abnormal smallness of the head) and 157 child deaths as of early March 2016.
That scenario is unlikely to repeat itself in the U.S., where living conditions are better for people than for the breeding of the offending mosquitos. Nevertheless, scientists are learning more about the Zika virus every day, and how to protect against it. Here are 5 things you should know about the virus.
1. How the Zika virus spreads and the devastation it may bring
The Aedes species of mosquito that spreads the virus, as well as the dengue and chikungunya viruses, doesn’t travel more than a mile from its birthplace and bites only during the day. So humans, particularly world travelers—not unlike whomever brought the virus to Brazil, possibly from French Polynesia on the occasion of the 2014 World Cup—are most susceptible and the likeliest to advance the contagion.
Sexual transmission of the virus, seemingly only from men to women through intercourse, is considered rare but of particular concern if a pregnancy is involved. The link researchers are finding between the Zika virus in women with fetuses afflicted with microcephaly and Guillain-Barre syndrome, a rare sickness of the nervous system that can cause paralysis, has prompted health officials in several countries to urge women to put off pregnancy so long as the scourge is present.
Dallas County, TX, health officials reported in early February that one of three confirmed cases of Zika virus infection was sexual transmitted. The other two patients contracted the virus while in Honduras and Venezuela.
The CDC advises women to refrain from having sex with men who live in, or have traveled to, countries with Zika. “While it is not known if infected men who never develop symptoms can transmit Zika virus through sex,” the CDC states, “the virus can be spread before, during, and after men have symptoms. The virus can be present in semen longer than in blood.”
2. International trade has helped the culprits spread
The Aedes aegypti species of mosquito in Africa and Aedes albopictus mosquito found in Asia spreads the Zika virus as well as the dengue, yellow fever, and chikungunya viruses. While they’re unable to fly on their own much more than a mile from their birthplace, they are believed to have been transported in water containers via international trade and adapted to more temperate climates. Aedes mosquitoes bite only during the day, making insect repelling strategies more effective than netting.
Populations of these mosquitos can be found in the United States, primarily in the Southeast, but it will take travelers infected outside the country to be bitten by local Aedes mosquitoes for the virus to spread.
3. It’s been in existence for nearly 70 years, only now it spreads worldwide
The virus was named after the Zika Forest in Uganda, where it was first identified in 1947. But because its unremarkable symptoms mimicked other maladies, there were only 14 documented cases of the Zika virus as of 2007, and no known hospitalizations prior to 2013.
Dozens of cases of Zika rashes and fever have been confirmed in the United States, but nearly all of them in people who were infected in other countries.
Six months after the virus first took hold in Brazil, a 48-year-old New Yorker returned from a trip there and several other south American countries. Feeling ill, he sought medical attention. And while a nurse practitioner was initially doubtful, the man correctly diagnosed himself as having the Zika virus based on news coverage he read during his travels.
That man, who asked not to be identified by the New York Times which interviewed him, was the first documented case of the virus in the U.S. That was in December 2013.
According to the World Health Organization, which declared a public health emergency on February 1, the Zika virus has now been transmitted to 33 countries in the Americas and 55 countries and territories worldwide.
4. Zika isn’t the only, or most deadly, disease borne by mosquitoes
While Zika dominates the news, the spread of Dengue Fever in Asia is being categorized as an epidemic. And cases of Chikungunya, spread by the same mosquito species, are popping up in New Zealand and neighboring islands.
Malaria remains the deadliest of the mosquito-borne diseases, still killing 40 percent of its victims. But because malaria, most prevalent in sub-Saharan Africa, is carried by Anopheles mosquitoes that bite at night, bed nets are an effective prevention method. To ward off Aedes mosquitos, the day-biting Zika virus spreaders, the use of insect repellent and protective clothing is advised.
5. How to Best Protect Yourself from Zika
Since no vaccine exists to prevent the Zika virus, the best prevention is to avoid getting bitten by mosquitos where they’re known to be carrying the virus.
Wearing long-sleeved shirts and pants and using insect repellents is advised, as is wearing clothes treated with the insecticide permethrin when outdoors.
Consumer Reports tested several mosquito repellents and found the most effective to contain more than 5 percent of the chemical picaridin and 7 percent deet. The organization did not recommend products containing natural plant oils.
In a CDC report titled “The Pre-Travel Consultation: Counseling & Advice for Travelers,” several means of protection against mosquitoes are listed, including spatial repellents or appliances that disperse insecticide to temporarily clear a small outside deck or backyard of annoying bugs.
The CDC paper says such devices, especially those that use metofluthrin and allethrin as repellents, are most effective when they supplement repellents applied to the skin or in clothing. Thermacell lanterns, for instance, vaporize allethrin, which is a synthetic copy of the active ingredient in chrysanthemum flowers that repels mosquitoes, black flies, and no-see-ums.
Visit the CDC’s “Zika Travel Information” website for the most up-to-date list of countries with confirmed cases of Zika transmission, and other useful information.