Summer is upon us, and that means the weather’s warm, school is out and families will be spending more time in the backyard. It also means the return of mosquitos, the pesky insects that love to bite us. A mosquito bite is usually just a nuisance, causing itching or some minor pain. But occasionally, a mosquito bite can be dangerous, as these insects can carry two serious viruses: West Nile and Zika.
West Nile Virus
West Nile virus is transmitted when mosquitos bite birds that are infected with the disease. A carrier mosquito can, in turn, infect other birds. Mosquitos can also spread the virus to mammals, including horses and humans, which are considered “dead-end” hosts. That means there is not enough of the virus in the mammal’s blood stream to spread to other mosquitos through subsequent bites.
West Nile Symptoms & Treatment
The good news is that most people who are infected with West Nile will never know it; the virus produces no symptoms in up to 80 percent of people who get it. In roughly 20 percent of cases, symptoms present, says Dr. Jeffrey Tessier, an infectious disease specialist. “West Nile virus symptoms include body aches, headaches, diarrhea, vomiting and rash,” he says. “If you experience any of these symptoms, you should make an appointment to see your doctor. While symptoms are likely to subside, fatigue and weakness can persist for months, so it’s important to get checked out.”
For a small number of people who are infected – less than one percent – West Nile virus leads to serious neurological illness, such as meningitis or encephalitis, both of which cause inflammation of the brain. Permanent brain damage is possible in these cases and around 10 percent of people who get this form of West Nile will die as a result. People over the age of 60 are most at risk.
There is no vaccine to prevent West Nile, nor is there a cure. For people who develop body aches and associated symptoms, a doctor may recommend pain relievers, such as ibuprofen or acetaminophen. For severe cases, hospitalization may be necessary.
Just like West Nile virus, Zika virus is spread primarily through mosquito bites. Zika is usually transmitted through the bite of an Aedes species mosquito, known for aggressive biting during daytime hours, although it can also bite at night. However, unlike West Nile, Zika can also be transmitted through sex.
As is also the case with West Nile, many people who are infected with Zika will experience no symptoms at all. When Zika does cause symptoms, they are generally mild and include fever, rash, joint pain, muscle pain, conjunctivitis (“pink eye”) and headache. These symptoms can last for up to one week. Just as with West Nile, there is not yet a vaccine or cure for Zika virus.
Zika poses the greatest danger to women who are pregnant or may become pregnant – the virus has been determined to cause serious birth defects, so expectant mothers must take special care to protect themselves from Zika.
Zika Risk to Pregnant Women
Zika virus is associated with a birth defect known as microcephaly, in which the baby’s head is smaller than it should be and the brain may be underdeveloped. Zika can cause other birth defects, including additional brain abnormalities, eye problems, hearing loss and impaired growth. A Zika infection does not automatically mean these things will happen, but it does increase the risk.
“As a precaution, all pregnant women should be evaluated for possible Zika exposure at every pre-natal care visit,” says Dr. William Maxwell, an OB/GYN. “In the unlikely event Zika is present, we need to know as soon as possible.”
Additional Zika Precautions
The U.S. Centers for Disease Control and Prevention (CDC) recommends additional precautions specific to Zika virus:
If you are pregnant, do not travel to an area in which Zika transmissions have been reported. Check the CDC website for countries, territories and cities affected by Zika before planning travel. In the continental United States, two areas of the country reported cases of Zika that were confirmed to have been caused by local transmission in 2016: Miami-Dade County in Florida and Brownsville, Texas.
The CDC recommends pregnant women “consider postponing travel” to these areas, although there has not been widespread transmission of the disease in either location. Further, the CDC recommends that any woman who is pregnant and traveled to Miami-Dade County after August 1, 2016 or to Brownsville, Texas after October 29, 2016 be tested for Zika.
Since Zika can be transmitted through sex, people who have traveled to an area with Zika, or who are partners with someone who has, need to take extra precautions. Even if the person who has traveled has not been diagnosed with Zika and is not experiencing symptoms, the CDC advises:
If your partner is pregnant, use a condom during all types of sex (including vaginal, oral and anal sex) for the entire duration of the pregnancy or abstain from sex throughout the pregnancy.
If you and your partner are planning a pregnancy: visit with your physician first.
If you or your partner are not pregnant and not planning a pregnancy, precautions are still advisable. For those who have symptoms or have been diagnosed, the CDC suggests men use condoms or abstain from sex for six months after symptoms began. Women should consider using condoms or abstaining for eight weeks after symptoms began.
For men and women who have traveled to a Zika area but have not been diagnosed or shown any symptoms, the CDC suggests using condoms or abstaining for eight weeks after travel.
“Because Zika has been linked to serious birth defects, it is highly advisable to take all of these precautions to minimize risk to a pregnancy,” says Dr. Brian Welsh, an OB/GYN.
Reducing Your Risk of West Nile & Zika
Since West Nile and most cases of Zika virus are caused by mosquitos, avoiding mosquito bites is the most important thing we can do to reduce risk.
Using insect repellant when outdoors is crucial. To make sure you are using a repellent that is proven to be effective, check to see that it contains one of these ingredients:
Oil of lemon eucalyptus (OLE)/para-menthane-diol (PMD)
NOTE: Do not use insect repellants on babies under two months old and do not use repellants containing OLE or PMD on children under three years of age.
“Remember, you don’t have to choose between sunburn and mosquito bites – you can prevent both! It is perfectly safe and effective to use insect repellant and sunscreen at the same time,” says Dr. Lynne Tilkin, a primary care physician.
Mosquitos will breed anywhere there is standing water. You can reduce opportunities for mosquitos to breed near your house by turning over any pots or containers that hold standing water and filling in low spots in the ground. Eliminating standing water is an important step to reduce the spread of Zika and West Nile.
If your summer plans include an extended period of time outdoors – such as camping and hiking – treat your clothes and gear with permethrin, an insecticide. You can also purchase items pre-treated with permethrin.
Stay Safe this Summer!
By taking the simple precautions discussed above, you can greatly reduce your risk of West Nile and Zika this summer. You’ll also be better able to enjoy the outdoors when you’re not getting eaten alive by mosquitos!
For more information on summertime health and safety, see our June, 2016 article.
This article contains information sourced from: