Mosquito bites may do more than bug you – they can make you sick

Mar 10, 2016 by Keith Murray

Besides being pests, mosquitoes can carry and transmit numerous diseases.  The U.S. Centers for Disease Control (CDC) reports that mosquitoes kill more than one million people a year through the transmission of malaria.

This, coupled with the large number of people sickened and killed by other mosquito related diseases such as dengue fever, yellow fever and West Nile virus (WNV) and you have a very nasty, dangerous little insect.

Recently, the Zika virus has been making the news.  According to the CDC, the Zika virus is spread to people through mosquito bites. The most common symptoms of Zika virus disease are fever, rash, joint pain, and conjunctivitis (red eyes). The illness is usually mild with symptoms lasting from several days to a week.  However, in women that are pregnant, the disease has been linked to birth defects.

Brazil, which has been hardest hit by Zika, indicated that 4,074 cases of infants with severe birth defects could be linked to the mosquito-borne virus.

Originally thought to only be transmitted through mosquitos, a person in Dallas, Texas is thought to have been infected by sexual contact with their partner who had returned from Venezuela, where Zika is active, according to the CDC.

There is no vaccine to prevent Zika, so it is important to prevent mosquito bites. Due to the potential risk of birth defects.

Dengue,  another mosquito borne disease has also been receiving a lot of media attention.  Dengue is a mosquito-borne infection that causes a severe flu-like illness, and sometimes a potentially lethal complication called dengue haemorrhagic fever.  

The incidence of dengue has grown dramatically in recent decades. It is estimated that 2.5 billion people – two fifths of the world’s population, are potentially at risk from dengue. The World Health Organization (WHO) estimates that there are 50 million dengue infections worldwide each year.  Currently, there is no specific treatment for dengue fever and there is no vaccine to protect against dengue. In a 2009 study, it was estimated that about 5 percent of the population of Key West, Florida was infected with dengue.

What are the signs and symptoms of Dengue?

Most people start to get sick about 3-14 days after being bitten. Individuals may experience high fever, headache, pain behind your eyes, bone pain, sore muscles and joints, a rash with spots on the skin and nausea and vomiting.  Often Dengue is mistaken for the flu.

Malaria is a mosquito-borne disease caused by a parasite. People with malaria may experience fever, chills, and flu-like symptoms. Without medical attention, a person with malaria may develop severe complications and die.

According to the CDC, in 2008 there were approximately 300 million cases of malaria worldwide. Malaria is the fifth leading cause of death from infectious diseases worldwide (after respiratory infections, HIV/AIDS, diarrheal diseases, and tuberculosis).

Treatment of malaria depends on many factors including the severity of the disease, the type of malaria you have, and where you were when you got malaria. Treatment also depends on your age, health, weight, and pregnancy status.

WNV is another potentially serious illness caused by mosquitoes. Experts believe WNV is established as a seasonal epidemic in North America that flares up in the summer and continues into the fall. As with malaria, West Nile fever often has flu-like symptoms.  More severe forms of WNV, which can be life threatening, may be called West Nile encephalitis (WNE) or West Nile meningitis, depending on what part of the body is affected.

Why do some people appear to get bitten more than others?

Believe it or not, Mosquitoes are picky eaters and choose whose blood they wish to suck. It is estimated that one in 10 people are highly attractive to mosquitoes. If you are one of the lucky ones Mosquitoes think taste great you should consider the following options.

Mosquito repellents

  1.     DEET – In my research I found DEET to be a very effective mosquito repellent.  DEET, which has been used since 1957, is available in different strengths however 25 percent should be adequate. A single application of DEET to your skin should offer five hours of protection from mosquitoes. DEET has been in use for more than 50 years and has very good safety record.
  2.     Permethrin – Another mosquito repellent option is to spray your clothing with the chemical insecticide permethrin. One treatment will last up to six washings or six weeks before clothing has to be treated again. One such product is Sawyer® Permethrin. According to their website “Permethrin is odorless when dry. During the drying process it tightly bonds with the fibers of the treated garment. It will not stain or damage clothing, fabrics, plastics, finished surfaces, or any of your gear and provides protection from mosquitoes and ticks through six washings.”
  3.     Use both – The combination of Permethrin on clothing and DEET repellent on your skin is the best way to repel mosquitoes and other biting, blood sucking and disease carrying insects.  This combination of protections is far greater than either a DEET based insect repellent or Permethrin alone.

The chemical IR3535, found in Avon’s Skin So Soft, is often used as a mosquito repellent in the U.S. however it appears to be less effective than DEET.

The two-legged crew are not the only ones at risk.  Mosquitoes can transmit several diseases and parasites that dogs and horses are very susceptible to. These include dog heartworm, WNV and Eastern Equine Encephalitis (EEE).  If you are traveling with pets, you should check with your veterinarian, and advise them where pets may be visiting to ensure that the four-legged travelers are protected when possible.

To learn more about First Aid emergencies at sea you should take a CPR AED First Aid class.  First Aid is more than just a class you take when you get your captain’s license, it’s a continuous process that requires you to always learn more and update your skills.

Keith Murray, a former Florida Firefighter EMT, is the owner of The CPR School, a mobile training company that provides shipboard CPR, AED and First Aid training throughout Florida.  In addition to training, The CPR School sells and services AEDs – automated external defibrillators.  Contact The CPR School at +1-561-762-0500 or Comments on this column are welcome at