The teeny tiny nuisances, mosquitoes are most often associated with an annoying buzz, an undetected bite and then an ensuing itch that seems to last for weeks. The urge to scratch isn’t all you need to worry about, though; mosquitoes can be more than harmless pests. Like many bugs, mosquitoes have the ability to carry and transmit disease and they thrive in the summer months.
One of the most notable and feared diseases is West Nile Virus. Most cases occur from June through September, according to the CDC, and though most people don’t experience any symptoms at all, a very small number (less than 1 percent) die from complications brought on by West Nile Virus.
It’s hard to say which areas of the country will be hit hardest and it’s tough to predict how bad the outbreak will be each year, as it changes drastically. With the start of summer, though, you should know about mosquitoes, West Nile Virus and how to protect yourself. We consulted the CDC and WHO (World Health Organization) for everything you need to know about mosquitoes and West Nile Virus this summer season.
West Nile Virus is typically spread to humans by infected mosquitoes. While most people with the virus don’t experience any symptoms, about 20 percent of those infected experience symptoms ranging in severity from a fever and headache to life threatening inflammation of the brain. The number of reported cases and the outbreak areas change significantly from year to year, made worse by unusually warm weather.
According to the CDC, “Anyone living in an area where West Nile virus is present in mosquitoes can get infected.” The virus has been found in every state in the continental U.S. and outbreaks have been happening in the country every summer since 1999. “The risk of infection is highest for people who work outside or participate in outdoor activities because of greater exposure to mosquitoes.” The map from the CDC shows West Nile Virus cases reported so far this season, the dark green shade represents human infections.
West Nile Virus is usually spread to humans from mosquitoes, but in rare cases humans have been infected in other ways. According to the CDC, in a “very small proportion of cases” patients have been infected via blood transfusion, organ transplant, exposure in a lab and from mom to baby during pregnancy, delivery or breastfeeding. This extremely small risk is not a reason to refuse a blood transfusion, organ donation or to stop breastfeeding.
There is no available vaccine for preventing West Nile Virus in humans, so the best way to avoid contracting the virus is to prevent mosquito bites. The CDC recommends using insect repellents “containing DEET, picaridin, IR3535, and some oil of lemon eucalyptus and para-menthane-diol,” as products with these ingredients provide long-lasting protection. It’s also recommended that you wear long sleeves and pants from dusk through dawn, as mosquitoes are most active then and spray the repellent on your clothing.
The CDC also recommends taking measures to prevent mosquitoes from gathering in your home and yard. Any missing or broken screens on windows and doors around your house should be fixed and, the CDC writes, if you have air conditioning, you should use it. To limit the number of mosquitoes on your property, empty standing water from flowerpots, buckets, gutters, pool covers, birdbaths and anything else that holds water.
Local governments are usually the leaders in controlling the mosquito population and limiting the spread of West Nile Virus and, according to the CDC, “Methods can include elimination of mosquito larval habitats, application of insecticides to kill mosquito larvae, or spraying insecticides from trucks or aircraft to kill adult mosquitoes.” The CDC also highlights the importance of reporting dead birds, as they might be an indicator that the virus is in your area.
Most people infected with West Nile Virus (between 70 and 80 percent) do not experience any symptoms whatsoever and the remaining few usually experience mild sickness. According to the CDC, about one in five people who are infected will develop a fever, along with other symptoms like a headache, vomiting, diarrhea, rash and aches and pains. Most people in these situations “recover completely,” but feelings of tiredness and weakness can last for weeks or months. People tend to develop symptoms between 3 and 14 days after getting bit by an infected mosquito.
A very small percentage of those infected with West Nile Virus (less than 1 percent), “develop a serious neurologic illness such as encephalitis or meningitis (inflammation of the brain or surrounding tissues),” writes the CDC. Symptoms of this type of illness might include high fever, disorientation, neck stiffness, tremors, seizures, paralysis and coma; those with certain medical conditions (cancer, hypertension, kidney disease, ect.) and the elderly are at a higher risk. About 10 percent of people who develop this type of infection due to West Nile Virus will die, recovery for others may take weeks or months and some people never fully recover.
Most cases of West Nile Virus clear up on their own, but if you develop severe symptoms (severe headaches or confusion) you should get medical help immediately. Those most at risk should be particularly vigilant and, according to the CDC, “Pregnant women and nursing mothers are encouraged to talk to their doctor if they develop symptoms that could be WNV.”
There is no vaccine or antiviral treatment for West Nile Virus infection in humans. Most people rely on over-the-counter pain relievers to bring their fever down and ease other symptoms and the body usually clears the virus out on its own. In the worst cases, though, those infected need to get to a hospital, where they provide fluids, pain medication and monitor the patient’s condition.