If you’re heading out to the great outdoors this summer or just having a backyard barbecue, taking common-sense precautions can help keep you and your family safe from mosquito- and tick-borne illnesses.
The Centers for Disease Control and Prevention (CDC) reported recently that across the country the number of cases of people getting sick from infected mosquitoes, ticks, and fleas tripled between 2004 and 2016.
The CDC cited many factors for the increase, including commerce, which can move infected mosquitoes, ticks, and fleas around the world, and infected travelers, who can introduce and spread germs internationally.
In the case of mosquito-borne illnesses, Darvin Scott Smith, MD, chief of Infectious Disease and Geographic Medicine at the Kaiser Permanente Redwood City Medical Center, said global warming is also to blame. A warming environment has increased habitats for disease-carrying mosquitoes.
A spokeswoman for the CDC said the geographic range where ticks and tick-borne diseases are found is also expanding.
Look insideKP Northern California spoke with Dr. Smith about these illnesses and how people can best protect themselves. Dr. Smith also teaches at Stanford University’s Medical School and Human Biology Department.
What should people in Northern California be most concerned about?
The biggest concerns here are West Nile virus, carried by infected mosquitoes and Lyme disease, carried by infected ticks. Let’s start with West Nile virus. Most people who are infected, about 4 out of 5, don’t even know it. But for people over age 50 and those with a weakened immune system, it can be serious. For 1 out of 150 of those infected, it can be devastating.
Mild symptoms may include fever, headache, feeling very tired, body aches, swollen lymph nodes, and a rash, usually on the chest. In the most serious cases, people can develop neurologic illnesses such as encephalitis or meningitis. Last year in California there were 553 reported cases of West Nile virus, including 44 deaths.
What about Lyme disease?
Lyme disease is a lot less common in California than it is in other parts of the United States. For example, in 2016 there were 90 confirmed cases in California, but there were nearly 9,000 confirmed cases in Pennsylvania and more than 3,000 in New Jersey. That’s because only about 2 percent of ticks in Northern California carry Lyme disease, compared to 30 to 50 percent of ticks in other parts of the country.
One possible sign of Lyme disease is a round, red rash that forms at the site of a tick bite. Flu-like symptoms are also common in the early stages. Lyme disease symptoms can start any time from 3 days to up to a month after you’ve been bitten. If the disease goes untreated with antibiotics, more serious symptoms can develop, such as joint pain, numbness, memory problems, and weakness or paralysis of the facial muscles.
How can people best protect themselves from ticks and mosquito bites?
If you’re walking through bushy areas or grasslands, make sure you’ve sprayed your shoes and clothing with a tick-repellant such as permethrin. Tuck your pants into your socks and do a tick check to make sure you don’t have ticks on your body, clothing, or pets. Ticks like tight, warm places like your armpits, neck, and around your ears and groin. You can find more information on dealing with ticks at the California Department of Public Health.
To avoid mosquito bites, stay inside at dusk, early evening, and dawn when mosquitoes are most active. If you need to be outside at those times, wear a long-sleeved shirt and long pants and apply an insect repellent. The CDC offers advice on repellants for adults, children, and babies.
Make sure your doors and windows have tight-fitting screens to keep out mosquitoes, and repair or replace screens with tears or holes.
To prevent mosquitoes from breeding near you, eliminate or drain standing water. This could be a fountain that’s not moving, rain gutters, bird baths, or pots with saucers full of water.
The increase in mosquito and tick-borne diseases is concerning, but it’s not a reason to panic. With some preparation and precautions, you and your family should be able to safely enjoy the outdoors.