How to protect yourself from dengue – and how your community can help too

As cases rise around the world, U.S. health officials are warning Americans about dengue fever, a potentially fatal disease transmitted by mosquitoes. The disease is endemic – or ever-present – ​​in many parts of the world, including Puerto Rico and other US territories. And cases have been reported annually among Americans returning from travel, as well as local transmission in some states, including Florida, Hawaii and Texas.

But this year is different. Massachusetts, where the disease has been historically rare, has reported 50 infections in travelers so far in 2024 and is on track to reach a record number of annual cases. Puerto Rico declared a state of emergency, the US reported more travel-related cases than would normally be expected (745, according to the Centers for Disease Control and Prevention) and local transmissions are also emerging. Seven have been reported in Florida, for example, including two in the Florida Keys.

The CDC is warning of an increased risk of dengue fever among Americans, but says the risk is still generally low. However, we asked experts what can be done to stay safe. Here’s what they had to say.

What to do: Individually at home

First, it’s important to recognize that the risk of being bitten by a dengue-infected mosquito near your home if you live in the continental U.S. is low, according to the CDC. But there are steps you can take, experts say.

1. Protect your body. The main things you can do to stay safe are “use mosquito repellent, avoid areas known to harbor a lot of mosquitoes, and wear clothing that doesn’t expose too much skin,” said the Johns Hopkins infectious disease expert. Dr.he told Yahoo Life.

2. Make your home less hospitable to mosquitoes. You can prevent your home from harboring mosquitoes by “cleaning up trash from your yard,” says Adalja. Mosquitoes breed in still water and thrive in the surrounding areas. Therefore, getting rid of or covering things like sandboxes, plastic pools, or other debris and containers that can collect water can help slow population growth and prevent mosquitoes from getting comfortable around your home.

What to do: Individually during the trip

To give you an idea, there have been 2,391 cases of dengue reported in U.S. states and territories since the beginning of 2024, according to the CDC. The vast majority of these cases (1,498) were reported in Puerto Rico, where the virus is endemic. Another 794 were acquired while people were traveling, while only 99 were acquired locally, outside of Puerto Rico.

The data is clear: you are at greater risk when traveling, specifically to countries with high rates of dengue fever. According to the CDC, these include most countries and territories in Central and South America, including Mexico, Puerto Rico, Costa Rica and Brazil, several countries in Africa and parts of Southeast Asia. You can find a complete list here. While traveling, you can protect yourself by:

1. Stay away from mosquito-infested areas. Adalja suggests asking your hotel, tour guides or other places where there are a lot of mosquitoes. If you can, avoid these areas.

2. Get ready. Just like you would at home, try to keep your skin covered as much as possible and use mosquito repellent, says Adalja.

3. Watch your legs. The species of mosquito that transmits dengue fever, Aedes aegypti, “is very skittish and adept at hovering around people, looking for the perfect opportunity to land and take a quick bite,” Chad Huff, public information officer for the Florida Keys Mosquito Control District, told Yahoo Life. “Often, they choose to gravitate toward the lower legs and ankles, where they are less likely to draw attention or a slap.” Therefore, you may want to take extra care to cover and protect your lower body.

4. Pay attention to the symptoms. Although even 80% of dengue cases are asymptomaticPay attention to how you would feel if you were bitten by a mosquito while traveling to a place with high dengue activity. Symptoms include high fever, headaches, body aches, and nausea (“which will likely make people think they have COVID,” Adalja says). If you have these symptoms, see a doctor and tell them about your recent travels and bites so they can test you. Although most illnesses are mild, the infection can cause potentially fatal internal bleeding, so antiviral treatment may be prescribed. Adalja says antiviral treatment may also be advisable if you live in areas of the US that currently have high levels of dengue activity, including Key West, Florida.

Although the growing incidence of dengue fever is worrying globally, Adalja says people do not need to cancel their travel plans. “It’s an endemic disease throughout the world,” he notes. The CDC recommendation “is not against travel, it just says it is riskier.”

What to do: At the public health level

The species of mosquito that transmits the dengue virus – as well as yellow fever, chikungunya and Zika – is still found throughout the country. “I think there’s a lot of complacency” around “vector control,” or efforts to keep populations of potentially disease-carrying mosquitoes low, Adalja says. To better combat dengue outbreaks, local, state, and federal authorities can:

1. Monitor mosquito breeding sites. It’s not just people who can (and should) be tested for dengue and other mosquito-borne diseases. County health departments can collect the bugs from the slimy pools in which they gravitate and test them for a range of viruses. Some localities do this (Austin, Texas, recently detected two clusters positive for West Nile virus), but a 2022 study survey found that only about 24% of surveillance programs are “fully capable.”

2. Do public cleaning. It’s one thing for individuals to do their part by cleaning up their own yards, but public trash provides even more opportunities for mosquitoes to breed, Adalja says. Communities – whether at the local or state level – “can organize the cleanup of areas with high levels of mosquito breeding sites, similar to what happened in Miami Beach when there was local transmission of Zika,” says Adalja.

3. Use mosquitoes against themselves. “The most effective [approach] and when [health officials] releasing genetically modified sterile male mosquitoes, as they did in Key West; Fresno, California; and parts of Texas,” says Adalja. Test This approach in other countries has shown that it can reduce dengue cases by up to 97%. Adalja says that in the US there is a stigma associated with genetic modification, but adds that releasing mosquitoes infected with bacteria or that have been irradiated it can also help contain populations.