Tainted alcohol, Legionnaires’ disease, COVID-19, and norovirus are just some of the unwelcome guests travelers may come across during an upcoming vacation.

As fall travel season gets under way, experts are urging the lay public and health care providers alike to be aware of the risks.

Watch out for crowds

“The primary things that I worry about are when people are crowded together, and so that's going to lead to an increased risk of any respiratory illness,” Dr. Dean Blumberg, Chief of Pediatric Infectious Diseases at UC Davis Health, tells MDLinx. “So certainly we have a surge in the US now of COVID, [and] we could have influenza as early as September."

The risk of Legionnaires’ disease

In June and July 2024, five people in New Hampshire developed Legionnaires’ disease. The New Hampshire Department of Health and Human Services said in a statement that the individuals may have been exposed via water droplets from a cooling tower located behind the RiverWalk Resort in Lincoln, NH.

New Hampshire Department of Health and Human Services. DHHS identifies five people diagnosed with Legionnaire's disease after visiting area in downtown Lincoln, NH [press release]. August 12, 2024.

The form of bacterial pneumonia can be contracted by inhaling water droplets that have been contaminated by the Legionella bacteria. According to the CDC, the number of reported cases of Legionnaires’ disease increased almost 900% between 2000 and 2018. However, the risk of developing Legionnaires’ is low for the majority of people.

Edens W. Legionnaires’ Disease & Pontiac Fever. CDC Yellow Book 2024. May 1, 2023.

“A lot of these places have very high concentrations of people,” Dr. Blumberg explains, “and then they have the units that will aerosolize the water, such as the cooling towers and other mechanisms. Sometimes it's related to ice machines. ... The risk at home just really isn't as much. So travel is going to expose people to much different situations that are going to increase the risk of Legionella.”

Tainted alcohol

Tainted or counterfeit alcohol is another potential concern for travelers this fall season.

Dr. Blumberg says while it can be fun to sample local delights on vacation, he advises people to exercise caution around street vendors: “I don't want to discourage people from being adventurous, but I'm wary of street vendors. Street vendors often don't follow any of the proper safety protocols, they're often not licensed, they're not regulated, and because of that, you really don't know what you're getting and whether you're getting something like the tainted alcohol."

“An establishment that has a brick and mortar presence, or a food truck or other sort of facility, is more likely to be regulated, more likely to follow common hygienic practices and use standard ingredients, and it's going to be less risky,” he says.

COVID-19 levels surging

“Some people are not at all concerned about COVID-19,” Dr. David Cutler tells MDLinx. Dr. Cutler is a board-certified family medicine physician with Santa Monica Family Physicians in California. “They view it as a fairly benign illness, and they don't take any greater precautions than they would for other respiratory illnesses. Other people, if they're older or their health is more fragile, feel much more vulnerable to that infection. If they don't want to get it, they should definitely be wearing a mask. And if they don't want to incur serious complications, they should stay up to date on their vaccines."

Both Dr. Cutler and Dr. Blumberg agree that the degree of precautions people take against COVID-19 is based on individual risk tolerance.

“With this current surge, I have seen more people masking," Dr. Blumberg notes. "I myself have been masking when traveling, wearing an N95 when I'm on an airplane, and masking in other crowded situations, such as in the airport. I just think it's prudent when there's such high levels of COVID being transmitted,” he says.

“I would have healthcare providers encourage their patients to be vaccinated. We do expect the updated COVID vaccine and influenza vaccines in the coming weeks, and to get people protected in that way," Dr. Blumberg advises.