JOINT BASE SAN ANTONIO-FORT SAM HOUSTON, Texas  –   JOINT BASE SAN ANTONIO-FORT SAM HOUSTON, Texas, June 30, 2023 -- Mosquitos aren’t just pesky insects that bite, they can spread some serious diseases such as Zika virus, West Nile virus, Chikungunya virus, dengue, and malaria.

Within the last two months, five cases of malaria spread by mosquitos have been reported in the United States. Four cases were in southwest Florida and one here in southern Texas. The five cases are the first in 20 years to be detected locally in the United States.

Malaria is a mosquito-borne disease caused by a parasite. People with malaria often experience symptoms such as fever, chills, and flu-like illness. Left untreated, they may develop severe, potentially fatal, complications.

“As of now, locally acquired malaria is uncommon, but most importantly it is diagnosable and curable,” said Army Lt. Col. (Dr.) Elizabeth Markelz, infectious diseases physician and deputy chief of operations and administration, Department of Medicine. “I think awareness and reassurance are key components. It is important for patients to seek care for an acute febrile syndrome (high fever) and to notify providers of mosquito exposure.”

“Providers should now include malaria in their differential diagnosis (a list of possible conditions that may be causing symptoms),” she added. “This area (Cameron County) may be frequently visited during the summer given close proximity to coastal areas/beaches (South Padre Island).”

According to the Centers for Disease Control and Prevention, West Nile virus is the leading cause of mosquito-borne disease in the continental United States.

While there are no vaccines to prevent or medications to treat West Nile virus,” fortunately, most people with West Nile virus do not feel sick,” explained Air Force Lt. Col. (Dr.) Alice Barsoumian, chief, Infectious Disease Service.

About one in five people who are infected develop a fever and other symptoms, and only one out of 150 infected people develop a serious, potentially fatal, illness.

Milder West Nile virus illness normally improves on its own and people do not necessarily need to seek medical attention for this infection. People who develop symptoms of severe West Nile virus illness, such as unusually intense headaches or confusion, should seek medical attention immediately.

People can reduce their risk of getting mosquito-borne diseases by using insect repellent and wearing long-sleeved shirts and long pants to prevent mosquito bites.

It’s also recommended to use Environmental Protection Agency (EPA)-registered insect repellents with diethyltoluamide (DEET), IR3535, oil of lemon eucalyptus, para-menthane-diol or 2-undecanone. When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breastfeeding women. However, do not use products containing oil of lemon eucalyptus or para-menthane-diol on children under 3 years old.

Markelz advises the use of mosquito repellent that contains at least 30 percent DEET.

It is also a good idea to use screens on windows and doors and stop mosquitos from laying eggs by eliminating standing water around the area, Barsoumian said.

“Mosquito larvae can survive in a bottle cap of water,” she said.
Additionally, people should:

• Avoid allowing puddles to form on lawns due to excessive watering.
• Place tiny holes in the bottom of recycling bins without lids.
• Frequently replace water in birdbaths.
• Get rid of old tires or other items that collect water.

“There are a lot of different species of mosquitos so different diseases can get introduced whether they are common or uncommon,” Barsoumian noted. “We have had outbreaks of West Nile virus here in the past, but occasionally I have seen cases of rarer diseases just because there are so many types of mosquitos.”

TRICARE beneficiaries who plan to travel to tropical areas can schedule an appointment at the Infectious Disease International Travel Clinic by calling 210-916-5554.

“The Travel Clinic can provide military beneficiaries with information, and vaccines to help keep you safe when traveling out of the country,” Markelz said.

Both doctors agree, “your best protection is to not get bitten.”