Public health officials are urging residents in Texas and Florida to be cautious following the CDC’s announcement that there have been instances of malaria being locally transmitted.

The CDC issued an advisory Monday after five cases of the illness were reported in the past two months. Four of the cases were in Florida, and one was in Texas, marking the first time the disease has been contracted within the United States in decades.

According to the advisory, the five affected individuals received treatment and were “improving.” The Texas Department of Health and Human Services (DHHS) confirmed that the diagnosed Texan is a Cameron County resident in southern Texas.

Though no cases have been reported locally, the DFW area ranks fifth on the list of the country’s most mosquito-ridden cities, as previously reported by The Dallas Express. As malaria is a mosquito-borne illness, citizens are advised to take precautionary measures such as wearing long clothing, using EPA-approved repellant, and disposing of standing water sources to prevent mosquito bites.

The City of Dallas began spraying for the insects earlier this month.

Malaria is a potentially fatal illness that causes flu-like symptoms such as aches, fever, and chills. The CDC recorded roughly 241 million malaria cases worldwide and 627,000 malaria-related deaths in 2020.

There are about 2,000 cases reported each year in the United States, most of those from travelers or immigrants where the disease is prevalent such as in South Asia or sub-Saharan Africa.

While the DHHS reported an annual average of 120 travel-related malaria cases in the state, the last locally acquired Texas case was in 1994.

CDC officials remained concerned that an increase in international travel this summer will create a potential rise in malaria cases in the United States.

Medical professionals in southern states where the climate is much more suitable for mosquitoes that spread malaria were advised to be vigilant of infection and consider keeping IV artesunate on hand, treatment for more severe cases.

The CDC also advised citizens who travel out of the country to consult their healthcare providers about prescription malaria medication.