Two other people have contracted malaria in South Florida, health officials say – after doctors were warned to watch for more cases.
The individuals were in Sarasota County and were diagnosed between June 25 and July 1, local health authorities said.
It brings the total number of reported malaria cases in the US this year to seven, with four others in Florida and one in Texas.
The disease has been discovered back in the US for the first time in two decades, with officials fearing local mosquitoes are now carrying and spreading the disease when they bite humans.
Experts warn mosquitoes are on the rise in the US and there is a risk another mosquito-borne disease could reach the country within a decade (stock image)
Sarasota County and neighboring Manatee County, home to 859,000 people, have been under malaria warnings since June 19.
On June 26, the Centers for Disease Control and Prevention (CDC) also issued a Florida-wide malaria alert.
To get a handle on the situation, Sarasota County says it is currently conducting mosquito sprays along coastal areas where the bugs are common. Manatee County regularly conducts mosquito repellent.
They also revealed that three wild mosquitoes in the county were carrying malaria in early June.
Residents are urged to use bug spray, avoid mosquito-infested areas and wear protective clothing when outside to prevent infection.
People are also told to throw away old tires and drums and to drain water from gutters, pool covers, flower pots and other areas where mosquitoes can breed.
Doctors in the state were also warned late last month to consider fever-stricken people who come to the hospital as potential malaria patients.
In the advisory, the agency said doctors should still routinely consider malaria as a cause of febrile illness in patients with a history of international travel to areas where malaria is transmitted’.
But it added: ‘clinicians should [also] consider a malaria diagnosis in any person with a fever of unknown origin, regardless of their travel history’.
Health officials fear there are other malaria in the community, but are being misdiagnosed as other diseases.
Malaria was eradicated in the United States in 1951 following a massive public health program that sprayed pesticides from airplanes onto mosquito breeding grounds and removed potential breeding grounds for the insects.
But since then, sporadic cases have repeatedly surfaced – although these have not led to wider community transmission.
These were probably sparked after a human infected with malaria but showing no symptoms came to the US and was bitten by a local mosquito, which became infected. When this insect bit another human, it passed on the disease. It may also have arrived in malaria-infected mosquitoes stashed on an airplane.
Early warning signs of the disease include fever, chills, headache, muscle aches, fatigue, and nausea.
Without treatment, these can develop into complications such as anemia – a low red blood cell count – and organ failure, which can be fatal.
Dr. Thomas Moore, an infectious disease expert at the University of Kansas, warned DailyMail.com last month that he expected malaria to become more prevalent in the US in the coming years.
He said, “I think it’s fair to say that given global warming, we’re probably going to hear about these cases a little more often.”
He said malaria would likely follow other diseases, such as dengue fever.
“With malaria comes dengue,” he said, “which almost goes hand in hand with malaria because they cover the same areas.”
Dr. Jason Rasgon, a mosquito expert at Penn State University, said there are occasional cases of malaria in the United States and this was no different.
“This happens every now and then,” he said.
Dr. Thomas Moore (left), an infectious disease expert at the University of Kansas, warned that the mosquito population was on the rise. Dr. Jason Rasgon, a mosquito expert at Penn State University, said more mosquito-borne diseases could reach the US
He explained how the latest cases probably originated, adding: ‘Someone came in somewhere with malaria – probably an asymptomatic carrier.
“Some local mosquitoes picked up on this and bit other people, causing disease.
“This has been recognized for some time. But I don’t think it’s anything to worry about.’
Both experts warned that global warming could allow mosquitoes to spread to new areas and increase the risk of bringing more disease.
The warmer weather led to heavier rainfall, and as a result, more stagnant pools of water were available for mosquitoes to breed in.
It also sped up their life cycle and meant their eggs could survive the winter further and further north, allowing them to disperse.
Dr. Rasgon said it was likely that another mosquito-borne disease would emerge in the US within the next decade.
He said this was caused by a “perfect storm” of an interconnected world, which made it easier for disease to spread from one area to another.
He said it can be brought in by infected mosquitoes stashed on an airplane or by an asymptomatic human who then passes it on to the local mosquito species.
The US already has several mosquito species that can transmit malaria, increasing the risk of the disease establishing itself here.
In the past two decades, three new mosquito-borne diseases have been identified in the US. West Nile virus reached the country in 1999 and was followed by Chikungunya virus, in late 2013, and Zika virus, which emerged in 2016.
Malaria is a potentially life-threatening disease contracted when a mosquito introduces a parasite into someone’s bloodstream.
It can be treated with antimalarial drugs that target the parasite, such as hydroxychloroquine, previously touted by Donald Trump as a cure for Covid.