Two more cases of locally acquired malaria in Florida’s Sarasota County would make the spread that started in May as extensive as the Palm Beach County cases 20 years ago.
The eight cases that popped up in Palm Beach in 2003 marked the last time the country experienced the spread of locally acquired malaria, according to the Centers for Disease Control and Prevention. Despite a total of six cases in Southwest Florida and one emerging in Cameron County, Texas, the risk of someone getting malaria in the U.S. remains low, according to the CDC.
That said, the federal CDC has issued a health advisory related to malaria cases, and the Florida Department of Health recently issued a statewide mosquito-borne illness advisory.
From 2003 to 2022, there were 1,322 cases of malaria reported in Florida, according to FloridaHealthCHARTS, an online database that tracks the frequency of diseases. The Florida Phoenix reviewed the state data from 20 years on July 12 to determine the total number of cases — those that specifically were acquired in Florida and others that came from outside the United States but have been identified in various counties.
Most of the cases that emerged during those years came from people who received a malaria diagnosis after traveling to places where transmission occurs. However, the database over the years shows that there were four cases of locally acquired malaria between 2004 and 2022: One in St. Lucie County in 2004, one in Manatee in 2009, one in Duval in 2010, and one in Hillsborough in 2018.
Aside from the six local cases of malaria this year, the state health department’s Florida arbovirus surveillance report shows 23 internationally acquired cases from people who traveled to Burundi, Côte D’Ivoire, Democratic Republic of the Congo, Equatorial Guinea, Ghana, Kenya, Nicaragua, Nigeria, Pakistan, Sierra Leone, Sudan, and Uganda.
Although the department didn’t report any cases between July 2 and 8, that doesn’t mean the spread is over. Since the agency reported the first case the week of May 21, there was a two-week period where no cases were reported. Then, five cases emerged in June, according to the weekly arbovirus reports from the health department.
The parasite causing the infections was Plasmodium vivax, according to the arbovirus surveillance report.
A local malaria outbreak is considered over when the most recent patient treated no longer has any parasites in their system capable of infecting a mosquito, any mosquito possibly infected by that same patient has died off, and no new patient has been detected, a CDC spokesperson wrote in an email to the Florida Phoenix.
In terms of time, it would usually take between eight to 10 weeks after treatment is completed, but if a patient does not receive or complete treatment or an infectious mosquito is identified in the area, it would take longer for the outbreak to be over, the spokesperson wrote.
Locally acquired cases of malaria garner more attention from health officials given that it means there are vectors — in the case of malaria, female mosquitoes from the genus Anopheles — that carry the disease in the area. But if someone contracts the disease elsewhere, they can only transmit it through blood transfusion, organ transplant, shared use of contaminated needles or syringes, or from a mother to her unborn infant before or during delivery, according to the CDC.
Symptoms of malaria appear within 10 to 15 days of a bite, according to the World Health Organization. The mild symptoms include fever and flu-like illness, including shaking chills, nausea, headache, muscle aches, and tiredness, but those infected might also suffer from vomiting, diarrhea, impaired consciousness, multiple convulsions, difficulty breathing, dark or bloody urine, jaundice
or abnormal bleeding, according to the CDC and WHO.
Using insect repellent when outdoors, wearing protective clothing, and staying in air-conditioned or well-screened areas is key to preventing infection.
A Flourish chart