The news that four people in Florida contracted malaria from local mosquito populations certainly drew attention because the disease is fatal if left untreated and is almost unheard of in modern times in this country.
There have been some suggestions that this is somehow vaguely connected to rising temperatures associated with climate change.
The reality is more complicated.
Malaria was once a common disease in Florida, according to some older schoolbooks titled Florida: Wealth of Waste? These books were published in the 1940s and 1950 and used in public and private schools and colleges.
In 1930, malaria was the fifth leading cause of death in Florida for children 1 through 4, causing 31.8 deaths per 100,000 population.
In 1940, (see figure above) Florida had the largest concentration of malaria cases in the Southeast. That year Florida officials reported 24,498 cases of malaria, 98 of them resulting in deaths.
There are a number of reasons malaria has declined in Florida.
Chief among them is the fact that homes had gradually become equipped with window screens and door screens to keep mosquitoes out. Today many homes are completely enclosed from the outside because they have air-conditioning.
Mosquito control efforts also increased, though the use of DDT in the early days had some serious environmental effects on wildlife that eventually led to its ban and its replacement with less harmful pesticides. Mosquito repellents also improved.
Also, as in the recent cases, public health surveillance for disease outbreaks is an important tool for detecting outbreaks early and taking appropriate action.