At least five persons in the United States have been infected with malaria – four in Florida and one in Texas, according to a health advice issued by the Centers for Disease Control and Prevention. These are the country’s first known instances of locally acquired malaria since 2003.
Malaria, which was historically endemic in the United States, is caused by various parasitic species spread by Anopheles mosquitos. This frequently causes flu-like symptoms such as fever and chills, but if left untreated, it can progress to serious disease and death. Plasmodium vivax, which is less likely to cause severe sickness than other malaria parasites, was responsible for the these new cases.
All five patients “have received treatment and are improving,” the C.D.C. said. “Despite these cases, the risk of locally acquired malaria remains extremely low in the United States,” the agency added.
Local Transmission of Malaria
The United States eradicated malaria decades ago, but the World Health Organization estimates that there will be about 250 million cases of malaria in 2021, with the vast majority occurring in Africa.
Prior to the Covid-19 epidemic, approximately 2,000 cases of malaria were documented in the United States each year, practically all of them in people who contracted the disease abroad, according to the C.D.C.
Moreover, pregnant women can pass the parasites to their children, and the sickness can be carried through blood transfusions, but such events are uncommon in the United States, according to the C.D.C., which reports one incidence related to transfusions every two years.
However, when infected persons return to the United States, local mosquitoes might feast on them and spread the parasites.
“Stuff like this happens,” said Colin Carlson, a scientist at Georgetown University. “You expect that in a country that has achieved disease eradication: reintroductions and a little bit of local transmission every now and then.”
Dr. Carlson believes the country is not on the verge of a catastrophic malaria breakout. However, when foreign travel increases this summer, the number of cases of imported malaria may rise, according to the C.D.C.
Does Malaria have something to do with Climate Change?
Dr. Carlson discovered in a recent study that some Anopheles mosquitoes had already expanded their ranges in ways that are consistent with climate change. However, it is difficult to say whether the new instances in the United States are related to climate change.
Dr. Carlson remarked that while climatic conditions in the southern United States may have become more conducive to malaria transmission, the region was already warm enough for the disease to spread.
Still, he believes that climate is playing a role in these cases in more subtle ways, such as making the disease more widespread in regions where Americans travel. This could lead to an increase in imported cases, allowing the parasites additional possibilities to spread within the US.
“If travelers are returning from places that are at the front lines of climate impacts, there’s just going to be more chances for malaria transmission to take off,” Dr. Carlson said. “We live in a connected world, and climate change impacts in other countries can be health problems in our country.
Protecting Yourself from Malaria
According to the CDC, best way to keep yourself protected from malaria is to avoid mosquito bites. You can do this by making sure that your surroundings are clean, while also spraying insecticides or applying insect repellents.
Moreover, wearing long-sleeved shirts, long pants, socks, and closed shoes might also provide an extra physical barrier against mosquito bites, particularly during peak biting hours. Those who have plans to travel should also research the risk of malaria in their destinations and talk to their doctors about preventive measures, the C.D.C. announced.