Malaria tends to spark less concern than other diseases transmitted by mosquitoes, such as Zika or West Nile virus. But the death this week of noted Maine philanthropist Peter Alfond from malaria serves as a reminder to Mainers traveling abroad to take precautions.
The disease typically results in a high fever, chills, and flu-like symptoms, according to the U.S. Centers for Disease Control and Prevention. It’s caused by a parasite that commonly infects a type of mosquito which then transmits the illness to humans through a bite.
Roughly 1,500 cases of malaria are diagnosed each year in the United States, mostly among travelers and immigrants returning from countries where malaria circulates, according to the CDC.
In Maine, four cases of the disease were reported through May of this year, a fairly typical number.
Malaria is usually preventable by taking medication and often curable if diagnosed and treated promptly. But it can lead to severe complications such as kidney failure, seizures, mental confusion and even death.
Globally, 212 million cases of malaria occurred in 2015, resulting in 429,000 deaths, most of them children in sub-Saharan Africa, according to the World Health Organization.
“I have seen people die from it…It’s a bad disease,” said Dr. August Valenti, in infectious disease specialist at Intermed in Portland.
He urged Mainers traveling to areas where malaria circulates to protect themselves against the illness.
Malaria is found in warmer regions of the world. Both the parasite and the Anopheles mosquito that carries it need higher temperatures to thrive, according to the CDC. Roughly half of the world’s population is at risk for malaria — in large swaths of Africa and South Asia, parts of Central and South America, the Caribbean, the Middle East, and areas around Polynesia. That includes popular vacation destinations such as the Dominican Republic and parts of Mexico.
People traveling to those areas should try to avoid mosquito bites by using insect repellents and bed nets treated with insecticide.
Taking antimalarial medication before travel usually prevents illness. The most popular is Atovaquone/Proguanil, known under the brand name Malarone, Valenti said. Others include doxycycline and mefloquine, which is less favored because it’s inconvenient to take and can cause psychotic reactions. “Occasionally they can fail,” Valenti said. “It’s unusual but it happens.”
The type of medication varies depending on where the patient is traveling and his or her health status.
Valenti recommends visiting a travel medicine clinic in advance of a trip to an area where malaria is present to receive the treatment and counseling about malaria prevention.
There is no vaccine for malaria approved in the U.S. The parasite has “learned to change its coat,” making it difficult to target a vaccine, he said. Exposure to malaria also leads to only temporary immunity, which is why even people from malaria-prone areas who return after time away should take preventive medication, Valenti said.
One form of the disease is particularly aggressive. While some types of malaria are fairly benign, the one doctors worry about most is called P. falciparum, Valenti said. It can lead to the feared “blackwater fever,” in which the parasite attacks the blood, and result in an enlarged spleen, kidney and liver problems, as well as infect the nervous system, he said. That strain is also increasingly resistant to medication, he said.
Early detection is key to successful treatment. Malaria is diagnosed by examining the parasite count on a blood smear, Valenti said. But identifying the disease isn’t always simple. “The diagnosis can be missed even by very good doctors,” he said.
“It can present with respiratory symptoms. It can present with diarrhea. That can throw people off.”
Mild cases can be treated with Malarone or other drugs, while severe cases require different medications, such as quinine, an effective but often toxic option, he said.
Travelers who become ill with a fever or flu-like symptoms while in a malaria-prone area or for up to a year after returning home should seek immediate medical attention and inform their physician of their travel history.
“It’s very, very important when anybody travels to an area with malaria to always consider malaria if they come back with symptoms,” Valenti said.