The parasites that cause malaria attack your red blood cells, typically causing a high fever, shaking chills, and other symptoms that may develop into life-threatening complications. Most cases of malaria occur in sub-Saharan Africa and South Asia, but the disease also affects several other areas of the world, including Latin America, Southeast Asia, and Oceania.
Parasites That Cause Malaria
P. falciparum This species is found in tropical and subtropical regions worldwide, but it’s especially common in Africa. Falciparum malaria is the deadliest form of malaria because it multiplies rapidly, rupturing red blood cells. These damaged cells can clog small blood vessels, including in your brain. P. vivax This species is found mostly in Asia, Latin America, and some parts of Africa. P. vivax has a dormant stage in the liver. As a result, it can invade your blood up to two years after the infecting mosquito bite, making you sick again. These delayed infections (relapses) can also reintroduce malaria to areas of the world where it was previously eliminated. P. ovale This species is found mostly in Africa and the islands of the western Pacific. Like P. vivax, it can also remain dormant in your liver and cause relapses months or years later. P. malariae This species is found worldwide. If untreated, it can cause a chronic lifelong infection or serious complications like nephrotic syndrome, a serious kidney disease. P. knowlesi This species is found throughout Southeast Asia in macaque monkeys. It can also infect humans and progress rapidly to severe infection.
Malaria Risk Factors
There hasn’t been ongoing transmission of malaria in the United States since the early 1950s. The disease was effectively eliminated through a combination of water management, insecticides, and other treatment and prevention efforts. But there are numerous cases each year of travelers leaving the United States, becoming infected, and returning to the country. Occasionally, a small outbreak of malaria occurs in the United States, when local mosquitoes spread the disease from an infected traveler. So far, these episodes have been contained effectively, without malaria posing an ongoing threat. Destination-related risk factors include: Geographic region Areas of the world where malaria is endemic (circulates widely) tend to be tropical, subtropical, or at low elevations. This is because warm temperatures are needed for the parasite to mature within mosquitoes. The Centers for Disease Control and Prevention has a table of malaria information by country to see if your travel destination has endemic malaria. In general, your risk is higher if you travel to sub-Saharan Africa than most areas of Asia or the Americas. Type of accommodation Lodging that has window screens or air conditioning poses a lower malaria risk than open-air or tented accommodations. You’re also at greater risk if your itinerary includes outdoor dining or entertainment, especially in the evening. Season Hotter and wetter times of the year tend to be associated with greater malaria transmission. One reason for this is that rainfall can create collections of water, encouraging the breeding of mosquitoes that transmit malaria. It’s possible that during cooler times of the year, you won’t need to take as many preventive measures if you travel to certain areas where malaria is endemic. Risk factors related to the type of traveler include: Pregnancy If possible, travel to an area with malaria transmission should be delayed until after giving birth. If delaying the trip isn’t possible, it’s essential to take a drug to help prevent malaria. Malaria during pregnancy raises the risk of miscarriage, premature birth, and low birth weight, reducing the chances of the baby’s survival. Visiting friends and relatives People who are originally from an endemic region but have moved, and then go back to visit, are the group at highest risk for malaria in the United States. A lot of these people don’t know that they need to take medicine to prevent malaria. Some may believe they have immunity from growing up in a malaria-prone area, but any such immunity is only temporary and is quickly lost when someone moves away. People who visit friends and relatives, as opposed to tourists or business travelers, are also likely to spend more time in the destination country and to stay in private residences rather than hotels. To diagnose malaria, your doctor will ask you about your health and travel history, perform a physical examination, and order blood tests.
Whether you have malariaWhat kind of parasite is causing your malariaWhether your parasite is resistant to certain drugs
In the United States and other areas where malaria is uncommon, diagnosing malaria can be difficult mostly because doctors may fail to consider malaria as a possible diagnosis and not order the right tests at the start.
Prognosis for Malaria
Infection with P. falciparum parasite (found in much of sub-Saharan Africa)Being an infant or young childBeing an older adultBeing pregnantTraveling from an area without malaria
Taking a preventive drug before you travel to an area with malaria can also lengthen the incubation period and delay the appearance of symptoms by weeks or even months.
If you develop malaria, your doctor will devise your treatment plan depending upon where you got infected, the parasite causing your malaria, and the severity of your symptoms, among other factors.
Medication Options
In general, the same drugs are used to help prevent malaria if you’re traveling to an area where it’s spread, and to treat malaria if you develop the disease. Commonly prescribed drugs for prevention and treatment of malaria include the following: Artemisinin-based combination therapies (ACTs) These combination medicines are each designed to fight malaria parasites in different ways. Chloroquine This drug is preferred whenever it’s likely to be effective, but many parasites are now resistant to it. Other drugs that are less commonly used to help prevent or treat malaria include:
Malarone (atovaquone and proguanil)Vibramycin (doxycycline) or Monodox (quinine and doxycycline)MefloquinePrimaquine
Prevention of Malaria
Preventing mosquito bites is crucial to preventing malaria. Anopheles mosquitoes bite between dusk and dawn and sometimes like to live inside houses.
Avoid outdoor exposure between dusk and dawnWear clothing that minimizes exposed skinWear insect repellent on your skin that contains DEETSleep under a bed net treated with an insecticide (such as permethrin)Wear clothing treated with permethrin or spray clothing with permethrin spray (available at outdoor supply stores)Stay in well-screened or air-conditioned rooms
Organ failure When you have malaria, your kidneys or liver can fail, or your spleen may rupture. Brain problems Damage to your red blood cells caused by malaria can block small blood vessels in your brain, leading to swelling and possible brain damage, also known as cerebral malaria. This condition can lead to coma or death. Anemia Damaged red blood cells can result in inadequate circulation of oxygen and vital nutrients in your blood. Low blood sugar Severe malaria can result in dangerously low blood glucose. Quinine, a drug used to treat malaria, can also lead to reduced blood sugar levels. If your blood sugar drops too low, coma or death can result. But the WHO estimates that in 2016, there were still 216 million cases of malaria, leading to 445,000 deaths. In a troubling development, malaria cases started to go up again from 2014 to 2016, with the greatest rise seen in Latin America.
It’s also important to put distance between yourself and mosquitoes by wearing long sleeves and pants, and staying in air-conditioned or screened areas whenever possible. Some mosquito-borne illnesses have no specific treatment, while others — like malaria — have effective treatments that should be started as soon as possible. Learn More About Mosquito Bites That Spread Disease Centers for Disease Control and Prevention — Malaria This online portal can connect you to information on nearly every aspect of the disease, from facts and statistics to information for travelers. You can dive into details about how malaria is diagnosed and treated, or read about prevention efforts around the world. World Health Organization — Global Malaria Programme This online resource links to information on various aspects of the WHO’s efforts to fight malaria, from controlling mosquitoes to diagnostic testing and new treatment strategies to disrupt transmission of the disease. National Institute of Allergy and Infectious Diseases — Malaria This division of the U.S. National Institutes of Health focuses on disease research, including developing a vaccine for malaria and other diseases spread by mosquitoes. MedlinePlus — Malaria This web page links to information on a number of different topics, including choosing a drug to help prevent malaria, spotting counterfeit drugs, and diagnostic tests for the disease. Additional reporting by Erin Archer Kelser, RN.
