What is malaria?
Malaria is a life-threatening disease. It’s typically transmitted through the bite of an infected Anopheles mosquito. Infected mosquitoes carry the Plasmodium parasite. When this mosquito bites you, the parasite is released into your bloodstream.
Once the parasites are inside your body, they travel to the liver, where they mature. After several days, the mature parasites enter the bloodstream and begin to infect red blood cells. Within 48 to 72 hours, the parasites inside the red blood cells multiply, causing the infected cells to burst open. Learn more about mosquitoes and treating mosquito bites.
The parasites continue to infect red blood cells, resulting in symptoms that occur in cycles that last two to three days at a time.
Malaria is typically found in tropical and subtropical climates where the parasites can live. The World Health Organization (WHO) stated that about half the world’s population were at risk in 2015.
In the United States, the Centers for Disease Control and Prevention (CDC) report 1,700 cases of malaria annually. Most cases of malaria develop in people who travel to countries where malaria is more common.
Read more: Learn about the relationship between cytopenia and malaria »
What causes malaria?
Malaria can occur if a mosquito infected with the Plasmodium parasite bites you. There are four kinds of malaria parasites that can infect humans: Plasmodium vivax, P. ovale, P. malariae, and P. falciparum. P. falciparum causes a more severe form of the disease and those who contract this form of malaria have a higher risk of death. An infected mother can also pass the disease to her baby at birth. This is known as congenital malaria. Malaria is transmitted by blood, so it can also be transmitted through:
an organ transplant
use of shared needles or syringes
What are the symptoms of malaria?
The symptoms of malaria typically develop within 10 days to four weeks following the infection. In some cases, symptoms may not develop for several months. Some malarial parasites can enter the body but will be dormant for long periods of time. Common symptoms of malaria include:
shaking chills that can range from moderate to severe
How is malaria diagnosed?
Your doctor will be able to diagnose malaria. During your appointment, your doctor will review your health history, including any recent travel to tropical climates. A physical exam will also be performed. Your doctor will be able to determine if you have an enlarged spleen or liver. If you have symptoms of malaria, your doctor may order additional blood tests to confirm your diagnosis. These tests will show:
whether you have malaria
what type of malaria you have
if your infection is caused by a parasite that’s resistant to certain types of drugs
if the disease has caused anemia
if the disease has affected your vital organs
Life-threatening complications of malaria
Malaria can cause a number of life-threatening complications. The following may occur:
swelling of the blood vessels of the brain, or cerebral malaria
an accumulation of fluid in the lungs that causes breathing problems, or pulmonary edema
organ failure of the kidneys, liver, or spleen
anemia due to the destruction of red blood cells
low blood sugar
How is malaria treated?
Malaria can be a life-threatening condition, especially if you have P. falciparum. Treatment for the disease is typically provided in a hospital. Your doctor will prescribe medications based on the type of parasite that you have. In some instances, the medication prescribed may not clear the infection because of parasite resistance to drugs. If this occurs, your doctor may need to use more than one medication or change medications altogether to treat your condition. Additionally, certain types of malaria, such as P. vivax and P. ovale, have liver stages where the parasite can live in your body for an extended period of time and reactivate at a later date causing a relapse of the infection. If you are found to have one of these types of malaria, you will be given a second medication to prevent a relapse in the future.
What is the long-term outlook for people with malaria?
People with malaria who receive treatment typically have a good long-term outlook. If complications arise as a result of malaria, the outlook may not be as good. Cerebral malaria, which causes swelling of the blood vessels of the brain, can result in brain damage. The long-term outlook for patients with drug-resistant parasites may also be poor. In these patients, malaria may recur. This may cause other complications.
Tips to prevent malaria
There’s no vaccine available to prevent malaria. Talk to your doctor if you’re traveling to an area where malaria is common or if you live in such an area. You may be prescribed medications to prevent the disease. These medications are the same as those used to treat the disease and should be taken before, during, and after your trip.
Talk to your doctor about long-term prevention if you live in an area where malaria is common. Sleeping under a mosquito net may help prevent being bitten by an infected mosquito. Covering your skin or using bug sprays containing DEET may also help prevent infection. If you’re unsure if malaria is prevalent in your area, the CDC has an up-to-date map of where malaria can be found.