Malaria is a life-threatening disease. It is 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. The parasites continue to infect red blood cells, resulting in symptoms that occur in two-to-three-day cycles.
Malaria is typically found in tropical and subtropical climates (e.g., Africa) where the parasites can live. The World Health Organization estimates that between 300 and 500 million cases of malaria are diagnosed each year (WHO). The disease kills 1 million people annually. In the United States, the Centers for Disease Control and Prevention report that 1,500 cases of malaria are reported each year (CDC). Most cases of malaria develop in people who travel to countries where malaria is more common.
Malaria can occur if a mosquito infected with the Plasmodium parasite bites you. In addition, an infected mother can pass the disease to her baby at birth. This is known as congenital malaria. Because malaria is transmitted by blood, it can also be transmitted through:
- an organ transplant
- a transfusion
- shared use of needles or syringes
Symptoms of malaria typically develop within 10 days to four weeks following the infection. In some patients, 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 are moderate to severe
- high fever
- profuse sweating
- muscle pain
- bloody stools
Diagnosis of malaria is made by your doctor. During your appointment, your doctor will review your health history, including any recent travel to tropical climates. He or she will also perform a physical exam. 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 or not you have malaria
- what type of malaria you have
- if your infection is caused by a parasite that is resistant to certain types of drugs
- if the disease has caused anemia
- if the disease has affected your vital organs
Malaria can cause a number of life-threatening complications that can result in death. The following may occur:
Malaria is a life-threatening condition. 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 will not be effective. Drug-resistant parasites have been reported. These parasites make many drugs ineffective. If this occurs, your doctor may need to change medications or use more than one medication to treat your condition.
Patients 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 produce additional health complications.
There is no vaccine available to prevent malaria. If you are traveling to an area where malaria is common, talk to your doctor. He or she may prescribe medications to prevent the disease. These medications are the same as those used to treat the disease and can be taken before, during, and after your trip.
You may also want to take extra precautions while traveling. 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.