Common symptoms of malaria
In the early stages, malaria symptoms are sometimes similar to those of many other infections caused by bacteria, viruses, or parasites. Symptoms may include:
Symptoms may appear in cycles and may come and go at different intensities and for different lengths of time. But, especially at the beginning of the illness, the symptoms may not follow this typical pattern.
The cyclic pattern of malaria symptoms is due to the life cycle of malaria parasites as they develop, reproduce, and are released from the red blood cells and livercells in the human body. This cycle of symptoms is also one of the major indicators that you are infected with malaria.
Other common symptoms of malaria
Other common symptoms of malaria include:
Infection with the P. falciparum parasite is usually more serious and may become life-threatening.
There are other conditions with symptoms similar to a malarial infection. It is important that you see your doctor to find out the cause of your symptoms.
What Increases Your Risk
Factors that increase your risk of getting malaria include:
- Living or traveling in a country or region where malaria is present.
- Traveling in an area where malaria is common and:
- Not taking medicine to prevent malaria before, during, and after travel, or failing to take the medicine correctly.
- Being outdoors, especially in rural areas, between dusk and dawn (nighttime), when the mosquitoes that transmit malaria are most active.
- Not taking steps to protect yourself from mosquito bites.
Exams and Tests
Doctors use thick and thin blood smears to determine whether malaria-causing parasites are present in your blood. These tests should be done if you have been in a region where malaria is present, were exposed to mosquitoes, and have developed flu-like symptoms.
- A blood smear is prepared from a blood sample.
- If the first blood smear does not show the presence of malaria parasites but your doctor suspects malaria, you should have a repeat test every 8 to 12 hours for 36 hours.
- During treatment, doctors use blood smears to see whether the number of malaria parasites in the blood is decreasing.
A blood test that can diagnose malaria rapidly also is available. If this rapid test indicates a person has malaria, the results are usually confirmed with a blood smear.
Other useful tests that may be done include:
- Liver function tests, to check for liverdamage.
- Complete blood count (CBC), to check foranemia or evidence of other possible infections. Anemia sometimes develops in people with malaria, because the parasites damage red blood cells.
- A blood glucose test, to measure the amount of a type of sugar, called glucose, in your blood.
Other tests being developed to diagnose malaria include genetic tests or other blood tests that highlight parasites by using special stains. These experimental tests are not as easy to do and are not as frequently used as blood smears.
You can take medicines called antimalarials to prevent and treat malaria. Malaria is a very serious disease, and its presence in many regions of the world is well known. So if you are traveling to an area where malaria is present, it is important to consider taking medicine before you travel, while you are in the area, and after you return home to reduce the risk of infection. Which medicine you take is based on:
- The country or areas in which you will be traveling.
- The resistance of malaria parasites to certain medicines in the area where you will be traveling.
- Your health condition (for example, you are pregnant, elderly or young, sick, or have immunity or resistance to malaria).
It is important to know which species of parasite is present, because serious complications may develop rapidly in a person who is infected with Plasmodium (P.) falciparum. Drug treatment is based on:
- The density of parasites. If the percentage of red blood cells infected (parasite density) is over 5%, treatment may include medicines given directly into a vein (intravenously, or IV) rather than medicine taken by mouth.
- Your health condition. You are at higher risk for having complications if you are pregnant, elderly, very young, or have a weak immune system. Different medicines may be prescribed for people in these groups.
- Drug resistance in the geographic area where the infection occurred. For instance, in many areas P. falciparum is resistant to the drug chloroquine.
During malaria treatment, your doctor may do daily blood smears to follow the course of the infection. Most medicines for malaria are ones you take by mouth. But you might get intravenous (IV) medicines if there are complications or your condition gets worse. If there are no complications, your fever will clear in 36 to 48 hours. And most parasites will disappear from your blood within 2 or 3 days.
The medicines used may change as malaria parasites develop resistance and as new medicines are developed.
There are several medicines for preventing and treating malaria.
Medicines to prevent malaria
A doctor or local health department can consult the CDC for specific treatment guidelines for your travel destination. Standard medicines for preventing malaria include:
- Chloroquine. You can take chloroquine to prevent P. falciparum and P. vivaxinfections in areas where medicine resistance to chloroquine has not been confirmed.
- Mefloquine. You can take mefloquine to prevent malaria infections unless the malaria parasite in the area you’re visiting is resistant to mefloquine. Do not take mefloquine if you have a history of active or recent depression or other mental illness, seizures, or some types of heart-rhythm problems.
- Doxycycline. You can take doxycycline if you cannot take mefloquine. Women who are pregnant and children younger than age 9 should not take this medicine.
- Primaquine. You take primaquine to prevent relapses of P. vivax and P. ovalemalaria. You should be tested for glucose-6-phosphate dehydrogenase deficiencybefore taking primaquine.
- Malarone. Malarone is a combination of two antimalarial medicines (atovaquoneand proguanil). Malarone is taken to prevent malaria caused by P. falciparum.
Medicines to treat infections
- Chloroquine is the most effective medicine for treating a malaria infection caused by P. ovale or P. malariae parasites. To prevent relapses of infections caused by these two parasites, continue taking chloroquine after you leave the area where these parasites are present. Chloroquine is also used to treat P. falciparum andP. vivax infections in areas where resistance to chloroquine has not been confirmed.
- Coartem is a combination of the two medicines artemether and lumefantrine. It is used to treat malaria caused by P. falciparum.
- When a malaria infection is caused by resistant strains of P. falciparum or P. vivax, treatment may be more difficult. When treatment with chloroquine does not work, you must take other medicines. These medicines may include:
- Malarone, which is a combination of two antimalarial medicines (atovaquone and proguanil). Malarone is taken to treat malaria caused by chloroquine-resistant P. falciparum.
- Doxycycline, for infections caused by P. falciparum and P. vivax in Thailand and Kenya.
- Quinine plus an antibiotic such as doxycycline, tetracycline, or clindamycin for most P. falciparum infections. It should not be used in Southeast Asia, wherequinine effectiveness is declining. It is only somewhat effective in Thailand.
- Coartem, which is a combination of the two medicines artemether and lumefantrine. It is used to treat malaria caused by chloroquine-resistant P. falciparum.
You can get antimalarials intravenously (IV) if you are unable to take pills. IV delivery is also used for severe malaria. In the United States, quinidine is the medicine typically used in these situations.
Antimalarials to prevent recurrences
Some people have recurring flu-like symptoms for years after the initial malarial infection. Relapses from infection of P. vivax or P. ovale are the most common and can be prevented by taking primaquine.
What To Think About
- Children who weigh less than 33 lb (15 kg)should not visit an area that has a risk of chloroquine-resistant malaria.
- How effective medicines are in preventing and treating malaria depends on the medicine resistance of the parasites in the geographic location where the malaria infection occurs.
- If you are going to a location where malaria is present, it is very important to take preventive medicines and to follow the correct schedule for taking them. The majority of people who become infected with malaria did not take preventive malaria medicines or did not follow the correct dosing schedule.
- Pregnant women should discuss medicine options with their doctors.