Malaria symptoms can begin with flu-like symptoms. In the early stages, infection from P. falciparum is similar to infection from P. vivax, P. malariae, and P. ovale. You may have no symptoms or symptoms that are less severe if you are partially immune to malaria.
The time from the initial malaria infection until symptoms appear (incubation period) typically ranges from:2
- 9 to 14 days for Plasmodium (P.) falciparum.
- 12 to 18 days for P. vivax and P. ovale.
- 18 to 40 days for P. malariae.
- 11 to 12 days for P. knowlesi.
The symptoms of malaria typically develop within 7 days to 4 weeks following the infection. Some malarial parasites can enter the body but will be dormant for long periods of time. In some people, the time between exposure and signs of illness may sometimes be as long as 8 to 10 months with P. vivax and P. ovale.
Here are some things to keep in mind:
- Because the signs are so similar to cold or flu symptoms, it might be hard to tell what you have at first.
- Malaria symptoms don’t always show up within 2 weeks, especially if it’s a P. vivax infection.
- People who live in areas with lots of malaria cases may become partially immune after being exposed to it throughout their lives.
- The incubation period may be longer if you are taking medicine to prevent infection (chemoprophylaxis) or because you have some immunity due to previous infections.
Malaria transmission cycle
Variation in Malaria symptoms
In regions where malaria is present, people who get infected many times may have the disease but have few or no symptoms.3
Also, how bad malaria symptoms are can vary depending on your general health, what kind of malaria parasite you have, and whether you still have your spleen.
A malaria infection is generally characterized by recurrent attacks with the following signs and symptoms:
- shaking chills that can range from moderate to severe
- high fever
- profuse sweating
- headache
- nausea
- vomiting
- abdominal pain
- diarrhea
- anemia
- muscle pain
- convulsions
- coma
- bloody stools
When to see a doctor
Talk to your doctor if you experience a high fever while living in or after traveling to a high-risk malaria region. The parasites that cause malaria can lie dormant in your body for up to a year. If you have severe symptoms, seek emergency medical attention.