What should you know about human malaria?

Malaria parasites enter the bloodstream after a bite from an infected mosquito. Illness may include fever, chills, sweating, headache, weakness or muscle aches. Symptoms can start after travel and may appear after you have returned home, so tell a clinician about recent travel, including dates and areas visited. Malaria can worsen quickly and symptoms may resemble other infections; a clinical assessment and blood testing are needed to confirm it.

Different malaria parasites and travel regions affect the choice of treatment. Previous malaria, pregnancy, age and other health conditions also matter.

If you develop a fever during or after travel to a malaria area, seek same-day medical advice and mention the travel history before the appointment. A blood test may be repeated when an early result does not explain ongoing symptoms. Take prescribed treatment exactly as directed and do not share leftover medicines. For future trips, arrange a travel health consultation and ask whether malaria prophylaxis is suitable for your destination.

Go to emergency care for confusion, seizures, difficulty breathing, collapse, severe weakness, repeated vomiting or inability to drink. Urgent assessment is also needed for fever after travel if you are pregnant, very young, older or immunocompromised. Chills or muscle aches with fever should not be dismissed after possible exposure.

Ask which blood tests are needed, whether treatment should begin while testing continues, how medicines should be taken, and what protection is recommended for your next trip.