The most characteristic symptom of malaria is fever, sometimes alternating with sweating and chills. Generally, the symptoms are non-specific, including headache, muscle pain, fatigue, nausea and vomiting, diarrhoea and cough.

All four malaria parasites can also cause the following symptoms:

• Anaemia.
• Low platelet counts (thrombocytopenia).
• A swollen or tender liver.
• Jaundice: yellowing of the skin and the whites of the eyes.
• A tender and enlarged spleen.

Sometimes, the spleen can burst.

P. falciparum can infect a wider variety of red blood cells than other species of parasite, leading to higher parasite burdens, and severe malaria in non-immune individuals. Mortality of severe malaria can exceed 30%^[1].

Cerebral malaria is a complication of severe malaria caused by infection of the brain. It begins with headaches, an impaired state of consciousness or seizures. Without treatment, symptoms can rapidly progress to coma or death. Even with treatment, a small percentage of those who survive will have persistent neurological abnormalities.

Other complications sometimes seen with severe P. falciparum malaria include fluid in the lungs with breathing problems, low blood sugar levels, bleeding and anaemia requiring blood transfusions, and kidney impairment or failure.

Malaria and pregnancy

Malaria is particularly dangerous to pregnant women. Women who have never acquired immunity may experience acute malaria, loss of pregnancy, stillbirth and abortion.

Women from endemic areas may partially lose acquired immunity when they are pregnant. These women usually experience asymptomatic infections but can develop malaria in the placenta that leads to birth retardation, low birth rate and increased infant death rates during delivery. The risk of placental malaria is greatest during the first pregnancy, and much lower during subsequent pregnancies. However, this may not be the case in HIV-positive mothers.