Some population groups are at considerably higher risk of contracting malaria, and developing severe disease, than others. These include pregnant women, infants, children under 5 years of age and patients with HIV/AIDS, as well as non-immune migrants, mobile populations and travellers. National malaria programmes need to take special measures to protect these population groups from malaria infection, taking into consideration their specific circumstances.
Malaria in pregnancy increases the risk of maternal and fetal anaemia, stillbirth, spontaneous abortion, low birth weight and neonatal death. Infants born to mothers living in endemic areas are vulnerable to malaria from approximately 3 months of age, when immunity acquired from the mother starts to wane.
In high-transmission areas of the world, children under 5 years of age (including infants) are the most vulnerable group. Severe anaemia, hypoglycemia and cerebral malaria are features of severe malaria more commonly seen in children than in adults.
HIV increases the risk of malaria infection, severe malaria and death, while malaria may result in the worsening of clinical AIDS. Interaction between malaria and HIV infection can have serious consequences, particularly for pregnant women.
Migrants, refugees and other mobile population groups often lack partial immunity to malaria, and have limited access to prevention, diagnostic testing and treatment services.