Malaria is the major cause of sickness and death in many developing countries. It is an infective disease caused by four species of the genus Plasmodium:

• P. falciparum - most dangerous form, accountable for majority of deaths throughout the world
• P. ovale - a relapsing malaria
• P. vivax - a relapsing malaria
• P. malariae - least common type present in UK (1)

A mixed infection commonly involving P. falciparum is seldom seen in patients (10 cases in 2005) (1).

Malaria is a tropical disease most commonly affecting people in Africa, South and Central America, Asia and the Middle East. It is not endemic in the UK (2). Rarely malaria can occur in people without a travel history which is known as "cryptic" malaria (2).

The infection is spread by female Anopheles mosquitoes.

P. falciparum malaria is the most severe being characterised by paroxysms of chills, sweats and haemolysis. Cerebral malaria is a potentially fatal complication.

Protective factors against malaria include sickle cell trait; HLA-B53 positive (1).

Reference:

• 1. Health protection agency 2007. Guidelines for malaria prevention in travelers from the United Kingdom
• 2. Health protection agency. Malaria