Clinical Picture Of Malaria

Malaria is an acute and chronic protozoan infection transmitted by Anopheles mosquitoes to humans or may also occur due to transfusion of infected blood.

There are four species that cause human infection:

Plasmodium falciparum, P.malarie, P.vivax and P.ovale. The infection is common in those who live in endemic areas or travellers.

Symptoms

The symptoms include high fever with chills and rigor followed by sweating. The fever may be periodic in nature (but most of the patients do not exhibit this). Other symptoms include headache, impairment in consciousness, behavioural changes, generalized flu-like symptoms, malaise, myalgia, anorexia, pain, vomiting and diarrhoea.

Pyrexia (high temperature) is seen often upto 40 degree Celsius. Splenomegaly is found in those with chronic infection. Seizure activity and increased muscle tone may be seen in case of cerebral malaria.

Periodicity

P.falciparum (also known as malignant tertian malaria) does not have a specific periodicity in a non-immune individual. The patient may have a persistent fever. Due to presence of massive parasitemia (parasites in blood), the patient may have serious complications like renal failure, CNS involvement, pulmonary oedema, gastroenteritis, anaemia and thrombocytopenia. This is the only infection that may have a fatal outcome.

P.malarie (also known as quartan malaria) in which the patient gets the attack after every 72 hours. This disease can become chronic and may even lead to nephritic syndrome.

P.vivax (also known as benign tertian malaria) and P.ovale in which the patient gets the attack after every 48 hours.

Diagnosis

Malaria can be diagnosed by full blood count (showing anaemia, leucopenia, thrombocytopenia, hemolysis and parasitemia). Three separate blood samples are examined (malarial smear). Head CT scan is done in case of cerebral malaria.

Treatment

The treatment is usually provided as outpatient except in acute phase or in non-immunized individuals. In severe cases, complications must be watched for such as severe anaemia, renal failure etc.

Prevention

Future exposures must be prevented through necessary preventive measures. These include prevention of mosquito bites and malarial chemoprophylaxis. Malarial prophylactic agents must be used when visiting an endemic area. Also, one must avoid blood donation if infected.

Awareness of risk, avoidance of mosquito bites at night, sleeping in screened (or bed net) accommodation and spraying insecticides every evening can be done. Anti-malarial drugs are contraindicated in pregnancy.

Prognosis

Only falciparum infection carries a poor prognosis with high mortality if untreated. However, if diagnosed early and treated appropriately, the prognosis is excellent.