Malaria

Malaria is an infectious disease spread by mosquitoes that usually produces high fever and chills.

Malaria is caused by Plasmodium parasites. Five species may infect humans:

• Plasmodium Falciparum
• Plasmodium Civax
• Plasmodium Ovale
• Plasmodium Malariae
• Plasmodium Knowlesi

Malaria is transmitted by the bite of an infected female mosquito of the Anopheles genus.

Malaria is most prevalent in sub-Saharan Africa, Southeast Asia, Oceania, Central America and the Amazon region.

The disease may affect anyone, but some groups are at considerably higher risk of contracting malaria, such as children under 5 years of age, pregnant women and patients with chronic diseases.

People in areas with intense malaria transmission can develop some type of immunity that provide protection against the infection. On the other hand, people who visit occasionally these areas are at a higher risk of infection.

Patients infected with malaria typically begin to develop the symptoms following a 10- to 15-day incubation period post-exposure.

The main symptoms are:

• High fever
• Chills
• Headache
• Sweating
• Myalgia (muscle pains)
• Anemia
• Diarrhea and vomiting
• Hepatosplenomegaly (enlargement of liver and spleen)
• Jaundice (yellowing of the skin and the whites of the eyes)

The most important complications of malaria are:

• Cerebral malaria (seizures or coma with a high mortality)
• Respiratory distress
• Septic shock

The best way to diagnose malaria involves the visualization of the parasites in a blood sample. For this matter, there are some screening tests available:

• Thick and thin smears for malaria
• Malaria rapid diagnostic tests (RDTs)
• PCR assay (Polymerase Chain Reaction)

The recommended treatment for malaria depends on the species of parasite that had caused the disease, the drug resistance, the geographic region and the severity of the disease.

The most used antimalarial drugs are:

• Artemether and Lumefantrine
• Artesunate
• Mefloquine
• Primaquine
• Quinine
• Amodiaquine
• Clindamycin
• Doxycycline
• Chloroquine

Prevention and control measures designed to halt the spread of malaria include:

• Malaria vaccine: Mosquirix is the name of the only approved vaccine to prevent malaria (limited efficacy)
• Indoor residual spraying (IRS)
• Netting windows or door screens
• Protective clothing (wearing light-colored and long-sleeved clothing)
• Use of mosquito repellents
• Insecticide-impregnated bed nets

Persons travelling to endemic areas should ask their doctor if it is necessary prophylaxis (measures to prevent infection) before the journey. Prophylaxis may include medication to reduce the risk of malaria for short-term travelers.