Clinician's Corner - Minnesota Department of Health

Malaria Quick Guide

On this page:
Screening and Diagnosis
Full Provider Guide Chapter: Malaria

Screening and Diagnosis

  • Clinicians should have a high index of suspicion for malaria, particularly for refugees from tropical and subtropical areas who have fever of unknown origin or other characteristic symptoms.

Asymptomatic Subclinical Infection

  • Sub-Saharan Africans frequently originate in highly endemic areas where potentially asymptomatic subclinical infection is common and should undergo either presumptive treatment on arrival (preferred) if there is no documentation of pre-departure therapy, or have laboratory screening.
    • Pregnant women, lactating women, and persons with other contraindications such as allergy or hypersensitivity to medications are excluded from all presumptive regimens. These individuals should undergo diagnostic testing and receive directed treatment if they are found to have malaria and may need to be referred to a specialist for therapy.
  • For all other refugees, subclinical infection is rare and testing should be performed only in individuals with signs or symptoms suggestive of disease.
  • Polymerase chain reaction is more sensitive in asymptomatic individuals and is the test of choice when available.

Symptomatic Infection

  • If malaria is suspected due to symptoms (e.g., fever), laboratory evaluation should be performed. Malaria blood films (i.e., thick and thin smears) and rapid antigen testing are the most widely available diagnostic techniques.
  • Diagnosis should be confirmed by experienced personnel.


  • Because treatment varies by species of Plasmodium and may be complicated, if the practitioner is not comfortable, expert advice should be sought.
  • When there is a diagnostic dilemma, or when appropriate treatment recommendations are sought, local infectious disease/tropical medicine experts or the CDC Malaria Hotline should be contacted.


  • Plasmodium falciparum is the most aggressive species of malaria to infect humans and can lead to death within less than 12 hours following the onset of symptoms among those with no immunity.
  • Acute clinical consequences of infection and disease are most severe in persons who are non-immune; as a result, in highly endemic areas young children account for most deaths due to malaria. In contrast, in highly endemic (hyper-, holoendemic) areas, a majority of the older individuals in the population have acquired partial immunity and as a result may have few symptoms or subclinical infection. Areas with high endemnicity of P. falciparum include most of West and Central and portions of East Africa
  • Other species of human malaria (non-falciparum) are found less frequently in sub-Saharan Africa and generally do not result in severe disease or death.
  • Other areas, such as Central Asia, South Asia, Southeast Asia, and parts of Latin America and the Caribbean have varying levels of malaria transmission, although rarely reaching hyper- or holoendemic levels and  have higher percentages of non-falciparum malaria (i).
  • Anopheles mosquitoes capable of transmitting malaria do exist in Minnesota. If the population of Anopheles mosquitoes were in sufficient numbers near a malaria-infected person(s), local transmission could occur.

Full Provider Guide Chapter: Malaria


i. Centers for Disease Control and Prevention. Malaria: domestic guidelines. Accessed Oct 29, 2009. Attention: Non-MDH link




Updated Thursday, September 15, 2011 at 04:21PM