Clinical manifestations of malaria
- Joel G Breman, MD, DTPH
Joel G Breman, MD, DTPH
- Senior Scientist Emeritus
- Fogarty International Center, National Institutes of Health
The clinical manifestations of malaria vary with geography, epidemiology, immunity, and age. In areas where malaria is highly endemic, groups at highest risk include young children (6 to 36 months), who can develop severe illness, and pregnant women, who are at risk for anemia and delivering low birth weight newborns. In areas where malaria is transmitted throughout the year, older children and adults develop partial immunity after repeated infections and are at relatively low risk for severe disease.
Travelers to malarious areas generally have had no previous exposure to malaria parasites or have lost their immunity if they left the endemic area; they are at very high risk for severe disease if infected with Plasmodium falciparum [1,2]. For this reason, it is important to consider malaria in all febrile patients with history of travel to malarious areas.
The clinical manifestations of malaria will be reviewed here. The epidemiology, pathogenesis, diagnosis, and treatment of malaria are discussed in detail separately. (See related topics.)
Following the bite of an infected female Anopheles mosquito, the inoculated sporozoites go to the liver within one to two hours. Individuals are asymptomatic for 12 to 35 days (depending on parasite species), until the erythrocytic stage of the parasite life cycle (figure 1). Release of merozoites from infected red cells when they rupture causes fever and the other manifestations of malaria.
In most cases, the incubation period for P. falciparum infection is about 12 to 14 days (range 7 to 30 days); most infections due to P. falciparum become clinically apparent within one month after exposure [3-5]. Longer incubation periods are more likely in semi-immune individuals and individuals taking ineffective malaria prophylaxis.
- Wilson ME, Weld LH, Boggild A, et al. Fever in returned travelers: results from the GeoSentinel Surveillance Network. Clin Infect Dis 2007; 44:1560.
- Svenson JE, MacLean JD, Gyorkos TW, Keystone J. Imported malaria. Clinical presentation and examination of symptomatic travelers. Arch Intern Med 1995; 155:861.
- Schwartz E, Parise M, Kozarsky P, Cetron M. Delayed onset of malaria--implications for chemoprophylaxis in travelers. N Engl J Med 2003; 349:1510.
- World Health Organization. International travel and health: Malaria. http://www.who.int/ith/diseases/malaria/en/ (Accessed on July 28, 2015).
- Centers for Disease Control and Prevention. Malaria: Disease. http://www.cdc.gov/malaria/about/disease.html (Accessed on July 28, 2015).
- White NJ, Breman JG. Harrisons Principles of Internal Medicine, 19th ed, Kasper D, Fauci A, Hauser S, et al (Eds), McGraw Hill, New York 2015, in press.
- Mühlberger N, Jelinek T, Gascon J, et al. Epidemiology and clinical features of vivax malaria imported to Europe: sentinel surveillance data from TropNetEurop. Malar J 2004; 3:5.
- Durante Mangoni E, Severini C, Menegon M, et al. Case report: An unusual late relapse of Plasmodium vivax malaria. Am J Trop Med Hyg 2003; 68:159.
- Brooker S, Akhwale W, Pullan R, et al. Epidemiology of plasmodium-helminth co-infection in Africa: populations at risk, potential impact on anemia, and prospects for combining control. Am J Trop Med Hyg 2007; 77:88.
- Severe malaria. Trop Med Int Health 2014; 19 Suppl 1:7.
- White NJ. The treatment of malaria. N Engl J Med 1996; 335:800.
- Devarbhavi H, Alvares JF, Kumar KS. Severe falciparum malaria simulating fulminant hepatic failure. Mayo Clin Proc 2005; 80:355.
- FIELD JW. Blood examination and prognosis in acute falciparum malaria. Trans R Soc Trop Med Hyg 1949; 43:33.
- Lampah DA, Yeo TW, Malloy M, et al. Severe malarial thrombocytopenia: a risk factor for mortality in Papua, Indonesia. J Infect Dis 2015; 211:623.
- Steketee RW, Nahlen BL, Parise ME, Menendez C. The burden of malaria in pregnancy in malaria-endemic areas. Am J Trop Med Hyg 2001; 64:28.
- Severe falciparum malaria. World Health Organization, Communicable Diseases Cluster. Trans R Soc Trop Med Hyg 2000; 94 Suppl 1:S1.
- Stanley J. Malaria. Emerg Med Clin North Am 1997; 15:113.
- Mung'Ala-Odera V, Snow RW, Newton CR. The burden of the neurocognitive impairment associated with Plasmodium falciparum malaria in sub-saharan Africa. Am J Trop Med Hyg 2004; 71:64.
- Seydel KB, Kampondeni SD, Valim C, et al. Brain swelling and death in children with cerebral malaria. N Engl J Med 2015; 372:1126.
- Lewallen S, Bronzan RN, Beare NA, et al. Using malarial retinopathy to improve the classification of children with cerebral malaria. Trans R Soc Trop Med Hyg 2008; 102:1089.
- Jakka SR, Veena S, Atmakuri RM, Eisenhut M. Characteristic abnormalities in cerebrospinal fluid biochemistry in children with cerebral malaria compared to viral encephalitis. Cerebrospinal Fluid Res 2006; 3:8.
- Christensen SS, Eslick GD. Cerebral malaria as a risk factor for the development of epilepsy and other long-term neurological conditions: a meta-analysis. Trans R Soc Trop Med Hyg 2015; 109:233.
- Reyburn H, Mbatia R, Drakeley C, et al. Association of transmission intensity and age with clinical manifestations and case fatality of severe Plasmodium falciparum malaria. JAMA 2005; 293:1461.
- Ranque S, Safeukui I, Poudiougou B, et al. Familial aggregation of cerebral malaria and severe malarial anemia. J Infect Dis 2005; 191:799.
- Idro R, Ndiritu M, Ogutu B, et al. Burden, features, and outcome of neurological involvement in acute falciparum malaria in Kenyan children. JAMA 2007; 297:2232.
- Barsoum RS. Malarial acute renal failure. J Am Soc Nephrol 2000; 11:2147.
- Taylor WR, Hanson J, Turner GD, et al. Respiratory manifestations of malaria. Chest 2012; 142:492.
- Berkley JA, Bejon P, Mwangi T, et al. HIV infection, malnutrition, and invasive bacterial infection among children with severe malaria. Clin Infect Dis 2009; 49:336.
- Morpeth SC, Ramadhani HO, Crump JA. Invasive non-Typhi Salmonella disease in Africa. Clin Infect Dis 2009; 49:606.
- INCUBATION PERIOD
- CLINICAL MANIFESTATIONS
- Uncomplicated malaria
- Complicated malaria
- Cerebral malaria
- Renal impairment
- Noncardiogenic pulmonary edema
- Hematologic abnormalities
- Liver dysfunction
- Concomitant infection
- CHILDREN VERSUS ADULTS
- RECRUDESCENCE OR RELAPSE
- COEXISTING CONDITIONS
- DIFFERENTIAL DIAGNOSIS
- INFORMATION FOR PATIENTS