๐ About
- ๐ฆ Malaria is a life-threatening disease caused by Plasmodium parasites, transmitted by infected female Anopheles mosquitoes.
- โก Even when not fatal, malaria causes major debility, reducing productivity and quality of life.
- ๐ฉโ๐ฆฑ๐ง Predominantly affects working-aged adults โ high socioeconomic burden.
- ๐ค Closely linked with poverty, high infant mortality, and chronic morbidity.
- ๐ See BNF for Current Treatment Guidelines
๐ Etymology
- The word "malaria" comes from Italian "mala aria" โ โbad air,โ from the ancient belief it arose from marsh vapours.
๐งฌ Types of Plasmodium
- โซ P. falciparum: Deadliest form, majority of severe disease & deaths, esp. Africa.
- ๐ข P. vivax: Relapses due to dormant hypnozoites, more common outside Africa.
- ๐ฃ P. ovale: Similar to vivax; forms hypnozoites โ relapse risk.
- ๐ก P. malariae: Milder, but can persist for years โ chronic infection.
- ๐ด P. knowlesi: Zoonotic (SE Asia); rapidly progressive, often misdiagnosed as P. malariae.
โ ๏ธ Risk Factors
- ๐งฌ Sickle cell trait โ partial protection vs P. falciparum.
- ๐ฉธ Duffy-negative blood group โ resistance to P. vivax (common in Africa).
- ๐ Repeated infections โ partial immunity but species/strain-specific.
- ๐ถ Infants & children โ highest risk of severe disease.
- ๐งโโ๏ธ Adults returning to endemic areas lose immunity โ vulnerable again.
โณ Incubation Periods
- โซ P. falciparum: 10โ14 days.
- ๐ข P. vivax / P. ovale: 10โ14 days + months/years later relapse.
- ๐ก P. malariae: 18 daysโ6 weeks; can persist long-term.
- ๐ด P. knowlesi: 9โ12 days.
๐ฉบ Clinical Presentation
- ๐ก๏ธ Cyclical fever, chills, and sweats (classic paroxysms).
- ๐ค Headache, myalgia, nausea, vomiting, malaise.
- โซ P. falciparum: Severe complications โ cerebral malaria, hypoglycaemia, anaemia, organ failure.
- ๐ Chronic infection โ splenomegaly, anaemia, higher risk of coinfections.
- ๐ถ Neonates relatively protected in first 6 months (maternal antibodies + fetal Hb).
๐ฌ Investigations
- Microscopy:
- ๐งช Thick film โ sensitive for detection.
- ๐ Thin film (Giemsa) โ species ID + parasitaemia quantification.
- Repeat over 48 hrs if negative but suspicion high.
- ๐ก RDTs: Detect antigens (useful without labs).
- ๐งฌ PCR: Species confirmation, low-level parasitaemia.
- ๐ Supportive: CBC (anaemia, thrombocytopenia), LFTs, RFTs, pregnancy test.
๐ Management
Depends on Plasmodium species, severity, and local resistance patterns.
๐ฟ Non-Falciparum Malaria
- ๐ข P. vivax, ๐ฃ P. ovale, ๐ก P. malariae, ๐ด P. knowlesi.
- ๐ Chloroquine (if no resistance).
- ๐ ACTs (e.g. artemether-lumefantrine, atovaquone-proguanil) if chloroquine-resistant.
- ๐ Primaquine for vivax/ovale radical cure (kills liver hypnozoites). โ ๏ธ Test for G6PD first!
- ๐งด Severe cases โ IV artesunate or IV quinine.
โซ Falciparum Malaria
- โฑ๏ธ Medical emergency โ rapid treatment needed.
- ๐ First-line: ACTs (artemether-lumefantrine, atovaquone-proguanil).
- ๐ Severe disease: IV artesunate preferred over quinine.
- ๐ ๏ธ Supportive: Correct hypoglycaemia, anaemia, seizures, renal failure.
- ๐คฐ Pregnancy โ special drug regimens (see NICE/BNF guidance).
๐ก๏ธ Prevention
- ๐๏ธ Bed nets + ๐ Indoor spraying + ๐ฆ source control.
- ๐ Chemoprophylaxis for travellers (per guidelines).
- ๐ Vaccination: RTS,S/AS01 in children in endemic regions.
- ๐๐งด Protective clothing + DEET repellents.
๐ Key Points
- โฑ๏ธ Early diagnosis + treatment = prevents deaths & reduces transmission.
- โ ๏ธ Drug resistance rising โ always follow updated guidance.
- ๐ฌ Ongoing research & public health measures are crucial for elimination goals.
Cases โ Malaria
- Case 1 โ Severe falciparum malaria ๐: A 27-year-old man returns from Nigeria with 3 days of fever, rigors, and confusion. Exam: jaundice, splenomegaly, GCS 12/15. Bloods: Hb 8.5 g/dL, platelets 40 ร10โน/L, creatinine 280 ยตmol/L. Blood film: Plasmodium falciparum parasitaemia 8%. Diagnosis: severe falciparum malaria. Managed with IV artesunate, ICU support, and careful fluid balance.
- Case 2 โ Relapsing malaria ๐: A 32-year-old woman returns from India with intermittent fevers every 48 hours, sweats, and malaise. Thick/thin films: Plasmodium vivax. Exam: splenomegaly, mild anaemia. Diagnosis: vivax malaria. Managed with chloroquine for acute episode, followed by primaquine to eradicate hypnozoites in the liver.
- Case 3 โ Imported uncomplicated malaria โ๏ธ: A 19-year-old student presents with fever, myalgia, and diarrhoea after a gap year in Ghana. She did not take prophylaxis. Blood film: ring forms of Plasmodium falciparum, parasitaemia 0.8%. Diagnosis: uncomplicated falciparum malaria. Managed with oral artemisinin-based combination therapy (e.g. artemether-lumefantrine) and supportive care.
Teaching Point ๐ฉบ:
- P. falciparum: most severe, risk of cerebral malaria, renal failure, ARDS.
- P. vivax / ovale: relapsing infection due to liver hypnozoites.
- P. malariae: quartan fevers, chronic nephrotic syndrome.
Diagnosis: thick & thin blood films, rapid antigen tests.
Management: species- and severity-specific antimalarials; prevention with prophylaxis and mosquito avoidance.