What are the symptoms and treatment options for malaria?

Malaria Symptoms and Treatment

Malaria presents with fever and flu-like symptoms including chills, headache, myalgia, and malaise, with symptoms often occurring in cycles, and requires prompt treatment with appropriate antimalarial medications based on Plasmodium species and regional resistance patterns. 1, 2

Clinical Presentation

Common Symptoms

• Fever (often cyclical)
• Chills
• Headache
• Myalgia (muscle pain)
• Malaise
• Fatigue
• Nausea and vomiting
• Diarrhea 1, 3

Additional Clinical Findings

• Anemia
• Jaundice
• Thrombocytopenia
• Splenomegaly
• Hepatomegaly (particularly in children in endemic areas) 4, 3

Warning Signs of Severe Malaria

• Depressed consciousness or coma
• Seizures
• Respiratory distress
• Hypotension (systolic BP <80 mm Hg or <70 mm Hg in children <1 year)
• Severe anemia
• Hemoglobinuria
• Oliguria or anuria
• Jaundice
• Hemorrhagic complications
• Hypoglycemia (<3 mmol/L)
• Metabolic acidosis 1

Diagnosis

Diagnostic Methods

• Gold standard: Microscopic examination of Giemsa-stained thick and thin blood films
  • Allows parasite detection, species identification, and quantification of parasitemia
• Rapid Diagnostic Tests (RDTs)
  • Sensitivity: 67.9-100% for P. falciparum; 66-91% for P. vivax
  • Specificity: 93.1-100% for P. falciparum; 98-100% for P. vivax
• Nucleic Acid Amplification Tests (NAATs)
  • 10-100 times more sensitive than microscopy or RDTs 2

Important Diagnostic Considerations

• All febrile travelers returning from malaria-endemic areas should be evaluated for malaria
• Three negative thick blood films, taken 12 hours apart, generally exclude malaria
• Further testing is warranted if clinical suspicion remains high 1, 5

Treatment Approach

Uncomplicated Malaria

P. falciparum or Unknown Species

• First-line: Artemisinin-based Combination Therapy (ACT)
  • Dihydroartemisinin-piperaquine preferred due to longer half-life
• Alternative options (if ACTs unavailable):
  • Atovaquone-proguanil: Four tablets (adult strength; 1g atovaquone/400mg proguanil) once daily for 3 days
  • Quinine plus doxycycline or clindamycin 2, 6, 5

P. vivax, P. ovale, P. malariae, P. knowlesi

• First-line: ACT or chloroquine (in chloroquine-sensitive regions)
• Chloroquine dosing:
  • Adults: 600mg base initially, followed by 300mg at 24 and 48 hours (total 1500mg)
  • Children: 10mg/kg initially, 10mg/kg at 24 hours, and 5mg/kg at 48 hours 2

Radical Cure for P. vivax and P. ovale

• Required to eliminate liver hypnozoites:
  • Primaquine: 15mg (base) daily for 14 days
  • OR Tafenoquine: single 300mg dose
• Important: G6PD testing required before administration
• Contraindicated during pregnancy and breastfeeding 2

Severe Malaria

• First-line: Intravenous artesunate
  • Dosing: 2.4mg/kg IV at 0,12, and 24 hours, then daily
  • Continue until parasitemia <1% and patient can take oral medication
  • Complete treatment with full course of oral ACT
• Alternative (if artesunate unavailable): IV quinine dihydrochloride 1, 2, 7

Special Considerations

• Persistent vomiting: Switch to IV therapy as this may reflect impending organ failure 8
• Pregnancy: Artemisinin combinations not recommended in first trimester
• Renal impairment: Avoid atovaquone-proguanil for prophylaxis in severe renal impairment; use with caution for treatment 6

Prevention

Chemoprophylaxis for Travelers

• Start 1-2 days before entering endemic area, continue daily during stay and for 7 days after return
• Options:
  • Chloroquine: 300mg base weekly (in chloroquine-sensitive areas)
  • Mefloquine: 250mg weekly (in chloroquine-resistant areas)
  • Atovaquone-proguanil: One tablet daily 1, 6

Additional Preventive Measures

• Insecticide-treated bed nets
• Protective clothing
• Insect repellents
• Vector control measures 2

Monitoring Response to Treatment

• Monitor parasitemia every 24 hours until negative for uncomplicated malaria
• For severe malaria, monitor every 12 hours until <1%, then every 24 hours until negative
• Consider treatment failure if symptoms persist after 48-72 hours of treatment 2

Common Pitfalls

• Failure to consider malaria in febrile travelers returning from endemic areas
• Inadequate prophylaxis (71.7% of US residents diagnosed with malaria had not taken chemoprophylaxis)
• Delayed treatment of severe malaria (should be considered a medical emergency)
• Failure to provide radical cure for P. vivax and P. ovale infections
• Not testing for G6PD deficiency before administering primaquine or tafenoquine 1, 5