Overview
Definition:
Fever in a child who has recently returned from an endemic area is a medical emergency and strongly suggestive of malaria until proven otherwise, regardless of chemoprophylaxis use
Malaria is a life-threatening parasitic disease transmitted by infected Anopheles mosquitoes.
Epidemiology:
Malaria is endemic in over 90 countries
Children, especially those under five years, are disproportionately affected and have higher morbidity and mortality
In India, malaria remains a significant public health problem, particularly in endemic states.
Clinical Significance:
Delayed diagnosis and treatment of malaria in returning pediatric travelers can lead to severe complications including cerebral malaria, severe anemia, acute respiratory distress syndrome (ARDS), renal failure, and death
Prompt and accurate testing is paramount for timely intervention.
Clinical Presentation
Symptoms:
Fever, often high and cyclical
Chills and rigors
Profuse sweating
Headache
Malaise
Myalgias
Nausea and vomiting
Diarrhea
Abdominal pain
Pallor
Jaundice may develop
In severe cases: altered mental status, seizures, difficulty breathing, oliguria.
Signs:
Fever (>37.5°C)
Tachycardia
Tachypnea
Pallor
Jaundice
Hepatosplenomegaly
Signs of dehydration
Signs of shock
Neurological deficits (e.g., lethargy, coma) in severe malaria.
Diagnostic Criteria:
No specific diagnostic criteria for malaria in returning travelers exist beyond the clinical suspicion combined with a travel history to an endemic region and subsequent laboratory confirmation of Plasmodium parasites.
Diagnostic Approach
History Taking:
Detailed travel history: destination country/region, duration of stay, dates of travel, activities undertaken (e.g., outdoor exposure, sleeping arrangements), use of malaria chemoprophylaxis (drug, adherence, adverse effects), previous malaria episodes
Symptom onset and progression
Febrile pattern
Any associated symptoms.
Physical Examination:
General appearance: assess for distress, dehydration, shock
Vital signs: temperature, pulse, respiratory rate, blood pressure
Full systemic examination, focusing on: neurological status (GCS), respiratory system (breath sounds), cardiovascular system (heart sounds, perfusion), abdominal examination (hepatosplenomegaly), skin (pallor, jaundice).
Investigations:
Microscopy: Peripheral blood smear (PBS) for malaria parasites (Giemsa-stained thick and thin films)
This is the gold standard for diagnosis and species identification
Sensitivity depends on parasite density and microscopist skill
Rapid Diagnostic Tests (RDTs): Detect malaria parasite antigens
Useful for quick diagnosis, especially in resource-limited settings
However, they cannot quantify parasitemia and may have lower sensitivity for low-grade infections or specific Plasmodium species
Polymerase Chain Reaction (PCR): Highly sensitive and specific for detecting Plasmodium DNA
Useful for species identification and detecting low-level parasitemia, but not routinely available for immediate diagnosis
Complete Blood Count (CBC): Anemia, thrombocytopenia are common
Liver function tests (LFTs): Elevated bilirubin, transaminases
Renal function tests (RFTs): Assess for renal impairment
Blood glucose: Hypoglycemia can occur, especially in severe malaria
Coagulation profile: May show coagulopathy.
Differential Diagnosis:
Other febrile illnesses in returning travelers: Dengue fever, Typhoid fever, Viral hepatitis, Rickettsial infections, Bacterial sepsis, Leptospirosis, Viral gastroenteritis
Non-malarial febrile illnesses acquired locally.
Management
Initial Management:
Immediate commencement of empirical antimalarial treatment if malaria is strongly suspected and diagnosis cannot be rapidly confirmed
Supportive care: hydration (oral or intravenous fluids), antipyretics (paracetamol)
Obtain blood for diagnostic tests before starting treatment if possible.
Medical Management:
Antimalarial treatment depends on the suspected or confirmed Plasmodium species, severity of illness, age, weight, and local drug resistance patterns
For *Plasmodium falciparum* malaria: Artemisinin-based combination therapy (ACT) is the first-line treatment in most regions
In India, specific ACT regimens (e.g., Artemether-Lumefantrine) are recommended
For *Plasmodium vivax* and *P
ovale*: Treatment involves an asexual blood stage treatment followed by a radical cure with an 8-aminoquinoline (e.g., primaquine) to eradicate dormant liver hypnozoites
Glucose-6-phosphate dehydrogenase (G6PD) deficiency testing is crucial before primaquine administration to prevent hemolytic anemia
Uncomplicated malaria: Oral ACT
Severe malaria: Intravenous artesunate is the drug of choice, followed by oral ACT
Specific dosages vary by age and weight and should be guided by national/WHO guidelines.
Surgical Management:
Not applicable for malaria itself, but surgical intervention may be required for complications such as splenic rupture or bowel obstruction if present.
Supportive Care:
Close monitoring of vital signs, fluid balance, neurological status
Management of complications: seizures (benzodiazepines), ARDS (mechanical ventilation), renal failure (dialysis), anemia (blood transfusion), hypoglycemia (intravenous glucose)
Nutritional support
Isolation is not necessary for malaria treatment.
Complications
Early Complications:
Cerebral malaria (coma, seizures, neurological deficits)
Severe anemia
Acute respiratory distress syndrome (ARDS)
Acute kidney injury (AKI)
Hypoglycemia
Metabolic acidosis
Shock
Jaundice
Hemolysis
Splenic rupture (rare).
Late Complications:
Post-malarial neurological sequelae (rare)
Anemia requiring prolonged management
Relapses of vivax/ovale malaria if radical cure is inadequate.
Prevention Strategies:
Travellers should be educated about malaria risks and preventive measures: chemoprophylaxis (appropriate drug selection and adherence), use of insect repellent, protective clothing, mosquito nets, and staying in screened or air-conditioned accommodations
Prompt medical attention for any febrile illness during or after travel.
Prognosis
Factors Affecting Prognosis:
Prompt diagnosis and treatment are critical
The Plasmodium species involved (*P
falciparum* being the most dangerous)
The parasite density
The patient's age and immune status
Presence and severity of complications
Adherence to treatment
Access to appropriate medical care.
Outcomes:
With prompt diagnosis and appropriate treatment, the prognosis for uncomplicated malaria is generally excellent
Severe malaria can be life-threatening and carries a significant risk of mortality and long-term sequelae, particularly in young children.
Follow Up:
Children treated for uncomplicated malaria usually require a short follow-up to ensure resolution of symptoms and absence of anemia
Those treated for severe malaria require close monitoring for any residual neurological deficits or organ dysfunction
Children treated for P
vivax or P
ovale malaria require follow-up to ensure completion of radical cure, particularly the primaquine course, and monitoring for G6PD deficiency related complications.
Key Points
Exam Focus:
Always consider malaria in a febrile traveler from an endemic area
Microscopic examination of blood smear is gold standard
RDTs are useful but have limitations
ACTs are first-line for P
falciparum
Primaquine requires G6PD testing for radical cure of P
vivax/ovale
Severe malaria is a medical emergency.
Clinical Pearls:
Do not rely solely on chemoprophylaxis
it is not 100% effective
Test ALL febrile travelers returning from endemic areas, even if they have taken prophylaxis
A negative RDT does not rule out malaria if suspicion is high
send PBS
Be vigilant for complications of severe malaria, especially in young children.
Common Mistakes:
Delayed diagnosis due to considering other common febrile illnesses without adequate travel history
Inadequate investigations or misinterpretation of results
Inappropriate antimalarial treatment selection (e.g., using non-effective drugs for the region or Plasmodium species)
Failure to administer radical cure for P
vivax/ovale
Forgetting to test for G6PD deficiency before primaquine use
Underestimating the severity of malaria in children.