Malaria: Causes, Symptoms, Treatment, and Prevention

Malaria: Causes, Symptoms, Treatment, and Prevention

Overview

• Malaria (also called paludism) is a serious and potentially deadly parasitic disease.
• It is caused by protozoa of the Plasmodium genus.
• Five species infect humans:
  • Plasmodium falciparum (most deadly)
  • Plasmodium vivax (most widespread)
  • P. malariae
  • P. ovale
  • P. knowlesi
• It is mainly transmitted through bites of infected female Anopheles mosquitoes.

High-Risk Groups

• Children under 5 years
• Pregnant women
• Infants
• Travellers to affected areas
• People living with HIV

Symptoms

• Appear 10–15 days after a mosquito bite (sometimes over a month later)
• Early symptoms:
  • Fever
  • Headache
  • Chills
• Severe symptoms (if untreated within 24 hours):
  • Extreme fatigue
  • Seizures
  • Bleeding
  • Difficulty breathing
  • Can lead to death
• In pregnancy:
  • Premature birth
  • Low birth weight
• Note: Some infected people show no symptoms

Diagnosis

• Thick blood smear (gold standard):
  • Blood examined under a microscope for parasites
• Thin blood smear:
  • Identifies parasite type and quantity
• PCR (molecular test):
  • Detects parasite DNA
• Rapid Diagnostic Tests (RDTs):
  • Detect parasite antigens
• Other methods:
  • Detect enzymes or antibodies

Global Impact (2023)

• 263 million cases worldwide
• 597,000 deaths
• Africa accounts for:
  • 94% of cases
  • 95% of deaths
• 76% of deaths occur in children under 5
• Most affected countries:
  • Nigeria
  • Democratic Republic of the Congo
  • Niger
  • Tanzania

Transmission

• Mainly through bites of infected female Anopheles mosquitoes
• Process:
  • Mosquito bites infected person → picks up parasite
  • Bites healthy person → transmits parasite
  • Parasites infect liver and then red blood cells
• Mosquito behavior:
  • Common in rural areas
  • Bite mostly from dusk to dawn
• Other transmission routes:
  • Blood transfusions
  • Organ transplants
  • Contaminated needles
  • Mother-to-child (during pregnancy or birth)

Treatment

• Depends on severity and parasite type
• Common medicines:
  • Artemisinin-based therapies (for P. falciparum)
  • Chloroquine (for P. vivax, where no resistance)
  • Primaquine or tafenoquine (to prevent relapse)
• Treatment methods:
  • Oral or intravenous medication
• Severe cases:
  • Require intensive care and monitoring

Prevention

• Focus on avoiding mosquito bites (vector control):
  • Use insecticide-treated bed nets
  • Install window screens
  • Apply strong mosquito repellents
  • Use indoor sprays/fumigation
  • Wear long-sleeved clothing
• Travellers should:
  • Take preventive (prophylactic) medication before travel