What is malaria, and how does it affect you?

Malaria is a life-threatening disease caused by Plasmodium parasites, which are transmitted to humans through the bites of infected female Anopheles mosquitoes. It is a major public health issue, particularly in tropical and subtropical regions, including parts of Africa, South Asia, and South America. According to the World Health Organization (WHO), malaria leads to hundreds of thousands of deaths annually, most of which occur in children under five years old.

The Plasmodium Species are Responsible for Malaria

There are five primary Plasmodium species that infect humans:

1. Plasmodium falciparum: The most dangerous and widespread species, responsible for severe malaria and most malaria-related deaths.
2. Plasmodium vivax: Common in Asia and Latin America, this species can remain dormant in the liver and cause relapses months or even years after the initial infection.
3. Plasmodium malariae: Less common but can lead to chronic infections.
4. Plasmodium ovale: Found primarily in West Africa and occasionally causes relapsing malaria.
5. Plasmodium knowlesi: A zoonotic species found in Southeast Asia, primarily infecting macaques but occasionally causing human infections.

Transmission and Lifecycle of Plasmodium

The malaria lifecycle involves two hosts: the human and the Anopheles mosquito. When an infected mosquito bites a human, it injects sporozoites into the bloodstream. These sporozoites travel to the liver, where they mature into schizonts and release merozoites. Merozoites infect red blood cells, leading to the clinical manifestations of malaria. Sexual forms (gametocytes) of the parasite develop in red blood cells and are taken up by mosquitoes, perpetuating the cycle.

Causes of malaria

Malaria occurs when a person is bitten by an Anopheles mosquito infected with Plasmodium parasites. Other causes include:

1. Blood transfusions: receiving contaminated blood.
2. Organ transplants: rare but possible.
3. Sharing needles: Infected blood can be transmitted.
4. Congenital transmission: from an infected mother to her baby during pregnancy or delivery.

Age-wise Causes and Symptoms

1. Infants (0-12 months)

• Causes: Infants are particularly vulnerable to malaria due to underdeveloped immune systems and maternal transfer of the infection during pregnancy.
• Symptoms:
  • High fever with chillsPoor nutritionLethargy or irritabilityVomiting seizures (due to cerebral malaria in severe cases)
  • Jaundice (yellowing of skin and eyes) from hemolysis

2. Children (1–5 years).

• Causes: Frequent exposure to Anopheles mosquito bites in endemic areas and lack of acquired immunity.
• Symptoms:
  • Recurrent fever with chills and sweats
  • Headaches
  • Loss of appetite
  • Vomiting or diarrhea
  • Convulsions in severe cases
  • Rapid breathing or difficulty breathing (indicative of severe anemia or respiratory distress)
  • Enlarged spleen or liver

3. School-Age Children (6-12 years)

• Cause: Increased outdoor activities increase the likelihood of mosquito exposure.
• Symptoms:
  • Periodic fever spikes (every 48-72 hours, depending on the species)
  • Muscle aches and joint pain
  • Fatigue and malaise
  • Abdominal pain
  • Anemia (pale skin, shortness of breath, weakness)

4. Adolescents and Adults (13+ years)

• Causes: travel to or residence in endemic areas; exposure to infected mosquitoes.
• Symptoms:
  • Classic malaria paroxysms (cycles of chills, fever, and sweats)
  • Severe headache
  • Nausea and vomiting
  • Generalized body aches
  • Dark urine (from hemoglobinuria).
  • In severe cases, organ failure, altered consciousness, or shock

5. Pregnant women.

• Cause: Increased susceptibility due to immune changes during pregnancy.
• Symptoms:
  • High fever and chills
  • Severe anemia, potentially leading to maternal and fetal complications
  • Miscarriage or stillbirth
  • Low birth weight in newborns

6. Elderly (65+ years).

• Causes: Weakened immunity due to age and coexisting chronic illnesses.
• Symptoms:
  • High fever with profuse sweating
  • Confusion or disorientation
  • Severe dehydration
  • Organ dysfunction (kidneys, liver).

Complications of Malaria

If untreated, malaria can lead to severe complications, including:

1. Cerebral malaria: seizures, altered mental status, and coma due to brain involvement.
2. Severe anemia: from the destruction of red blood cells.
3. Respiratory distress: difficulty breathing due to fluid in the lungs or metabolic acidosis.
4. Organ failure: including kidney failure, liver damage, or cardiovascular collapse.
5. Hypoglycemia: Particularly in children and pregnant women.

Diagnosis of Malaria

Malaria is diagnosed through:

1. Microscopic Examination: Blood smears stained with Giemsa to identify Plasmodium species.
2. Rapid Diagnostic Tests (RDTs): Detect specific antigens derived from malaria parasites.
3. Polymerase Chain Reaction (PCR): For precise identification of Plasmodium species.
4. Serological tests: identify antibodies against Plasmodium.
5. Clinical History: Symptoms, recent travel, or residence in endemic areas.

Treatment of Malaria

Treatment depends on the severity of the disease, patient age, and the Plasmodium species involved.

1. Uncomplicated Malaria:
   1. Artemisinin-based Combination Therapies (ACTs) for P. falciparum.
   1. Chloroquine for P. vivax, P. ovale, and P. malariae where resistance is absent.
   1. Primaquine for liver stage eradication in P. vivax and P. ovale.
2. Severe Malaria:
   1. Intravenous artesunate or quinine followed by ACTs.
   1. Supportive care (fluid management, oxygen therapy, blood transfusions).
3. Preventive measures:
   1. Prophylactic antimalarials for travelers.
   1. Insecticide-treated bed nets (ITNs).
   1. Indoor residual spraying (IRS).
   1. Vaccination (e.g., RTS, S/AS01 vaccine for children in endemic areas).

When to See a Doctor

1. High fever and chills, particularly after traveling to a malaria-endemic region.
2. Persistent vomiting or diarrhea.
3. Severe headaches or confusion.
4. Seizures or loss of consciousness.
5. Signs of severe anemia: pale skin, fatigue, or difficulty breathing.
6. Yellowing of the skin and eyes (jaundice).

Early diagnosis and treatment are critical to prevent complications and reduce the risk of death.

Prevention of malaria

1. Avoid mosquito bites:
   1. Use insect repellent containing DEET.
   1. Wear long-sleeved clothing and trousers, especially at dusk and dawn.
   1. Sleep under ITNs.
2. Environmental control:
   1. Eliminate standing water to reduce mosquito breeding.
   1. Use insecticides and larvicides.
3. Chemoprophylaxis:
   1. Take prescribed antimalarial drugs when traveling to endemic areas.
4. Vaccination:
   1. Administer the RTS/AS01 vaccine to children under five in endemic regions.

Malaria remains a significant global health challenge despite advances in prevention and treatment. Recognizing age-specific symptoms, seeking timely medical care, and implementing preventive measures are crucial to controlling the spread and reducing the mortality associated with this disease. Public health efforts, combined with community awareness, are essential to eradicate malaria and improve health outcomes worldwide.