Malaria: Understanding the etiology, symptoms, risk factors, and complications

Introduction
Malaria is a vector-borne disease caused by Plasmodium parasites transmitted to humans by biting female Anopheles mosquitos. Five parasitic species cause malaria in humans, two of which are the most dangerous P.falciparum and P. vivax. The malaria parasite Plasmodium falciparum is the deadliest and most common in the African continent. In most places outside of Sub-Saharan Africa, P. vivax is the most common malaria parasite.
The first signs of malaria, such as fever, headache, and chills, come 10–15 days after the infective mosquito bite and might be mild and difficult to distinguish from other illnesses. However, if left untreated, P. falciparum malaria can escalate to severe sickness and death in as little as 24 hours.
Malaria posed a threat to over half of the world’s population in 2019. Pregnant women, newborns, children below five years, HIV/AIDS patients, and people such as migrant workers, nomads, and travelers, traveling to areas with high malaria transmissions are at a higher risk of contracting malaria.

What causes malaria?
Malaria is contracted when an infected female anopheles mosquito bites a person. The female anopheles mosquito gets infected when it sucks blood from a person already suffering from malaria. This is a cycle, and when it enters into the healthy person’s bloodstream, the parasite matures and reproduces in the liver.

In rare cases, pregnant women suffering from malaria can pass the disease on to their unborn children. The other route of malaria transmission can be through blood transfusions, organ donations, and the use of hypodermic needles.

What are the symptoms of malaria?
Symptoms of malaria usually appear a few weeks after being bitten by an infected mosquito. On the other hand, some malaria parasites can remain dormant in your body for up to a year. Shivering and chills are common symptoms of malaria attack, followed by a high fever, sweating, and a return to normal temperature.
Signs and symptoms of malaria may include:

• Chills and fever
• Fatigue
• Diarrhea
• Discomfort
• Cough
• Headache
• Nausea and vomiting
• Muscle or joint pain
• Abdominal pain
• Rapid breathing
• Rapid heart rate

What are the risk factors of malaria?
Living in or visiting locations where malaria is common is a significant risk factor for contracting the disease. These comprise the tropical and subtropical regions of the following countries:

• Sub-Saharan Africa
• Pacific Islands
• Northern South America and Central America
• South and Southeast Asia

The degree of danger is determined by local malaria control, seasonal fluctuations in malaria rates, and mosquito bite prevention procedures.

Risks of a more severe malarial condition
People who are at a higher risk of developing a severe illness include:

• Infants and small children
• Adults in their later years
• Travelers visiting malaria-endemic areas
• Pregnant women
• The economically weaker section who cannot afford healthcare facilities at the right time and live in slums or unhygienic places

Complications of Malaria
Four malarial parasites infect humans: Plasmodium falciparum, P. vivax, P. ovale, and P. malariea. Among the four types, Plasmodium falciparum is the parasite responsible for almost every case and complication of severe malaria. Malaria can be dangerous if it is not recognized and treated on time. It’s because health concerns will manifest within hours or days following the onset of the first symptom. The complications of malaria include:

1. Cerebral malaria
   The most severe neurological consequence of Plasmodium falciparum malaria infection is cerebral malaria. In cerebral malaria, malarial parasite-filled blood cells block the small blood arteries of the brain and thus lead to swelling and damage to the brain. As a result, cerebral malaria leads to persisting impairment of the cognitive and neurological functions of the human brain. Seizures and coma are possible side effects of cerebral malaria. Patients with Brain Malaria or Cerebral Malaria, after experiencing a seizure, usually fall into a coma that lasts for more than 30 minutes. The mortality rate in cerebral malaria is substantial, and some survivors suffer brain injuries that result in long-term neurocognitive deficits.
2. Difficulty in breathing/Respiratory Distress
   Pulmonary edema is a severe complication of malaria that involves the lungs. In pulmonary edema, fluids get accumulated in the lungs causing difficulty in breathing. Pregnant women infected with malaria are prone to have pulmonary edema. Researchers say that the malarial parasite increases alveolar-capillary permeability that leads to intravascular fluid loss into the lungs. Thus, malaria is responsible for acute lung injury (ALI) and acute respiratory distress syndrome (ARDS).
3. Anemia
   The malarial parasite inside the human body can damage the red blood cells. As a result, it causes severe anemia resulting in insufficient oxygen delivery to the human body’s muscles, organs, and tissues.
4. Renal Failure
   Renal failure is a rare complication associated with malaria, but it is reversible. However, the patient has to undergo dialysis until the kidney completely recovers and starts functioning correctly. In rare cases, if the patient has been severely infected with the P.malariae parasite, this will cause nephrotic syndrome.
5. Low blood sugar levels
   Severe forms of malaria can cause low blood sugar or hypoglycemia. In addition, the quinine drug used to treat malaria can also cause hypoglycemia. Extreme low blood sugar levels might lead to coma or death.
6. Other Health Complications associated with severe malaria

• • Jaundice and failure in the functions of the liver
  • Dehydration
  • Swelling and rupture of the spleen
  • A sudden drop in blood pressure

Conclusion
The complete eradication of malaria is an ambitious goal, and advances in medical and pharmaceutical research hope to achieve the goal as early as possible. In 2021, the World Health Organization authorized RTS, S/AS01 (brand name Mosquirix), as a malaria vaccine to treat malaria caused by the P.falciparum parasite. The RTS, S/AS01 malaria vaccine, according to the WHO, should be given to children starting at the age of five months on a four-dose regimen to reduce malaria sickness and burden. However, educating the patients and ordinary people about malaria and its prevention is the essential task of any healthcare authority. People living in dengue-endemic regions should prevent themselves from mosquito bites and report to a medical practitioner if they have a severe fever. People should know the importance of mosquito nets, covered drainage, mosquito repellent creams, and a clean environment. People living in dengue-endemic regions should spray insecticides and remove stagnant water near their surroundings to curb the spread of malaria.

References

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