Malaria

Clinic

• Malaria is a mosquito-borne infectious disease that affects humans and other animals.

Cause

• Malaria is caused by single-celled microorganisms of the Plasmodium group.
• Five species of Plasmodium can infect and be spread by humans.
• Most deaths are caused by P. falciparum, whereas P. vivax, P. ovale, and P. malariae generally cause a milder form of malaria.
• The species P. knowlesi rarely causes disease in humans.

Sign / Symptoms

• Symptoms that typically include fever, tiredness, vomiting, and headaches.
• In severe cases, it can cause jaundice, seizures, coma, or death. Symptoms usually begin ten to fifteen days after being bitten by an infected mosquito.

• Chills and fever classically in periodic intense bouts lasting around six hours,
• Followed by a period of sweating and fever relief – as well as headache, fatigue, abdominal discomfort, and muscle pain.
• Children tend to have more general symptoms: fever, cough, vomiting, and diarrhea.

Initial manifestations: Flu-like symptoms

The presentation may include headache, fever, shivering, joint pain, vomiting, hemolytic anemia, jaundice, hemoglobin in the urine, retinal damage, and convulsions.

The classic symptom of malaria is paroxysm—a cyclical occurrence of sudden coldness followed by shivering and then fever and sweating, occurring every two days (tertian fever) in P. vivax and P. ovale infections, and every three days (quartan fever) for P. malariae. P. falciparum infection can cause recurrent fever every 36–48 hours, or a less pronounced and almost continuous fever.

Symptoms typically begin 10–15 days after the initial mosquito bite, but can occur as late as several months after infection with some P. vivax strains. Travellers taking preventative malaria medications may develop symptoms once they stop taking the drugs.

Severe malaria is usually caused by P. falciparum (often referred to as falciparum malaria). Symptoms of falciparum malaria arise 9–30 days after infection. Individuals with cerebral malaria frequently exhibit neurological symptoms, including abnormal posturing, nystagmus, conjugate gaze palsy (failure of the eyes to turn together in the same direction), opisthotonus, seizures, or coma.

Complications

• Development of respiratory distress, which occurs in up to 25% of adults and 40% of children with severe P. falciparum malaria. Possible causes include respiratory compensation of metabolic acidosis, noncardiogenic pulmonary oedema, concomitant pneumonia, and severe anaemia.
• Although rare in young children with severe malaria, acute respiratory distress syndrome occurs in 5–25% of adults and up to 29% of pregnant women.
• Coinfection of HIV with malaria increases mortality.
• Kidney failure is a feature of blackwater fever, where haemoglobin from lysed red blood cells leaks into the urine.
• Infection with P. falciparum may result in cerebral malaria, a form of severe malaria that involves encephalopathy. It is associated with retinal whitening, which may be a useful clinical sign in distinguishing malaria from other causes of fever.
• An enlarged spleen, enlarged liver or both of these, severe headache, low blood sugar, and haemoglobin in the urine with kidney failure may occur. Complications may include spontaneous bleeding, coagulopathy, and shock.