clinical features of falciparum malaria

Last reviewed 02/2023

The incubation period is generally 7 to 14 days (may be up to a year, if the patient is semi-immune or has taken prophylaxis).

Malaria caused by falciparum malaria parasite or a mixed infection (which includes falciparum parasites) can be divided into:

• uncomplicated
• severe or complicated (1)

Uncomplicated malaria

There is a prodrome of flu-like symptoms:

• headache
• malaise
• myalgia
• anorexia
• diarrhoea
• cough (2)

Following the prodrome the patient develops paroxysms lasting 8 to 12 hours, which consists of 3 stages:

• a cold stage - sudden coldness, followed by a severe rigor for up to an hour
• a hot stage - a high temperature, vomiting, flushing and
• finally a sweating stage - sweating, return to normal temperature, tiredness (3)
• paroxysms are generally daily but may be irregular

Typically these attacks occur every 48 hours, but this pattern is observed rarely in patients (3,4).

On examination the patient may be anaemic, jaundiced and have hepatosplenomegaly without lymphadenopathy or a rash and an increased respiratory rate (3).

Severe or complicated malaria:

• in adults:
  • impaired consciousness or seizures
  • renal impairment (oliguria < 0.4 ml/kg bodyweight per hour or creatinine > 265mmol/l)
  • acidosis (pH < 7.3)
  • hypoglycaemia (<2.2 mmol/l)
  • pulmonary oedema or acute respiratory distress syndrome (ARDS)
  • haemoglobin <=8 g/dL
  • spontaneous bleeding/disseminated intravascular coagulation
  • shock (algid malaria e BP < 90/60 mmHg)
  • haemoglobinuria (without G6PD deficiency) (1)
• in children
  • impaired consciousness or seizures
  • respiratory distress or acidosis (pH<7.3)
  • hypoglycaemia
  • severe anaemia
  • prostration - inability to sit or stand
  • parasitaemia - >2% of red blood cells parasitized (4)

Reference:

• 1. Lalloo DJ et al. UK malaria treatment guidelines. Journal of Infection 2007;54:111-121
• 2. National travel health network and centre 2007. Travel health information sheets - malaria
• 3. Centers for disease control and prevention 2006. Malaria
• 4. Health protection agency 2007. Guidelines for malaria prevention in travelers from the United Kingdom