clinical features

Last edited 12/2019

The clinical features of this condition are dependent on the organism involved.

Presentation of patients with symptoms varies according to the incubation period of the parasite.

• falciparum infection - most present within the first month or months after exposure and all most all present within 6 months
• vivax and ovale infection - most present later than 6 months after exposure or may be years after exposure (1)

"Uncomplicated malaria" may present with a prodrome of non specific symptoms:

• malaise
• headache
• muscular ache
• diarrhoea
• dry 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)

• every 48 hours with "tertian" infection (P. falciparum, P. vivax, and P. ovale)
• every 72 hours with "quartan" infections (P. malariae) (2,3)

• 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)

PHE have summarised clinical features as (5):

• 1. Lalloo DJ et al. UK malaria treatment guidelines. Journal of Infection 2007;54:111-121
• 2. Health protection agency 2007. Guidelines for malaria prevention in travelers from the United Kingdom
• 3. Centers for disease control and prevention 2006. Malaria
• 4. Griffith KS et al. Treatment of malaria in the United States. JAMA 2007;297(20):2264-2277
• 5. Public Health England. Guidelines for malaria prevention in travellers from the UK 2019