Infectious Diseases Flashcards
Pathophysiology malaria
Female Anopheles mosquitos
Infected blood is sucked up by feeding mosquito.
The malaria in the blood reproduces in the gut of the mosquito producing thousands of sporozoites (malaria spores).
bites another human or animal - the sporozoites are injected.
sporozoites travel to the liver of the newly infected person. They can lie dormant as hypnozoites for several years in P. vivax and P. ovale.
They mature in the liver into merozoites which enter the blood and infect red blood cells.
In red blood cells the merozoites reproduce over 48 hours, after which the red blood cells rupture releasing loads more merozoites into the blood and causing a haemolytic anaemia.
This is why people infected with malaria have high fever spikes every 48 hours
Symptoms and signs malaria
Non-specific Symptoms
Fever, sweats and rigors
Malaise
Myalgia
Headache
Vomiting
Signs
Pallor due to the anaemia
Hepatosplenomegaly
Jaundice as bilirubin is released during the rupture of red blood cells
Diagnosis malaria
malaria blood film.
This is sent in an EDTA bottle (the red top bottle used for a FBC). Examining the malaria blood film will show the parasites, the concentration and also what type they are.
3 samples are sent over 3 consecutive days to exclude malaria
Most severe type of malaria
Plasmodium falciparum
Management malaria
Intravenous options in severe or complicated malaria:
- Artesunate. This is the most effective treatment but is not licensed.
- Quinine dihydrochloride
Oral options in uncomplicated malaria:
- Artemether with lumefantrine (Riamet)
- Proguanil and atovaquone (Malarone)
- Quinine sulphate
- Doxycycline
Falciparum complications
Cerebral malaria
Seizures
Reduced consciousness
Acute kidney injury
Pulmonary oedema
Disseminated intravascular coagulopathy (DIC)
Severe haemolytic anaemia
Multi-organ failure and death
Malaria prophylaxis
Proguanil and atovaquone (Malarone)
Mefloquine
Doxycycline
