Yellow normocytic anaemia Flashcards
What is malaria
Malaria is a parasitic infection caused by protozoa of the genus Plasmodium.
Epidemiology of malaria
- Malaria is a serious global health problem that affects millions of people, particularly:
- Young children under the age of 5
- Pregnant women
- Patients with other health conditions like HIV and AIDS
- Travellers who have had no prior exposure to malaria
Tropical and subtropical countries
Most severe is plasmodium falciparum
Aetiology of malaria
Protozoa of plasmodium genus:
- Plasmodium falciparum
- Plasmodium vivax
- Plasmodium malariae
- Plasmodium ovale
- Plasmodium knowlesi
Pathophysiology of malaria
Malaria is spread through bites from the female Anopheles mosquitoes that carry the disease.
Once the plasmodium gets into the bloodstream, it starts to infect and destroy mainly liver cells and red blood cells, which causes a variety of symptoms and sometimes even death.
Active infection of malaria
incubation time, which is the period of time between infection and symptom onset
Plasmodium falciparum incubates for a few days, whereas Plasmodium malariaieincubates for a few weeks.
release of tumour necrosis factor alpha and other inflammatory cytokines, causes fevers that typically occur in short bursts, and correspond to the rupture of the infected red blood cells
Malaria causes haemolytic anaemia - what are the symptoms?
- extreme fatigue,
- headaches,
- jaundice
- splenomegaly
What do most plasmodium infections have?
mild course of symptoms and are generally regarded as uncomplicated malarial infections. These typically resolve with treatment.
What is recurrent malaria?
After recovery, some individuals can get symptoms after a period of time and divided and into 3 underlying causes recrudescence, relapse, and reinfection.
What are the 3 causes of recurrence in malaria?
- Recrudescence refers to ineffective treatment that didn’t completely clear the infection
- Relapse refers to situations where the blood was cleared of merozoites but hypnozoites persisted in the liver, and then emerged to cause more problems
- Reinfection is when an individual was effectively treated, but a completely new infection caused a new bout of malaria
What does plasmodium falciparum do? (complicated malaria)
known for causing the worst infections.
PF generates a sticky protein that coats the surface of the infected red blood cells.
protein causes the red blood cells to clump together and occlude tiny blood vessels - a process called cytoadherence.
Causes organ failure
Signs of malaria
- Pallor: due to anaemia
- Jaundice: due to unconjugated bilirubin from destruction of RBCs
- Hepatosplenomegaly: due to compensation for anaemia
Symptoms of malaria
- Fever, sweats and rigors (occurs in spikes)
- Fatigue: due to anaemia
- Headaches
- Myalgia
- Vomiting
Investigations for malaria
- FBC, U&E, LFT: thrombocytopenia, elevated lactate dehydrogenase levels due to haemolysis, and normochromic, normocytic anaemia
- Malaria blood film: will show the parasites, the concentration and also what type they are.
Management of uncomplicated malaria
- Artemether with lumefantrine (Riamet)
- Proguanil and atovaquone (Malarone)
- Quinine sulphate
- Doxycycline
Complicated or severe malaria management
IV:
- Artesunate: this is the most effective treatment but is not licensed.
- Quinine dihydrochloride
Prevention of malaria:
- Full body clothing
- Mosquito repellent
- Sleeping in insecticide covered mosquito nets
- Indoor insecticide sprays
- Clean water
- Use antimalarials e.g. malarone, mefloquine, doxycycline
Complications for complicated malaria
- Cerebral malaria: altered mental status, seizures and coma
- Bilious malaria: diarrhoea, vomiting, jaundice and liver failure
- Acute kidney injury
- Pulmonary oedema
- Disseminated intravascular coagulopathy (DIC)
- Severe haemolytic anaemia
- Multi-organ failure and death
What is the definition of Hereditary spherocytosis (HS)?
inherited haemolytic anaemia and is autosomal dominant in the majority of cases (75%), but can also be autosomal recessive.
Epidemiology of HS
- HS is the most common genetic haemolytic disease.
- It is more common in Northern Europe and North America but can affect people of any race.
- It is diagnosed in 1 in 2000 people, whilst a large proportion of these individuals are asymptomatic
RFs for HS
- amily history
- Northern European descent
Why does HS occur?
Defect in red cell membrane proteins (ankyrin + spectrin) > causes RBC to lose biconcave shape and become spherical > leads to accelerated degradation of RBCs in spleen resulting in normocytic anaemia