Malaria Flashcards
malaria is the
commonest imported infection to the UK (1500/ year)
disease vector
female Anopheles mosquito
how many species of plasmodium
5
which are the main malaria causing plasmodium
Plasmodium falciparum (most common) and Plasmodium vivax
patient risk factors
Risks of more severe disease:
• Young children and infants
• Older adults
• Pregnant women
most cases outside Africa
occurs in travellers and immigrants returning from countries where malaria transmission occurs (sub-Saharan Africa and South Asia)
resident of a malaria region may be exposed to the disease so frequently that they acquire
partial immunity- lesson severity of malaria symptoms
malaria infections affect which system
CVD Resp Renal CNS Blood Metabolic
symptoms and signs of Severe falciparum malaria: CVS
- Tachycardia
- Hypotension
- Arrhythmias
symptoms and signs of Severe falciparum malaria: Resp
• ARDS
symptoms and signs of Severe falciparum malaria: GI
- Diarrhoea
- Deranged LFTs
- Bilirubin
symptoms and signs of Severe falciparum malaria: Renal
acute kidney injury
symptoms and signs of Severe falciparum malaria: Blood
- Low/ normal WCC
- Thrombocytopenia
- DIC
- Low Hb
- Anaemia
symptoms and signs of Severe falciparum malaria: metabolic
- Metabolic acidosis
* Hypoglycaemia
patient symptoms
- Fever (cycle every 3rd or 4th day)
- Chills
- Flu-like illness
- Nausea and vomiting
- Muscle pain and fatigue
- Sweating
- Chest or abdominal pain
- Dry Cough
- Enlarged spleen
modes of transmission of malaria
- Mosquito vector
- From mother to unborn child
- Blood transfusions
- Sharing needles used to inject drugs
lifecycle of plasmodium
1) Mosquito feed on human, simultaneously injecting malaria sporozoites into the bloodstream
2) Sporozoites make way to liver where they infect hepatocytes
3) Within heptocytes sporozoite develops into mature schizont creating many merozites
4) Merozites burst out of the hepatocyte and journey back to the bloodstream and infected healthy blood cells
5) Merozites reproduce and rupture the RBC, liberating more merozites
6) Merozoites develop into gametocytes which can remain in the bloodstream for several days to be injected by other mosquitos
7) The blood stage parasites are those that cause the symptoms of malaria.
8) When certain forms of blood stage parasites (gametocytes, which occur in male and female forms) are ingested during blood feeding by a female Anopheles mosquito, they mate in the gut of the mosquito and begin a cycle of growth and multiplication in the mosquito.
9) After 10-18 days, a form of the parasite called a sporozoite migrates to the mosquito’s salivary glands.
10) When the Anopheles mosquito takes a blood meal on another human, anticoagulant saliva is injected together with the sporozoites, which migrate to the liver, thereby beginning a new cycle.
management: prevention
ABC
A
assess risk
- Knowledge of at risk areas
- Regular/returning travellers
B
bite prevention
- Repellent, adequate clothing, nets
- Chemoprophylaxis before travel
- Must include regular/returning travellers
C
chemoprophylaxis
- Specific to region
- Start before & Continue after return (generally 4 weeks)
diagnosis
- Serology (blood film x3)
- PCR
- Drug-resistance testing
gold standard
microscopic examination
rapid diagnostic test
detects specific malaria antigen sin the blood
preferably treatment for malaria should no be imitated unti
diagnosis
treatment should be guided by
- The infecting plasmodium species
- Clinical status of the patient
- Expected drug susceptibility of the infecting parasite
- Previous use of antimalarials including those taken from malaria and chemoprophylaxis
treatment for P. falciparum (malignant)
- Artesunate
* Quinine and doxycycline
treatment for P. viva, vale, malariae (benign)
• Chloroquine
• Dormant hypnozoites (liver)
Can recur months-years later
Give additional primaquine
if left untreated the pt will
develop severe complications and die
complications
cerebral malaria breathing problems organ failure anaemia low blood sugar
Cerebral malaria.
If parasite-filled blood cells block small blood vessels to your brain (cerebral malaria), swelling of your brain or brain damage may occur. Cerebral malaria may cause seizures and coma.
Breathing problems.
Accumulated fluid in your lungs (pulmonary edema) can make it difficult to breathe.
Organ failure
Malaria can cause your kidneys or liver to fail, or your spleen to rupture. Any of these conditions can be life-threatening.
- due to destruction of RBC- splenomegaly
anaemia
Malaria damages red blood cells, which can result in anemia.
low blood sugar
Severe forms of malaria itself can cause low blood sugar (hypoglycemia), as can quinine — one of the most common medications used to combat malaria. Very low blood sugar can result in coma or death.
