8.1 Travel-related Infections Flashcards
5 main species of Plasmodium
Falciparum
Vivas
Ovale
Malariae
Knowlesi
Vector of malaria
Female Anopheles mosquito
Incubation period of malaria
Min. 6 days
P.falciparum: 4 weeks
P.vivas/ovale: ~1yr
Symptoms & signs of malaria
Fever, chills, headache, confusion, seizures, jaundice, haemoglobinuria
Investigation for malaria
Blood film (thick and thin smears)
Blood test: FBC, U&E,LFT
CXR
CT-Head
Management of malaria
Removal of vector: bed nets, sanitation facilities
Drugs:
Severe: Artesunate (IV/IM)
Uncomplicated: Quinine (IV/PO), Doxycycline
Chloroquine (non-faciparum)
Primaquine (liver-related) :not for G6PD patients
Why can you not give Primaquine to G6PD patients to treat malaria
The risks of developing hemolytic anemia outweigh the benefits of the treatment
Primaquine can cause destruction of RBCs, leading to haemolytic anemia G6PD deficiency.
Haemolytic anaemia can cause fatigue, jaundice, dark urine and in severe cases can lead to kidney failure.
Where in the world is malaria a common prevalent infection
Sub-Saharan Africa
South-east Asia
South America
Describe the life-cycle of P.falciparum
Path 1: Invades&destorys RBCs
-Sporozite enters the bloodstream and go straight into the liver parenchyma
-Sporozoite matures into Merozoite
-Merozoite burst out from liver into the bloodstream where they attack&enter erythrocytes
-Plasmodium begins to replicate&mature. Schizont: ready to burst out of erythrocytes.
Path 2:
-Plasmodia becomes gametocytes which stay inside the erythrocyte & sucked up by a diff. mosquito
-The infected erythrocyte makes its way to the mosquito’s gut and forms a zygote, matures inside the mosquito by sexual rep., release a mass of sporozoites
-These sporozoites travel to the mosquito’s salivary gland, ready for the mosquito to feed on someone else
What are the three categories for recurrent malaria
Recrudescence (treatment didn’t kill the parasite)
Relapse (cleared of merozoites, but dormant hypnozoites are no longer dormant)
Reinfection (cured but new case of same disease)
Signs & Symptoms of Dengue fever
Mild: headache, muscle/joint pain, fever, widespread red rash
Severe: restlessness, severe abdominal pain, bleeding/bruising under skin, nosebleeds, ↓BP, platelet count
Management of Dengue fever
Mild: supportive treatment (paracetamol, fluids)
Severe: IV fluids, Oxygen therapy alongside blood&platelet transfusions (haemorrhagic fever)
Drugs: Paracetamol
NOT aspirin (blocks COX-enzymes that are vital for blood clotting)
Vectors of dengue
Aedes aegytpi
Aedes albopictus
Incubation period of Dengue fever
3-10days
Incubation period of Enteric fever
7-14 days
