Infectious Diseases Flashcards
Which types of hepatitis viruses cause chronic infection?
Blood borne viruses
Hep B, C
Which hepatitis viruses do we vaccinate against?
A, B
Which hepatitis viruses are RNA and DNA-based?
B - DNA
Others - RNA
Which heptitis viruses are enteric?
A, E
Name one key complication of hepatitis A
fluminant hepatitis (liver failure)
What is odd about Heptitis D?
You can only get it if you have Hepatitis B, as it attaches to the ABsAg
How would you treat Hepatitis D?
Pegylated IFN-alpha
only 20% respond though
Which Hep E genotypes are more common in the developing and the developed world?
What is the difference in mortality between the two?
Developing - !, 2
20-25% mortality in pregnancy women
Developed - 3, 4
self-limiting illness yay
What is the risk of developing chronic hep B in different populations?
90% for neonates
30% for children <5
<10% for adolescents
What proportion of patients with chronic Hep B will develop complications?
Liver cirrhosis <5%
Hepatocellular carcinoma <0.05%
What does HBsAg suggest?
Active infection
What doe HBeAg suggest?
Viral replication, high infectivityWha
What does HBcAb suggest?
past / current infection
What does HBsAb suggest?
Vaccination or past or current infection
Which children do you test for Hep B?
Hep B + mums
Migrants from endemic areas
Close contacts
How do you reduce the risk of vertical Hep B transmission?
within 24 hours
Vaccine
Ig Infusion
What proportion of adults with Hep C develop chronic Hep C?
75%
Relatively few of these will develop cirhrosis / hepatocellular carcinoma
How do you test foor Hep C?
Hep C Ab - screening
RNA - confirmation
What is the vector for dengue fever?
Aedes aegypti mosquito
How do you manage dengue fever?
Supportive management
What are the 3 phases of Dengue fever?
Febril days 1-7 (fever rash)
Critical days 3-5 (abdo pain)
Recovery days 2-3 (isle of white rash)
How might you classify dengue?
Probably dengue
Dengue with warning signs (abdo pain, bleed…)
Severe dengue (plasma leak, haemorrhage, organ involvement)
What 3 tests would you use to investigate Dengue?
NS1 antigen (1st 4 days)
IgM (after 5 days illness)
IgG (after 7 days)
How migh you differentiate EBV from a run of the mill URTI?
Tonsilitis
Splenomegaly (50%)
Jaundice / hepatomegalu (rare)
Use centor criteria / FeverPAIN to differentiate from bacterial tonsilitis
How do you manage EBV?
AVOID ABX
resolves within 1-2 weeks
What is the vector for Malaria?
Female Anopheles mosquitoesN
Name 5 types of malaria
Plasmodium falciparum
… vivax
… ovale
… malariae
… knowlesi
Who gets really ill with plasmodium falciparum?
Those with their first acute infection later on in life
Those who grow up with it might not be that affected
What problem is associated with Plasmodium vivax and ovale?
How would you overcome this?
Have a dormant stage in the liver
May relapse so you offer primaquine to target them in the liver
What is the incubation period of malaria?
1-4 weeks
Name 3 key signs of malaria on examination
Pallor (anaemia)
Hepatosplenomegaly
Jaundice (haemolysis)
+ fever
How do you diagnose malaria?
Malaria blood film -> EDTA bottle