Infectious Disease 1 Flashcards
Particular food implicated in Hep A transmission?
Shellfish
Symptoms of Hep A?
Nausea, vomiting, malaise
Arthralgias
Rash
Signs of Hep A?
Jaundice
Fever
Lymphadenopathy
Hepatosplenomegaly
What test is diagnostic of Hep A?
anti-HAV IgM
What test can be used to investigate previous HAV infection?
anti-HAV IgG
3 preventative measures for Hep A?
Good sanitation in developing countries
Good hygiene practises
IgG vaccine
How is HBV transmitted?
Blood-borne, sexual/bodily fluids and vertically
Particular RFs for HBV infection?
Sexual contact with infected person IVDU Tattoos, particularly foreign countries Medical treatment abroad Blood transfusions before 1991
What 3 features are more prominent in HBV than HAV if present?
Rash
Jaundice
Arthralgia
How does HBV often present?
It’s often asymptomatic; otherwise like a more severe HAV with prominent jaundice, rash and arthralgia
What blood tests indicate an acute HBV infection?
HBcIgM, HBcIgG
HBsAg
HBV DNA
Acutely deranged LFTs
What 2 blood markers are only found during the acute phase of HBV infection?
HBsAg
HBV DNA
What is HBV DNA used to monitor?
Treatment and infectivity
What unusual HBV marker is used to indicate high infectivity?
HBeAg
What blood tests indicate if someone has had a past HBV infection and recovered?
HBsAb
HBcIgG
What blood test indicates someone who has been vaccinated against HBV?
HBsAb (but no HBcIgG)
What blood test is used as a screening test for HBV?
HBsAg
Someone is HBV DNA, HBsAg positive as well as HBcIgM positive and has deranged LFTs. Diagnosis?
Acute infection
Someone is positive only for HBsIg. Diagnosis?
Vaccinated therefore immune
Someone is positive for HBsIg and HBcIgG. Diagnosis?
Immune due to previous infection
Someone is positive for HBsAg, HBcIgG and HBeAb but negative for HBcIgM and HBsIg. Diagnosis?
Chronic infection
What is the most likely outcome of HBV infection?
Complete recovery -
What LFT picture does Hep A give?
Hepatic damage + raised bilirubin
Apart from complete recovery and chronicity how else can HBV infection resolve?
Carrier state
What 3 blood tests indicate chronic HBV infection?
HBsAg
HBcIgG
HBeAb
How is HCV spread?
Bloodborne, sexual, vertical
If hep C presents symptomatically, how does it present?
Milder flu-like illness with fever +/- jaundice
How is HCV infection detected in the acute phase?
HCV RNA (PCR) + deranged LFTs
How is chronic HCV infection detected?
Anti-HCV Abs
What proportion of HCV goes on to become chronic? Future complications?
2/3 chronic
1/3 liver cirrhosis
1/10 HCC
Treatment of HCV? (Chronic)
PEG interferon alpha
Ribavirin
Prevention of HBV?
Vaccine (HBsAb)
Safe sex, clean needles, blood screening etc.
Is there a vaccine for HCV?
No
What is the role of Hep D virus infection?
Can only occur in context of HBV as it is an incomplete RNA virus
How is HDV spread?
In the blood
2 types of HDV infection?
Occurring at same time to make more severe infection (co-infection)
Causing flare up of chronic infection (superinfection)
Investigating HDV infection?
HDV RNA (PCR)
Treatment of HDV virus?
Alpha interferon (limited success)
Potential implications of HDV infection?
Increased risk of fulminant hepatitis and liver failure
But no chronic state
How is HDV prevented?
HBV vaccine!
How is HEV spread?
Fecal oral
But more like pork, deer, water supplies (and sexual)
Where is HEV common?
Indochina
Symptoms of HEV?
Similar to HAV - icterus, flu like Sx, pruritis, organomegally
What are the 2 phases of HAV infection?
Prodromal phase (non-specific, nausea vom headaches etc.) Icteric phase (jaundice, fever, pruritis etc.)
How is HEV infection detected?
HEV RNA serology (PCR) via serum or stool
In whom does HEV infection carry particular significance?
Pregnant women - mega high mortality
What food is implicated in HEV infection?
Pork, deer
How is Hep A transmitted?
Fecal-oral route - contaminated food and water
Acute presentation of mastoiditis?
Often follows acute or recurrent OM, bulging erythematous TM
Otalgia, retroaural pain (swelling, redness, boggy)
Fever and malaise
Discharge and perforation
What CN and hearing findings might be consistent with mastoiditis?
CN5, 7, 8 involvement
Conductive deafness