Hepatitis and STIs Flashcards
What type of virus is hepatitis A?
RNA Virus
What is the epidemiology of HAV?
Suspect in the returning traveller with Hepatitis features
1.5 million infections worldwide, most are probably sub-clinical
You can do population wide testing to determine the epidemiology of HAV in your country:
* Use IgG to determine population exposure
* Low <15%, intermediate 15-50%, high >50%
High population exposure = high levels of immunity
Explain who Low, Intermediate and high endemnicity are important concepts in HAV?
Areas with Low transmission: probably people are unlikley to present with the virus, so from a public health perspective you don’t need to worry too much about the virus
Areas with high transmmission: The general population have a baseline good immunity against HAV so are unlikely to get very sick from it
Intermediate: There is reasonably high risk of getting HAV + reasonably low risk of having immunity against it –> highest clinical burden of HAV disease
How is HAV spread?
Faecal - Oral route
**wash your fruit and veg
Who is more likely to present with HAV - children or adults?
Adults –> do have clinical symps of HAV, adults only need a low serovar, but children need a very high level of infection to show symptoms
> 90% of children under 5 are asymptomatic
What is the incubation of HAV?
7-14 days (hence, the returning traveller); it is an ACUTE virus remember!
How does HAV present?
Acute Hepatitis:
* Jaundice
* Anorexia, fever, fatigue, malaise, diarrhoea,
abdominal pain
* Spontaneous resolution without chronic sequelae
Extra-Hepatic features:
- myocarditis, GBS, AKI, Interstitial nephritis
What is the Liver Enzymes picture in HAV?
ALT >1000
Raised AST, raised GGT, raised Alk Phos
How do you diagnose HAV?
Anti-HAV IgM (acute infection)
Anti-HAV IgG (shows immunity; can be raised for decades after initial infection)
HAV RNA
What are the complications of HAV?
- Recurrence (3-20%)
- Fulminant Hepatitis (more common in Hep E)
- Death (2-5% in adults)
How do you prevent HAV?
WASH
Food Hygiene
Vaccination (2x dose vaccine in high-risk people; travellers, MSM, children in intermediate risk countries)
How do you manage HAV?
Supportive care only
some patients might be considered for liver transplant
What is the epidemiology of Hep B?
Western Pacific
Subsaharan Africa
Asia
What kind of virus is Hep B?
DNA
Does HBV cause acute or chronic infection?
Primarily chronic (but some people do present with acute hepatitis)
How is Hep B transmitted?
Blood Borne
Why is PMTCT important in the context of HBV?
90% of infants infected will go on to have chronic liver damage/chronic infection
Maternally acquired HBV associated with:
* Increased risk of progression to cirrhosis
* Lower rate of spontaneous HBsAg loss
* Higher rate of viral replication
What 3 things can you do to prevent HBV vertical transmission?
- Vaccine neonate within the first 24h of life
- Give tenofovir to mothers with High HBV DNA (>200000) or HBeAg
- Give HBV immunoglobulin to the neonate within 24h if maternal HBV DNA >200000 or HBeAg +ve
Re: HBeAg = indicator of actively replicating virus
Is there a vaccine for Hep B?
Yes - 3 doses
**Birth dose is crucial, but often missed, increasing the risk of maternal to child transmission
How do you diagnose HBV?
HBsAg - indicates active infection
±HBV DNA (helps to determine severity)
±HBeAg (indicates actively replicating)
–> can be RDT or ELISA
In regards to HBV, What does HBeAg tell you?
Presence of actively replicating virus
In regards to HBV, what does Anti HBc tell you?
Exposure to HBV (past or current)
In regards to HBV, what does Anti-HBs tell you?
Immunity to HBV
Who and how do you treat HBV?
WHO:
All people who are also HIV +ve
Pregnant women with high viral loads
In HIV negative people, people should be treated for
HBV based on:
* ALT
* HBV DNA
* HBeAg
* Age
* Family history of HCC
* Extent of liver fibrosis
HOW:
Tenofovir or entecavir
