Day 2 of 30 for #DistanceMedEd

Why don't we talk about a different virus for a change?

Hepatitis A (HAV) seems to get glossed over but is an important pathogen to know!

1/

First a hopeful graph. HAV was a scourge in the US until 1995 (red arrow) the year that the vaccine was introduced.

Since then there has been a 95% reduction in cases.

2/

Age determines severity of acute hepatitis:

<6 y/o non specific symptoms. Rare to develop jaundice

Adolescents / Adults usually develop jaundice

3/

During incubation period hosts are highly infective, shed in stool

Common symptoms:
Fever
Fatigue
N/V
Abd pain
Dark urine
Clay colored stools
Joint pains 

4/

The good news:
Nearly 100% of acute infection is self limiting, usually lasts < 2mo

The bad news:

That "nearly" part.

Fulminant liver failure occurs in 0.1-0.3% cases

5/

How do you diagnose HAV?

Acute: presence of anti-HAV IgM, lasts 3-6 mos (highly infectious, shed in stool)

Anti-HAV IgG lasts decades, marker of immunity

Anti- HAV IgG w/o IgM had infection or vaccinated

6/

Immunization is a killed vaccine and needs 2 doses at least 6 months apart for long-lasting protection.

Kids usually get this b/w their 1st & 2nd birthdays.
7/

If your patient needs both HAV &HBV immunity, good news! A combined vaccine (TWINRIX) is available.

Standard schedule:

1st dose
2nd dose (1 month later)
Last dose (6 months after the 1st)

8/

Travel Prevention (HIGH YIELD FOR BOARDS):
* If leaving < 2 wks and pt is > 40y/o, immunosuppressed or has chronic liver dz give one dose of vaccine and IG infusion
* Healthy patients can receive one dose of vaccine (but would ideally get 2 before leaving)
9/

I'll end w/ key points for HAV:

Calculate R factor for all patients w/ elevated liver tests ( https://www.mdcalc.com/r-factor-liver-injury) & think viral hep if >5

Monitor while acute HAV to catch liver failure ASAP

Wash your hands!!!

Remember to follow along & tweet using the #DistanceMedEd
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