HAV/HBV Flashcards
1
Q
Acute vs Chronic Hepatitis
A
- All viral hepatitis causes acute infections and some cause chronic (lasts >6 mo)
- Likelihood of developing chronic infection also depends on immune system, age, infectious agent, etc
2
Q
Hepatitis + Symptoms
A
- No differentiating symptoms between different viral hepatitis
- Symptoms: fever, fatigue, loss of appetite, N/V, pain, dark urine, joint pain, hepatosplenomegaly
3
Q
Hepatitis A
A
- Non-enveloped RNA virus known as a picornavirus
- Acute infection only
- Most recover and have lifelong immunity but it can cause fulminant hepatitis and death
- Most children <6 y.o. are asymptomatic
- > 6 y.o. is most likely to experience jaundice
- Incubation: ~28 days
- Can survive outside the body for months (extreme heat kills)
- Infectivity peaks 2 weeks before and 1 week after symptoms begin
4
Q
Hep A Transmission
A
- Poor sanitation, poor hygiene, contaminated food/water
- HAV shed in stool is primary spread via food/water contamination with infected fecal matter
- If good sanitation/safe water, seen more with injection drug use, male homosexual intercourse, travel to countries with high HAV rates
- Adequate chlorination of of water kill HAV in water
5
Q
Hep A Lab Diagnosis
A
- Elevated anti-HAV for identifying acute HAV (5-10 days post-exposure)
- Total anti-HAV includes IgM an IgG and doesn’t differentiate between acute and previous infection
- Elevated aminotransferase (ALT > AST), bilirubin (occurs second to ALT/AST), and alkaline phosphatase are also seen but connected to general hepatitis
6
Q
HAV Prevention
A
- Vaccination! - long term
- Monovalent vaccines inactivated, no preservative, given IM
- Seroconversion >=94% with first dose but booster recommended for maximal titers
- Don’t restart interrupted series
- Travelers should get first dose as soon as travel is considered
- Need at least 1 dose at least 1 mo before exposure to avoid pre/post prophylaxis
7
Q
HAV Vaccination Recommended Groups
A
- All children at least 1 y.o.
- Children 2-18 y.o. living in state/community where routine Hep A vaccination is implemented from high incidence
- Travel/work in countries with high/moderate endemicity
- MSM
- IDU
- Occcupational risk
- Clotting factor disorders patients
- Chronic liver disease patients
- International adoptions from at risk countries
8
Q
HAV + Immunoglobulin
A
- Used if vaccine can’t be used
- Provide passive transfer of antibody to body
- Most effective if given during incubation period
9
Q
Hep A Immunoglobulin Groups
A
- Children <12 mo
- Adults > 40 y.o.
- Immunocompromised
- Hemodialysis
- Chronic liver disease
- Allergy to vaccine/vaccine component
10
Q
Hepatitis B
A
- Transmitted via percutaneous or mucosal contact with infectious blood/fluids
- Survives outside body at least 7 days
- Incubation: ~90 days
- Often occurs < 40 y.o. and in absence of cirrhosis
11
Q
Hep B Presentation
A
- Signs/symptoms vary by age
- Most immunosuppressed adults and kids <5 y.o. are asymptomatic
- 30-50% of those >=5 y.o. have initial symptoms
12
Q
Hep B Risk Groups
A
- High prevalence HBsAg areas
- Infants born to infected mothers
- Contacts with chronic HBV infected persons
- IDU
- Sexually active non-monogomous long-term relationships
- MSM
- Health care/public safety wrokers
- Residents/staff at disabled persons facilities
- Chronic liver disease and hemodialysis patients
- Travel to risk areas
- Immunocompromised
13
Q
HBV Infection Course
A
- DNA virus that becomes part of host DNA
- Active or inactive phases
- Active infection requires treatment evaluation depending on ongoing liver injury
- Risk HBV disease progression is based on HBV serologies
- ~30% will develop cirrhosis
- Can develop liver cancer at ANY point in infectious process
14
Q
Common HBV Serology Tests
A
- HBsAg: protein found on surface of HBV and is detectable in acute or chronic infection
- anti-HBs: antibody produced after a successful vaccine series
- Total anti-HBc: indicates prior or ongoing infection, negative with lack of immunization, includes IgM and IgG
IgM = < 6mo (recent infection), IgG > 6 mo (prior infection)
15
Q
Other HBV Serology Tests
A
- HBeAg: present during active viral replication
- anti-HBe: formed in response to HBeAg and is present during antiviral therapy, predictor of long-term HBV clearance
