Hepatitis

Viral Hepatitis

Viral hepatitis A, B, C, D (delta), E and G
Viral Hepatitis A
Infectious hepatitis, Epidemic hepatitis, Epidemic jaundice, Catarrhal jaundice, Type A hepatitis, HA
1. Identification:
Onset of illness in adults in non endemic areas is abrupt with fever, malaise, anorexia, nausea and abdominal discomfort. After few days the jaundice appears.
Severity range: Asymptomatic (children) mild illness (1-2 weeks) severely disabling disease (several months). Relapsing H for up to 1 year occurs in 15 % of cases. No chronic carriers. CFR is low 0.1 0.3 %; it can reach 1.8 % for > 50 y.
2. Infectious agent:-
HAV RNA virus, the virus is fairly resistant to heat and chemicals and not affected by usual dose of chlorine in water.
3. Occurrence:-
Worldwide.
Geographic endemicity levels: high, intermediate, or low endemicity countries.
High endemicity levels: adult usually immune and epidemics are uncommon.
Intermediate or highly endemic areas → Africa, Middle East, Asia, Eastern Europe and Central and South America.
4. Reservoir: Humans, rarely chimpanzees.
5. Mode of transmission:
Person-to-person by fecal-oral route (directly or indirectly). HAV found in feces, reaches peak level 1-2 weeks before onset of symptoms and diminished rapidly after symptoms appear.
Contaminated water or foods → common source outbreaks (food handler …etc).
Unusual routs of transmission:
Injecting and noninjecting drug use.
Blood and clotting factors transfusion (donors in incubation period) has been reported, very rarely.
Sexual contact: homosexual men because of oral-anal contact.
6. Incubation period: Average 30 days (range 15 -50 days).
7. Period of communicability:
2 weeks ← Jaundice → max up to 1 week
Chronic shedding of HAV in feces does not occur.
8. Susceptibility: General. Immunity after infection probably last for life.
9. Method of control:
A- Preventive measures:
Educate the public …
Personal hygiene particularly food handlers…etc.
Travelers to intermediate or highly endemic areas → vaccine prior to departure + IG if departure < 2 weeks
Immunization (active, passive):
4 inactivated vaccines; not used in children < 1 year, Safe, effective.
2 doses (6-18 months apart) give long –term protection.
Note: IG if given after onset of symptoms, no benefit from it.
Combination HA & HB vaccine since 1996.
Indications of HA Vaccine:
1) In developed countries (low endemicity) → high risk groups: chronic liver disease, clotting factor disorders, homosexual male, injecting drug users, lab workers and traveler to endemic areas.
2) Close personal contacts (household): vaccine + IG.
B- Control of patient, contacts and environment:
Reporting: (class II).
Isolation: Enteric precautions during the 1st 2 weeks of illness and 1 week after the jaundice.
Disinfection of feces, urine and blood.
Quarantine: Not applicable.
Immunization of contacts (post exposure prophylaxis): Vaccine and IG should be given as soon as possible, but not later than 2 weeks after exposure. Only close personal contacts.
Specific treatment: none.
Viral Hepatitis B [Serum hepatitis, Type B hepatitis, HB]
1. Identification:
Clinically recognized (icteric cases): 10% in children
30 50% in adults
Similar clinical features. After few days the jaundice appears. Severity range: Asymptomatic severely fatal cases. CFR is 1 %; it higher in patients aged above 40 years.
Chronic HB infection varies inversely with age:
Infant infected at birth → 90% chronic
Children 1-5 years → 20 – 50%
> 5 y. and adults → 1 – 10%
15 - 25% of chronic → premature death from liver cirrhosis or hepatocellular Ca.
Up to 80% of hepatocellular Ca are caused by HBV worldwide.
Factors that increase occurrence of carrier state:
Infection early in life.
Immunodeficiency state.
Chronic liver diseases as hepatic schistosomiasis.
Down syndrome.
Risky groups as hemodialysis, addicts, hemophilic, homosexual..etc.
Chronic carrier defines as the presences of HBsAg +ve for > 6 months.
Dx: Demonstration in sera of Ag and/or Ab confirms diagnosis:
HB surface Ag → HBsAg and anti-HBs.
HB core Ag → HBcAg and anti-HBc.
HB e Ag → HBeAg and anti-HBe.
Anti-HBc appears at the onset of illness and persists indefinitely so when detected in serum means current or past infection.
High titer of IgM anti-HBc indicate acute infection (IgM anti-HBc usually disappear within 6 months).
HBsAg present in serum in acute infection and persist in chronic infection. The presence of HBsAg indicates that the person is potentially infectious.
2. Infectious agent:- HBV DNA virus 1963 (Dane particles)
3. Occurrence:-
Worldwide.
WHO estimates: 2 billion people have been infected with HB (including 250 million chronically infected).
Each year: 1 million die from HB and over 4 million new acute clinical cases occur.
Endemicity levels: measured by HBsAg prevalence
If HBsAg prevalence ≥ 8% highly endemic areas.
2 -7% intermediate.
< 2% low endemicity.
4. Reservoir: Humans, rarely chimpanzees.
5. Mode of transmission:
Body fluids capable of transmitting HBV include: blood and blood products; saliva, CSF, peritoneal, pleural, pericardial and synovial fluid; amniotic fluid; semen and vaginal secretions and any other body fluid containing blood.
Parenteral (IV, IM, SC, ID) and permucosal exposure to infective body fluids.
Blood and clotting factors transfusion, hemodialysis, acupuncture, dentist, surgical procedures, needle stick, ear and nose piercing, tattoo parlorsetc.
Injecting drug users → sharing needles, syringes and drug equipments
Sexual and close household contact with an infected person.
Sexual: male → female 3 times effective than female → male, multiple partners
Anal intercourse → high risk for both.
Vertical; mother to fetus transmission: the mechanism of perinatal transmission is uncertain, but most infections appears to occur at birth due to leak of maternal blood into the baby`s circulation.
Indirect inoculation of HBV via inanimate objects
Toothbrushes and razors
Fecal-oral route or vector-borne transmission not occurs.
Arthropod (vector) not occurs.
6. Incubation period: Average 60 - 90 days (range 45 -180 days).
7. Period of communicability:
All persons who are positive HBsAg are potentially infectious.
Weeks ← Jaundice → throughout acute disease and if chronic carrier remain infectious.
Chronic carriers (HBeAg +ve) → highly infectious.
8. Susceptibility: General.


9. Method of control:
A- Preventive measures:
Health education…; instructions to carriers…
Effective HB vaccines and IG.
Adequately sterilization of syringes and needles and lancets, use disposable equipment whenever possible, discourage tattooing.
In blood bank, all donors should be tested for HBsAg; reject all donors with a:
History of viral H.
History of injecting drug users or drug addicts.
History of tattooing or receive blood in the past 6 months.
Paid donors (except in emergency)
Effective HB vaccines
Safe, highly protective, immunity persist for at least 15 years, not contraindicated during pregnancy.
Site: for infancy and children → anterolateral aspect of the thigh.
For adults → deltoid muscle.
Indications of HB vaccine:
In all countries, routine infant immunization is the primary strategy in the prevention of HB infection.
In Iraq 3 doses IM 1st dose at birth
2nd dose at 2 months age.
3rd dose at 6 months age.
At high risk persons (preexposure immunization):
Hemodialysis (CRF) and blood disorders patients
Homosexual men, promiscuity
Household contacts of HBsAg +ve
Health care workers
Travelers to intermediate or highly endemic areas (spend >6 months).
B- Control of patient, contacts and environment
Reporting: (class II).
Isolation: Universal precautions to prevent exposures to blood and body fluids until HBsAg ve and appearance of anti-HBs.
Disinfection: of equipment contaminated with blood or infectious body fluids.
Quarantine: Not applicable.
Immunization of contacts: (post exposure prophylaxis)
Vaccine and HBIG should be given as soon as possible (IG given 2 doses one month apart):
Infants born to HBsAg +ve mother → HBIG + 1st dose of vaccine [within 12 hours of birth].
Accidental percutaneous → HBIG + start vaccine schedule [within 24 hours of exposure].
After sexual contact with HBsAg +ve → HBIG + start vaccine schedule [within 14 days of last sexual contact].
Specific treatment: none. Alpha interferon, lamivudine for chronic HB.
Viral hepatitis C
Parenterally transmitted non-A non-B hepatitis, HCV infection
1.Identification:
Similar to HB but less severe. Chronicity commoner (50 -80% develop chronic infection) → half of them develop liver cirrhosis or hepatocellular Ca.
Dx: antibody to HC → anti-HCV by EIA
2. Infectious agent:- HCV RNA virus 1989
3. Occurrence:-
World wide, HCV prevalence related directly to persons sharing injection equipment. World prevalence 3%.
4. Reservoir: Humans, rarely chimpanzees.
5. Mode of transmission:
Like HB but mainly parenterally. Its the most common post-transfusion hepatitis (paid donors). Sexual and mother to fetus also occur but less frequent than parenteral route.
6. Incubation period: Average 40 - 60 days.
7. Period of communicability:
One or more weeks ← Jaundice → throughout acute disease and may persist in most persons for indefinitely
8. Susceptibility: General. Repeated infection may occur.
9. Method of control: Same as HB except that IG not used.
Rx of chronic HC → ribavirin + slow release interferon → 40 – 80% response rate but very expensive. Ribavirin is teratogenic. Steroids and acyclovir is not effective.


Delta Hepatitis [ Viral Hepatitis D ]
1. Identification: Similar to HB always associated with a coexistent HBV infection (either co-infection with HBV or super-infection with chronic HBV).
2. Infectious agent: HDV RNA virus.
3 – 9: Similar to HB.

Viral Hepatitis E [ Enterically transmitted non-A non-B hepatitis ]

1. Identification: Similar to HA, no evidence of chronic form.
CFR same HA except in pregnancy 20%.
2. Infectious agent: HEV RNA virus 1990.
3. Reservoir: Humans, rarely chimpanzees.
4. Mode of transmission: Primarily fecal-oral route (may be a zoonotic disease).
5. Method of control: As HA.

Hepatitis G1996

HYPER13PAGE HYPER15

5

Community Med. Depart.

October – 2017