1. 16/3/20091Dr. Salwa Tayel

2. 16/3/20092Dr. Salwa Tayel Viral Hepatitis

3. 16/3/2009Dr. Salwa Tayel3 Acute Hepatitis – Clinical Symptoms Asymptomatic > Symptomatic > Fulminant Liver Failure > Death Symptoms (if present) are the same, regardless of cause (e.g., A, B, C, other viruses, toxins) Nausea, vomiting Abdominal pain Loss of appetite Fever Diarrhea Light (clay) colored stools Dark urine Jaundice (yellowing of eyes, skin)

4. 16/3/2009Dr. Salwa Tayel4 Infectious hepatitis, epidemic hepatitis, epidemic jaundice. Onset is usually sudden with fever followed within few days by jaundice.Onset is usually sudden with fever followed within few days by jaundice. Complete recovery is the rule (no chronicity).Complete recovery is the rule (no chronicity). The case-fatality rate among persons of all ages is approximately 0.3%The case-fatality rate among persons of all ages is approximately 0.3%

5. 16/3/2009Dr. Salwa Tayel5 It is worldwide In developing countries, it occurs in endemic and epidemic forms due to: Poor environmental sanitation Overcrowding Lack of personal hygiene.

6. 16/3/2009Dr. Salwa Tayel6 Geographic Distribution of HAV Infection

7. 16/3/2009Dr. Salwa Tayel7 Hepatitis A Virus Hepatitis A Virus Picornavirus (RNA) Picornavirus (RNA) Stable at low pH Stable at low pH Inactivated by high temperature, formalin, chlorine Inactivated by high temperature, formalin, chlorine

8. 16/3/2009Dr. Salwa Tayel8 Human  clinical  sub-clinical cases  incubating carriers Through anal orifice with faeces.

9. 16/3/2009Dr. Salwa Tayel9 1. Fecal-oral route. Close personal contact; house hold contact, sex contact, day care centers. 2.Common vehicle; contaminated water and food; raw shellfish food handlers.

10. 16/3/2009Dr. Salwa Tayel10 Through the mouth. Susceptibility is general. Post infection immunity after the attack probably lasts for life.

11. 16/3/2009Dr. Salwa Tayel11 Incubation period 28 days (range 15-50 days) The maximum infectivity is during the latter half of the incubation period (2 weeks before and 1 week after onset of jaundice).

12. 16/3/2009Dr. Salwa Tayel12 Agent Susceptible Host Reservoir Mode of transmission Cycle of infection Portal of Exit Portal of Inlet IP PC

13. 16/3/2009Dr. Salwa Tayel13 Prevention of Hepatitis A Vaccination Vaccination Immune globulin Immune globulin Good hygiene (hand washing) Good hygiene (hand washing) Clean water systems; avoidance of food contamination Clean water systems; avoidance of food contamination Food sanitation especially shell fish and raw eaten food. Food sanitation especially shell fish and raw eaten food.

14. 16/3/2009Dr. Salwa Tayel14 Pre-exposure Pre-exposure – travelers to intermediate and high HAV-endemic regions Post-exposure (within 14 days) Post-exposure (within 14 days)Routine – household and other intimate contacts Selected situations – institutions (e.g., day care centers) – common source exposure (e.g., food prepared by infected food handler) Hepatitis A Prevention – Immune Globulin

15. 16/3/2009Dr. Salwa Tayel15 Hepatitis A Vaccine Inactivated whole virus vaccine. Inactivated whole virus vaccine. Schedule 2 doses Schedule 2 doses First dose then booster dose 6 months after first. First dose then booster dose 6 months after first. The vaccine should be administered intramuscularly. Site: deltoid muscle.

16. 16/3/2009Dr. Salwa Tayel16

17. 16/3/2009Dr. Salwa Tayel17 A, B, Cs of Viral Hepatitis A –fecal-oral spread: hygiene, drug use, travelers, day care, food –vaccine-preventable B –sexually transmitted – –100x more infectious than HIV –blood-borne (sex, injection drug use, mother- child, and health care) –vaccine-preventable C –blood borne (injection drug use primarily) – 4-5 times more common than HIV –NOT vaccine-preventable!