HAV for level of medical student 4th year

Viral Hepatitis Aكبدي أفيروس التهاب

Physician - Epidemiologist / Khaled M. AlmazAssistant lecturer, Community Medicine Department,

Aswan University hospital, Aswan, EgyptMaster Degree in Public Health , October 2011Master Degree in Internal Medicine , April 2015

Type : RNA- Picorna virusRoute : Feco-oralIncubation : 2-6 weeksAge : children and young age

Outcome : self limiting – but fulmination is 0,5% Malignancy : noChronicity : noCarrier : no

Markers of HAV : ( Hepatitis A antibody)If +ve infection:

Ig M : recent infectionIg G : old infection

Prevention & Control

Prevention & ControlPrimordial (prevention of risk factors).Primary ( General & Specific ) : Health Education – Personal Hygiene –

Immunization - Cleaning environment.Secondary: Early Diagnosis and detection by screening – Treatment.Tertiary : TTT of Complication – Rehabilitation ( to increase survival).*** Complications are 3 : Illness – Disability – Handicapped.

Note : Immunization : pre exposure – post exposure.So differentiate between immunization if primary or secondary.• Active immunization > vaccine • Passive immunization > Immunoglobulin.

Primary Prevention in infections are :General ( Non-Specific ) in infections : according to :route of transmission = mode of transmission …

For improving level of health ,, mainly for : -Population ,

in addition to Families Individuals

Triad مثلث: Poverty الفقر – Illiteracyالجهل – Disease المرض

Disease

Illiteracy Poverty

1- General (Non-specific) PreventionI) Primary prevention

1. Sanitary Environment = Environmental sanitation. 2. Health Education3. Health Promotion4. Personal hygiene5. Clean instrument when hair cutting or dental treatment6. Infection control measures in health care services7. Nutritional care = healthy food . 8. Healthy good life style. 9. Health legislation. 10. Community development.11. Avoid Over Crowding.

General Prevention in HAVPrevention :1. Health education2. Healthy life style3. Personal hygiene4. Clean the hand5. Wash the food6. Vaccination for food handlers7. Save the food in refrigerator if possible8. Clean place that is without vectors

2- Specific preventionI) Primary prevention

B) Specific prevention : intervention for specific disease :• Active immunizations • Passive immunizations • Chemoprophylaxis = Anti-biotics , Anti-microbial , Anti-bacterial.• Nutrient Fortification & Supplementation = Therapeutic diets.• Wearing protective clothes or masks to prevent occupational

hazards.

Specific PreventionVaccine : prevention for all bacteria

,,, except Tetanus bacteria by Ig (Immuno-globulin)…Ig , Immuno-globulin : prevention for all viruses ,,, except Influenza Virus by vaccine…

Specific Prevention in HAVProphylaxis:

Active immunization >> vaccine1 -for who travel to endemic place with HAV

2 -chronic liver patient

Passive immunization >> Immunoglobulin1 -for contact with recent exposure (must given within 6 days)

2 -travel to endemic place with HAV.

3- International Prevention MeasuresI) Primary prevention

International travellers : • valid international vaccination certificate• Chemoprophylaxis is required for travellers

Imported animals : quarantine measuresImported goods : authorized disinfection certificateMeans of transportation as ships or planes :

الفئران إبادة من إعفاء derrating certificateشهادة

II) Secondary prevention

• Early detection of diseases : a) Periodic examination (individual-oriented) ( follow up): To be cost-effective,

periodic examinations should be based on the at-risk concept (Priority is given to vulnerable groups)…

b) Screening tests (Disease-oriented, community- based) : e.g. Schistosoma survey..

• Proper treatment : to achieve cure & prevent complications (e.g. proper treatment in streptococcal pharyngitis to prevent rheumatic fever).

Treatment of diseaseTreatment of symptoms (symptomatic treatment)

III) Tertiary prevention (rehabilitation) Def.: applied to individuals with a disability.

Forms of rehabilitation: • Medical rehabilitation : to achieve maximum physical abilities (even by

appliances) • Social/Vocational rehabilitation : include education & training for a suitable

job. • Psychological rehabilitation : To the individual to cope with the disability. To the family to accept the handicapped & learn how to deal with him. To the social environment (e.g. school environment) to accept the handicapped as an active member, & provide him with proper environment.

III) Tertiary prevention

Treatment of Complications as :1. Illness2. Disability3. handicapped

Control Measures to be taken for existing infections

Objectives :1. Case finding : detection & diagnosis of cases (patients)2. Treatment of cases & prevent complications3. Measures for contacts & protect high risky groups4. Prevent spread of infections

3 C `s in Control MeasuresControl of Human : control of Cases & control of Carriers & control of Contacts

Control of cases :• Case finding : diagnosis & laboratory confirmation• Notification : to local health office & ministry of health & WHO• Isolation : at home or hospital or special place according to nature &

severity of infection• Disinfection : process to destroy causative organism• Treatment : antibiotics = antibacterial =antimicrobial =

chemoprophylaxis >> for bacterial infection – symptomatic treatment – anti toxins

• Release of case : after recovery and case is clinically free from infection• Other measures : tertiary prevention & treatment of complications &

follow up & social support (social services)…

No carrier in viral Hepatitis ASo No >> Control of carriers

ExaminationEpidemiological studyPre-employment examination & periodic medical examination in

certain occupational workers

Control of contacts:• Enlistment : list of contacts >> name – age • Examination : general health status , examination for case finding• Surveillance : infection under supervision every day or more• Isolation : as in cholera , plagueSpecific prevention : 1. Immunization : seroprophylaxis (passive immunization) >>

immunoglobulin , active immunization >> vaccine2. Chemoprophylaxis : antimicrobial (antibacterial)

Community Control measures :1- preventive measures.2- control measures.

1- preventive measures

Control of environment >> control of vehicles & vectors :-• regarding respiratory infections1. Adequate ventilation2. No crowding• regarding food borne & water borne infections1. Super chlorination of water supply2. Sanitary collection3. Disposal of community wasteHealth education for high risky groupsSpecific prevention >> mass active immunization or chemoprophylaxis at risky groups

2- Control measures

Case findingControl of cases & contactsEpidemiological study & investigations to detect sources of infections &

channels of infection ( as chains or cycles of infections)Drastic control measures ,,, if necessary .. e.g.: closing schools , public

places , food markets

Meanings of Drastic control measures :a plan or course of action taken to achieve a particular purpose. (especially of actions) severe and sudden or having very noticeable effects.