Hepatitis-b

Mode of transmission: hepatitisB
1-Body substances: blood & blood products, saliva, CSF, peritoneum, pleura, pericardial & synovial fluid, amniotic fluid, semen & vaginal discharge
HBV is stable on environmental surfaces for at least 7 days, indirect inoculation of HBV can occur via inanimate objects
2-transmission occur by percutanous (IV, IM, SC & intradermal)
3-Sexual or household contact with infected persons
4-Perinatal transmission from mother to infant 5-Injecting drug use
6-Organ transplantation
7- 7-Nosocomial infection — HBV is the most commonly transmitted blood-borne virus in the healthcare setting. Transmission generally occurs from patient to patient or from patient to health care personnel via contaminated instruments or accidental needle stick. Approximately 30% of those how become infected with HBV have no known risk factors
Risk group:
1-Sexually active heterosexual men & women,Sexual partner & household contacts of HBs Ag positive persons
2-Health worker who contact with blood or blood contaminated body fluid
3-Hemodialysis patients , Patients with bleeding disorder who receive blood products Injectable drug addicts, tattooing
4-International travelers
5-Patients with chronic liver diseases
Incubation period: Usually 45–180 days, average 60–90 days
Period of communicability: all persons who are HBs Ag positive are potentially infectious ,blood remain infected many weeks befor the onset of first symptoms & to remain infective through the acute clinical course of the disease