Preventive measures includes (1) education of the public (especially food handlers and preparation personnel) concerning personal hygiene and good sanitation, e.g., good handwashing and sanitary disposal of human feces; and (2) stressing handwashing among the staff after each diaper change in child care centers. If one or more cases occur, consider giving immune globulin to the staff, to other children who attend, and to the families of children attending.
Also, travelers to highly endemic areas who plan to remain for up to 3 months may be given human immune globulin in a dose of 0.2 to 0,4 ml/kg of body weight (or 2 ml total for adults). For continued long-term exposure, 0.6 ml/kg of body weight (5 ml total for adults) may be given; it should be given every 4 to 6 months while in the area. At this time a vaccine specifically against hepatitis A is not available for general use.
Management of patients, contacts, and nearby environment includes (1) isolation of patients with enteric precautions for the first 2 weeks of illness; (2) passive immunization with human immune globulin for usually only household and sexual contacts (intimate contacts); and (3) investigation of contacts to include a search for missed cases, a search for a common source, and a surveillance of household or close contacts. There are no requirements for quarantine.
When necessary during epidemics, several measures are required. An investigation should be conducted to determine the method of transmission and to identify the population at risk of infection. If viral hepatitis A is diagnosed in a food handler, give human immune globulin to other food handlers in the facility. However, it is recommended that patrons not be immunized unless an infected food handler prepared foods that were not cooked, his or her personal hygiene was deficient, and human immune globulin can be given within 2 weeks of exposure to the index case. If necessary, sanitary practices should be improved to prevent fecal contamination of food and water. Mass administration of human immune globulin should be considered to control outbreaks in institutions. Epidemics of hepatitis A may be expected during disaster situations where large numbers of people are crowded together with poor sanitation and inadequate water supplies. If cases occur, it is recommended that efforts be made to improve sanitation and water supplies. Administration of human immune globulin cannot be recommended as a substitute for proper environmental health measures. There is no requirement for international measures.
VIRAL HEPATITIS B. The onset progresses gradually. There is loss of appetite, slight abdominal discomfort, nausea, vomiting, joint pain, rash, and jaundice. Fever, if present, is usually mild. The severity of this disease ranges from inapparent cases to death due to severe hepatic injury.
The diagnosis can be confirmed by demonstration of a specific blood virus particle, the hepatitis B surface antigen (HBsAg), or the recent development of antibody to core and/or surface antigens (anti-HBc, anti-HBs, respectively). HBsAg can be found in the serum for several weeks before the appearance of symptoms and for weeks to months after the onset and remains present in chronic infections. The infectious agent is the hepatitis B virus. Man is the only recognized reservoir.
Although HBsAg is found in numerous body secretions/excretions, only blood, saliva, semen, and vaginal fluids have proven to be infectious. Transmission occurs by percutaneous inoculation (such as a needle stick) with infective body fluids or by sexual exposure. Human blood, plasma, serum, and other blood products may transmit the hepatitis B virus. Thus all blood products are screened in the laboratory for HBsAg. Contaminated needles, syringes, and other intravenous equipment are frequently involved in transmission, especially among drug abusers. The infection is also rarely spread through open wound contamination by blood or sera from another infected individual. The agent may also be transmitted by heterosexual and homosexual contact. The shared use of personal items, e.g., razors, and toothbrushes, has been implicated as a rare cause.
The average incubation period is from 60 to 90 days. Blood is infective several weeks before the first symptoms appear, during the acute clinical disease, and, in those cases that develop into the chronic carrier state, it may be infectious for years. The is no specific treatment except for supportive measures.
There are several preventive measures. Inactivated vaccines are now commercially available against viral hepatitis B. The vaccine is recommended for those persons who may come into contact with blood, persons who receive repeated blood transfusions or blood fractions, household contacts of carriers, the sexually promiscuous, staff in institutions for the retarded, hemodialysis patients, and illicit injectable drug users. Pregnancy is not necessarily a contraindication for immunization.
Pregnant women in high risk groups should be tested for the presence of HBsAg and, if positive,