Some observations on viral hepatitis.

Epidemiologic patterns of viral hepatitis continue to change over time. Our understanding of its behavior began to change with the recognition that multiple distinct etiologic agents (hepatitis viruses A, B, and non-A/non-B) produce similar clinical syndromes and that there is a broad variability of age-related host response to infection with a given agent. Dorothy Horstmann was among the first to point to the relative mildness of symptoms in children and to the potential epidemiologic significance of such infections. Although hepatitis type A appears to be on a steady decline in overall national incidence, there is an increasing recognition of adult cases epidemiologically related to relatively mild or inapparent infections among infants and children attending day-care centers.

A validation procedure for air sampling-analysis systems.

Validation of solid sorbent air sampling-analytical systems used to evaluate employee exposures to substances in the work place air is a fundamental part of any industrial hygiene air sampling program. In April, 1977, the National Institute for Occupational Safety and Health (NIOSH) published "Documentation of the NIOSH Validation tests", as part of the Standards Completion Project. This paper presents an alternative validation procedure which is more easily understood, is more rigorous, and provides for greater accuracy and precision.

A randomized, double blind controlled trial of the efficacy of immune serum globulin for the prevention of post-transfusion hepatitis. A Veterans Administration cooperative study.

A double blind, randomized, controlled trial has been conducted in 11 Veterans Administration hospitals during a 49-month period to compare the relative efficacies of immune serum globulin (ISG) and an albumin placebo for the prevention of post-transfusion hepatitis (PTH). A total of 2204 patients, of whom 1094 received ISG, participated in the study. The results indicate that ISG significantly reduced the incidence of icteric type non-B hepatitis only (inferred to be also type non-A hepatitis). Adverse reactions were rare, and the ISG did not significantly alter the incubation period or duration of the disease. The data suggest, however, that a similar reduction in type non-A, non-B hepatitis would have occurred had commercial blood been excluded from use. Analysis of the 241 patients who developed hepatitis indicates that type B hepatitis constituted less than 20% of the cases each year of the study. Furthermore, the efficacy of the ISG, manufactured in 1944, against apparent type non-A, non-B hepatitis suggests that this overlooked disease has existed from at least that time. Host- and transfusion-related factors that might have modified the development of PTH were examined. The use of commercial blood was observed to be the most important risk factor. It is concluded that the PTH incidence can be most effectively reduced by eliminating commercial donor blood, and continuing to screen volunteer donors for hepatitis B surface antigen (HBsAg) by sensitive procedures. Of prime importance is the need to define the agent(s) responsible for type non-A, non-B hepatitis.

Nonhuman primate-associated viral hepatitis type A. Serologic evidence of hepatitis A virus infection.

Since 1961, viral hepatitis has been recognized as an occupational hazard among handlers of newly imported chimpanzees and other nonhuman primates. To determine whether previously reported cases were caused by human viral hepatitis type A, we tested paired serum samples from two outbreaks for antibody to hepatitis A antigen (anti-HA) by immune adherence hemagglutination (IAHA), recently available test. In both outbreaks, one of hepatitis transmitted from chimpanzee to man (Michigan, 1964), the second from chimpanzee to chimpanzee, man, and woolly monkey (Connecticut, 1971), serologic data documented recent hepatitis A virus infection among contacts-human and nonhuman primate-of implicated chimpanzees. This confirms serologically a previously noted epidemiologic association between nonhuman primate-associated hepatitis and human viral hepatitis, type A.

Va cooperative study of post-transfusion hepatitis, 1969-1974: incidence and characteristics of hepatitis and responsible risk factors.

The Veterans Administration has been conducting a cooperative randomized, double-blind, controlled trial to evaluate the efficacy of conventional and hepatitis B immune serum globulin for the prevention of post-transfusion hepatitis. Data collected between 1969 and 1974 provide the opportunity to describe the annual incidence and characteristics of the hepatitis that has developed, and the risk factors which have been identified. Anicteric hepatitis has developed four times more frequently than icteric hepatitis, the total incidence for all six years being 11.3 per cent. The incidence of HBs Ag-associated hepatitis declined dramatically after 1973 with the institution of routine screening of donor blood by radioimmunoassay techniques, although no change in the incidence of antigen-negative hepatitis has occurred. There is indirect evidence to suggest that an undefined agent is responsible for the majority of instances of post-transfusion hepatitis occurring presently. The most important risk factor responsible for the development of hepatitis is the use of commercial blood, and it is strongly urged that this form of blood be removed from general use.