Occupational and geographic risk factors for hepatitis B among US Army enlisted personnel during 1980

Hepatitis B hospitalization rates for US Army enlisted personnel were determined by occupation and geographic area for 1980. The only group in the US Army currently recommended to receive hepatitis B vaccine is medical personnel regularly exposed to blood. Other groups of Army personnel, specifically those working in areas of high hepatitis B endemicity, have been thought to be at higher risk. Therefore, this work was undertaken to document hospitalization rates for all personnel using occupational blood exposure criteria as well as geographic area of assignment as risk factors for hepatitis B. The hospitalization rates underestimate true rates of hepatitis B incidence by a wide margin, and therefore were not used to calculate specific costs and specific benefits for a new vaccination strategy. In spite of this limitation, these data were useful for calculating relative risk, attributable risk, and amount of vaccine preventable disease. The risk of hospitalization for blood-exposed employees was consistently higher than that for non-blood-exposed personnel. The magnitude of the relative risk for blood exposure may be as high as 3.8 times or as low as 1.2 times, depending on which occupational comparison group is used. The relative risk of hospitalization in South Korea vs. the United States was 3.1 (p less than 0.0001), that for Europe vs. the United States, 2.1 (p less than 0.0001). Of all occupational and geographic risk comparisons, assignment to South Korea carried the highest attributable risk: 225 per 100,000. The amount of vaccine preventable disease in personnel assigned to South Korea was similar to that in occupationally blood-exposed employees (5.5 vs. 5.2 hospitalized cases per 1,000 vaccinees) after prorating exposure to risk based on average number of days of exposure to risk over three years. These data support the argument that geographic factors are as important as occupational blood exposure in defining risk of hepatitis B hospitalization among the US Army enlisted personnel.