Clinical and subclinical hepatitis A occurring after immunoglobulin prophylaxis among Swedish UN soldiers in Sinai.

This study was performed to investigate the efficiency of 5 ml of 16.5% immunoglobulin (Ig) with an antibody titer against hepatitis A (anti-HAV) of 1:4000, using the HAVAB RIA technique, as pre-infection prophylaxis in 610 Swedish UN soldiers stationed in Sinai for 6 months. Sera were collected from 553 of these soldiers before, during, and after their service and were tested by the HAVAB technique for anti-HAV. Only 13 of 553 (2.4%) were immune before their service. During the first 5 months in Sinai, only one subclinical case of hepatitis A occurred among the men. Thereafter, two subclinical and four clinical cases occurred, although one of the subclinical cases and the four clinical ones did not occur until after the 6-month period. Thus, the Ig prophylaxis scheme used seems to offer almost complete passive protection for 5 months.