| outbreak of hepatitis a in rotterdam associated with visits to 'darkrooms' in gay bars. | an unexpectedly large number of hepatitis a virus (hav) infections were notified among homosexual men in rotterdam in the first five months of 1998. a case control study was conducted to investigate the hypothesis that this outbreak was associated with sexual practices and to collect information with which to focus preventive activities. notified cases and controls selected from male members of a gay sports club completed anonymous questionnaires about known risk factors for hav infection and se ... | 1999 | 10462895 |