Rate of subclinical hepatitis A virus infection in adult HIV-1-infected patients.

through contaminated fわod or water (1,2). It can also be transmitted person-to-person as a sexually transmitted disease (STD) in homosexual men (315). We encountered an outbreak of acute HAY infection in HIV1 -infected homosexual men livlng ln the Tokyo Metropolitan area from August 1998 through September 1999 (6). We here report the rate of subclinical HAY infection in adult HIV1 -infected cases. A total of 404 HIVI -infected patients visited the ambulant clinic in September 1999. Among them, 137 patients were homosexual men and 5 I (38%) of these homosexual patients had anti-HAV IgG antibodies. Twenty-three of these patients had experienced typical clinical symptoms of acute HAY infection, such as fever, general fatigue, nausea, vomiting,and jaundice,inthe previous year. The diagnosis was confirmed bythe presence of anti-HAV IgM antibodies in cases presenting with clinical symptoms. Sera from 28 additional patients had been stored since January 1998 (this outbreak started in August 1998). They had not experienced any clinical manifestations of HAV infection. However, serologlCal tests revealed that 1 7 patients among them had the lgG antibodies at that time; the remainlng ll patients did not. Accordingly, the ll patients were seroconverted despite having no clinical symptoms during this period. Consequently, lt Was Calculated that 23 plus1 1 (i.e., 34 patients; 24.8% of the 137 homosexual men) Were infected with HAV in this outbreak. The rate of subclinical infection was 32.3% (95% confidence interval lCI]: 16.6%48.0%) in adult HIV1 -infected patients. The characteristics of these patients are listed in Table 1. There was no significant difference between HAV infection manifest and non-manifest groups with respect to age, CD4 counts, CD8 counts, and anti-HIV-1 treatment. The HIV-1 viral load of patients with clinical manifestation was slgnif1cantly higher than that of patients with subclinical HAV infection. However, analysts Of the symptomatic patients revealed no correlation between severity of symptoms and