MONTREAL — A surprising number of American teen-agers are becoming infected with the AIDS virus during early adolescence, the U.S. Centers for Disease Control reported Monday.
The findings, presented at the Fifth International Conference on AIDS, were part of the most complete report to date on "sentinel" hospital surveillance for AIDS virus infections. Federal health officials consider the ongoing surveillance project at a national sample of 27 urban hospitals one of the most accurate measures of the distribution of human immunodeficiency virus, or HIV, infections among different segments of the population.
The researchers also said they were disturbed by "epidemic proportions" of infections--6% to 8%--in surveys of presumably low-risk male and female patients from two of the hospitals, one in Newark, N.J., and one in the South Bronx, N.Y. The infection rates at the two hospitals were particularly high, about 20%, for men ages 25 to 44 hospitalized with conditions thought unlikely to be related to infection with HIV.
These rates reflect the fact that HIV infection has become a common problem for all residents of these poor urban communities, not just for members of identified AIDS risk groups, researchers said.
The report included the first cross-sectional data on infections in hospitalized adolescents. At hospitals from areas of the country with high numbers of AIDS cases, 1.4% of 15- and 16-year-olds tested positive for HIV, according to the CDC, and a few HIV infections were detected among youths ages 12 to 14.
"Urgent efforts are needed to prevent HIV infections among adolescents throughout the United States," said Dr. Michael E. St. Louis, the CDC researcher who presented the findings. St. Louis said the data suggested that HIV prevention efforts "could not wait" until teen-agers entered high school. School districts have widely varying policies on when to begin AIDS education or whether to offer it at all.
Even at hospitals in areas of the country where AIDS is rare, some infections were detected in those ages 15 and 16, St. Louis said. By comparison, there were no infections detected in children ages 9 to 11 at any of the hospitals studied.
In an interview, St. Louis called the findings in adolescents "surprising" given the criteria for excluding patients from the study. He said follow-up studies are planned to determine the circumstances in which adolescents are most likely to be exposed to the deadly virus.
The report was based on AIDS antibody testing on the blood of about 80,000 patients at 27 hospitals in 21 cities over the last two years. Some of the cities, such as Los Angeles, New York and San Francisco, have had large numbers of AIDS cases; other cities have had relatively few cases.
The testing was conducted anonymously on blood samples obtained for other reasons from patients with illnesses thought unlikely to be related to HIV infection. Specifically excluded were blood specimens from gay men, intravenous drug users and others with known AIDS risk factors. As a result, the statistics are likely to underestimate than overestimate the total number of HIV infections in the hospitals, St. Louis said.
Statistically, on the other hand, hospitalized patients are more likely to have illnesses, perhaps including HIV infection, than others.
In total, about 0.7% of the patients tested positive for AIDS antibodies. Among those 25 to 44 years of age, 2.2% of males and 0.4% of females tested positive.
The findings from the sentinel hospitals study were "consistent" with the CDC's previous estimates that a total of 1 million to 1.5 million Americans are HIV-infected, the CDC's Dr. Timothy J. Dondero said. He also said the estimates were supported by the bulk of other data from military recruits, childbearing women, Job Corps applicants and other sources.
The estimate is to be revised with the help of outside experts in the late summer or early fall.
Area of Highest Rates
In the sentinel hospitals study, the highest infection rates were found at Bronx Lebanon Hospital in New York City and University Hospital in Newark, areas where most new AIDS cases are occurring in intravenous drug users and their sexual partners. The CDC maintains the confidentiality of the hospitals in the study, but these two institutions chose to make their identities public as a means of drawing attention to the gravity of the problem.
"HIV infection has reached epidemic proportions in the poor urban populations served by these hospitals," the CDC's St. Louis said.
At Bronx Lebanon Hospital, 6% of the 3,502 presumably low-risk patients studied tested positive for AIDS antibodies, including 18% of men ages 25 to 44, according to Dr. Jerome A Ernst, a physician at the hospital. The hospital's patients are almost all black or Latino.
"In our neighborhood, (HIV infection) is a disease of poverty," Ernst said.