Correspondence

AIDS among Heterosexuals in Surveillance Reports

N Engl J Med 2001; 344:611-613February 22, 2001

Article

To the Editor:

The Centers for Disease Control and Prevention (CDC) tabulates and reports AIDS cases in the United States biannually. Using these official data, we analyzed trends in the distribution of AIDS cases according to sex, race or ethnic group, and various categories of exposure to human immunodeficiency virus (HIV); we analyzed trends for five-year intervals using end-of-the-year data from 1989, 1994, and 1999.1-3 Both the 1993 change in the case definition of AIDS4 and the increasing use of highly active antiretroviral therapy for HIV-infected persons5 complicate the interpretation of these surveillance data, but they probably have a limited effect on comparisons of the characteristics of reported patients at different times.

Table 1Table 1Cases of AIDS Reported in the United States in 1989, 1994, and 1999, According to Sex, Race or Ethnic Group, and Category of Exposure. shows the number of cases reported each year according to sex, race or ethnic group, and category of exposure. Homosexual or bisexual men, including those who also injected drugs, make up the largest group each year. Homosexual or bisexual men, including those who injected drugs, accounted for 62 percent of cases reported in 1989, 48 percent of cases in 1994, and 37 percent in 1999. The groups in which there were the greatest percentage increases over time were the group with heterosexual contact and the group for whom the risk factors were not reported or identified.

The latter group grew most rapidly, accounting for 5 percent of the reported cases in 1989, 12 percent in 1994, and 24 percent in 1999. In fact, this group includes a significant number of patients who deny having other known risk factors but report multiple heterosexual partners and are unable or unwilling to identify one or more of those partners with HIV infection or at higher risk for exposure to HIV.6,7 Identification and inclusion of these “probable heterosexual cases” in the HIV/AIDS Surveillance Report would further expand the number of cases attributed to heterosexual contact and would, in our opinion, represent a more complete description of the epidemiology of AIDS in the United States. We encourage the CDC to gather and provide additional information about the patients with AIDS whose risk factors are not initially reported or identified.

(The opinions and assertions in this letter are those of the authors and do not necessarily represent the official position of the Department of the Army or the Department of Defense.)

Harry W. Haverkos, M.D.
Raymond C. Chung, M.D.
Walter Reed Army Medical Center, Washington, DC 20307

7 References

1. 1

   HIV/AIDS surveillance report. Year-end edition. Atlanta: Centers for Disease Control, January 1990:1-22.
   

2. 2

   HIV/AIDS surveillance report. Year-end edition. Vol. 6. No. 2. Atlanta: Centers for Disease Control and Prevention, 1994:1-39.
   

3. 3

   HIV/AIDS surveillance report. Year-end edition. Vol. 11. No. 2. Atlanta: Centers for Disease Control and Prevention, 1999:1-44.
   

4. 4

   1993 Revised classification system for HIV infection and expanded surveillance case definition for AIDS among adolescents and adults. MMWR Morb Mortal Wkly Rep 1992;41:1-19
   Medline

5. 5

   Palella FJ, Delaney KM, Moorman AC, et al. Declining morbidity and mortality among patients with advanced human immunodeficiency virus infection. N Engl J Med 1998;338:853-860
   Full Text | Web of Science | Medline

6. 6

   Update: heterosexual transmission of acquired immunodeficiency syndrome and human immunodeficiency virus infection -- United States. MMWR Morb Mortal Wkly Rep 1989;38:423-4, 429
   Medline

7. 7

   Castro KG, Lifson AR, White CR, et al. Investigations of AIDS patients with no previously identified risk factors. JAMA 1988;259:1338-1342
   CrossRef | Web of Science | Medline

Author/Editor Response

The above letter was sent to the CDC, which offers the following reply:

To the Editor: The letter by Haverkos and Chung describes the increasing percentages of women, members of racial or ethnic minority groups, and persons infected through heterosexual contact among persons with AIDS. It calls on the CDC to provide additional information about those with AIDS for whom risk factors for exposure to HIV were undetermined and to report cases in persons who had multiple heterosexual partners as “probable heterosexual cases.”

Many patients whose cases are initially reported without data on behavioral risk factors are reclassified in an exposure category after the CDC has conducted follow-up with health care providers or patients. Of 44,392 men with AIDS initially reported as having undetermined risk factors but later reclassified, 54 percent were men who have sex with men, 23 percent were injection-drug users, 5 percent were both of the above, and 16 percent contracted HIV through heterosexual contact.1 Of 15,300 such women who were later reclassified, 27 percent were injection-drug users, and 68 percent contracted HIV through heterosexual contact. The proportions reclassified are lowest among cases reported most recently. Of the 745,103 men and women with AIDS reported through June 2000, 8 percent and 15 percent, respectively, have undetermined risk factors; during the most recent annual period, 22 percent of men and 33 percent of women have undetermined risk factors.1

Many factors account for the increasing proportion of AIDS cases reported with undetermined risk factors. In addition to those cited by Haverkos and Chung, they include the large volume of case reports generated between 1993 and 1995, an increased reliance on laboratory reports (which usually lack information about behavioral risk factors), and competing demands on state resources for public health. It is no longer feasible to gather additional timely information about behavioral risk factors by means of reviews of medical records and interviews of all persons with AIDS. This challenge is exacerbated as states expand AIDS surveillance to include all persons with a diagnosis of HIV.2

Although additional data on behavioral risk factors in all cases would be desirable, the CDC is instead pursuing a more efficient approach that involves statistical adjustments based on follow-up of a representative sample of cases.3 The CDC surveillance reports currently include both the raw data that Haverkos and Chung cite and data that are statistically adjusted for delays in reporting cases and for undetermined risk factors.1 The latter data should be used in order to avoid underestimating the proportion of cases due to heterosexual contact (which increased from 5.9 percent in 1989 to 24.8 percent in 1999, after adjustments for delayed reporting and estimated risk-factor reclassification).

Although men who have sex with men continue to account for the largest proportion of cases reported annually, the heterosexual transmission of HIV affects members of racial and ethnic minority groups disproportionately.4 Behavioral surveillance to characterize the populations that are at risk and infected is crucial for effective prevention. A scientific approach based on a standard definition of high-risk heterosexual behavior and rigorous statistical sampling should ensure that data from all states are of high quality and are comparable; such an approach is preferable to the presumption that all cases reported with undetermined risk factors and multiple sexual partners are due to heterosexual transmission.

Patricia L. Fleming, Ph.D.
Harold W. Jaffe, M.D.
Centers for Disease Control and Prevention, Atlanta, GA 30333

4 References

1. 1

   HIV/AIDS surveillance report. Vol. 112. No. 1. Atlanta: Centers for Disease Control and Prevention, 2000:1-41.
   

2. 2

   Guidelines for national case surveillance, including monitoring for human immunodeficiency virus infection and acquired immunodeficiency syndrome. MMWR Morb Mortal Wkly Rep 1999;48:1-31
   Medline

3. 3

   Klevens RM, Fleming PL, Neal JJ, Li J. Is there really a heterosexual AIDS epidemic in the United States? Findings from a multisite validation study, 1992-1995. Am J Epidemiol 1999;149:75-84
   Web of Science | Medline

4. 4

   Neal JJ, Fleming PL, Green TA, Ward JW. Trends in heterosexually acquired AIDS in the United States, 1988 through 1995. J Acquir Immune Defic Syndr Hum Retrovirol 1997;14:465-474
   CrossRef | Medline

Citing Articles (2)

Citing Articles

1. 1

   Curt G. Beckwith, Timothy P. Flanigan, Carlos del Rio, Emma Simmons, Edward J. Wing, Charles C. J. Carpenter, John G. Bartlett. (2005) It Is Time to Implement Routine, Not Risk‐Based, HIV Testing. Clinical Infectious Diseases 40:7, 1037-1040
   CrossRef

2. 2

   E. Simmons, A. Monroe, T. Flanigan. (2004) Testing for HIV to Destigmatize and Improve Diagnosis of HIV Infection. Clinical Infectious Diseases 39:8, 1259-1260
   CrossRef