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Resurgent Bacterial Sexually Transmitted Disease Among Men Who Have Sex With Men -- King County, Washington, 1997-1999

During the late 1980s and early 1990s, King County, Washington (1998 population: 1.6 million), experienced a substantial epidemic of infectious syphilis (i.e., primary, secondary, and early latent). Subsequently, reported cases of infectious syphilis declined to six cases in 1995 and one in 1996; five of the 1995 cases and the case in 1996 were believed to have been acquired outside King County. However, in 1997, sustained spread of syphilis was reestablished in King County (1). To determine whether this reemergence was associated with changes in the epidemiology of other sexually transmitted diseases (STDs), Public Health-Seattle and King County (PHSKC) analyzed notifiable STD data for 1997-1999. This report summarizes the results of this analysis, which indicate that infectious syphilis among men who have sex with men (MSM) in King County increased to 46 cases during January-June 1999, and chlamydia and gonorrhea also increased among MSM attending public health clinics.

For this report, PHSKC analyzed surveillance data on infectious syphilis, chlamydia, and gonorrhea reported to PHSKC from health-care providers and laboratories. Data included disease, sex, stage of disease, racial/ethnic group, age, and in some cases sexual orientation and anatomic site of infection. Persons with these diseases were interviewed by PHSKC staff for partner management. Data collected included number and sex of sex partners, sexual orientation, and other risk factors.

Syphilis cases increased steadily from late 1997 to mid-1998, appeared to stabilize in the second half of 1998, then increased during January-June 1999 (Figure 1). The proportion of cases in MSM increased from 21% (four of 19) in 1997 to 85% (75 of 88) in 1998 and 1999 (pless than 0.01). Among 79 MSM, the median age was 35 years (range: 19-56 years) and 70% were aged greater than 30 years. Primary, secondary, and early latent infection accounted for 23%, 61%, and 16% of cases in MSM, respectively; these proportions did not differ significantly from 1997 to 1999. Among the 79 MSM with early latent syphilis in 1997 through June 1999, 48 (72%) of 67 had human immunodeficiency virus (HIV) infection and two others were HIV seropositive near the time syphilis was diagnosed.

From 1997 through June 1999, laboratory-confirmed infections with Neisseria gonorrhoeae and Chlamydia trachomatis among MSM attending the PHSKC STD clinic also increased (Figure 2). In addition, cases of rectal gonococcal infection in males reported by providers outside the STD clinic increased from six cases in 1997 to 25 cases in 1998 and 13 cases during January-June 1999. The median age of the 427 MSM who received a diagnosis of gonorrhea or chlamydial infection in the STD clinic from 1997 through June 1999 was 32 years (range: 20-53 years), and 17% with chlamydial infection and 19% with gonorrhea were known to be infected with HIV; this proportion did not vary significantly through the period of analysis.

Data on sex partners were provided by 63 (80%) of the 79 MSM with infectious syphilis from 1997 through June 1999. During the interval when syphilis was likely to have been acquired or transmitted (mean: 6 months), these men reported 740 sex partners, of whom 653 (88%) were met at anonymous venues such as bath houses, bars, or clubs; 50 (79%) of 63 men had had at least one anonymous partner (median: three partners; range: one to 100). MSM with gonorrhea or chlamydial infection reported a mean of 3.5 sex partners during the 2 months before treatment, and approximately 20% apparently acquired infection from anonymous partners.

Based on an estimate of PHSKC that 40,000 MSM reside in King County, the annual rate of infectious syphilis per 100,000 MSM increased from zero in 1996 to approximately 10 in 1997 and 90 in 1998, and the projected annual incidence in 1999 is 200 cases per 100,000. An estimated 10% of MSM in King County are infected with HIV (PHSKC, unpublished data, 1999). If 4000 HIV-infected MSM reside in King County, the projected annual incidence of infectious syphilis in the HIV-infected MSM population in 1999 is approximately 1500 per 100,000. The minimum incidence of gonorrhea in MSM, based on the number of cases diagnosed in the PHSKC STD clinic plus rectal infections in males diagnosed elsewhere (data on sexual orientation are not available outside the STD clinic), increased from 180 per 100,000 MSM in 1997 to 430 and 420 in 1998 and 1999, respectively. In comparison, the reported rate of gonorrhea in presumptively heterosexual persons in King County was 50 per 100,000 in 1997 and 1998.

PHSKC has used outreach activities, targeted publications in the local gay press, and community forums to encourage MSM to follow safer sex practices and to be screened for STDs. STD and HIV testing and counseling are being offered at bath houses and other venues, screening has been expanded among MSM attending public clinics, and King County health-care providers have been encouraged to expand STD screening among at-risk MSM.

Reported by: HH Handsfield, MD, WLH Whittington, S Desmon, C Celum, MD, B Krekeler, MHA, STD Control Program, Public Health-Seattle and King County, Seattle; Washington Dept of Health. Div of Sexually Transmitted Diseases Prevention, National Center for HIV, STD, and TB Prevention, CDC.

Editorial Note:

The incidence of STDs among MSM declined substantially during the early 1980s as a result of a decrease in sexual risk behavior (2,3). However, high-risk behaviors and STDs among MSM have increased in some cities (4,5). In Washington, the proportion of cases of primary and secondary syphilis among MSM declined from 81% in 1973 to 8% in 1988 (3). The findings in this report indicate that syphilis transmission in King County is occurring predominantly among MSM. When STDs are introduced into a community, the size of the subsequent outbreak depends on the sexual mixing patterns of the community, the numbers of sex partners, concurrency of sexual partnerships, condom use, and the frequency of partner change (3,6). In King County, syphilis, gonorrhea, and chlamydia apparently have been introduced into a population of MSM who have large numbers of anonymous partners, which can result in rapid and extensive transmission of STDs (7). In addition to this outbreak, recent reports have suggested increases in gonococcal infection in several western states and in the frequency of unprotected anal sex among MSM (4,5). Some MSM may be recruiting sex partners in anonymous venues more often now than in the recent past (8).

The high proportion of persons with syphilis, gonorrhea, and chlamydial infection who also were infected with HIV is of particular concern. Persons with STDs, including genital ulcer disease and nonulcerative STD, have a twofold to fivefold increased risk for HIV infection (9,10). Control of STDs is a central component of HIV infection prevention efforts in the United States (10); resurgence of bacterial STD threatens national HIV infection prevention efforts.

Reasons for the increasing rates of bacterial STD in MSM in King County are unknown but may include an increased frequency of unprotected sex among some MSM. Anecdotal reports by MSM with bacterial STDs suggest that such behaviors are linked to sex with anonymous partners in bath houses, which may be related to improvements in the treatment of HIV infection or to changing patterns of recreational drug use. The age distribution of syphilis cases suggests that in King County, relapse in sexual safety among older MSM is a more important determinant than failure of young, newly sexually active MSM to adopt safer sex practices.

The findings in this report are subject to at least three limitations. First, reporting of STDs is incomplete, which could result in an underestimate of the incidence of disease in this population. Second, MSM attending STD clinics probably are not representative of all MSM at risk. Finally, some persons may not have given accurate responses when asked about sexual relationships, HIV serostatus, or high-risk behaviors.

PHSKC has employed several control measures to contain these outbreaks. Although partner notification is effective for the known partners of persons with syphilis and gonorrhea, its ability to reach exposed persons is greatly limited in situations such as the syphilis outbreak in King County, where 88% of partners were met at venues where anonymous sex is common. The high frequency of anonymous sex strongly suggests that sex partner management services for identifiable partners alone would be insufficient to control the outbreak. Print media, public service announcements, outreach, and expanded screening have been used in this outbreak to augment traditional partner management services. These interventions may have encouraged timely symptom recognition and health-seeking behavior by infected men. Among men with syphilis, 72% knew they were HIV positive and many were receiving health care for the disease, indicating that enhanced STD prevention efforts may be needed for HIV-infected MSM in health-care settings and other venues. This outbreak demonstrates the need to sustain surveillance for STDs even after rates have decreased in a community.


  1. CDC. Gonorrhea among men who have sex with men--selected sexually transmitted diseases clinics, 1993-1996. MMWR 1997;46:889-92.
  2. CDC. Increases in unsafe sex and rectal gonorrhea among men who have sex with men--San Francisco, 1994-1997. MMWR 1999;48:45-8.
  3. Williams LA, Klausner JD, Whittington WLH, Handsfield HH, Celum C, Holmes KK. Elimination and reintroduction of primary and secondary syphilis. Am J Public Health 1999;89:1093-7.
  4. Handsfield HH, Schwebke J. Trends in sexually transmitted diseases in homosexually active men in King County, Washington, 1980-1990. Sex Transm Dis 1990;17:211-5.
  5. Aral S, Holmes KK. Social and behavioral determinants of the epidemiology of STDs: industrialized and developing countries. In: Holmes KK, ed. Sexually transmitted diseases. 3rd ed. New York: McGraw-Hill, 1999:39-76.
  6. Aral SO. Sexual network patterns as determinants of STD rates: paradigm shift in the behavioral epidemiology of STDs made visible. Sex Transm Dis 1999;26:262-4.
  7. Anderson RM, Gupta S, Ng W. The significance of sexual partner contact networks for the transmission dynamics of HIV. J Acquir Immune Defic Syndr 1990;3:417-29.
  8. Sowell RL, Lindsey C, Spicer T. Group sex in gay men: its meaning and HIV prevention implications. J Assoc Nurses AIDS Care 1998;9:59-71.
  9. Mertz KJ, Weiss JB, Webb RM, et al. An investigation of genital ulcers in Jackson, Mississippi, with use of a multiplex polymerase chain reaction assay: high prevalence of chancroid and human immunodeficiency virus infection. J Infect Dis 1998;178:1060-6.
  10. CDC. HIV prevention through early detection and treatment of sexually transmitted diseases--United States. MMWR 1998;46(no. RR-12).

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