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During June-August 1998, the Tuberculosis (TB) Control Program of the Baltimore City Health Department (BCHD) identified four cases of TB among young black men. Three of these men also had human immunodeficiency virus (HIV) infection. The four reported belonging to a social network of transgender persons (i.e., persons who identify with or express a gender and/or sex different from their biologic sex).1 By October 1998, test results on Mycobacterium tuberculosis isolates from the four men demonstrated a matching 11-band DNA fingerprint pattern,2 suggesting that these case-patients were epidemiologically linked. This report describes the public health investigation of these TB case-patients to identify contacts in Baltimore and the New York City area (NYC); the findings suggest that an interstate outbreak of TB has occurred within a social network that includes transgender persons.
The four patients were identified as men who have sex with men (MSM) and belonged to a transgender social network. Some network members dressed as women and participated in dance and fashion competitions known as "balls." These social networks include "houses" (i.e., a guild providing a social framework for young MSM and transgender persons) that exist in many large U.S. cities (house leader, personal communication, 2000). All four also were commercial sex workers.
An additional 22 TB patients were identified and linked to this cluster through interviews, provider and hospital referrals, and contact investigations. Twenty-four of the 26 cases were culture-confirmed, and DNA fingerprinting of 23 isolates demonstrated a matching fingerprint pattern. All isolates were susceptible to first-line anti-TB drugs (e.g., isoniazid and rifampicin). Of the 26 case-patients, 24 were U.S.-born, and 25 were black. The median age was 24 years (range: 20-47 years) and 22 (85%) were men. Sixteen case-patients (62%) were known to have HIV infection or acquired immunodeficiency syndrome (AIDS) when TB was diagnosed.
Among the 15 male case-patients in Baltimore, 13 (87%) were epidemiologically linked; 11 (73%) were members of a house; eight (73%) belonged to House A. The index case-patient (patient 1) was a 24-year-old transgender man and a member of House A. Patients 4 and 14 were roommates of patient 1. Patients 6 and 8 shared living accommodations. Despite having isolates with matching fingerprints, patients 18 and 23 had no epidemiologic link to other patients in the outbreak and reported not being MSM (both were HIV-negative). Patient 20 was an HIV-positive man who has sex with men, was not a member of a house, and reported contact with commercial sex workers. DNA fingerprint results are pending for patient 25, a contact of patient 1. The four female patients included an outreach worker (patient 5) who had contact with two case-patients, a physician (patient 10) who spent approximately 1 hour with patient 1 administering medical care, a friend (patient 15) of several House A members, and the biologic mother (patient 16) of patient 11.
Patient 0 had TB diagnosed in the Maryland corrections system in April 1997. He had been incarcerated since May 1996. Patient 0 was not associated with this outbreak until early 1999 when the fingerprint of his isolate was found to match the outbreak strain. During the 2-year period before incarceration, patient 0 lived with patient 11 and frequented balls in Baltimore and NYC.
During BCHD investigations of 105 contacts of these TB patients, 14 persons were named as contacts by 12 infectious TB case-patients. To reach additional persons who may have had contact with infectious persons, a profile of the social network was developed by BCHD and included any history of membership in a house, attendance at particular nightclubs or balls, or cross-dressing. An additional 91 contacts were identified through visits for home-based anti-TB therapy, two location-based screenings at a nightclub, and referrals from HIV clinics. Among all 105 social network contacts, 96 (91%) had a tuberculin skin test (TST), 65 (68%) tests were read, and 24 (37%) were TST-positive. Six of 19 (32%) Baltimore case-patients were detected through the social network. Because one infectious patient traveled with a community marching band, TST screening was offered to all band members. Screening of 83 band members resulted in a TST-positive rate of 7%, significantly lower (p < 0.01) than in the social network screening. These investigations identified 37 contacts (including 14 TST-negative, HIV-positive contacts) as candidates for treatment for latent TB infection, which was initiated in 24 (65%).
Because of the travel by some of the Baltimore case-patients, transmission of the outbreak strain was suspected in NYC. Patients 9 and 22 had resided for a short time in Baltimore before TB was diagnosed. Identified by a Baltimore case-patient, patient 22 regularly associated with House A members from Baltimore and NYC and participated in balls. Because of the two NYC-diagnosed and reported cases, in late 1999, CDC conducted DNA fingerprint analysis on M tuberculosis isolates from 1998 and 1999 NYC cases among HIV-positive black males aged 15-35 years. Four of 37 (11%) typed isolates matched the Baltimore strain (patients 2, 3, 19, and 21). Interviews of the patients revealed that all four were house members and participated in balls, and all except patient 21 traveled to Baltimore to attend balls.
Patient 24 was from Jersey City, New Jersey, and was linked to this outbreak because M tuberculosis isolates from all TB cases in New Jersey were fingerprint typed through the National TB Genotyping and Surveillance Network. The patient died before the investigation. Medical record review and interviews with relatives indicated the man was transgender and made frequent trips to Baltimore. Five of the seven TB patients identified in NYC were HIV-positive, and three have died.
TR Sterling, MD, RL Stanley, D Thompson, GA Brubach, A Madison, S Harrington, MPH, WR Bishai, MD, RE Chaisson, MD, Baltimore City Health Dept. J Betz-Thomas, Baltimore County Health Dept; S Bur, N Baruch, GC Benjamin, MD, Maryland Dept of Health and Mental Hygiene. CR Driver, MPH, TB Control Program, City of New York Dept of Health; B Kreiswirth, PhD, Public Health Research Institute, New York City. Diagnostic Mycobacteriology Section and Immunology and Molecular Pathogenesis Section, TB/Mycobacteriology Br, Div of AIDS, STD, and TB Laboratory Research, National Center for Infectious Diseases; Surveillance and Epidemiology Br, and Field Services Br, Div of TB Elimination, National Center for HIV, STD, and TB Prevention; and an EIS Officer, CDC.
This outbreak of TB among transgender persons occurred within a social network that is both at high risk for TB and difficult to reach using a traditional public health investigative approach. Early in the outbreak, BCHD recognized the initial cluster of four cases with matching DNA fingerprint patterns. This prompted further investigation to explore chains of transmission not detected through routine epidemiologic links. Traditional contact investigations, where health officials rely on persons with infectious TB to identify persons with whom they have contact regularly at home and in the work place,3 were inadequate to control this outbreak. As a result, contacts might have been overlooked if patients had not been asked about the transgender social network, particularly the houses. Most contacts were identified at location-based TST screenings or by TB outreach workers and nurses who encountered contacts while administering TB therapy.
Transgender persons are heterosexual, homosexual, or bisexual and may be cross-dressers (transvestites) or preoperative and postoperative transsexuals.4 Transgender persons often fear discrimination and ridicule and may conceal their identity, move frequently, engage in illicit activities such as commercial sex work, and mistrust public health authorities.5,6 In this investigation, many infected persons were reluctant or unable to identify contacts.
The transgender social network includes biologic male house members who appear as women and members who neither cross-dress nor are transgender. Most houses are affiliated with houses in other U.S. cities. An important activity of the social network is attendance and participation in balls, and some house members travel to numerous east coast cities to participate in balls.
The findings in this report are subject to at least two limitations. First, the total number of persons within this transgender social network is unknown; therefore, the extent of transmission cannot be determined. Second, although matching DNA fingerprints of M tuberculosis isolates obtained from different patients strongly suggest common chains of transmission, conclusions should not be drawn in the absence of sufficient epidemiologic data. Despite routine DNA fingerprinting of all M tuberculosis isolates within Maryland and New Jersey, with the exception of patients 18 and 23, this particular 11-band fingerprint pattern has been observed only in persons associated with this social network. Epidemiologic links for patients 18 and 23 were not established.
This outbreak strain was detected in 13 (14%) of the 96 culture-confirmed TB cases reported in Baltimore during June 1998-December 1999, and 10 (67%) of 15 culture-confirmed cases reported among U.S.-born black males aged 15-35 years during this period. Frequent travel and social network links identified among the Baltimore and NYC cases have raised concern that this strain of M tuberculosis may be circulating in other cities among young, mobile, transgender persons with HIV infection. One house leader estimated that there are at least 35 houses in major east coast cities. However, three of the more recent Baltimore patients associated with this outbreak did not acknowledge being transgender or affiliating with a house, raising the possibility that transmission may be occurring beyond the transgender community. CDC is working with TB control staff in Baltimore, Boston, NYC, Philadelphia, Washington, D.C., and Atlanta to determine whether additional TB cases are linked to this outbreak. Health-care providers should report cases to local TB control programs. Health departments may contact CDC for technical assistance at (404) 639-8117.
HIV-Related Tuberculosis in a Transgender Network—Baltimore, Maryland, and New York City Area, 1998-2000. JAMA. 2000;283(19):2515-2516. doi:10.1001/jama.283.19.2515