Tuberculosis testing among populations with high HIV risk in Tijuana, Baja California, Mexico.

OBJECTIVE: To assess the prevalence of prior tuberculin skin testing (TST) among populations at risk for HIV infection in Tijuana, Mexico, and to identify factors associated with TST. METHODS: Sex workers, injection drug users, noninjecting drug users, and homeless persons > 18 years old were recruited by using targeted sampling for risk assessment interviews and serologic testing for HIV and Mycobacterium tuberculosis infection. Univariate and multivariate logistic regression were used to identify correlates of self-reported TST history. RESULTS: Of 502 participants, 38.0% reported prior TST, which was associated with previous incarceration in the United States of America [odds ratio (OR) = 13.38; 95% confidence interval (CI) = 7.37-24.33] and injection drug use (OR = 1.99; 95% CI = 1.27- 3.11). Positive results on serologic tests for M. tuberculosis infection (57%) and HIV (4.2%) were not associated with a prior TST. CONCLUSIONS: A history of TST was lower in HIV-positive participants even though TST is indicated for persons with HIV in Mexico. Fewer than half the individuals at high risk for HIV in this study had a history of TST; however, TST was fairly common among those individuals with a prior history of incarceration. Increased tuberculosis screening is needed for populations at risk of contracting HIV in Tijuana, particularly those outside of criminal justice settings.

Latent tuberculosis among persons at risk for infection with HIV, Tijuana, Mexico.

Because there is little routine tuberculosis (TB) screening in Mexico, the prevalence of latent TB infection (LTBI) is unknown. In the context of an increasing HIV epidemic in Tijuana, Mexico, understanding prevalence of LTBI to anticipate emergence of increased LTBI reactivation is critical. Therefore, we recruited injection drug users, noninjection drug users, female sex workers, and homeless persons for a study involving risk assessment, rapid HIV testing, and TB screening. Of 503 participants, the overall prevalences of TB infection, HIV infection, and TB/HIV co-infection were 57%, 4.2%, and 2.2%, respectively; no significant differences by risk group (p>0.05) were observed. Two participants had TB (prevalence 398/100,000). Incarceration in Mexico (odds ratio [OR] 2.28), age (OR 1.03 per year), and years lived in Tijuana (OR 1.02 per year) were independently associated with TB infection (p<0.05). Frequent LTBI in marginalized persons may lead to increases in TB as HIV spreads.

Surveillance or support: The experience of direct observation during tuberculosis treatment.

Directly observed therapy (DOT) is a cornerstone of tuberculosis (TB) control. DOT has been criticised as paternalistic, but it has also been argued that the interaction with healthcare workers (HWs) can be a source of support for patients. We explored the experience of patients in antituberculosis treatment, with the aim of understanding the balance between surveillance and support from the recipient's point of view. We interviewed 27 patients in Tijuana, Mexico, employing narrative analysis to understand how participants made sense of their illness and their experience of DOT. We found a core narrative of biographic disruption and self-reconstruction, in which HWs helped participants to attribute a less negative meaning to TB. Interviewees accepted DOT's as necessary for other people to avoid treatment abandonment, but felt that in their case it was unnecessary. Only a few felt that DOT represented mistrust on the part of the HWs. We conclude that DOT can be a source of support when it is enacted in a patient-centred way. We discuss whether participants' lack of criticism of DOT is a case of adaptive preference, in the context of a power differential between patient and health system.

Tuberculosis testing among populations with high HIV risk in Tijuana, Baja California, Mexico / Prueba de tuberculosis en poblaciones con riesgo alto de VIH en Tijuana, Baja California, México

OBJECTIVE: To assess the prevalence of prior tuberculin skin testing (TST) among populations at risk for HIV infection in Tijuana, Mexico, and to identify factors associated with TST. METHODS: Sex workers, injection drug users, noninjecting drug users, and homeless persons > 18 years old were recruited by using targeted sampling for risk assessment interviews and serologic testing for HIV and Mycobacterium tuberculosis infection. Univariate and multivariate logistic regression were used to identify correlates of self-reported TST history. RESULTS: Of 502 participants, 38.0% reported prior TST, which was associated with previous incarceration in the United States of America [odds ratio (OR) = 13.38; 95% confidence interval (CI) = 7.37-24.33] and injection drug use (OR = 1.99; 95% CI = 1.27- 3.11). Positive results on serologic tests for M. tuberculosis infection (57%) and HIV (4.2%) were not associated with a prior TST. CONCLUSIONS: A history of TST was lower in HIV-positive participants even though TST is indicated for persons with HIV in Mexico. Fewer than half the individuals at high risk for HIV in this study had a history of TST; however, TST was fairly common among those individuals with a prior history of incarceration. Increased tuberculosis screening is needed for populations at risk of contracting HIV in Tijuana, particularly those outside of criminal justice settings.

OBJETIVO: Evaluar la prevalencia de la prueba de la tuberculina previa, e identificar los factores asociados con ella, en poblaciones con riesgo de infección por el VIH en Tijuana, México. MÉTODOS: Se reclutó a profesionales del sexo, consumidores de drogas inyectables y no inyectables y personas sin hogar > 18 años de edad mediante un muestreo dirigido a fin de efectuar entrevistas para evaluar el riesgo y pruebas serológicas para la infección por el VIH y Mycobacterium tuberculosis. Para identificar la correlación de los antecedentes de la prueba de la tuberculina proporcionados por el propio individuo se usó regresión logística de una sola variable y con múltiples variables. RESULTADOS: De 502 participantes, 38,0% informaron una prueba de la tuberculina previa, que se asoció con encarcelamiento anterior en los Estados Unidos de América (razón de posibilidades [OR] = 13,38; intervalo de confianza de 95% [IC] = 7,37-24,33) y consumo de drogas inyectables (OR = 1,99; IC de 95% = 1,27-3,11). Los resultados positivos en las pruebas serológicas para la infección con M. tuberculosis (57%) y VIH (4,2%) no se asociaron con una prueba de la tuberculina previa. CONCLUSIONES: Los antecedentes de una prueba de la tuberculina fueron menores en los participantes seropositivos para el VIH, a pesar de que en México esta prueba está indicada en las personas con VIH. En este estudio menos de la mitad de los individuos con alto riesgo de VIH tenían antecedentes de la prueba de la tuberculina; sin embargo, esta fue bastante frecuente en los individuos con antecedentes de encarcelamiento. En las poblaciones en riesgo de contraer el VIH en Tijuana se requiere un mayor tamizaje de tuberculosis, en particular en aquellas no relacionadas con el ambiente de la justicia penal.