Negative latent tuberculosis at time of incarceration: identifying a very high-risk group for infection.

The main aim was to measure the incidence of latent tuberculosis infection (LTBI) and identify risk factors associated with infection. In addition, we determined the number needed to screen (NNS) to identify LTBI and active tuberculosis. We followed 129 prisoners for 2 years following a negative two-step tuberculin skin test (TST). The cumulative incidence of TST conversion over 2 years was 29·5% (38/129), among the new TST converters, nine developed active TB. Among persons with no evidence of LTBI, the NNS to identify a LTBI case was 3·4 and an active TB case was 14·3. The adjusted risk factors for LTBI conversion were incarceration in prison number 1, being formerly incarcerated, and overweight. In conclusion, prisoners have higher risk of LTBI acquisition compared with high-risk groups, such as HIV-infected individuals and children for whom LTBI testing should be performed according to World Health Organization guidance. The high conversion rate is associated with high incidence of active TB disease, and therefore we recommend mandatory LTBI screening at the time of prison entry. Individuals with a negative TST at the time of entry to prison are at high risk of acquiring infection, and should therefore be followed in order to detect convertors and offer LTBI treatment. This approach has a very low NNS for each identified case, and it can be utilized to decrease development of active TB disease and transmission.

High prevalence and risk factors associated with latent tuberculous infection in two Colombian prisons.

SETTING: Two prisons in Medellín and Itagüí, Colombia. OBJECTIVE: To determine the prevalence of tuberculin skin test (TST) positivity in prisoners and the annual risk of tuberculous infection (ARTI), to identify risk factors associated with a positive result, and to describe progression to active disease. DESIGN: Cross-sectional study. Inmates were included if time of incarceration was ⩾1 year and excluded if subjects had had previous or active tuberculosis (TB), or conditions that could hamper TST administration or interpretation. RESULTS: We screened 1014 inmates. The overall prevalence of TST positivity was 77.6%. The first TST administration resulted in 66% positivity, and the second TST an additional 11.6%. In Prison One, the ARTI was 5.09% in high TB incidence cell blocks and 2.72% in low TB incidence blocks. In Prison Two, the ARTI was 2.77%. Risk factors associated with TST positivity were history of previous incarceration and length of incarceration. Among all those included in the study, four individuals developed active pulmonary TB. CONCLUSION: Prevalence of TST positivity in prisoners and the ARTI were higher than in the general population, but differed between prisons; it is important to apply a second TST to avoid an overestimation of converters during follow-up.

Comparación de la inmunofluorescencia, ensayo inmunoenzimático y cultivo celular para el diagnóstico de chlamydia trachomatis en infecciones urogenitales / Comparison of immunofluorescence, enzyme immunoassay and cell culture for the diagnosis of Chlamydia trachomatis in urogenital infections

We evaluated the usefulness of the direct immunofluorescence test with monoclonal antibodies and the enzyme immunoassay in comaprison with isolation in cell cultures for the diagnosis of Chlamydia trachomatis in 55 endocervica specimens from female prostitutes and 21 urethral specimens fro men with diagnosis of nongonococcal urethritis. In comparison with culture, the enzyme immunoassay had a sensitivity of 100% and a specificity of 95%. The immunofluorescence test had a sensitivity of 92% and a specificity of 98%. The positive and negative predictive values for the enzyme immunoassay were 81% and 100% and for immunofulorescence 92% and 98% respectively. The immunologic methods appear to be satisfactory alternatives to culture for detecting C trachomatis in genital specimens in the studied populations

Detección de chlamydia trachomatis en muestras endocervicales por un método rápido de ensayo inmunoenzimático / Detection of chlamydia trachomatis in endocervical samples by a quickly method of inmunoenzimatic essay

Se evaluó la utilidad de un método rápido de ensayo inmunoenzimático (TestPack, Chlamydia, Abbott Laboratories), en comparación con la técnica de cultivo celular, para la detección de Chlamydia trachomatis de muestras endocervicales obtenidas de 120 mujeres provenientes d dos poblaciones de Santiago. La sensibilidad global del ensayo inmunoenzimático fue 88,9% y su especificidad 99,1%. Los valores predictivos positivo y negativo fueron 90 y 99,1% respectivamente. En síntesis, la técnica evaluada demostró ser muy simple y rápida de realizar y de alta especificidad. No obstante, su sensibilidad inferior al cultivo celular, permite sugerir su uso en pacientes sintomáticos o población femenina de alto riesgo de infección por C. trachomatis