Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2013 Nov 21;8(11):e80592.
doi: 10.1371/journal.pone.0080592. eCollection 2013.

High incidence of tuberculosis, low sensitivity of current diagnostic scheme and prolonged culture positivity in four colombian prisons. A cohort study

Zulma Vanessa Rueda  1 , Lucelly López, Lázaro A Vélez, Diana Marín, Margarita Rosa Giraldo, Henry Pulido, Luis Carlos Orozco, Fernando Montes, María Patricia Arbeláez
Affiliations

High incidence of tuberculosis, low sensitivity of current diagnostic scheme and prolonged culture positivity in four colombian prisons. A cohort study

Zulma Vanessa Rueda et al. PLoS One. .

Abstract

Objective: To determine the incidence of pulmonary tuberculosis (TB) in inmates, factors associated with TB, and the time to sputum smear and culture conversion during TB treatment.

Methods: Prospective cohort study. All prisoners with respiratory symptoms (RS) of any duration were evaluated. After participants signed consent forms, we collected three spontaneous sputum samples on consecutive days. We performed auramine-rhodamine staining, culturing with the thin-layer agar method, Löwestein-Jensen medium and MGIT, susceptibility testing for first-line drugs; and HIV testing. TB cases were followed, and the times to smear and culture conversion to negative were evaluated.

Results: Of 9,507 prisoners held in four prisons between April/30/2010 and April/30/2012, among them 4,463 were screened, 1,305 were evaluated for TB because of the lower RS of any duration, and 72 were diagnosed with TB. The annual incidence was 505 cases/100,000 prisoners. Among TB cases, the median age was 30 years, 25% had <15 days of cough, 12.5% had a history of prior TB, and 40.3% had prior contact with a TB case. TB-HIV coinfection was diagnosed in three cases. History of prior TB, contact with a TB case, and being underweight were risk factors associated with TB. Overweight was a protective factor. Almost a quarter of TB cases were detected only by culture; three cases were isoniazid resistant, and two resistant to streptomycin. The median times to culture conversion was 59 days, and smear conversion was 33.

Conclusions: The TB incidence in prisons is 20 times higher than in the general Colombian population. TB should be considered in inmates with lower RS of any duration. Our data demonstrate that patients receiving adequate anti-TB treatment remain infectious for prolonged periods. These findings suggest that current recommendations regarding isolation of prisoners with TB should be reconsidered, and suggest the need for mycobacterial cultures during follow-up.

PubMed Disclaimer

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1
Figure 1. Flowchart of inmates included in the study.
Figure 2
Figure 2. Time to sputum smear and culture conversion after anti-TB treatment initiation.
Figure 3
Figure 3. Time to culture conversion during TB treatment, stratified by sputum smear status at diagnosis.
See this image and copyright information in PMC

References

    1. Baussano I, Williams BG, Nunn P, Beggiato M, Fedeli U et al. (2010) Tuberculosis Incidence in Prisons: A Systematic Review. PLOS Med 7: e1000381. doi: 10.1371/journal.pmed.1000381. PubMed: 21203587. - DOI - PMC - PubMed
    1. WHO (2010) | Treatment of tuberculosis: guidelines for national programmes. WHO.. Available: http://whqlibdoc.who.int/publications/2010/9789241547833_eng.pdf. Accessed 4 July 2013
    1. Cain KP, McCarthy KD, Heilig CM, Monkongdee P, Tasaneeyapan T et al. (2010) An Algorithm for Tuberculosis Screening and Diagnosis in People with HIV. N Engl J Med 362: 707–716. doi: 10.1056/NEJMoa0907488. PubMed: 20181972. - DOI - PubMed
    1. Federal Bureau of Prisons (2010) | Management of Tuberculosis. Clinical Practice Guidelines. BOP.. Available: http://www.bop.gov/news/PDFs/tuberculosis.pdf. Accessed 4 July 2013
    1. Fitzwater SP, Caviedes L, Gilman RH, Coronel J, LaChira D et al. (2010) Prolonged Infectiousness of Tuberculosis Patients in a Directly Observed Therapy Short-Course Program with Standardized Therapy. Clin Infect Dis 51: 371–378. doi: 10.1086/655127. PubMed: 20624064. - DOI - PMC - PubMed