New Admissions and Asymptomatic TB Cases fuel TB Epidemic in Prisons, a Cross Sectional Survey in Tanzania

Background There is an increased risk for tuberculosis (TB) infection and disease progression in prison settings. TB prevalence in prisons of high and middle/low income countries have been measured to be between 5 and 50 -times higher than in the general population. Methods We performed TB active case finding in five central prisons, Keko, Segerea, Ukonga, Butimba and Ruanda prison in Tanzania, using the Xpert MTB/RIF® assay on early morning or spot sputum sample from inmates and new entries between April 2014 and July 2015. Results Out of 13,868 prisoners tested, 13,763 had valid results. TB prevalence was 1.55% (214/13,763); new admissions contributed to the majority (61.68%) of TB cases, but prevalence was higher among inmates (1.75%) compared to new admissions (1.45%). Ukonga, an urban prison which incarcerates long-term convicted inmates had the highest prevalence of 4.02%. Male gender (OR=2.51, p<0.001), repeated incarcerations (OR=2.85, p<0.001), history of TB treatment (OR=1.78, p =0.002), TB symptoms (OR=2.78, p=0.006) and HIV infection (OR=2.86, p=0.002) were associated with positive TB results. Conclusion New admissions could be the driving force of the TB epidemic in the penitentiary system. However, prison environments remain a major risk factor for developing active TB disease. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement Funding for this work was obtained from TB REACH grant, Wave 3, from the TB Stop Partnership. The funders had no additional role in actual implementation of the project or writing of the manuscript. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: National Health Research and Ethics Committee (NatREC), Tanzania I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The data can be made available only with permission form the Tanzania Ministry of Home Affairs and Prison Authority and other local regulatory bodies due to the sensitivity of the prison data.