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HERDIN Record #: PCHRD03021103034127 Submitted: 02 March 2011 Modified: 12 November 2019

Prevalence of bacteriologically confirmed pulmonary tuberculosis among prisoners and jail officers in selected prisons in the Philippines.

M.P. Borja,
L.L Mortera,
W.A. Palasi,
J.P. Benedicto,
E.V. Cadena

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INTRODUCTION: According to WHO, approximately 1.3 million people died of tuberculosis (TB) in 2008 with the highest number of deaths (34%) occurring in the South East-Asia. (World health Organization, 2010) In the Philippines, it is estimated that an average of 75 Filipinos die of TB every day. (Dateline Philippines, 2010) Although the rate of case finding of active TB  has improved over the years (Department of Health, 2006), challenges remain in its prevention and control. One of these is the poor monitoring of TB prevalence in some high risk populations like prisoners. Its prevalence in prisons has been reported to be ten times more than that of the general population (ICRC, 2008). Nevertheless, negligible number of local studies has been done to determine the magnitude of the TB problem in prisons in the country. Thus, this study was conducted among prisoners and jail officers to determine the baseline magnitude of active TB in some prisons in the Philippines. Specifically, the objectives of the study were to: (1) estimate the prevalence of bacteriologically-confirmed pulmonary tuberculosis; (2) estimate the prevalence of multi-drug resistant TB; and, (3) determine the knowledge, attitudes, practices and behavioral intentions of inmates and jail officers regarding tuberculosis.

METHODS: This cross-sectional study was conducted in seven target prisons in the Philippines. The two-stage cluster random sampling design recommended by the International Committee of the Red Cross and the World Health Organization was adopted(Bone, et al., 2000). Adjusted for finite population, it was estimated that a minimum sample size of 2690 respondents was required to ensure a reliability level of 95 % and a maximum error of 1.39% in our estimates.

The respondents were screened for TB using both chest radiography and TB symptom questionnaire. Subjects with chest x-ray suggestive of pulmonary tuberculosis (PTB) or cough of at least two weeks' duration (TB symptomatic) or both were considered TB suspects and were requested to collect two sputum specimens, one early morning and one random specimen for direct smear sputum microscopy (DSSM) and culture. The sputum specimens were stained by Ziehl-Neelsen method and examined for acid-fast bacilli (AFB). Both specimens must be positive before the patient is considered DSSM positive. Sputum specimens were also cultured onto Lowenstein-Jensen (LJ) solid culture media and incubated for eight (8) weeks. Niacin test was utilized as biochemical test for the identification of the oreganism. All specimens with positive growth on LJ slant underwent drug sensitivity test (DST) for Isoniazid (H), Rifampicin (R), Sreptomycin (S), Ethambutol (E), Kanamycin, Ofloxacin and levofloxacin. There were two readers both for DSSM and chest x-ray. Discordant results were resolved by an umpire.

To determine the knowledge, attitudes and behavioral intentions of the respondents, a structured pre-tested questionnaire was administered through computer-assisted face-to-face interviews.

RESULTS: A total of 2,622 subjects (97% of the sample size required) participated in the study. However, only 2,450 (93% of recruited subjects) completed all survey procedures. 55% of the recruited respondents were male inmates; 24% were female inmates and 21% were jail officers. The mean age of the respondents was 39.7 years.

A total of 630 (24% of the respondents; 95% CI: 22%-26%) were TB symptomatics, 530 male inmates (37%), 60 female inmates (9%) and 40 were Jail Officers (7%). The overall prevalence of radiographic abnormalities  suggestive of pulmonary tuberculosis (35%) is almost six times higher than the prevalence in the general population (6.4%) as documented by the National Tuberculosis prevalence Survey (NTPS, 2007).

Only 1,117 of the 1,204 TB suspects (92.8%) had DSSM results. Of these, 25 were positive all of whom were male inmates. After adjusting for the missing specimens, the prevalence of DSSM  positivity per 1,000 is 18.1 for male inmates, 12.5 for all inmates and 9.9 for all respondents. There were 42 culture positive results for Myobacterium tuberculosis (MTB), 38 male and 4 female inmates and 30 positive results for non-Tuberculosis Myobacteria (NTM). Hence, the adjusted overall prevalence rates are 16.8/1000 and 12.3/1000 for MTB and NTM, respectively. By type of respondents, the adjusted prevalence of TB positive culture per 1,000 are 27.9 for male inmates: 6.2 for female inmates; and, 21.2 for all inmates.

In this study, those with positive DSSM and/or positive culture were considered to be bacteriologically confirmed cases of pulmonary tuberculosis (PTB). The overall adjusted prevalence of bacteriologially confirmed PTB is 17.5/1000 (95% CI: 13/1000, 23/1000). Among males, females and all inmates, the adjusted prevalence per 1000 are 29 (95% CI:20,38), 6 (95% CI: 0, 12) and 22 (95% CI: 16, 28 ) respectively.

Of the 42 culture positive specimens, only 30 had DST results (71%). Among the cases with DST results, 22 were sensitive to all drugs (73%); 3(10%) have multi-drug resistant tuberculosis (MDR-TB); 4 (13%) were mono-resistant; 1 (3%) was poly-resistant; 8 (27%) were resistant to at least one drug; and 4 (13%) were resistant to at least two drugs.

Among TB suspects, the sensitivity and specificity of chest x-ray are 98% and 24% respectively; among TB symptomatics, these are 96% and 44%, respectively. The predictive value positive among TB suspects and TB symptomatics are unacceptably low at 5% 7%, respectively. In contrast, the predictive value positive of DSSM is higher at 72%. However, its sensitivity is unacceptably low at 41%; its specificity is at par at 99%,

Only a minority are aware of the signs and symptoms of TB and of its transmission through droplet infection. Health workers, family, friends and television are important sources of information on TB that are considered effective and credible. About 11% had a history of previous treatment with anti-TB drugs some of whom were self-medicating. The most common anti-TB drug taken was Rifampicin followed by Ethambutol. Practically all respondents averred that they would consult a health professional as soon as they manifest TB signs and symptoms. The positive attitudes that favor behavior change for the prevention of TB are: perceived vulnerability, perceived seriousness of the disease and compassion for cases. Meanwhile, negative attitudes that must be turned positive are: stigmatization of TB, fatalism and perceived inaccessibility of health care costs.

CONCLUSIONSPulmonary tuberculosis is a major Public Health problem among prisoners in the Philippines, particularly among the male inmates as evidenced by the high prevalence of bacteriologically confirmed pulmonary tuberculosis which is 4 to 5 times higher compared to the prevalence in the general population; high proportion of isolates that are drug resistant including MDRTB; high proportion with chest x-ray results that were suggestive of pulmonary tuberculosis; high DSSM positivity rate; and, high prevalence of sputum culture positive.

X-ray findings suggestive of TB should not be the sole basis for treatment since it was shown to have very low specificity and positive predictive value. However, its utility as a screening tool to capture patients with active TB is recommended because of its high sensitivity among TB suspects and TB  symptomatics. Similarly, the predictive value positive of DSSM even in this high prevalence group is only 72% and the false positive results are due to NTM. While its specificity is relatively high at 99%, the sensitivity of DSSM is only 41% which implies a very high false negative rate of 59%.

Behavioral change interventions should consider the following psychosocial results: (1) health workers, family, friends, and television are important sources of information on TB that are considered effective and credible; (2) the minority are aware of the signs and symptoms of TB and of its transmission through droplet infection; (3) relatively high proportions previously treated with anti-TB drugs some of whom were self-medicating; and, (4) behavioral intentions to consult health professional as soon as they manifest TB signs ad symptoms.

Negative attitudes that must be turned positive are: stigmatization of TB. fatalism and perceived inaccessibility of health care costs. On the other hand, positive attitudes that favor behavior change: perceived vulnerability, perceived seriousness of the disease and comparison for cases.


1. The following recommendations which are pertinent to the jails and prisons where the TB in Prisons Prevention and Control Program is being piloted are contingent on adoption at the local level of the MOU forged at the national level.

1.1. Ensure availability of financial and other logistical support for the program.

1.2. Strict adherence to the technical and operational guidelines stipulated by AO No. 2009-003 of the DOH, MC No. 2009-003 of the BJMP, and MC No. 2009-018 of the DOJ.

1.3. Re-training of the clinical staff by DOH certified trainers on screening of TB cases, on sputum collection procedures, on provision of health education to prisoners and on the International Standards for TB Care (ISTC)

1.4. Health education and behavioral change interventions for inmates and their families using targeted messages that utilize the findings of the study.

1.5. As provided for by AO No. 2009-003, the jail/Prison DOTS Team should prepare a discharge/release plan for cases that are still under retirement.

2. Plans for the expansion of the program to other jails and prisons nationwide should be drawn-up at the earliest possible time by the Task Force for the Prevention and Control of TB in prisons.

3. Decongestion of correctional facilities.

4. Screening for and identifying cases of TB among inmates and prison staff.

5. A detailed protocol to be followed for MDR-TB cases should be fleshed-out.

6. Establishment of a two-way referral system which is crucial to the successful identification and completion of treatment of inmates with TB.

7. The research agenda should include:

  • Identification of the determinants of development of drug resistance so that appropriate control strategies could be planned and  implemented not only for prisons but also for the society at large.

  • Validity studies, field testing and cost-benefit analysis of using rapid diagnosis techniques which are recommended by international agencies such as the World Health Organization purportedly because they have accuracy higher than DSSM.

  • Development of, and subsequent testing of interventions that would make certain completion of treatment for released inmates.

Publication Type
Research Project
LocationLocation CodeAvailable FormatAvailability
Philippine Council for Health Research and Development Library LG 995 P74 2010 Fulltext Print Format
Philippine Council for Health and Research Development Fulltext pdf (Request Document)


1. Validity of direct sputum smear microscopy (DSSM) in diagnosing PTB among prisoners and jail guards: Bayesian approach.