Effect of diabetes on tuberculosis presentation and outcomes in Kiribati.

OBJECTIVES: To determine the association between diabetes and the clinical features and treatment outcomes of TB in Kiribati. METHODS: We enrolled consecutive patients with TB who presented from August 2010 to February 2012 and compared clinical features and TB treatment outcomes for patients with and without diabetes, as measured by haemoglobin A1c assay. Poor outcome was defined as death, default or treatment failure, and good outcome as treatment success or cure. RESULTS: Two hundred and seventy-five eligible persons with TB disease were enrolled; 101 (37%) had diabetes. TB patients with diabetes were more likely to have acid-fast bacilli (AFB) seen on sputum smear microscopy (RR: 1.3; 95% CI: 1.03-1.62). The risk of poor outcome did not differ between patients with or without diabetes (RR: 1.1; 95% CI: 0.5-2.7). CONCLUSION: TB patients with diabetes are more likely than those without to have sputum with AFB on microscopy. This could increase transmission in the community. Early detection of TB by screening patients with diabetes, and the converse, could be important public health interventions where diabetes and TB are prevalent.

Tuberculosis and diabetes mellitus in the Republic of Kiribati: a case-control study.

OBJECTIVES: To better inform local management of TB-diabetes collaborative activities, we aimed to determine the prevalence of diabetes among persons with and without TB and to determine the association between TB and diabetes in Kiribati, a Pacific Island nation. METHODS: We compared consecutively enrolled TB cases to a group of randomly selected community controls without evidence of TB. Diabetes was diagnosed by HbA1c, and clinical and demographic data were collected. A tuberculin skin test was administered to controls. The chi-square test was used to assess significance in differences between cases and controls. We also calculated an odds ratio, with 95% confidence intervals, for the odds of diabetes among cases relative to controls. Unweighted multivariate logistic regression was performed to adjust for the effects of age and sex. RESULTS: A total of 275 TB cases and 499 controls were enrolled. The diabetes prevalence in cases (101, 37%) was significantly greater than in controls (94, 19%) (adjusted odds ratio: 2.8; 95% CI 2.0-4.1). Fifty-five percent (108) of all diabetic diagnoses were new; this proportion was higher among controls (64.8%) than cases (46.5%). Five patients with TB were screened to detect one patient with diabetes. CONCLUSIONS: There is a strong association between TB and diabetes in Kiribati and bidirectional screening should be conducted in this setting.

Mass treatment to eliminate tuberculosis from an island population.

SETTING: The global target of tuberculosis (TB) elimination by 2050 requires new approaches. Active case finding plus mass prophylactic treatment has been disappointing. We consider mass full anti-tuberculosis treatment as an approach to TB elimination in Kiribati, a Pacific Island nation, with a persistent epidemic of high TB incidence. OBJECTIVE: To construct a mathematical model to predict whether mass treatment with a full course of anti-tuberculosis drugs might eliminate TB from the defined population of the Republic of Kiribati. METHODS: We constructed a seven-state compartmental model of the life cycle of Mycobacterium tuberculosis in which active TB disease arises from the progression of infection, reinfection, reactivation and relapse, while distinguishing infectious from non-infectious disease. We evaluated the effects of 5-yearly mass treatment using a range of parameter values to generate outcomes in uncertainty analysis. RESULTS: Assuming population-wide treatment effectiveness for latent tuberculous infection and active TB of ⩾90%, annual TB incidence is expected to fall sharply at each 5-yearly round of treatment, approaching elimination in two decades. The model showed that the incidence rate is sensitive to the relapse rate after successful treatment of TB. CONCLUSION: Mass treatment may help to eliminate TB, at least for discrete or geographically isolated populations.

Sputum smear examination and time to diagnosis in patients with smear-negative pulmonary tuberculosis in the Pacific.

SETTING: National tuberculosis programmes (NTPs) in Kiribati and the Marshall Islands, 2006-2010. OBJECTIVE: To determine the proportion of all tuberculosis (TB) cases that were pulmonary smear-negative, and for these patients to determine how many sputum smears were examined and the time from sputum smear examination to registration. DESIGN: A retrospective cross-sectional study involving a record review of national TB and laboratory registers. RESULTS: Of 2420 TB cases identified, 709 (29%) were registered as smear-negative pulmonary TB. Of the 695 (98%) with information on smear examination, 222 (32%) had no smear recorded, 61 (9%) had one smear, 86 (12%) two smears and 326 (47%) three smears. Among the 473 patients who had at least one smear, 238 (50%) were registered before sputum examination, 131 (28%) within 1 week, 72 (15%) between 1 and 4 weeks, and 34 (7%) >4 weeks after sputum examination. CONCLUSION: NTPs in Kiribati and the Marshall Islands are diagnosing 29% of all TB patients as smear-negative pulmonary TB. Many patients do not have smears done or are registered before undergoing smear examination. Corrective measures are needed.