‘Cough‐triggered’ tuberculosis screening among adults with diabetes in Tanzania

Abstract

Aims Diabetes increases the risk of tuberculosis and the prevalence of diabetes is rising in tuberculosis-endemic regions such as sub-Saharan Africa. Resource-appropriate strategies for tuberculosis case finding among African adults with diabetes are needed. The aims of this study were to determine prevalence of tuberculosis and evaluate one screening strategy among adult Tanzanians with diabetes. Methods In this prospective cohort study, we evaluated a “cough-triggered” strategy for tuberculosis case finding among adults with diabetes at our zonal hospital in Tanzania. All adults with diabetes and cough underwent further tuberculosis symptom assessment and those with productive cough had sputum collected for microscopy and M. tuberculosis culture. Results Between September 2011 and March 2012, 700 adults with diabetes attended our hospital. A total of 693 were enrolled, 121/693 (17.5%) had cough and 32/693 (4.6%) had at least 2 of the classic symptoms of tuberculosis. Of note, 87/121 (71.9%) of patients with cough could not produce sputum spontaneously. Nine patients were diagnosed with tuberculosis for a prevalence of 1299/100,000 (1.3%), 7-fold greater than the national average. Conclusions Tuberculosis is common among Tanzanian adults with diabetes but tuberculosis case finding is challenging due to the high prevalence of non-productive cough. This low-cost, ‘cough-triggered’ tuberculosis case-finding strategy may serve as a reasonable first step for improving tuberculosis screening among adults with diabetes in sub-Saharan Africa.

The prevalence and determinants of active tuberculosis among diabetes patients in Cape Town, South Africa, a high HIV/TB burden setting

“…The prevalence rate of active TB in our study was within the range of 0.1–6.2%; reported prevalence rates from previous screening studies conducted in similar high TB burden settings such as Tanzania and Ethiopia [16] , [17] . However, our study differs from many others in that all DM patients were screened for active TB irrespective of reported symptoms.…”

“…However, our study differs from many others in that all DM patients were screened for active TB irrespective of reported symptoms. In similar screening studies, sputum samples were collected from only DM patients clinically suspected of having TB [15] , [16] , [30] . Previous evidence has shown that symptom screening may not be an effective method in detecting TB in those with HIV [31] , [32] and DM [33] .…”

“…Studies investigating the prevalence of TB among persons with DM in the SSA context are limited [16] , [17] , [18] . In Tanzania, 1.3% of screened adults with DM had TB, 7–fold greater than the general population [16] . A modelling study estimated that up to 15% of TB cases in South Africa (SA) might be attributed to DM [19] .…”

TB-diabetes co-morbidity in Ghana: The importance of Mycobacterium africanum infection

“…The few studies that have been performed show varying prevalence of DM in TB patients, ranging from 3% [12] to 36% [13], more than 5 folds greater than in the general population [14,15]. In Tanzania, 1.3% of screened adults with DM had TB, 7–fold greater than the general population [16]. A review of 13 observational studies, of which only one was from a low-income country and none from Africa, found that diabetes was associated with TB regardless of study design [17].…”

Synergism between diabetes and human immunodeficiency virus in increasing the risk of tuberculosis

“…Extrapolation is difficult, but we expect rates of TB disease among symptomatic patients in this South African study to resemble those in similar sub-Saharan countries such as Tanzania (7.4%) or Botswana (13.9%). 20,34…”