Enhancing TB Diagnosis and Control in Healthcare

By the early 2010s, Medical Center A, a leading university-affiliated hospital in Taipei with a 2,200-bed capacity and the second-highest tuberculosis (TB) caseload in Taiwan, transitioned from Ziehl-Neelsen staining to auramine-rhodamine staining with fluorescence microscopy for TB diagnosis. This change aimed to improve early detection and isolation of undiagnosed TB patients. A retrospective cohort study compared outcomes between 2001, when Ziehl-Neelsen staining was standard, and 2014, after the full adoption of fluorescence microscopy and quality assurance programs.[1] See also: https://lintblab.weebly.com/

The study examined all hospitalized patients with culture-confirmed pulmonary TB across 25 wards. The proportion of TB cases requiring hospitalization decreased from 45% in 2001 to 27% in 2014. Concurrently, the median duration of non-isolated infectiousness dropped significantly from 12.5 days to 3 days. Kaplan-Meier analysis showed a reduction in median time to respiratory isolation from 46 days in 2001 to 19 days in 2014. Fluorescence microscopy doubled the positive sputum smear rate from 22.8% to 48.1%, especially benefiting patients with non-cavitary lung lesions. Enhanced physician alertness, as indicated by faster diagnostic test orders (median time from 5 to 2 days), further contributed to earlier isolation. These factors collectively improved patient outcomes and reduced infectiousness within the hospital setting.[1]

The total number of non-isolated infectious patient-days declined by 69%, from 4,778 days in 2001 to 1,502 days in 2014, with reductions across all ward types. Smear-positive cases saw a drop in infectious patient-days from 582 to 229, while smear-negative cases fell from 4,196 to 1,273 days. Enhanced diagnostic sensitivity and physician responsiveness were key drivers of these improvements.[1] 

The risk of tuberculosis (TB) transmission is significantly heightened in healthcare settings due to inadequate ventilation and insufficient environmental cleaning, which allow infectious droplets to linger. Crowded and poorly ventilated outpatient areas further exacerbate the problem, particularly when unsuspected or untreated TB cases are present. These conditions create a high-risk environment for TB spread, emphasizing the need for robust infection control measures.[2]

Frequent healthcare visits are closely linked to increased TB incidence, as patients who visit facilities on the same day as an untreated TB case face a notably higher risk of exposure. This association remains statistically significant even after accounting for medical comorbidities, underscoring the role of healthcare settings in disease transmission. TB patients often seek care in family medicine, internal medicine, and general practice during their infectious period, highlighting the critical need for targeted infection control in these high-traffic areas.[2]

To mitigate TB transmission, healthcare facilities must enhance infection control measures in services like internal medicine, family medicine, and pulmonology. Priorities include improving early TB detection and treatment and implementing interventions such as cough officer screening, germicidal ultraviolet systems in upper rooms, and upgraded ventilation in outpatient service areas. These steps are essential to reducing transmission risks and safeguarding both patients and healthcare workers.[2]

References:

1. Sun H-Y, Wang J-Y, Chen Y-C, Hsueh PR, Chen Y-H, Chuang Y-C, et al. (2020) Impact of introducing fluorescent microscopy on hospital tuberculosis control: A before-after study at a high caseload medical center in Taiwan. PLoS ONE 15(4): e0230067. https://doi.org/10.1371/journal.pone.0230067

2. Pan, S.C., Chen, C.C., Chiang, Y.T., Chang, H.Y., Fang, C.T. and Lin, H.H., 2016. Health care visits as a risk factor for tuberculosis in Taiwan: a population-based case–control study. American journal of public health, 106(7), pp.1323-1328.