Tuberculosis Infection Control in Health-Care Facilities: Environmental Control and Personal Protection

Abstract

Transmission of tuberculosis (TB) is a recognized risk to patients and healthcare workers in healthcare settings. The literature review suggests that implementation of combination control measures reduces the risk of TB transmission. Guidelines suggest a three-level hierarchy of controls including administrative, environmental, and respiratory protection. Among environmental controls, installation of ventilation systems is a priority because ventilation reduces the number of infectious particles in the air. Natural ventilation is cost-effective but depends on climatic conditions. Supplemented intervention such as air-cleaning methods including high efficiency particulate air filtration and ultraviolet germicidal irradiation should be considered in areas where adequate ventilation is difficult to achieve. Personal protective equipment including particulate respirators provides additional benefit when administrative and environmental controls cannot assure protection.

Heating, ventilation and air conditioning (HVAC) in intensive care unit

“…Airborne diseases have been linked to poorly functioning HVAC system: improper function of temperature control, humidity control, air distribution and filtration of HVAC systems [16][17][18][19][20][21][22][23][24][25][26][27][28]. Lutz et al reported an outbreak of Aspergillus infection among inpatients who had been operated in the same operating room in a 12-day period.…”

“…Lee suggested that diseases like tuberculosis require 'threelevel' hierarchy to control the spread of disease in hospitalized patients: first, medical-administrative role in early diagnosis, isolation and treatment; second, environmental aspect by reducing the concentration of airborne bacilli by increasing number of air changes per hour (ACR) and single-pass ventilation systems where 100% supplied air is exhausted to avoid re-circulation; and the third level, being the use of personal protective equipment [25].…”

Medidas de protección respiratoria de tuberculosis en personal de salud: revisión integrativa

“…La prueba de ajuste es una de las estrategias que permite evaluar la capacidad de hermeticidad entre los bordes del respirador N95 y la superficie facial del TS para identificar fugas; se mide a través del factor de ajuste expresado como la relación entre la concentración de partículas en el ambiente y las encontradas al interior del respirador; un valor mayor o igual a cien significa que el respirador tiene un adecuado ajuste a la cara del trabajador, por ende, este valor se constituye en un factor protector que disminuye el riesgo de penetración de partícu-las patógenas que puedan ser inhaladas (31,32). Por tanto, la prueba de ajuste proporciona un medio para determinar el modelo y el tamaño del respirador que se ajusta mejor al TS así como para comprobar y evaluar la postura correcta del respirador (33).…”

Infection prevention in general medical wards: A call to action

“…[12] It is advisable that patients with suspected or confirmed pulmonary TB be isolated in a single room with negative pressure and en suite facilities. [13] This is, however, not always possible. Where negative pressure facilities are not available, natural ventilation can be an effective and cost-efficient way of ensuring adequate air mixing.…”