An evaluation of the compliance to the ventilation aspects of airborne infectious disease control in Cape Town, South Africa

• Main Author: Groenewald, Coenraad
• Other Authors: Morrow, Brenda M
• Format: Dissertation
• Language: English
• Published: University of Cape Town 2017
• Subjects: Emergency Medicine
• Online Access: http://hdl.handle.net/11427/23398

Background: Tuberculosis (TB) is a major healthcare problem worldwide and is endemic to Cape Town, South Africa. Health Care Workers in Emergency Centers (ECs) are at high risk of nosocomial TB infection. The aim of this study was to determine whether the isolation rooms (IRs)in emergency centers, for patients with diagnosed or suspected TB, comply with set National Core Standards. Methods: This was a cross-sectional descriptive study of ECs in the Cape Town Metropolitan area. .The characteristics of IRs with regards to air changes per hour (ACH), negative pressure ventilation with relation to the surrounding areas and appropriate discharge of air outdoors or via filters before recirculation was measured using standard objective engineering methods. Results: 19 IRs in 8 ECs were evaluated, none of which complied with the National Core Standard's ideal requirements for IRs. Five complied with minimal requirements . Eleven (57,9%) IRs were designed to have negative pressure; and 8 (42,1%) rooms were not designed for isolation purposes, . IR volumes ranged from 15,5 m³ to 67,2 m³ (median 35,6 m³). Five (26,3%) IRs were under negative pressure; 7 (36,8%) had erratic air flow; and 7 (36,8%) showed positive airflow from the IR into adjacent clinical areas. Fifteen (78,9%) IRs had central provision of air via a ventilation system; 6 (31,6%) had central air extraction; 6 (31,6%) had local extraction; and 7 (36,8%) used natural ventilation only. Four local extraction units had zero flow rate. Airflow in naturally ventilated IRs was significantly lower than flow with other systems (p = 0,0002). The ACH ranged from 0 (n=4) to 112.37 (median 11,9); and was significantly greater in rooms ventilated with central extraction compared to other systems (p = 0,00002). Discussion: The ventilation aspects of airborne infectious disease control are generally poorly implemented. This may contribute to, and fail to mitigate, the high risk of nosocomial transmission of airborne infectious diseases to staff and other patients utilising emergency facilities in the TB endemic areas of Cape Town. Conclusion: Existing ECs should improve adherence to standards of airborne infectious disease transmission prevention in order to protect patients and staff from nosocomial airborne transmitted diseases, such as TB. New Hospitals should place a high priority on the amount, positioning and maintenance of IRs when planning their facility.