Extensive drug-resistant tuberculosis and health care workers

Article 3: Personal protection

Personal respiratory protection is the last resort for protection of Health Care Practioners (HCPs) against nosocomial transmitted tuberculosis (TB). It is important to note that personal respiratory protection, such as wearing respirators, are not a substitute for other forms of infection control, such as administrative and engineering controls. Personal protection consists of the wearing of respirators, looking after one’s health and lifestyle, and regular screening for TB in the workplace.

Respirators are not masks
There are important differences between a surgical mask and a respirator. Surgical masks are made to prevent the spreading of micro-organisms from the wearer and do not provide adequate protection to the wearer from inhaling infectious droplet nuclei in the air. The latter is the way Mycobacterium TB is suspended in the air when coughing. Surgical masks have limited filtration capacity and are loosely fitted over the mouth and nose and allow free entrance for the aerosolised TB organisms. Masks can be worn by patients if they have to leave the ward for medically essential procedures.

Respirators are a type of mask that covers the mouth and nose, and contain a special filter. Respirators are also designed to fit the face tightly to prevent leakage between the face and the edge of the mask. Disposable particulate respirators, eg N95 particulate filter respirators, are the simplest and most reasonably priced devices which are used for this purpose in the health care setting. The N95 respirators are designed to filter particles of 0,3 microns, including air borne M. TB.

For a respirator to be effective there must be a tight seal between the mask and the wearer’s face and if not fitted correctly, it will allow mycobacteria to enter the mouth or nose. There are a number of different manufacturers and designs in respirators and they come in different sizes. Each HCP needs to be fit-tested for a range of respirators and wear only the specific size and design which fit them the best. Disposable respirators are costly and may be re-used, but discard the respirators when; 1) soiled, 2) wet, 3) appear too lose, or 4) if the respirator has been worn for longer than 8 hours. If respirators are in a condition to be re-used, they should be stored in a clean, dry location.

Health care provider medical surveillance
Action to protect HCPs from workplace infection is specifically required by law under the Occupational Health and Safety Act, 1993. Additionally, under this act a separate policy is needed to protect HCPs that contract TB. The objective of such a policy is to encourage HCPs who may have active TB to present as early as possible to clinical services and if the diagnosis is positive, to be disclosed to the occupational health service. Often HCPs do not present early, or fail to disclose their condition if under treatment, because of perceived stigma or fear of alteration of job or conditions of service.

Immunocompromised HCP
HIV infected HCPs are at high risk for active TB should they become infected with TB. HCPs who are immune compromised should not work in high risk TB environments. All HCPs who work in high risk settings should be provided with confidential HIV counseling outside the workplace. Where an HCP is working in a high risk environment and is HIV infected, arrangements should be made to transfer the individual to a low risk TB environment.

References
Migliori, GB. Loddenkemper, Blasi, RF. Raviglione, MC. (2007) 125 years after Robert Koch's discovery of the tubercle bacillus: the new XDR-TB threat. Is "science" enough to tackle the epidemic? European Respiratory Journal Vol 29 pp 423-427.

Centers for Disease Control and Prevention. [online] http://www.cdc.gov/features/MasksRespirators. Accessed 30/04/2010

This article is also available in Afrikaans, Xhosa, Zulu, Sotho and Tsonga. Contact Joey Lancester at joey.lancester@mrc.ac.za or (012) 339-8561.

This article was developed and published in collaboration with the Tuberculosis Epidemiology and Intervention Research Unit and the Web and Media Technologies Platform of the South African Medical Research Council.

This series of publications has been made possible through a grant from the United States Department of Health and Human Services (HHS).