8. How to Reduce the Risk of Transmitting TB Infection in Health care facilities?
8.1 What are the Key Management Control Measures?
The managerial control provides a framework for the implementation of the infection prevention and control measures. This framework outlines interventions that must be implemented at all levels - national, provincial, district, facility and community.
1. National and Provincial level managerial control activities include:
- The development of minimum standards for health facility design which take airborne infection control into consideration.
- Ensuring compliance to these standards for any new construction and renovations
- Developing occupational health policies for staff working in the health facilities
- Ensuring that regular TB medical surveillance for all health workers is conducted.
- Building capacity for staff to conduct facility risk assessments and developing IPC plans
- Ensuring that risk assessments are conducted in all health facilities annually
- The development and distribution information, education and communication (IEC) materials on infection control health care workers and communities
- Conducting social mobilization and awareness campaigns on TB infection control
- Engaging civil society in TB prevention and control activities
- Monitoring and evaluation of the implementation of the TB infection control measures.
- Support operational research activities in TB IPC.
2. District level managerial activities
- The establishment of an Infection Prevention and Control committee and appoint infection prevention and control officer, where this exists ensuring that TB infection prevention and control is included in their responsibilities.
- Appointment of an IPC Officer to coordinate the implementation of infection prevention and control programme within the district
- Conduct health facility TB risk assessments annually
- Review facility TB IPC plans annually
- Provide occupational health services for all staff working in the health facilities
- Monitoring the number of health staff diagnosed with TB monthly
- Train and educate health workers on infection prevention and control measures.
- Ensure availability of appropriate commodities for TB IPC
- Monitoring of the implementation of TB Infection Prevention and Control interventions.
- Facilitate operational research activities in TB IPC.
8.2 What are the Key Administrative Control Measures?
1. Infection control plan
Each facility must have a written TB Infection Prevention and Control plan that outlines a protocol for the prompt recognition, separation, provision of services, investigation for TB and referral of patients presenting with TB symptoms or confirmed TB disease. The plan will include, but not be limited to, the following measures:
- Early recognition of people with TB symptoms through symptomatic screening of all patients entering facility or soon after arrival. A staff member should be assigned to screen patients using the TB screening tools (adult and children). The form must be completed and included in the patients file. Presumptive TB cases should be investigated immediately.
- People with chronic cough must wait in a designated, well-ventilated waiting area, for example in outdoor waiting areas, or a well-ventilated section of the waiting area.
- They must be educated on cough hygiene and provided with a face mask or tissue to cover their mouth and nose when coughing. Tissues and facemasks should be provided in the waiting areas and discarded in the bins after use. Hand washing should be encouraged after contact with respiratory secretions.
- Fast tracking confirmed TB cases coming for follow up appointments or to take/ collect their treatment to ensure that they spend as little time as possible in the facility.
- Educating health care personnel, patients and communities to seek health care early when symptoms of TB are present and to protect themselves and others e.g. through appropriate cough hygiene and good ventilation in the household.
- Improved TB and HIV integration in the health facility, with symptomatic TB screening of HIV positive patients at routine clinical visits and appropriate tests for those who are symptomatic, to aid early diagnosis.
• Training of facility staff on IPC plan
Infection prevention and control is effective only if all staff working in a facility understands the importance of the infection prevention and control policies and their role in implementing them. Training should include the following:
- Basic concepts of M. tuberculosis transmission and pathogenesis;
- Risk of TB transmission to health care workers and staff;
- Symptoms and signs of TB;
- Impact of HIV infection on increasing risk of developing TB disease and the importance of TB as a major cause of disease and death in PLWHA;
- Importance of the infection prevention and control plan and the responsibility that each staff member has to implement and maintain;
- Specific infection prevention and control measures and work practices that reduce the likelihood of transmitting TB;
- Measures staff can take to protect themselves from TB; and
- TB disease surveillance among HCW
• Community education and awareness. Educate communities and patients on the following:
- To recognize symptoms of TB and promptly seek health care;
- To undergo HIV Counselling and Testing;
- Cough hygiene; and
- Prevent ion of transmission in the community
• Surveillance of TB disease among health workers
Surveillance of TB among Health Care Workers serves as an indication of performance of IPC Plan. All facility staff must be included in the TB medical surveillance programme in line with Occupational Health and Safety Act (Act No. 85 of 1993). This medical surveillance programme consist of the following main components:
- Pre-aemployment medical: Baseline screening and testing for M. tuberculosis infection for all newly employed HCWs as part of the pre-employment. This serves as a baseline for comparison in the event that a person contract TB disease. It provides an opportunity to identify high risk individuals (HIV, diabetes etc) for appropriate placement and enables early detection and initiation of treatment.
- Periodic medical: Sceening and testing for TB every six months. This should also be conducted as part of outbreak investigations.
- Exit medical: Screening and testing for TB disease to exclude undiagnosed TB disease at the time of leaving the facility and ensure early treatment.
- Training of staff on TB medical surveillance programme, and
- Education of staff on the importance of using the service.
All staff with confirmed infectious TB disease pose a risk of transmitting TB infection and should be initiated on treatment promptly.
• Administrative Control Strategies to prevent TB transmission in Health Care settings
In general, administrative control measures have the greatest impact on preventing TB transmission and they are the first priority in any setting regardless of available resources. These measures aim to reduce the droplet nuclei in health facilities by eliminating the generation of droplet nuclei and risk of exposure. The administrative control activities include;
- Early recognition of people with TB symptoms through screening of all patients entering the health facility
- Separation of people who are coughing from the other patients, this will require identification of a well- ventilated area that can be used as a sub-waiting area.
- Prompt investigation for TB in symptomatic patients
- Sputum test results must be followed up and patient started on treatment immediately if diagnosed with TB.
- Educating all patients on respiratory hygiene
- Isolation of confirmed TB patients
8.3 What are the Environmental Control Measures?
Environmental controls are used to prevent the spread and reduce the concentration of droplet nuclei in the air. The managerial and administrative control must be in place for the environmental controls to be effective. The types of controls implemented will vary from one facility to another based upon the results of the risk assessments. There are three main types of environmental controls namely;
- Ventilation (natural and mechanical)
- High Efficiency particulate air filtration (HEPA)
- Ultraviolet germicidal irradiation (UVGI)
8.4 How to Ensure Proper Ventilation?
Ventilation is the movement and the replacement of air in a building with air from the outside or with re circulated air that has been sanitized. When fresh air enters a room, it dilutes the concentration of droplet nuclei in room air.
1. Natural ventilation is created by the use of external natural forces such as wind. It is however difficult to control the direction of the airflow as this depends on the wind speed or direction. It relies on open windows and doors to allow the air to move in and out of the room. Designing waiting areas and examination rooms in such a way they maximize natural ventilation can help reduce the spread of TB. Open air shelters with a roof to protect patients from sun and rain can be used as waiting areas.
2. Directional airflow: Fans can be used to enhance flow of air in and out of the room when installed in the windows or wall opening where there are inadequate windows. They can also be used to exhaust air outside, away from people. For example, in a room which has a door/ window on one side and nothing on the opposite side, when the door/ window is kept open, the overall effect of installing fans on the opposite side is to draw in fresh air through the front of the building and exhaust air out.
It is therefore important to be mindful of the direction of airflow in a room to ensure that the sitting arrangement is such that air will blow from behind the health care worker over the patient and out of the room.
3. Mechanical ventilation: This is created using an air supply or an exhaust fan to force air exchange and to drive airflow. Such ventilation works by generating negative or positive pressure in the room to drive air changes. To be effective, all doors and windows must be kept closed, with controlled air leakage into or out of the room.
8.5 What is High Efficiency Particulate Air (Hepa) Filtration?
High efficiency particulate air filters are capable of removing 99.97% of particles that are 0.3 microns or greater in diameter. They are used to clean air which is recirculated to other areas of a facility, or recirculated within a ward/room, for rooms where there is no general ventilation system, where the system is incapable of providing adequate airflow, or where increased effectiveness of room airflow is required.
HEPA filtration may have a place as an additional measure to adequate ventilation in booths or enclosed areas designed for sputum collection/ induction. Portable units are available but have not been evaluated adequately to determine their role in tuberculosis infection control.
However, recirculating air from areas intended to isolate a patient with tuberculosis is not recommended and these units are also expensive and need regular engineering attention.
8.6 What is Ultraviolet Germicidal Irradiation (UVGI)?
Priority should be given to achieving adequate ventilation. Where this is not possible because of climatic conditions for example where it gets very cold in winter or during the night and it is not feasible to keep windows opened or the design of the building makes it impossible to ensure adequate ventilation, UVGI may be considered as an adjunctive measure.
UVGI is dependent on room air mixing to be effective because contaminated air must be circulated to the irradiated upper part of the room where the organisms can be rapidly inactivated. Several studies have shown that well-designed UVGI upper room devices can disinfect mycobacteria in conditions that have an equivalent of 10–20 air changes per hour. It is ineffective in humid and dusty environments. UVGI devices have to be installed properly for maximum effect; testing and maintenance must be conducted regularly.
Upper UVGI devices are hazardous if not properly designed or installed. The NIOSH guidelines recommended the occupational exposure limit of 6mJ/cm2 over an 8 hour period for a short wave ultraviolet irradiation (254 nm). It has been reported that exposure above this limit may result in erythema/ photo dermatitis and photo- keratitis and/or conjunctivitis.