STLS: Infection Prevention and Control [IPC]

Infection prevention and control (IPC) practices are important in maintaining a safe environment for everyone by reducing the risk of the potential spread of disease.

IPC is a practical, evidence-based approach which prevents patients and health workers from being harmed by avoidable infection. It is relevant to health workers and patients at every single health-care encounter.

Biosafety measures along with Universal Precautions like hand hygiene, personal protective equipment, safe injections, respiratory hygiene and cough etiquette is important in IPC to address the safe handling and containment of infectious microorganisms and hazardous biological materials.

IPC is essential in TB as:

1. specific population groups have a higher risk of acquiring TB infection and progressing to disease once infected; these groups include people living with HIV, health workers and others in settings with a high risk of transmission of M. tuberculosis

2. incident cases of TB among children (aged <15 years) reflect ongoing community transmission

3. primary person-to-person transmission of drug-resistant TB (as opposed to acquired resistance) is the dominant mechanism sustaining the global transmission of drug-resistant TB

4. to prevent TB transmission, interventions are needed that reduce the concentration of infectious particles in the air and the exposure time of susceptible individuals

Resources

1. Guidelines on Airborne Infection Control in Healthcare and Other Settings.

2. WHO guidelines on tuberculosis infection prevention and control 2019 update (https://apps.who.int/iris/bitstream/handle/10665/311259/9789241550512-e…)

• Standard precautions are a group of infection control practices to reduce the risk of transmission of pathogens.
• These are based on the principle that all blood, body fluids, secretions, excretions except sweat, non-intact skin, and mucous membranes may contain
  transmissible infectious agents.
• Standard precautions are applicable to all patients in all healthcare settings and combine the major features of universal precautions, body substance isolation, and airborne precautions.
• Implementation of standard precautions is based on risk assessment in all healthcare activities.

Image

Figure: Elements of Standard Precautions; Source: Guidelines on Airborne Infection Control in Healthcare and Other Settings

Resources

1. Guidelines on Airborne Infection Control in Healthcare and Other Settings
2. Health-care facility recommendations for standard precaution

Hand hygiene is one of the most important elements of infection control. The aim of hand washing is to remove transient micro-organisms, acquired through everyday tasks in the laboratory/ clinical setting, from the surface of the hands.

Good hand hygiene protects both patients and staff.

The World Health Organization (WHO) guidelines on “Hand Hygiene in Healthcare” describe five key situations where hand washing is required:

• Before touching a patient
• Before a clean or aseptic procedure
• After body fluid exposure/risk
• After touching a patient
• After touching patient surroundings

Hand hygiene includes hand washing using soaps or hand rubbing with 70% alcohol-based formulations.

Important Considerations for Hand Hygiene

• Perform hand washing with soap and water if hands are visibly soiled and after using the restroom.
• Availability of running water supply is important for hand washing.
• If resources permit, perform hand rubbing with an alcohol-based preparation.
• Ensure availability of hand hygiene products (clean water, soap, single-use clean towels, alcohol-based hand rub).
• Alcohol-based hand rubs should ideally be available at the point of care.

Technique of Hand Hygiene (Figure)

• Handwashing (40–60 sec): Wet hands and apply soap; rub all surfaces; rinse hands and dry thoroughly with a single-use towel.
• Hand rubbing (20–30 sec): Apply enough product to cover all areas of the hands; rub hands until dry

Figure: Handwashing Technique; Source: WHO Handwashing Poster

Resources

1. Guidelines on Airborne Infection Control in Healthcare and Other Settings.
2. Health-care facility recommendations for standard precaution.
3. WHO Handwashing Poster.

Respiratory hygiene is vital to prevent the spread of TB via aerosols and person-to-person transmission.

Respiratory hygiene includes:

• Covering the nose/mouth with a tissue when coughing/sneezing and appropriate disposal of used tissues

  • If tissues are not available, cough or sneeze into the inner elbow (upper sleeve) rather than into the hand
• Keeping contaminated hands away from the mucous membranes of the eyes and nose.
• Carrying out hand hygiene after contact with respiratory secretions and contaminated objects/materials
• Using appropriate Personal Protective Equipment (PPE) during aerosol generating procedures
  • Use PPE including gloves, long-sleeved gowns, eye protection (goggles or face shields), and facial mask (or respirators) during aerosol-generating procedures 

Figure: Respiratory hygiene (Ministry of Ayush, https://twitter.com/moayush/status/1243852404640153601)

Resources

1. Guidelines on Airborne Infection Control in Healthcare and Other Settings
2. Infection Prevention and Control of Epidemic- and Pandemic-Prone Acute Respiratory Infections in Health Care
3. Ministry of Ayush, https://twitter.com/moayush/status/1243852404640153601

Assessment

Guidelines for Laboratory Cleaning

• All personnel should don appropriate Personal Protective Equipment (PPE) prior to cleaning the facility.
• Laboratory personnel should perform all daily housekeeping routines within the TB laboratories, including trash removal. Cleaning staff should only enter the laboratories under the supervision of the laboratory staff.
• All the cleaning and decontamination procedures in the TB containment laboratory should be performed only by trained laboratory staff.
• Work surfaces are decontaminated when work is finished, at the end of every workday, and immediately after any spill of viable material.
• Large equipment, such as incubators and centrifuges, will have inner and outer surfaces damp-wiped with disinfectant on a routine basis.
• Sinks in the laboratories should be cleaned and flushed with agent appropriate disinfectants
• The floor of the TB containment laboratory should be thoroughly and routinely wiped down with a suitable chemical decontaminant, and workspaces that do not get daily attention should be disinfected
• Solid waste should be decontaminated by autoclaving prior to removal from the facility and disposed off by authorized personnel

Unidirectional Flow of Cleaning

• There should be an effective separation of various sections and activities of the lab to prevent cross-contamination.
• Unidirectional flow of cleaning should be maintained in specific areas.
• Cleaning items, such as mops, buckets and brushes, used in dirty areas of the laboratory should never be used in the cleaner areas.

Good Laboratory Practices to Keep Laboratories Clean and Clutter-free

• Floors and work surfaces should be kept as free of clutter as possible.
• Materials should be stored in closed cupboards, where possible.
• Excess reagents should be boxed, labelled and stored in the storeroom.
• Check spill kit contents on a monthly basis. The fresh disinfectant must be prepared each week.
• Record in the 'Laboratory Cleaning and Maintenance Logbook'.

​Resources 

• WHO TB Lab Safety Manual, 2012, p18-19.
• WHO Lab Biosafety Manual, 3rd ed., p82-90.
   

The following work practices are recommended to ensure that microscopy laboratory technicians are not exposed to aerosols from sputum specimens.

1. Administrative Control at DMC

• The layout and design of the DMCs should include natural ventilation, mechanical ventilation (exhaust fan) and unidirectional airflow.
• The sputum collection area should be separated from the laboratory.
• Provisions for biomedical waste management in deep burial pits, sharps pits or appropriate disposal via the health facility biomedical waste management system.

2. Environment Control at DMC 

• Doors and windows should be kept open for air exchanges.
• Sputum must be collected in a well-ventilated area with direct sunlight. It should not be collected inside the laboratories, toilets, waiting rooms, reception rooms, or any other enclosed space.

3. Personnel Level Control at DMC 

• Laboratory technicians should wear laboratory coats, gloves and masks when handling sputum containers and during smear preparation and staining.
• Smears should be prepared in a well-ventilated environment near an open flame.
• Work benches should be cleaned daily with disinfectants.
• Sputum containers, applicator/ broomsticks, and used slides should be disinfected with 5% Phenol overnight before discarding.

Resources

• Guidelines on Airborne Infection Control in Healthcare and Other Settings, 2010.

PPE refers to physical barriers which are used alone or in combination to protect an individual's mucous membranes, airways, skin and clothing from contact with infectious agents, hazardous material, conditions or processes.

Components of PPE

• Protective clothing: Surgical gowns and laboratory (lab) coats​
• Respiratory devices: N95 respirators​
• Hand protection: Gloves ​
• Head protection: Headgear/ hair covers/ caps​
• Foot protection: Shoe cover, safety shoes/ closed-toe shoes​
• Eye protection: Safety glasses/ goggles, shields​​

PPE Hazard Assessment

• Evaluation of the PPE requirements for a specific activity or work environment is carried out by the lab director.
• For TB labs it is based on the risk assessment. PPE requirements will thus differ according to whether activities are classified as low risk, medium risk or high risk.

PPE Usage in Different Sections of the TB Laboratory

The table below lists the different PPE requirements for different sections of the TB lab.

Resources

• National Guidelines for Infection Prevention and Control in Healthcare Facilities, 2020, MoHFW, GoI.

Resources

• National Guidelines for Infection Prevention and Control in Healthcare Facilities, 2020. Ministry of Health and Family Welfare, Government of India

The use of appropriate Personal Protective Equipment (PPE) in a TB laboratory is determined by risk assessment (according to the procedure and suspected pathogen).

Designated Microscopy Centres (DMCs) are low-risk TB laboratories, hence PPE should be used as follows:

• Laboratory coats should be worn at all times by the Laboratory Technician (LT) while working in the laboratory.
• Gloves and long-sleeved laboratory coats should be used during sample collection, opening sample transport boxes, handling leaky specimen containers, smear preparation and staining smears.
• Masks are not required for use during the preparation of sputum smears in well-ventilated areas.
• LTs and support staff handling biological waste should wear gloves.
• Patients that visit DMC to provide sputum samples should be advised to wear masks.

It is advised that the laboratory should maintain adequate ventilation by keeping the windows open all the time or installing exhaust for the personal protection of the laboratory staff.  

Resources

• Guidelines on Airborne Infection Control in Healthcare and Other Settings, MoHFW, 2010.
• Infection Prevention and Control of Epidemic- and Pandemic-Prone Acute Respiratory Infections in Health Care, WHO, 2014.
• Training Modules (1-4) for Programme Managers and Medical Officers, NTEP, 2020.

Assessment

Mycobacterium tuberculosis is transmitted in airborne particles called droplet nuclei that are expelled when a person with pulmonary TB coughs, sneezes, shouts, or sings. People nearby may breathe in these bacteria and become infected. 

Airborne infection control is essential to prevent the spread of TB within a health facility and other settings.

Hierarchy of Controls to Reduce Risk of Transmission of TB (see the Figure)

Figure: Hierarchy of controls to reduce risk of transmission of TB

Environmental factors that influence transmission of M. tuberculosis are elaborated in the table below.

Resources

1. Guidelines on Airborne Infection Control in Healthcare and Other Settings.
2. Tuberculosis Infection Control.

Ventilation is defined as the supply/ distribution/ exchange or removal of air from spaces by mechanical or natural means.

Airflow is a natural process whenever there is change in temperature or pressure. Air keeps moving displacing the room air, and the time to replace the entire in-room air depends on the size of the room, the openings, and the presence of additional/mechanical force. This air-flow, also called ventilation, will allow the entry of outside air or clean recirculated air to remove extra heat, humidity and infectious aerosols from occupied spaces to meet health and comfort requirements. 

When fresh air enters a room, it dilutes the concentration of particles in room air including aerosols responsible for the transmission of TB that can otherwise remain suspended in the air for significant periods of time.

Thus, ventilation is recognized as an important factor influencing the transmission of airborne diseases.

Types of Ventilation at Designated Microscopy Centres (DMCs)

1. Natural Ventilation (Figure below)

• Natural ventilation at DMCs is achieved by designing a laboratory layout that supports the unrestricted flow of natural air.
• Doors and windows should be kept open to bring in fresh air from outside.
• Opening windows and doors on opposite walls will also allow for cross ventilation.
• The placement of furniture, equipment, supplies etc. at DMCs should not block or restrict the opening of doors and windows.

Figure: Natural ventilation achieved by opening doors and windows or using mechanical ventilation using fans and an exhaust fan for air mixing and directional flow (A); the flow of natural air should not be restricted by blocking doors and windows (B); Cross ventilation is not adequate if there is only one entry point for outside air (C); Source: Tuberculosis and HIV Co-Management and Tuberculosis And Airborne Infection Control.

2. Mechanical Ventilation: When the movement of air is driven by a mechanical device, it is called mechanical ventilation.

• DMCs are equipped with fans and exhaust fans as the simplest means of mechanical ventilation for air circulation and directional flow of air. Exhaust fans fitted in windows/ ventilators exchange air from inside the laboratory to the outdoors.
• Ceiling fans/ tabletop fans/ pedestal fans have rotating blades to circulate air inside the room. Tabletop and pedestal fans can be positioned in the room to allow the directional flow of air.

3. Hybrid/ Mixed-mode Ventilation

• In hybrid/ mixed-mode ventilation exhaust and/or fans are used in DMCs in combination with natural ventilation to obtain adequate air dilution when sufficient airflow cannot be achieved by natural ventilation alone.

The table below compares the advantages and disadvantages of the different modes of ventilation.

Table: Summary of Advantages and Disadvantages of Different Types of Ventilation; Source: Guidelines on Airborne Infection Control in Healthcare and Other Settings.

Resources

• Guidelines on Airborne Infection Control in Healthcare and Other Settings.
• Tuberculosis Infection Control, CDC.
• Tuberculosis and HIV Co-Management.
• Tuberculosis and Airborne Infection Control.

The administrative measures at a health care facility play an important role in preventing the spread of TB in health care settings. It includes Administrative controls for outpatient and inpatient settings

Administrative measures at Outpatient(OPD) settings
1. Screen for respiratory symptoms as early as possible upon patient’s arrival at the health care facility thereby reducing the overall stay of such patients in the healthcare facility

• screening at registration counter itself by asking simple questions related to chronic respiratory symptoms, and those suspected to have TB can be prioritized for further management
• screening when patients are in waiting area- by volunteers/health staff

2. Provide patient education and counseling on cough hygiene and sputum disposal

• paramedical staff or volunteers should educate and reinforce cough etiquette while the patient is in the waiting area
• educate patients on availability of bins with disinfectants for disposal of sputum
• display of posters on cough hygiene and sputum disposal in the waiting areas

3. Segregate patients with respiratory symptoms

• having separate waiting area for chest symptomatics within the overall outpatient area
• implement a patient flow control mechanism so that screened chest symptomatics are diverted to special area rather than the common waiting area
• well ventilated waiting areas to reduce overall risk of airborne transmission

4. Fast-track patients with respiratory symptoms

• fast-track patients for clinical and laboratory evaluation
• fast track chest radiography and sputum examination with priority slips/referrals

Administrative measures at Inpatient (IPD) setting
1. Minimize hospitalization of TB patients

• whenever possible, manage patients entirely as outpatients thereby avoiding hospitalization and the risk of exposing other patients and staff

2. Establish separate rooms, wards, or areas within wards for TB patients

• patients with TB should be physically separated in different rooms/wards from other patients so that others are not exposed to the infectious droplet nuclei
• separation of TB patients from vulnerable and immune-compromised patients is essential

3. Educate and counsel inpatients on cough hygiene and provide adequate sputum disposal

• educate and display posters on cough hygiene and safe disposal of sputum in bins with disinfectants
• provide masks to all admitted patients and educate on proper use of masks

4. Establish safe radiology procedures for TB patients

• schedule inpatient chest radiography for non-busy times
• provide priority service to minimize the length of time spent in the department

Resources

1. Guidelines on Airborne Infection Control in Healthcare and Other Settings.
2. Tuberculosis Infection Control.