Control and Prevention of Aspergillosis and other Invasive Fungal Infections during any building works

• Summary of Guideline
• Background
• Management:Reducing the risks of Aspergillosis during building
• Appendix 1 - Building/Refurbishment Risk Assessment Tool
• Appendix 2 - At risk patient groups
• Appendix 3 - Aspergillosis During Building Activities For Patients, Relatives and Staff

Summary of Guideline

When any building work is taking place within the hospital environment, some patients are at increased risk of developing invasive fungal infections.
During demolition, construction and renovation work, dust is generated that may contain fungal spores that can be inhaled by the patient. There have been several documented outbreaks of invasive fungal infections whilst such work was ongoing.
This guideline provides advice on the measures that should be taken in order to minimise the risk to certain patient groups.
Building work should be regarded as any new build, demolition, renovation, refurbishment, redecoration or maintenance work that involves disturbance to any fabric of the building, including ceiling tiles.

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Background

The most important fungi associated with invasive infections are aspergillus, with the majority of infections being caused by A. fumigatus.

Aspergillus species and other fungi associated with invasive disease are capable of producing spores, which can persist in the environment and remain suspended in the air for significant periods of time.

These fungal spores are resistant to many disinfectants, extremes of temperature and light, allowing them to survive for long periods in the environment.

This guideline concentrates on aspergillus species, but the recommendations are applicable to other fungi capable of causing invasive infection.

These fungi occur naturally in the environment in reservoirs such as soil, water and decaying vegetation.

In the hospital setting, fungi have been isolated from unfiltered air, ventilation ducts, dust (especially dust generated during building work), flowers and damp/decaying wooden fittings.

Hospital outbreaks of aspergillosis have been reported in transplantation units, haematology and oncology units, intensive care units, Renal units and medical wards where immunosuppressed patients are nursed. Therefore it is imperative that the Infection Prevention and Control Team is consulted prior to any work commencing to provide a thorough risk assessment. ‘At risk’ patient groups can be found in appendix 1.

Usually by the inhalation of fungal spores liberated during the building/demolition process. The spores are inhaled and cause infection in the lungs, which can spread to other parts of the body.

Occasionally the initial site of infection may be the paranasal air sinuses.

For certain groups of patients invasive fungal infections can be fatal e.g. for some bone marrow transplant patients, mortality rates of 80-100% are typical.

Aspergillosis is difficult to diagnose and testing techniques may produce positive results only in the later stages of infection.

Invasive techniques may be required for diagnosis (e.g. lung biopsy) which may not be appropriate for thrombocyotpenic patients. Many cases of Aspergillosis are diagnosed only at post mortem.

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Management: Reducing the risks of Aspergillosis during building

What measures should be taken to prevent invasive fungal infections?

• ‘At-risk’ groups should be identified ( see appendix 1)
• Environmental measures including the provision of High Efficiency Particulate Arrestance (HEPA)-filtered air. HEPA filter is an air filter that must remove (from the air that passes through) 99.97% of particles that have a size of 0.3 micrometers should be used
• Antifungal prophylaxis. This has an unproven role in this setting, but is used where other methods are not available or are considered insufficient
• Invasive fungal infections are also difficult to treat due to the limited range of anti-fungal drugs available. Those that are available can be highly toxic and are very expensive.

Environmental measures to be undertaken during building work

A formal risk assessment should be carried out by the Infection Prevention and Control Team along with where applicable one of the Trust Contractors/Project Managers prior to commencement of any work see appendix 1

If the building work is located close to patients deemed at high risk of Aspergillosis (see appendix 2: groups 3 and 4), they should be removed to an alternative area. If this is not possible, it may be necessary to consider postponement of immunosuppressive treatment and commencement of anti-fungal prophylaxis along with robust environmental measures. This requires discussion with the Consultant Microbiologist.

Robust, dust-proof barriers that are at least double polythene sheeting should be constructed between patient care areas and any building work. They should have air tight seals that prevent the passage of any dust that may contain fungal spores. These barriers must be inspected by the Infection Prevention and Control Team prior to commencing any work and daily by a designated individual.

In certain situations, additional dust containment measures may be necessary, such as the use of water sprays.

Ventilation ducts within the construction/building work area should be sealed. Where possible, air from the construction site should be exhausted to the outside of the building.

Consideration may need to be given to sealing service ducts in adjacent high-risk areas.

Where possible, the building site workers should have designated access to the work area as far away as possible from patient care areas. If building work takes place on upper floors, consideration should be given to designating a lift for the sole use of the construction workers and their equipment or an external hoist system considered for removal of debris.

If the contractors are not given sole use of lifts, then all internal surfaces of the lift car should be visibly clean and dust-free before being used by patients and catering staff.

Construction workers whose clothes have potentially become contaminated with possible fungal sporese.g coming into contact with dust should avoid contact with non-construction areas and they must not enter patient areas.

All waste material must be removed with minimal creation of dust. E.g. bagging of waste, covering of skips.

Any dustsheets should be single-use.

If there are no contraindications, the areas where building work is taking place should be at negative pressure relative to the patient care areas.

Consideration should be given to the isolation and disabling of ventilation in areas where building work is ongoing.

If building work is occurring in the vicinity of high-risk areas, it is necessary to seal windows for the duration of the work and for at least a week following completion of the work.

An information sheet should be provided to inform patients, relatives of patients, healthcare workers and those involved in the construction process, of the potential risk of aspergillosis during construction work (appendix 2) This information should be considered as introductory only.

Staff, patients and visitors should not enter construction areas.

There should be an increase in the frequency of cleaning in areas adjacent to where the work is taking place. Consultation with Facilities staff is required to decide on how frequent and quality of cleaning monitored by the Facilities Supervisor and Infection Prevention team.

Newly constructed/refurbished areas should be cleaned thoroughly with a chlor- clean product before high-risk patients are allowed to enter. This should include vacuuming of areas above false ceilings where necessary.
The Infection Control Team will inspect areas to ensure that they have been cleaned appropriately.

If there is a water leak during any building work, it must be repaired and cleaned as soon as possible, as damp materials encourage fungal growth. If it cannot be rectified within 72 hours of the incident, affected fabric and materials will need to be disposed of safely.

When building work is finished, the ventilation system, direction of airflow and room pressurisation should be tested and adjusted if necessary before patients are allowed to enter.

In cases where it is necessary for a severely immuno-compromised patient to be transported through a construction area a risk assessment would need to be carried out on the state of the construction site, antifungal prophylaxis status and the need for the patient to wear a fit-tested FFP3 mask.

Environmental measures should be monitored on a daily basis. Dust-proof barriers should be inspected daily to ensure that the seals are intact.

The value of air and environmental sampling during building work is unclear.
However, in certain circumstances it may be necessary. The Infection Control
Prevention and Control Team will advise.

If a case of aspergillosis occurs (or is suspected) the environmental control measures will need a thorough review

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