Microbiologists’ Perspective: The definitive guide to hospital cleaning

While the infection control team of every hospital consists of multiple stakeholders who work in a coordinated manner, the team is always led by a microbiologist, who sets cleaning and hygiene standards, formulates do’s and don’ts, assesses cleaning equipment, and finds gaps between policies and practices. Over and above this, microbiologists also track and analyse hospital-acquired infections (HAIs), attempt to find a cause for each case, test hospital surfaces and indoor air for the presence of microbes before and after cleaning, and recommend interventions based on their findings.

In this exhaustive article, four microbiologists – Dr Dhruv Mamtora, HOD-Laboratory & Infection Control and Quality & Accreditation Coordinator – Blood Centre, Bai Jerbai Wadia Hospital for Children and Nowrosjee Wadia Maternity Hospital, Mumbai; Dr Tejas Gohel, Consultant – Microbiology & Nodal Officer, Infection Control, Lilavati Hospital & Research Center, Mumbai; Dr Manisa Sahu, Consultant, Microbiology and Medical Administration, Ramkrishna Care Hospital, Raipur; and Dr Shripad Taklikar, Associate Professor of Microbiology at a leading tertiary care public hospital – weigh in on the what, where, why, when and how of hospital housekeeping infection control.

Cleaning schedules

Hospitals are active and buzzing 24×7. There are very few quiet windows when the housekeeping team has an area to itself for undisturbed cleaning. Cleaned floors also need to be allowed to dry before allowing facility users to cross them. Planning cleaning schedules around the hospital’s operations can be a challenge, but there are ways around it.

Dr Mamtora pointed out that the time intervals between 7-9 am and 4-6 pm precede the morning rush hour and evening visiting hours; housekeeping teams can plan their schedules accordingly.

Routine cleaning is done before the start of the day, at multiple points during the day, and also at the end of the day. Dedicated staff needs to be deputed for continuous cleaning of high-traffic areas, as is done in airports and malls.

Deep cleaning of critical areas can be scheduled from Saturday afternoon until evening, while deep cleaning of non-clinical areas can be done one Sunday a month. Deep cleaning of critical areas may also have to be done every time a patient is discharged.

Before cleaning, preliminary risk assessment can be done to ensure the patient is not under any kind of airborne precautions, there are no obstacles or broken furniture, no spillages and that cleaning can be done smoothly without disturbing the patient. High-touch surfaces should be prioritised.

Dr Sahu shared that many hospitals are evaluating long-term disinfection strategies like creating self-disinfecting surfaces by coating medical equipment with metals such as copper or silver, or applying liquid compounds that have persistent antimicrobial activity surfaces. These have residual activity, do not leave stains and keep surfaces microbe-free.

Mechanised cleaning

Since the discovery of asepsis, hospital cleaning has relied almost exclusively on manual methods, using tools and cloths. While other facilities have gradually embraced mechanised cleaning, can the narrow, crowded, always-populated areas of healthcare facilities permit the use of cleaning machines?

The consensus seems to be that they are best suited for floor and wall cleaning. Dr Takilikar said: “Mechanical cleaners are good for big and plain surfaces like corridors and floors of wards/ ICUs.” For this application, they are quick, effective and decrease reliance on manpower.

Dr Mamtora elucidated: “Cleaning machines improve the quality of cleaning, which is superior and accomplished in a relatively less amount of time. The benefits are manifold. However, they require initial investment and need to be properly maintained, otherwise they themselves can become sources of infection – especially those that use water.”

Another downside to manual cleaning is inconsistency of results. As Dr Gohel explained, “When doing manual cleaning, it is difficult to avoid human errors. With the use of modern cleaning machines, these errors can be avoided. e.g. auto dilution of cleaning chemicals by cleaning machines can ensure that the right dilution is achieved each time, unless the machine itself is out of order.”

He also suggested newer, no-touch (automated) decontamination technologies such as aerosol and vaporised hydrogen peroxide, mobile devices that emit continuous ultraviolet (UV-C) light, a pulsed-xenon UV light system and use of high-intensity narrow-spectrum (405 nm) light.

According to Dr Sahu, mechanised cleaning has benefits for patients too: “While dust mopping is a common way to remove dirt and dust from your floors, you can also use a commercial vacuum to clean the floor of the patient room. For patients who have respiratory sensitivities, a vacuum with HEPA filter will be able to trap dust and dirt particles without redistributing them into the air.”

Vacuum cleaners which make little or no noise are available in the market, and are ideal for occupied rooms. Damp mopping the floor using a microfibre flat mop and a neutral floor cleaner is a good practice.

Stubborn microbes

While microorganisms are naturally present in air and on surfaces, only some of them cause hospital-acquired infections, and of these, a few are very difficult to eliminate from the hospital environment. They form a long list; Vancomycin-Resistant Enterococcus (VRE), Carbapenem-resistant Klebsiella pneumoniae, Acinetobacter baumannii complex and Candida auris are potential agents for outbreaks in hospitals, especially critical care areas, if cleaning and isolation protocols are not properly maintained.

In Indian ICUs, gram-negative microbes like klebsiella, burkholderia and stenotrophomonas are particularly difficult to eradicate, as are some gram-positive microorganisms like Methicillin-Resistant Staphylococcus Aureus (MRSA), Clostridium difficile and enterococcus species.

The role of airborne respiratory viruses in causing HAIs is grossly underestimated as many facilities do not have the appropriate diagnostics facilities to detect them. Dr Mamtora advocates a setting-specific approach to raising an alarm; if any of the aforementioned microbes are found in ICUs, transplant units or haematology units, where immunocompromised patients are admitted, an urgent intervention is required.

Housekeeping errors

When the task of cleaning hospitals is entrusted to personnel who have little understanding of the link between environmental cleaning and HAIs, there are bound to be lacunae. Starting with the fact that housekeeping staff tend to approach cleaning clinical areas and non-clinical areas in the same manner, when in fact, they require totally different approaches. Each member of the housekeeping team needs to understand which areas are critical, semi-critical and non-critical, and their supervisors should avoid rotating untrained individuals from non-critical to critical areas.

Incorrect dilution of disinfectants is a common complaint. The dilution recommended by the manufacturer needs to be conveyed to the ground-level staff in their local language; pictorial instructions can be more effective.

Mops cannot be used willy-nilly across different areas of the hospital. They should not be taken from the corridor area to the ICUs, for example, and need to be cleaned properly and adequately after each use. A separate duster/cloth for each patient is of utmost importance to prevent cross infection from one patient to another.

Rather than look at these as errors, it is better to approach them as gaps between the limitations of the housekeeping staff and the expectations of the hospital. These gaps can be minimised with better cleaning devices and training.

Staff issues

Housekeeping service providers need to be responsible for the basic health checkup of all their employees as per NABH norms, and vaccinate them against Hepatitis B and Tetanus at the very least. Since infection control is a specialised function, any service provider who has a dedicated pool of staff for critical area cleaning will always be preferred.

Surface cleaning

Thorough cleaning and disinfection at more frequent intervals than in non-critical areas with a focus on high-touch surfaces and strict hand hygiene are the main interventions to reduce HAI’s in ICU set-ups.

Hand hygiene is perhaps the most important way to prevent cross-infections between patients. Cleanliness of equipment designated for patients, bundle care for prevention of HAIs, safe injection and infusion practices, standard precautions and occupational health of healthcare workers are some of the important ways of preventing HAIs in not just patients but healthcare staff as well. “Vascular access and safety are very important; similarly, maintenance of asepsis and antisepsis during invasive procedures is of prime importance,” said Dr Mamtora.

Clearly, surface cleaning is the first step to infection control. “Cleaning of critical surfaces like monitors, syringe pump, bed railings etc should be done at least twice a day with recommended disinfectant and for each patient bed, a dedicated cleaning duster/cloth should be used”, recommended Dr Gohel.

He also pointed out that disinfection of OTs between surgical cases and at the end of the day is different compared to cleaning other areas of the hospital. “Deep cleaning between cases is done in such a manner that there is no cross contamination or cross infection from one patient to another. Proper cleaning helps in preventing post-operative or surgical site infection to the patient.”

Not to forget, biomedical waste that is left lying around or is improperly discarded can be an eminently avoidable source of contamination.

Indoor air quality

Beyond hand hygiene and surface disinfection, monitoring and controlling indoor air quality, especially in critical areas, is vital to prevent airborne HAIs. The facility management team, infection control team, housekeeping team and engineering team need to work in tandem to follow ASHRAE guidelines for cleaning protocols of HVAC systems, and ensure that they are regularly followed.

The ventilation system needs to be monitored for moisture and air exchanges per hour. “The air vents and HVAC systems should be regularly cleaned according to the routine maintenance schedule; both preventive and breakdown maintenance need to be done,” advised Dr Mamtora. “Extra precautions should be taken to ensure that all the air in a room is replaced with fresh air, once the patient is discharged. This takes about 40 minutes, depending upon the size of the room; this time should be utilised for deep cleaning of the room.” Regular maintenance of the air vent and periodic deep cleaning as and when an isolated patient gets discharged are the only ways to prevent airborne infections.

Device maintenance

Not all patients breathe room air; critical patients may be dependent on ventilators, which also need to be maintained to prevent infections – a task that is increasingly outsourced to facility management companies. “The engineering team should be made aware that installation and maintenance of mechanical ventilation in ICUs is important to avoid infections”, said Dr Taklikar. “A Dispersed Oil Particulate (DOP) test should be performed to check the installation and leakage in filters.”

Assessing effectiveness

According to Dr Sahu, effectiveness of disinfectants used can be determined by the following direct methods:

• The disk-diffusion method is used to test the effectiveness of a chemical disinfectant against a particular microbe.
• The use-dilution test determines the effectiveness of a disinfectant on a surface.
• In-use tests can determine whether disinfectant solutions are being used correctly in clinical settings.
• Direct observation of the appropriate dilutions used, storage conditions, the method of cleaning, the contact duration.
• There are other methods like ATP detection or fluorescent gel based techniques to verify whether effective cleaning is happening or not.

Indirect markers include the rates of and trends in hospital-acquired infections due to resistant bugs, which are an indirect estimate of whether effective cleaning is happening or not.

According to Dr Mamtora, the simplest method to assess cleaning is visual inspection; look for dust-free surfaces. “We can use fingers to check for dust or an audit checklist can be used to ensure all areas are covered in surface cleaning. Sophisticated methods include microbiological methods like air settle plates and surface swabbing.” These are especially useful for measuring disinfection of OTs.

“Surface swabs are no longer recommended”, he continued, “except where there is major renovation work happening. We can also use advanced methods like ATP luminosity, provided the budget for the same is available.”

Dr Gohel prefers taking surface swabs post-cleaning and also direct testing the chemicals with recommended dilution for usage inoculated with different pan resistant microorganism like Klebsiella, Pseudomonas, MRSA, VRE, C. auris at different times (within 5, 10, 15 and 20 minutes).

Half measures

As Dr Taklikar very rightly pointed out, most hospitals tend to avoid measuring the effectiveness of cleaning in non-critical areas. Surface swabs are taken only from critical areas at predefined intervals, and routine aerobic cultures are performed as validation at most hospitals.

Air quality validation

HEPA filter validation and maintenance is done as recommended by national and international guidelines. “Routinely, we do air particle counts to ensure proper cleaning and HEPA filter functioning. Air sampling at regular intervals is done. We don’t do routine surface swab cultures, as it is no longer recommended by CDC. Swab cultures are done only in cases of outbreaks,” shared Dr Sahu.

Clearly, there are conflicting opinions about the appropriateness of relying on surface swabs. They continue to be the mainstay where more sophisticated methods like ATP meters are not available or affordable.