Can hospitals fully stop airborne transmission?

The World Health Organisation estimate that at any one time, over 1.4 million people worldwide suffer from hospital acquired infections.

In the UK we have made enormous strides to improve standards and HCAI rates fell one third in 2010 alone. But with well established procedures and protocols now standardised across the healthcare sector, what more can been done to further reduce this hazard?  

The battle against HCAI has been raging for over a century now; we’ve all seen the arrival of hand sanitizers at every hospital door, noticed the mandatory controlled ventilation in health facilities and watched healthcare workers don their aprons, gloves and face masks.

In addition to these enforced dress codes and barrier protection, there are now strict guidelines and protocols implemented by the Health Protection Agency to try and ensure tighter control and prevention of infection. It is undeniable that an enormous amount of time and money has been spent trying to develop effective infection control policies, such as hand-washing and isolation. But still these infections have not been eliminated, and continue to compromise the health and recovery of patients from across the country.

It is time the NHS approached the idea of eliminating the risks of HCAI from a new direction. The steps taken to reduce risks of infection transmission by direct contact have been undoubtedly successful, but there is one viable means of providing effective protection from HCAIs that has not yet been entirely explored.

The “air” around us is inhaled by patients an average of 30,000 times a day after having been in constant contact with wounds, skin and fluid. Yet still, the air is a frequently overlooked infection source that is all around us in the modern alcohol-gel packed hospitals. Why has air disinfection been overlooked so far, and why should hospitals consider it as another string to their bow in the continual battle to protect their patients?

Previously passive air disinfection products used UV filters and HEPA filters; these relied on air being dragged across an enclosed space, which limits how effective the disinfection process is, a problem exacerbated by blocked filters which can be difficult to combat. Similarly, ionisers are available which use positive and negative ions to clean the air however, there have been concerns over low levels of filtered air being circulated by the air ionisers. 

There is however, an innovative alternative that makes it possible to harness the very powerful air disinfection abilities of naturally occurring hydroxyl radicals (OHº) in order to effectively eliminate airborne infection routes. Hydroxyl radicals are transient energy sources which are produced naturally by plants and flowers to compose an integral part of the air we breathe. Despite the capabilities of hydroxyl radicals to target all invading pathogens which attack our bodies, and being critically important in the upkeep of the immune system; hydroxyl radicals have remained until now an untapped source of air disinfection. Air disinfection is paramount in reducing the threat of airborne transmission; including evaporated droplets, droplet nuclei, and even those adhered to dust particles.

By using air disinfection to combat pathogens (spores, viruses, bacteria, dust and fungi) in the air, we can recreate the protective properties of naturally occurring fresh air to keep infection levels at a minimum. In addition to well-known airborne diseases such as the flu and colds, there is an increasing body of evidence that deadly microorganisms are found in the air – for example, MRSA, pneumonia and Norovirus.

It has been suggested that MRSA carriers with respiratory symptoms project MRSA bacteria when they sneeze or cough, threatening the health of other patients who may inhale it. To effectively contain MRSA and other diseases, this airborne mode of transmission cannot be ignored.

Hydroxyl radicals neutralise any dangerous bacteria and viruses, by altering their structures so that they become nonviable. The hydroxyl radicals emitted provide a cascade reaction until pathogen concentration has been significantly reduced. The chain reaction begins when the hydroxyl radicals strip molecules in the air of a hydrogen atom; this destabilizes the structural integrity of the cells organic components producing other radicals, which in turn can continue to target other pathogens rendering them pathologically harmless

A recent study estimated that the cost to the NHS per surgical site infection is £3,500. Last year, the health secretary announced that the responsibility for hospital readmission costs incurred within 30 days of patient discharge will be transferred back to hospital - meaning each HCAI will now have a direct financial consequence for the hospital.

NICE and the HPA have collaborated to develop guidelines to minimise levels of hospital acquired infections. Surveillance schemes enable improved monitoring of MRSA as well as C.difficile associated infections and reports from the HPA show that there has been a 22 per cent reduction in cases of MRSA bloodstream infections from 2009-10 to 2010-11.  

Similarly, in England and Wales the National Office of Statistics has reported that in 2010 the number of deaths from MRSA fell by 40 per cent, while cases of C.difficile were down 31 per cent on the previous year. The report promotes increased surveillance in combination with an air disinfection system.

It is a mystery to me why air quality control measures such as this have not already become the norm. I would advise all hospitals to explore the option of air disinfection to ensure maximum levels of protection. The cost of HCAI safety programmes now pay for themselves by reducing the number of bed days and staff sick days, so there is little excuse for airborne transmission routes not being eliminated in the coming years.