WATER SYSTEM HYGIENE
Taking the risks out of cleaning shower hoses
Gary Parkinson, MD of Water Environmental Treatment Ltd (W.E.T), examines what the company says is ‘growing evidence’ that cleaning of shower hoses using a ‘traditional hand and bucket approach’ will not eliminate harmful waterborne bacteria such as Pseudomonas aeruginosa, and explains the fundamentals of the of water hygiene and Legionella compliance business’s new Hygiene 20 Shower Management service. It says this is not only saving facility teams time and money, but also achieves ‘an impressive 99.9% kill rate of bacteria currently thriving in shower systems’.
Shower hoses known to be cleaned using a ‘hand and bucket’ procedure have been found to contain significantly high levels of bacteria. Most notably, a count of 2.4 m cfu P. aeruginosa in just 1 ml of water was observed by W.E.T during a recent research project investigating the link between showers and healthcare- associated infections (HCAIs).
Why is this being researched? According to the National Institute for Health and Care Excellence (NICE), up to 300,000 patients annually acquire a healthcare-associated infection (HCAI) as a result of care within the NHS. To help combat this, NHS Improvement has tasked Infection Prevention and Control teams with reducing the number of healthcare- associated Gram-negative bloodstream infections by 50% by March 2021. More specifically, Public Health England, the body responsible for monitoring the number of infections that occur in healthcare settings, extended the surveillance of Gram-negative organisms to include Pseudomonas aeruginosa, which was recently mandated in September 2017. It is widely accepted that showers are a source of contamination and a distributor of pathogenic bacteria such as Legionella pneumophila and Pseudomonas aeruginosa. This is because showers are an ideal environment for the development of biofilms, as they operate within temperatures prime for bacteriological proliferation, contain crevices which harbour bacteria, and are manufactured from nutrient-rich materials. When you combine these factors with the shower atomising water, it is logical to determine showers as a key risk for managing HCAIs.
What is the current problem? A shower hose will often contain more bacteria than the rest of the building’s plumbing system. A research team led by Frederik Hammes has been investigating this topic for the past four years. In the
96 Health Estate Journal October 2018
W.E.T says shower hoses known to be cleaned by a ‘hand and bucket’ procedure have been found to contain ‘significantly high levels of bacteria’.
team’s latest global study, the team members analysed biofilms in 78 shower hoses from 11 countries, and in 21 of them they detected Legionella. Guidance documents such as HTM 04-01 and HSG 274 provide clear advice with regard to regular cleaning and disinfection of showers. As a result, maintenance teams and water hygiene companies have quite rightly included this as a planned preventative maintenance task in their water hygiene control schemes, adopting a ‘hand and bucket’ cleaning and de-scale approach.
During W.E.T’s research, one study took 16 shower hoses from healthcare settings known to be cleaned using a hand and bucket methodology and tested them for TVCs and Pseudomonas. Ninety-four per cent of these hoses were found to be contaminated with Pseudomonas, with an average count of nearly 200,000 cfu/ 100 ml sample.
This result may seem high against routine sampling at the shower outlet, which is due to the methodology of sampling. Instead of simply relying on planktonic counts at the outlet, W.E.T dissected the hoses into 10 mm lengths
and vortexed the material in a sterile solution, which released biofilm and bacteria off the internal surfaces. This demonstrated the high levels of contamination adhered to the internal hose surfaces, which provide perfect breeding grounds for opportunistic pathogens such as Legionella, presenting a real risk to shower users.
Drawbacks of ‘hand and bucket’ cleaning
Why are hand and bucket procedures seemingly not working?
In W.E.T’s view there are several possible limitations with the hand and bucket process. These include: n Too much focus on the shower head, instead of on the shower hose.
n Air pockets during disinfection, preventing full surface contact of the disinfectant.
n Pitted surfaces of materials hampering disinfection by shielding biofilms.
n Biofilm and organic matter not effectively removed from the shower hose length.
n Contact time of disinfectant not sufficient.
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116