INCREASED RISK OF LEGIONELLA IN HOSPITALITY SECTOR POST LOCKDOWN.
Evidence is emerging of the significant increase in Legionella growth in premises offering overnight accommodation where the usage/occupancy was affected during the 2020/21 COVID lockdown. The information strongly suggests that there is a potentially increased risk of Legionella exposure for those people staying in hotels or similar accommodation when the sites come back into full use in 2021. Legionella infections include the potentially fatal Legionnaires’ disease, an atypical form of pneumonia, with a high mortality rate.
The study carried out by the UKAS accredited laboratory at Feedwater Ltd, an LCA registered water treatment service provider, looked at a series of hotels for whom sampling data was available before and after lockdown. Some of the hotels operated a temperature control regime and some use chlorine dioxide as an alternative to temperature. There is a marked increase in the numbers of samples testing positive for Legionella before and after lockdown, even in systems where Legionella colonisation was not easily detectable before March 2020. For some systems two-thirds of samples taken were positive for Legionella in post-lockdown sampling.
The data shows that even in premises considered under control prior to the pandemic, Legionella become much more commonly detected bacteria in samples taken post-lockdown. Data also suggests that chlorine dioxide treated systems have much lower levels of Legionella than systems treated with temperature. It appears that the protective effect of an appropriate biocide, provides greater inhibition of Legionella growth in these systems, thus reducing risk in these circumstances. It is also clear that sites with historic positive results show significant increases in positive results following lockdown.
Table 1: Proportion of samples testing positive for Legionella before and after lockdown
Commenting on the results, Feedwater Technical Manager, Gary Hogben, stated that ‘Owners and operators of water systems must not assume that successful historic control of Legionella means that the systems have remained under control during the low usage period. These results strongly indicate that low usage is likely to cause an increase in colonisation with Legionella, even where flushing has taken place. Further control measures will need to be taken to allow buildings to open safely once the lockdown is fully over’.
“An HSE spokesperson said ‘If your building was closed or had reduced occupancy during the coronavirus (COVID-19) pandemic, water system stagnation can occur due to lack of use, increasing the risks of Legionnaires’ disease.
You should review your risk assessment and manage the legionella risks when you reinstate a water system or start using it again.
If hot and cold water outlets are used infrequently, flush them at least weekly to minimise water stagnation. If you cannot do this or monitoring results indicate a problem, ensure water systems are cleaned (if required) and disinfected before the building (or part of the building) is occupied’.
For further information is available in L8 Approved Code of Practice and the associated technical guidance:
- Legionnaires’ disease. The control of legionella bacteria in water systems – Approved Code of Practice and guidance (L8 ACOP)
- Legionnaires’ disease – Technical guidance (HSG274 Part 2) (PDF) ”
For further information on this study or to discuss Activ-Ox Chlorine Dioxide which was used in this study please contact Accepta using the below contact form.