Abstract
The present investigation was performed to determine the hygienic situation of public
toilets in a large German city, to address possible risks for the human health and, if
necessary, to propose solutions to existing problems.
To this effect various surfaces of municipal public conveniences and privately operated
self-cleaning toilets were examined by means of swabs to determine the level of microbial
and virological germs.
Shigella sp. was detected in low concentrations on five surfaces of a public toilet,
indicating a low hygienic risk which must, however, not be neglected. Furthermore,
enterobacteriacea were found in 27% of the samples taken and faecal streptococci were
identified in 19%. In particular, the toilet seat, the floor surface in front of it, the urinal
and the door handles were found to be sensitive and hygienically relevant surfaces.
Moreover, a large number of samples taken after the cleaning showed higher
concentrations of germs, particularly hydrophilic germs such as Pseudomonas sp. and
Aeromonas sp., than samples taken before the cleaning. This suggests the
non-observance of cleaning routines, presumably in particular with regards to the use of
the cleaning equipment.
The comparison between gentlemen's toilets and ladies' toilets tends to show no
significant differences.
In general terms, the results of this investigation indicate that the surfaces of certain
installations and implements of public toilets only show a low degree of contamination.
The examination of self-cleaning public conveniences which was limited to the bacterial
contamination, revealed an even lower level of germs in this type of toilet. No obligate
pathogenic germs could be isolated. Enterobacteriaceae were found In 22% of the
samples taken, but neither Escherichia coli nor St. aureus could be confirmed in any
case.
In view of the low level of contamination supposedly due to the user-friendly operation
and the less frequent use, such toilet systems can be considered to be a commendable
alternative to municipal public conveniences.
During this field study Enterovirus could not be found in any of the toilets examined.
Using ECBO virus, the virological laboratory tests were carried out on plastic and
stainless steel surfaces.
On the one hand, the objective of the tests was, depending on the virus concentration
applied, to identify on which surface lower virus concentrations can be determined by
means of the methodology described, and, on the other hand, to establish from which
surface more virus can be regained at identical drying times.
The virus concentration applied was identical for both surfaces whilst the swabs regained
less virus from the steel surface after identical drying times.
These findings lead to conclude that the virus either survives on the steel surface for a
shorter period of time or that the swabs can resolve it from the surface less easily. Both
explanations would support the use of stainless steel in public conveniences, this already
being the case in most of the facilities subject to this investigation. |
