In June 2020, five babies in the neonatal unit at Flinders Medical Center were infected with a rare bacteria – Serratia marcescens – which can cause meningitis and other conditions such as urinary tract and respiratory infections. The outbreak was linked to a sink in the neonatal ward, where a swab from the drain tested positive for the bacteria.
A 2017 study published in Applied and environmental microbiology used a designated hand washing sink lab gallery to model the dispersal of bacteria – in this case expressing green fluorescent protein (GFP) Escherichia coli – wastewater from sinks to the surrounding environment. Examination of the bacteria dispersal mechanism demonstrated that bacterial transmission can occur through sewage plumbing connections to nearby sinks.
The dispersion of bacteria was studied in three experiments to test whether organisms living in the trap P of a sink could be dispersed by running water. ∼10ten CFU / mL expressing GFP E. coli in saline solution was added to an autoclaved P-trap and installed in a pre-autoclaved drainage line.
The researchers found that when the expression of GFP E. coli cells were allowed to mature in the P trap under conditions similar to a hospital environment, a biofilm extended upward over seven days to reach the strainer. This led to a dispersion of droplets when the tap was turned on. The authors of the study express concern at “a growing number of reports involving Gamma-proteobacteria often carrying drug resistance genes from colonized traps to vulnerable hospital patients ”.1
Faucets discharged into or near the waste transfer bacteria and biofilm, negating all the benefit of hand washing and causing dangerous situations around the bowl area. A staggered rear waste ensures that faucets will not be thrown into waste, and the handwashing spray pattern will not aerosolize bacteria and biofilms from internal waste.
The Australian company Gentec Australia has launched a range of treatment basins specially designed to prevent infections by compensating for the drainage hole. Patented design prevents aerosol biofilms and bacteria as well as splashing waste when washing hands. Basins are designed to improve infection control, with: back shift waste to remove aerosol from faucets and spray from hand washing; seal the installation to eliminate bacteria infiltrating the ponds; antimicrobial technology; and sloping surfaces to prevent bacteria growth in standing water.
These solutions are designed to prevent infectious diseases from spreading from hospital staff to other staff and patients.
1. Kotay, S., Chai, W., Guilford, W., Barry, K. and Mathers, A., 2017. Spread from the Sink to the Patient: In Situ Study Using Green Fluorescent Protein (GFP) -Expressing Escherichia coli To model the bacterial dispersion of hand washed sink traps. Applied and Environmental Microbiology, 83 (8). Creative commons 4.0 license