AS schools plan to reopen and parent-teacher associations fundraise for hand sanitiser, may I, as a paediatrician and public health specialist, suggest a cheaper, more sustainable, and safer alternative for the long term?
Hand-washing with soap and water, if done properly, has been shown to be more effective than alcohol-based hand rubs in reducing viral contamination of hands. This is even more relevant when, to save costs, sanitisers have to be rationed in timing and amount. As with hand-washing, there is a proper technique when using alcohol-based hand sanitisers. Enough should be applied to the hands to allow coverage of all surfaces of the hands and fingers. The hands should be rubbed vigorously together (with some friction) until they are dry.
Antibacterial gels can quickly reduce the number of germs on your hands but they do not kill some viruses such as Norovirus, or bacteria such as C difficile. Both cause severe gastroenteritis. Alcohol-based sanitiser (over 60 per cent alcohol) are highly effective for killing bacteria and viruses, but only if there is direct contact of alcohol with the microorganisms and enough contact time. If there is a lot of dirt on the hands, the antibacterial hand gel may not reach the microorganisms under the dirt. The gel will not remove dirt.
Preschool teachers helping to clean kids’ snotty noses should take note that mucus protects viruses from the killing effect of the sanitiser. A Japanese study found that alcohol based hand rubs took eight times longer to inactivate influenza A viruses (IAV) in mucus than in saline. When the mucus is completely dry, IAV can be killed within 30 seconds.
Dirty hands soiled with dirt or organic matter (such as after the playground, toilet, before and after meals, or helping kids clean up) should be washed with soap and water, not just ‘dry cleaned’ with sanitiser. An antibacterial hand gel can substitute for hand washing only when there is no organic material (dirt or mucus) on one’s hands.
If you can see or feel some dirt on your (or your kids’) hands, it is best to wash with soap and water. Soap helps break down organic material. Running water will rinse the dirt and germs away. Washing the virus off with water alone might work. But soapy water is better at loosening the strong, glue-like interactions between the skin, virus, and dirt. Soap, like alcohol (over 60 per cent concentration) damages the protective viral lipid membrane, and kills it.
CDC studies have shown that there is no added benefit to using antibacterial soap over regular soap. However, liquid soap (and dispensers) is preferred to solid pieces of soap, because the latter (sitting in wet open containers) will pick up germs from users and may be less hygienic with multiple users.
Lanolin containing soaps may cause some children/adults with allergic eczema to develop washer-woman dermatitis of the hands. Such individuals may have to bring their own soaps.
Schools and institutes of higher learning should invest in more hand-washing facilities not just in toilets, but also in strategic locations for students to hand-wash before re-entering class or after PE or when the toilet queue is too long.
Role of toilets
The potential role of toilets in the spread of Covid-19 became an issue when faeces from Covid-19 patients tested positive for SARCoV2 RNA. A few studies were able to either identify the virus on Electron Microscopy or on culture.
In a pooled analysis of 4,243 Covid-19 cases in China and five other countries, 17.6 per cent reported gastrointestinal symptoms. This may be the only initial symptom in some Covid cases. Loss of appetite was the most common, followed by diarrhoea, nausea/vomiting, and abdominal pain or discomfort.
A total of 48.6 per cent stool samples tested positive for viral RNA. Stool Viral RNA was detected as early as day three of illness onset and remained positive in a 78-year-old patient for up to 33 days from illness onset.
Healthcare workers have to exercise caution while handling faeces or performing endoscopic procedures in Covid patients, even during the recovery phase, because of the prolonged presence of viral RNA even after the nasal swabs are negative.
The faecal oral spread of SARSCoV has not been proven.
Epidemiological investigation of an outbreak of SARS (a coronavirus) in Amoy apartment traced the 187 cases to case#0. Airflow dynamics studies suggested the aerosolised virus may have been sucked out by the patient’s toilet exhaust fan and vented into the apartments above and beyond.
In two hospitals in China, aerosol samples collected from a Covid patient’s toilet tested positive for viral RNA. The ICU, CCU, and general patient rooms and patient hall had undetectable or low airborne SARS-CoV-2 concentration.
Flushing creates aerosolised eruption of viral particles
We know that toothbrushes left in proximity to the toilet gain germs quite rapidly, mirroring levels observed in the toilet itself. That same thing can occur for mobile phones, which most take with them into the bathroom.
The high concentration of the virus in the air samples taken from patients’ toilets in the Chinese study has been confirmed by other researchers. Toilet lids should be closed before flushing to minimise the volcanic dispersion of germs aerosols. Room ventilation, open space, proper use, and disinfection of toilet can effectively limit aerosol transmission of Covid-19.
Take home message
1. Numerous studies have shown that sanitiser is not more effective than soap and water in stopping the spread of colds, flu, and other respiratory diseases.
2. Alcohol-based hand sanitiser is better than alcohol-free sanitiser because the alcohol serves as a preservative. It is less likely to be contaminated.
3. Alcohol based sanitiser – beware of accidental or self-poisoning.
4. For healthcare or nursing homes, the CDC recommends the use of alcohol based hand rubs for the decontamination of hands between each patient contact (of non-soiling type) and the use of liquid soap and water for cleaning visibly contaminated or soiled hands. The availability of bedside alcohol-based solutions have increased compliance with hand hygiene among healthcare workers.
It’s an opportune time to audit toilets in Malaysian schools. If we want to teach our kids to respect the next user and flush after use, the flush cistern must fill up quickly between users. The flush must flush and not splash faecal water all over your shoes as the toilet bowl is blocked. If the flush handle is broken, there must be a bucket and access to a tap so flushing can be manual. If we want kids to wash their hands, the sink and taps have to be reachable and there must be water, not little dribbles like a baby’s pee.
This investment is not just good for Covid-19, but for all the other food-borne illnesses including polio, cholera, typhoid, acute gastroenteritis, worms, and parasites.
Where flush cisterns have short lifespans and good plumbers hard to afford, the humble low tech pour flush toilet can be a very good alternative, especially in rural areas. Please do not rush to insist on funding for five-star toilets or extra cleaners in school. We just need five star plumbing and fixtures maintenance, good water source, and users with a five-star mentality.
Dr Tan Poh Tin is a public health trained paediatrician whose work experience includes installation of pour-flush toilets in ulu Sarawak.