What can we learn from COVID-19?

Published on 10/28/2020 | by Waterline Admin

As featured in waterline Autumn 2020

What can we learn from COVID-19?

Jimmy Walker


So, like many organisations there was WMSoc organising their 2020 conferences and before we knew it the world was in lockdown and all events were rescheduled for 2021. Many freedoms were taken away, most people isolated at home and were practicing social distancing during the biggest pandemic in our lifetime. The emergence of severe acute respiratory syndrome coronavirus 2 (SARSCoV- 2; previously named 2019 novel coronavirus or 2019-nCoV) disease (COVID-19) in China at the end of 2019 has become the largest public health disaster in our lifetime(1). And then, the public were asked to consider wearing face coverings in certain situations and then before we knew it wearing a facemask was compulsory to protect those around us.

So what is Covid-19?

Coronaviruses are enveloped viruses with a singlestranded RNA genome that were first recognised in the 1960s(2,3), are roughly spherical, moderately pleomorphic (can change their form) and have the largest genomes among all RNA viruses. The name “coronavirus” was derived from Latin corona, meaning “crown” or “wreath”, and refers to the characteristic appearance of virions (the infective form of the virus), which are large bulbous surface projections that create an image reminiscent of a crown or of a solar corona(4).

Infection / transmission route

Whilst the initial transmission was considered to be human exposure in a large seafood and live animal market in Wuhan city, it is clear that the main human to human routes are respiratory droplets produced during coughing, sneezing, talking, singing and of contact with contaminated surfaces(5,6). The virus has been identified in respiratory tract specimens 1–2 days before the onset of symptoms and peaks at around the time of symptom onset(7). Hence, those droplets that we are expelling have received much attention. Van Doremalen et al., (2020) were able to demonstrate that SARS-CoV-2 was more stable on plastic and stainless steel than on copper and cardboard, and the viable virus was detected up to 72 hours after application to those surfaces(8). Meanwhile SARS-CoV-2 RNA was identified on a variety of surfaces in cabins of both symptomatic and asymptomatic infected passengers up to 17 days after cabins were vacated(9). Such evidence has led to recommendations to wash hands after touching surfaces and there are those that wash their groceries after getting them home.

Interestingly whilst there was much conjecture in on-line forums that aerosols may play a role in dispersal and transmission, an analysis of 75,465 COVID-19 cases in China, did not identify airborne transmission as a route of transmission(6,10,11). Chia et al., were only able to recover the virus from aerosols in rooms of two of 30 patients in a hospital(8,12). This does not mean the aerosol routes should be completely discounted as Van Doremalen et al., (2020) were also able to demonstrate that SARS-CoV-2 remained viable in aerosols for 3 hours(8).

Having published a manuscript in 2013 entitled “Testing the efficacy of homemade masks: would they protect in an influenza pandemic?” we started receiving communications and queries about our methods and results. This work was carried out by Anna Davis and led by Allan Bennett(13). The conclusions of the study were “Improvised homemade face masks may be used to help protect those who could potentially, for example, be at occupational risk from close or frequent contact with symptomatic patients. However, these masks would provide the wearers little protection from microorganisms from other persons who are infected with respiratory diseases”.

There is no doubt that the wearing of homemade face coverings by the public has caught the imagination of the press and many scientists as a way to combat the spread of the virus.

We know that healthcare professionals are trained in standard and isolation precautions, which will include wearing respiratory protective equipment (RPE) and a mask that will control the transmission of the virus (FFP3 respiratory mask) and that each mask needs to be fit tested to each individual.

The HSE have a practical guide to RPE at work (https://www.hse.gov.uk/pubns/priced/hsg53.pdf) which is relevant to a variety of organsations and service providers, including WMSoc members.

So would encouraging the public to wear face masks make a difference? Greenhalgh et al., have recently published a review on whether wearing facemasks by the public would make a difference and were not able to find any conclusive publications that supported wearing of the masks by the public(14). However, despite these conclusions they felt that now was not the time to wait for randomised controlled trials and advocated the precautionary principle that the public should wear facemasks in certain enclosed situations such as public transport.

Bearing in mind that the rates for asymptomatic carriers vary e.g. on board the Diamond Princess cruises ship, the proportion of asymptomatic individuals among those who tested positive for SARS-CoV-2 on board the ship was 17.9%(15). Of the Japanese citizens who were evacuated from Wuhan to Japan, 33.3% were considered to be asymptomatic(16). However, alarmingly the BMJ reported that up to 78% of new coronavirus cases could be asymptomatic.

If you do not have any symptoms but are shedding the virus then clearly a face covering would significantly reduce dispersal of contaminated respiratory droplets(17). My own precautionary principle will stand, thus far on the scientific evidence which will include social distancing, regular and rigorous hand washing, respiratory etiquette (for example, by coughing into a flexed elbow), as well as not touching my face. I initially questioned the efficacy of wearing a face covering as I was not convinced that enough people would wear them to actually make a difference, but the tide of public opinion changed when face coverings became mandatory in shops and on public transport. It will take time to gather evidence on the efficacy of wearing face coverings by the general public to what impact this has made on the pandemic.

Whilst we are now all encouraged to wear a face covering and some of these are fantastic looking (indeed, fashion items) there is no doubt that the public need training in wearing their face coverings as it is not an uncommon sight to see face-masks being worn on top of the head as a sweatband, below the nose, or as a chin-strap and almost everyone will have a common route of infection via touching their face, contaminated objects and then using their mobile phone. Whilst they regularly gel or wash their hands that phone is often forgotten about.

Lessons learned (so far!)

Some COVID-19 symptoms are similar to those of Legionnaires’ Disease (LD) and it is possible that LD was not always clinically tested for at the height of the pandemic. A study by Zhou et al., (2020) showed that half of COVID-19 fatalities had experienced a secondary infection and a further small study by Xing, et al., (2020) showed 20% of patients studied were infected with Legionella pneumophila antibodies. This suggests that COVID-19 patients are at increased risk of secondary infections both during recovery and for some months after, including those caused by waterborne pathogens such as Legionella and Pseudomonas aeruginosa. Many wards designated as “COVID” wards, were not necessarily on the augmented care testing schedule.

We are much more aware of the importance of hand-washing in breaking the onward transmission of the virus. This is important to remember when considering aseptic sampling techniques for taking water samples as cross-contamination from bacteria will be very similar. In the early stages of the COVID-19 water management and monitoring of water systems may not have been as rigorous as it should have been. As a consequence a number of water microbiologists worked with the ESCMID Study Group for Legionella Infections (ESGLI) to produce guidance for hospitals, temporary and converted buildings or parts of buildings and field hospitals as well as care homes and dental surgeries used for treating COVID-19 patients(18–20).

Other safety precautions must include the use of correctly fitted RPE when using or preparing chemicals such as chlorine or chlorine dioxide used in the control of waterborne infections.

In summary, it looks like this pandemic is going to be with us for some time and the Government is working hard on introducing more testing and improving track and trace. As a water industry we too must play our part in ensuring that we adhere to the precautionary principals to ensure that we are protecting those around us including our families, employees and customers.

WMSoc wish to acknowledge that an earlier version of this article was published in the April 2020 International Biodeterioration and Biodegradation Society (IBBS) newsletter. Dr Jimmy Walker has kindly updated it to make it relevant to the WMSoc membership and to include the latest in ever-changing information and guidance and many thanks to Elise Maynard for her contributions.


1. Lai C-C, Shih T-P, Ko W-C, Tang H-J, Hsueh P-R. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus disease-2019 (COVID-19): The epidemic and the challenges. Int J Antimicrob Agents [Internet]. 2020 Feb 17 [cited 2020 Apr 14]; Available from: https://www.ncbi. nlm.nih.gov/pmc/articles/PMC7127800/

2. Lauber C, Ziebuhr J, Junglen S, Drosten C, Zirkel F, Nga PT, et al. Mesoniviridae: a proposed new family in the order Nidovirales formed by a single species of mosquito-borne viruses. Arch Virol. 2012;157(8):1623–8.

3. Almeida JD, Tyrrell DAJ. The Morphology of Three Previously Uncharacterized Human Respiratory Viruses that Grow in Organ Culture. J Gen Virol. 1967;1(2):175–8.

4. Masters PS. The molecular biology of coronaviruses. Adv Virus Res. 2006;66:193–292.

5. Li Q, Guan X, Wu P, Wang X, Zhou L, Tong Y, et al. Early Transmission Dynamics in Wuhan, China, of Novel Coronavirus–Infected Pneumonia. N Engl J Med. 2020 Mar 26;382(13):1199–207.

6. Fuk-WooChanMDab*ShuofengYuanPhDa*Kin- HangKokPhDa*Kelvin Kai-WangToMDab*Hi nChuPhDa*JinYangMDbFanfanXingMDbJiel ingLiuBNursbCyril Chik-YanYipPhDaRosana Wing-ShanPoonPhDaHoi-WahTsoiMPhilaSimon Kam-FaiLoMPhilbKwok-HungChanPhDaVincent Kwok-ManPoonMPhilaWan-MuiChanPhDaJonathan DanielIpMScaJian-PiaoCaiBScaVincent Chi- ChungChengMDa…ProfKwok-YungYuenMD. A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-toperson transmission: a study of a family cluster – ScienceDirect [Internet]. [cited 2020 Apr 15]. Available from: https://www.sciencedirect.com/ science/article/pii/S0140673620301549

7. Coronavirus disease 2019 (COVID-19) pandemic: increased transmission in the EU/EEA and the UK – seventh update. :31.

8. van Doremalen N, Bushmaker T, Morris DH, Holbrook MG, Gamble A, Williamson BN, et al. Aerosol and Surface Stability of SARS-CoV-2 as compared with SARS-CoV-1. N Engl J Med. 2020 Apr 16;382(16):1564–7.

9. Public Health Responses to COVID-19 Outbreaks on Cruise Ships — Worldwide, February–March 2020 | MMWR [Internet]. [cited 2020 Apr 19]. Available from: https://www.cdc.gov/mmwr/volumes/69/wr/mm6912e3.htm?s_cid=mm6912e3_w

10. Liu J, Liao X, Qian S, Yuan J, Wang F, Liu Y, et al. Early Release – Community Transmission of Severe Acute Respiratory Syndrome Coronavirus 2, Shenzhen, China, 2020 – Volume 26, Number 6—June 2020 – Emerging Infectious Diseases journal – CDC. [cited 2020 Apr 15]; Available from: https://wwwnc.cdc.gov/eid/article/26/6/20-0239_article

11. Faridi S, Niazi S, Sadeghi K, Naddafi K, Yavarian J, Shamsipour M, et al. A field indoor air measurement of SARS-CoV-2 in the patient rooms of the largest hospital in Iran. Sci Total Environ. 2020 Apr 6;725:138401.

12. Chia PY, Coleman KK, Tan YK, Ong SWX, Gum M, Lau SK, et al. Detection of Air and Surface Contamination by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Hospital Rooms of Infected Patients [Internet]. Infectious Diseases (except HIV/AIDS); 2020 Apr [cited 2020 Apr 17]. Available from: http://medrxiv.org/lookup/ doi/10.1101/2020.03.29.20046557

13. Davies A, Thompson K-A, Giri K, Kafatos G, Walker J, Bennett A. Testing the efficacy of homemade masks: would they protect in an influenza pandemic? Disaster Med Public Health Prep. 2013 Aug;7(4):413–8.

14. Greenhalgh T, Schmid MB, Czypionka T, Bassler D, Gruer L. Face masks for the public during the covid-19 crisis. BMJ. 2020 Apr 9;m1435.

15. Mizumoto K, Kagaya K, Zarebski A, Chowell G. Estimating the asymptomatic proportion of coronavirus disease 2019 (COVID-19) cases on board the Diamond Princess cruise ship, Yokohama, Japan, 2020. Eurosurveillance. 2020 Mar 12;25(10):2000180.

16. Nishiura H, Kobayashi T, Miyama T, Suzuki A, Jung S, Hayashi K, et al. Estimation of the asymptomatic ratio of novel coronavirus infections (COVID-19). medRxiv. 2020 Feb 17;2020.02.03.20020248.

17. Day M. Covid-19: four fifths of cases are asymptomatic, China figures indicate. BMJ [Internet]. 2020 Apr 2 [cited 2020 Apr 17];369. Available from: https://www.bmj.com/content/369/bmj.m1375

18. ESGLI. ESGLI Guidance for managing Legionella in dental water systems during the COVID-19 pandemic. 2020; Available from: https://www.escmid.org/fileadmin/src/media/PDFs/3Research_Projects/ESGLI/ESGLI_GUIDANCE_FOR_MANAGING_LEGIONELLA_IN_DENTAL_WATER_SYSTEMS_DURING_THE_COVID-19_PANDEMIC_22042024_v01.01.pdf

19. ESGLI. ESGLI Guidance for managing Legionella in nursing & care home water systems during the COVID-19 pandemic. 2020; Available from: https://www.escmid.org/fileadmin/src/media/PDFs/3Research_Projects/ESGLI/ESGLI_GUIDANCE_FOR_MANAGING_LEGIONELLA_IN_DENTAL_WATER_SYSTEMS_DURING_THE_COVID-19_PANDEMIC_22042024_v01.01.pdf

20. ESGLI. ESGLI Guidance for managing Legionella in hospital water systems during the COVID-19 pandemic. 2020; Available from: https://www.escmid.org/research_projects/study_groups/study_groups_g_n/legionella_infections/

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