Sunday, 31 May 2020

Tetanus vaccines

The Ph. Eur Commission adopted 16 revised monographs on tetanus vaccines, following a reassessment of toxicity testing requirements. The revisions include the suppression of three tests and the harmonisation, as far as possible, of the Ph. Eur.’s toxicity testing requirements for tetanus vaccines for human and veterinary use. The Ph. Eur. Commission is committed to phasing out the use of animal tests by continuously reviewing in vivo tests described in Ph. Eur. texts and applying, whenever possible, the 3Rs principles set out in the European Convention for the Protection of Vertebrate Animals used for Experimental and other Scientific Purposes (ETS No. 123). The reassessment of toxicity testing requirements for tetanus vaccines and the decision to delete three animal tests is an illustration of this commitment.

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (

Saturday, 30 May 2020

Plastic eating bacterium offers pollution hope

German scientists have found a small solution to this big problem – plastic-eating bacteria.
This newly identified strain of Pseudomonas bacteria was discovered by a team consisting of researchers from Helmholtz Centre for Environmental Research (Leipzig, Germany), Freiberg University of Mining and Technology (Germany) and Helmholtz Centre for Infection Research (Braunschweig, Germany), who have demonstrated its ability to break down polyurethane, a toxic type of plastic that is particularly hard to recycle.

In 2015 alone, polyurethane accounted for 3.5 million tons of the plastic produced in Europe. Its lightweight, insulating and flexible properties make it suitable for use in many products, from shoes and refrigerators to kitchen sponges. However, it’s incredibly difficult and energy-intensive to recycle, so most ends up on landfill sites where it releases toxic, often carcinogenic, chemicals.

Most bacteria are unable to withstand the toxic fumes released by the plastic, but, as demonstrated in a recent study published in Frontiers in Microbiology, this newly discovered strain is able to not only withstand and survive in the harsh environment, but also degrade some of the chemical building blocks of polyurethane and use these for energy.

For further details, see Biotechniques:  

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (

Friday, 29 May 2020

TB eradication update – WHO

There’s an interesting article in Biotechniques, looing at progress with the World Health Organizations tuberculosis eradication strategy. Here is an extract:

Active TB infection is defined by the presence of clinical symptoms, such as cough, fever and weight loss, as well as positive microbial cultures for acid-fast bacteria. Due to widespread dissemination throughout the body, patient infection is defined as pulmonary or extra-pulmonary TB infection.

Globally, 3.4% of all new cases, and 18% of previously treated TB patients, possess drug-resistant bacteria. Therefore, active TB infection is also classified by the degree to which the bacteria are resistant to antibiotic combinations. Quick identification of antibiotic resistance is key in preventing the development of further antibiotic resistance and restricting the morbidity associated with active TB infection. Furthermore, rapid initiation of treatment helps to limit the spread.

Early diagnosis and universal drug susceptibility testing are considered two of the main priorities of the WHO’s End TB Strategy. The current ‘gold standard’ rapid diagnostic test for TB is Xpert MTB/RIF (Cepheid Inc., CA, USA). The diagnostic utilizes real-time PCR technologies via a cartridge-based system. Samples of varying types, including sputum, lymph node aspirate and cerebrospinal fluid, can be taken to diagnose both pulmonary and extrapulmonary infection, with the results detecting both the bacteria and ripanfacin-resistance – the surrogate marker for multi-drug resistant TB. Xpert MTB/RIF is cost-effective and also has proven utility for targeted testing of individuals, for example in prisons where TB burden and risk of cross-infection is high.

The article can be viewed here:  

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (

Thursday, 28 May 2020

EMA publishes ICH guideline Q12

This guideline provides a framework to facilitate the management of post-approval CMC changes in a more predictable and efficient manner. A harmonised approach regarding technical and regulatory considerations for lifecycle management will benefit patients, industry, and regulatory authorities by promoting innovation and continual improvement in the pharmaceutical sector, strengthening quality assurance and improving supply of medicinal products.

The concepts outlined in prior ICH Quality Guidelines (ICH Q8(R2), Q9, Q10 and Q11) provide opportunities for science-and risk based approaches for use in drug development and regulatory decisions. These guidelines are valuable in the assessment of Chemistry, Manufacturing and Controls (CMC) changes across the product lifecycle. ICH Q8(R2) and Q11 guidelines focus mostly on early stage aspects of the product lifecycle (i.e., product development, registration and launch). This guideline addresses the commercial phase of the product lifecycle (as described in ICH Q10); and it both complements and adds to the flexible regulatory approaches to post-approval CMC changes described in ICH Q8(R2) and Q10 Annex 1.

For details, see:

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (

Wednesday, 27 May 2020

How Pharma Manufacturers Can Cut Costs and Improve Productivity Now

Time and money are the two most precious humanmade resources. For pharmaceutical companies — especially those on the front lines fighting infectious diseases and treating stubborn ailments — making the most of these resources is especially critical.

By Megan R. Nichols 

The following recommendations can help pharmaceutical manufacturers of all sizes retool their enterprises to save both time and money and become an even more indispensable part of the world's health care community:

1. Adopt Predictive Maintenance Systems

Run-to-failure is no longer an option in a modern manufacturing setting. Preventive maintenance improved on that model, but current technologies can take things to another level. That new level is called predictive maintenance.

Pharmaceutical manufacturing is even more vulnerable to downtime and maintenance lapses than other fields. Failure to keep machines clean, stable and efficient invites contamination, product defects, costly downtime and more expensive maintenance over the lifetime of critical devices.

Deploying predictive maintenance using the Industrial Internet of Things (IIoT) allows manufacturers to capture ongoing metrics and measurements for their equipment. Sensors and edge computing technology work together to monitor assets, catch malfunctions before they impact the product or halt the production line and communicate findings automatically with managers and engineers.

These technologies ensure machines stay in optimal condition for as long as possible, without the costly wear-and-tear of running equipment until it fails.

2. Improve Inventory Management to Boost Margins

According to McKinsey, the average pharmaceutical company holds around 180 days' worth of inventory at any given time. Companies identified as "top performers" tend to shave this down to 100 days. However, available research supports even leaner inventory management practices.

Consumer goods manufacturers target 60 days on average as the optimal amount of inventory to keep on hand. Pharmaceuticals are often time-sensitive and life-saving, so McKinsey points to an optimal window of between 80 and 100 days instead. Targeting this window during inventory management could help pharmaceutical companies free up around $25 billion in operational capital, making their businesses leaner and more financially stable over the long term.

3. Automate Repetitive Tasks Such as Compliance

The pharmaceutical industry consistently ranks among the most heavily regulated industries on the planet. Dealing with multiple regulatory environments across states and territories only compounds these challenges.

From sales reports and quality checks to compliance documentation, pharmaceutical companies have many reasons to adopt automation tools. Repetitive tasks and those requiring frequently changing data from multiple sources are error-prone time sinks.

Automated documentation and reporting tools equipped with machine learning can populate frequently used forms and templates with accurate information, leading to fewer errors and less wasted human effort as documents move between different workflows, facilities or partners.

4. Become a Multi-Product Facility

Manufacturing facilities of all kinds can no longer rely on churning out the same couple of products each year. This issue is especially true in the pharmaceutical industry, thanks to more substantial competition, more frequent calls for small-batch manufacturing and emerging health crises. Each of these factors requires more agile and efficient manufacturers and facilities.

There is a clear need for pharmaceutical manufacturers to become more flexible and adaptable. Becoming a multi-product pharma manufacturing plant requires strong segregation between steps in the fabrication process, cross-contamination protocols and the ability to retool production lines quickly to meet small-batch requirements.

Newer technologies can help with this, including continuous flow chemistry reactors. Static batch reactor systems don't provide the efficiency or speed required by multi-product facilities. In contrast, continuous flow reactors offer more safety and scalability and result in cleaner and more consistent product batches.

5. Hire for Soft Skills and Embrace a Growth Mindset

Every pharmaceutical manufacturer needs to embrace a growth mindset if they want to boost productivity, save money and become more efficient and competitive. For many companies, these objectives must start at the beginning with hiring and recruiting.

Factory managers, supply chain managers, quality control specialists and many other critical positions rely on learned skills. As a result, the hiring process tends to focus on subject matter knowledge. This quality is important, undoubtedly. But campaigns to improve productivity need soft skills, too — as well as driven, thoughtful, out-of-the-box individuals to embrace change, growth and ongoing improvement.

Some of the soft skills required to adopt this mindset include open communication, the ability to engage with employees, leadership skills and, of course, an inventive spirit.

Companies that foster a growth mindset through hiring for soft skills will find it much easier to adopt a systematic approach to improvement, including Lean Six Sigma and others. There are several tenets of Six Sigma that offer substantial value to the pharma industry, including:

· Reducing fulfillment time.

· Finding and eliminating sources of error.

· Making supply chains more responsive and resilient.

· Reducing waste in time, materials and labor.

· Keeping the company organized.

Every workplace inevitably finds different ways to redesign their processes for productivity and eliminate redundancies — but the goal of ongoing improvement begins with finding the right people.

It's hard to understate the importance of pharmaceutical manufacturing. It's how we take ongoing breakthroughs in biotechnology and bring them into the global marketplace, where they improve medical outcomes and enhance human life.

The global pharmaceutical industry is set to reach $1.5 trillion by 2023, with a compound annual growth rate (CAGR) of between 3% and 6%. That's a lot of opportunity for companies that make wise investments in technologies, personnel and forward-thinking, cost-cutting process improvements.

The World Needs More Cost-Effective and Efficient Pharma Manufacturers

Pharma manufacturers can make significant gains within the industry if they adopt more time-saving and cost-effective techniques and processes. By doing so, they can usher in a new era of pharmaceutical practice that's much more productive than its predecessor.
Pharmaceutical Microbiology Resources (

Coronavirus: geospatial tool to analyze and visualize the capacities of intensive care beds

The technology allows authorities and hospital operators to identify risk areas and take action before shortages arise. It can be rolled out across nations and applied to other medical capacity questions as well as different areas, such child care facilities, schools and public transport.

The technology has been developed by, a Targomo is a Berlin-based analytics company, using AI and location intelligence to convert complex geospatial research into actionable insights.

The geospatial tool to analyze and visualize the capacities of intensive care bed units in the face of the coronavirus pandemic. Built on Targomo’s Location Intelligence platform, the technology allows authorities and hospital operators to identify risk areas and take action before shortages arise. It can be rolled out across nations and applied to other medical capacity questions as well as different areas, such child care facilities, schools and public transport.

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (

Tuesday, 26 May 2020

Royal College of Nursing opens up its information hub

The Royal College of Nursing (RCN), the world’s largest nursing union and professional body, has partnered with digital preservation specialist Preservica to ensure vital medical and clinical guidance is made available online and preserved for its 450,000 members during the COVID-19 pandemic.

The information is critical to supporting front-line NHS nurses, midwives, student and newly qualified nurses, support workers and retired nurses “returning to duty” at this unprecedented time. The initiative is helping reassure RCN staff and senior decision-makers that records documenting decisions and actions of the RCN, as well as advice given to members, are being actively collected. Actions include the RCN lobbying the UK government on the availability of testing and PPE (Personal Protective Equipment) for its members.

Led by the RCN’s archives team, the college has already made more than a thousand historical clinical guidance publications available online through a secure members portal. The very latest information on tackling infectious diseases and a full summary of all UK government advice and statements is available on the RCN website.

The team is also actively capturing and preserving RCN website bulletins related to COVID-19, and working with the RCN’s comms team to harvest testimonials of front-line nurses that have been shared on social media. The aim is to document the contribution of the college and its members for future generations and enable the RCN to supply evidence that demonstrate its role and actions during the pandemic.

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (

Monday, 25 May 2020

Laboratory Techniques with Applicability in Routine Practice

A new book of interest has been published, focusing on key techniques for those working in bioscience laboratories and students. The reference is:

Chesca, A., Abdulina, G. and Sandle, T. (2020) Laboratory Techniques with Applicability in Routine Practice, Lambert Academic Publishing, Mauritius, IBSN 978-620-056942-4

Tim Sandle as contributed two chapters, which are:


Gram-staining remains the fundamental method for determinative bacteriology, dividing bacteria into Gram-positive and Gram-negative organisms. This test provides information as to the origin of any contamination and is a pre-requisite for many microbial identification methods. Despite the longevity of the test, the test is highly reliant upon analyst technique and therefore errors occur. While there are a few studies looking at errors in the clinical context, research has not been extended to the pharmaceutical and healthcare context. In this study, we present a review of over 6,000 Gram-stains and establish an error rate of around 3%, with the most common reason for error being an over-decolourisation step resulting in organisms that should be Gram-positive appearing as Gram-negative. The analysis enables others to benchmark their facilities against.

Sandle, T. (2020) Assessing Gram-stain error rates in the healthcare context. In Chesca, A., Abdulina, G. and Sandle, T. (2020) Laboratory Techniques with Applicability in Routine Practice, Lambert Academic Publishing, Mauritius, pp7-20

With the second chapter, the abstract reads:

In order to improve the efficiency and detectability of disease, and to streamline services, pathology services have been undergoing a digital transformation. Areas of application extend from the automated scanning of slides to the use of artificial intelligence to aid with the interpretation of data. Furthermore, the implementation of digital workflows, which includes integration between systems and software, is key to achieving widespread adoption and driving improvements. This chapter assesses the main changes taking place and looks at the impact upon the workstream of the pathology function. In doing so, the chapter also considers the advantages and disadvantages that such new technology comes with.

The chapter reference is:

Sandle, T. (2020) Advances in pathology services for diagnosing disease. In Chesca, A., Abdulina, G. and Sandle, T. (2020) Laboratory Techniques with Applicability in Routine Practice, Lambert Academic Publishing, Mauritius, pp21-38

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (

Sunday, 24 May 2020

Understanding sepsis - a film about sepsis for young people

To know what sepsis is and recognize the symptoms is important. This film aims to give everyone an understanding of sepsis, but especially young people. The film demonstrates how the body’s immune system works and explains what happens when you get sepsis.

This video comes from the Sewdish Sepsisfonden Sepsisfonden

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (

Saturday, 23 May 2020

Which disinfectants will kill coronavirus?

Human coronaviruses can remain infectious on inanimate surfaces at room temperature for up to 9 days. At a temperature of 30°C or more the duration of persistence is shorter. Surface disinfection with 0.1% sodium hypochlorite or 62–71% ethanol significantly reduces coronavirus infectivity on surfaces within 1 min exposure time. We expect a similar effect against the SARS-CoV-2

In this video, Tim Sandle explains more:

Friday, 22 May 2020

Handwashing in the clinical setting

The importance of handwashing in the clinical setting is demonstrated by 80% of sepsis cases are contracted outside of the hospital (see video below), hand hygiene plays a critical role in the prevention of infections, and therefore the prevention of sepsis.

Consequently, the WHO and the GSA urge all healthcare institutions, all health workers, as well as all policymakers and other stakeholders to address hand hygiene, infection prevention and control, and sepsis holistically as pillars of a coordinated strategy.

There are between 47 and 50 million cases of sepsis every year worldwide, with 11 million deaths per year. 20% of all worldwide deaths per year are associated with sepsis, including many from SARS-CoV-2 / COVID-19.

In May 2017, the World Health Assembly adopted a resolution on improving the prevention, diagnosis, and treatment of sepsis, spearheaded by the Global Sepsis Alliance.

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (

Thursday, 21 May 2020

Is there a relationships between coronavirus and sepsis?

The rapid global spread of the novel coronavirus SARS-CoV-2 has caused societal, economic, and medical upheaval not seen since the 1918 influenza pandemic. As of April 7th, the World Health Organization has confirmed cases in 203 countries, areas or territories, with over 1.2 million confirmed cases and over 65,000 deaths.  Further, many experts believe these numbers to be a gross underestimate for a variety of reasons, including inadequate testing capacity and suboptimal reporting of cases. Despite extensive modeling by epidemiologists all over the world, it is not possible to accurately predict the course and duration of this pandemic. It is important that we continue to obtain objective data on which we base recommendations. A calm and rational approach from both society and individuals is necessary during these uncertain times.

There remains considerable confusion regarding the differences between seasonal influenza and COVID-19 (the illness caused by SARS-CoV-2). While both viruses are capable of causing severe illness and can spread rapidly, it appears that SARS-CoV-2 is a more deadly pathogen on a case-by-case basis, can be spread during the asymptomatic phase, and is capable of much more rapid spread. The higher burden and mortality may be attributed to the fact that SARS-CoV-2 is a “newly emerged” virus, and consequently, there is very little innate immunity to it among humans, unlike with influenza where both prior infection and annual vaccination can provide protection. Overall, however, the sheer contagiousness of this new virus has led to the high morbidity and mortality seen globally – simply put, healthcare systems have been unable to cope with the number of infected persons seeking care. Indeed, a proportion of the reported deaths are due to overwhelmed medical systems rather than the virulence of COVID-19. This is a crucial factor explaining the “flatten the curve” strategy adopted by many countries.

Now that more scientific data are available on COVID-19, the Global Sepsis Alliance can more definitively state that COVID-19 does indeed cause sepsis.

To read more, see: World Sepsis Day

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (

Wednesday, 20 May 2020

Has a second patient been cured of HIV?

A study of the second HIV patient to undergo successful stem cell transplantation from donors with a HIV-resistant gene, finds that there was no active viral infection in the patient's blood 30 months after they stopped anti-retroviral therapy, according to a case report published in The Lancet HIV journal and presented at CROI (Conference on Retroviruses and Opportunistic Infections).

Although there was no active viral infection in the patient's body, remnants of integrated HIV-1 DNA remained in tissue samples, which were also found in the first patient to be cured of HIV. The authors suggest that these can be regarded as so-called 'fossils', as they are unlikely to be capable of reproducing the virus.

Lead author on the study, Professor Ravindra Kumar Gupta, University of Cambridge, UK, says: "We propose that these results represent the second ever case of a patient to be cured of HIV. Our findings show that the success of stem cell transplantation as a cure for HIV, first reported nine years ago in the Berlin patient, can be replicated."

He cautions: "It is important to note that this curative treatment is high-risk, and only used as a last resort for patients with HIV who also have life-threatening haematological malignancies. Therefore, this is not a treatment that would be offered widely to patients with HIV who are on successful antiretroviral treatment.

While most HIV patients can manage the virus with current treatment options and have the possibility of living a long and healthy life, experimental research of this kind following patients who have undergone high-risk, last-resort curative treatments, can provide insight into how a more widely applicable cure might be developed in the future.

See: Evidence for HIV-1 cure after CCR5Δ32/Δ32 allogeneic haemopoietic stem-cell transplantation 30 months post analytical treatment interruption: a case report. The Lancet HIV, 2020; DOI: 10.1016/S2352-3018(20)30069-2

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (

Tuesday, 19 May 2020

4 Types of ELISA with Their Advantages and Disadvantages

ELISA (Enzyme-linked Immunosorbent Assay) is a technique used in labs to measure the levels of antigens or antibodies in biological fluids. ELISA kits are commonly used to analyze plasma, saliva, urine, serum, cell culture supernatants, and lysates of broken-down cells and tissues due to enzymes and viruses.

A guest post by Emma Willson.

There are four different types of ELISA, each with its benefits and drawbacks.

Direct ELISA

A direct ELISA involves immobilizing an antigen to the surface of a microplate (usually a 96-well microplate) and adding only one enzyme-labeled (conjugated) antibody to directly bind to the antigen.

With the addition of a substrate for the enzyme, the antibody creates a signal that shows the level of analytes in the sample.


A straightforward and fast method
No risk of cross-reactivity


Not very specific results due to using only one antibody
Risk of high background reading

Indirect ELISA

An indirect ELISA is very similar to a direct ELISA, but it includes two antibodies. After immobilizing an antigen to the well of a plate, an unconjugated primary antibody is added to bind to the antigen.

The next step involves adding a secondary conjugated antibody to bind to the primary antibody. Then, a substrate is added to trigger a reaction of the enzyme in the secondary antibody that will produce a signal for measuring antigens.


Higher sensitivity due to amplifying the signal with a second antibody
Higher specificity
High flexibility


The secondary antibody increases the risk of cross-reactivity.
Potential cross-reactivity could cause high background noise.

Sandwich ELISA

A sandwich ELISA test also includes adding two antibodies to an antigen sample, to “sandwich” the antigen.

As opposed to direct and indirect ELISA tests, a sandwich ELISA doesn’t immobilize the antigen, but rather one of the two antibodies, or matched antibody pairs.

After immobilizing a capture antibody to the microplate, an antigen is added to bind to it. The next step is binding the antigen by adding a detection antibody, which can be either conjugated or unconjugated.

In case the antibody is unconjugated, a secondary enzyme-labeled detection antibody is used to link to the primary one. Finally, a substrate for the enzyme is added to produce the signal for measurement.


Highest level of sensitivity
Highest specificity due to using two antibodies
High flexibility


Takes more time than any other type of ELISA
Can be more expensive

Competitive ELISA

A competitive ELISA is similar to a sandwich ELISA, except there are no detection antibodies in the test. Instead, an enzyme-labeled antigen is added to a microplate after immobilizing a capture antibody to the surface.

An enzyme-labeled or conjugated antigen then binds to the antigen in the sample. Again, the last step involves adding a substrate for the specific enzyme that will create a signal for measuring the analytes in the sample.

If the signal is weak, it means that the enzyme-labeled antigen binds less to the capture antibody, which means that a high level of analytes is present in the sample.


High sensitivity and flexibility
Ability to measure tiny molecules
Great for measuring immune responses


Using only one antibody means lower specificity
Requires an enzyme-labeled antigen
The most complex ELISA test

ELISA kits are excellent for getting quick and accurate results when measuring antigens in various biological fluids. They’re very easy-to-use and allow for great flexibility, such as adjusting sample volumes to low concentrations of antigens and meeting various other quantitative demands.

Pharmaceutical Microbiology Resources (

Monday, 18 May 2020

Ready for The Count? Back-To-Basics Review Of Microbial Colony Counting

Microbiological laboratories remain reliant on the accurate determination of the number of colony forming units (CFUs) on growth media; this is notwithstanding advances with rapid microbiological methods, at least for some applications. Mainstay methods include pour plates, spread plates, and membrane filtration. Counting of microbes is important as it enables a laboratory to estimate the microbial population in a variety of products (bioburden). Yet there are limitations with plate count methods, including the fact that they only count viable cells and culturable organisms.

Tim Sandle looks at the issue of colony counting from a new perspective, including limitations with the human eye, and with how data integrity can be improved.

The reference is:

Sandle, T. (2020) Ready for The Count? Back-To-Basics Review Of Microbial Colony Counting, Journal of GxP Compliance, 24 (1) :

For details, please contact Tim Sandle

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (

Sunday, 17 May 2020

A natural history!

If you thought the human body was only made of human cells, then think again. What scientists now know is that for every one human cell in a healthy body there are about ten times as many microbial cells, mainly bacteria. There's likely to be several thousand different microbes associated with the human body. This collection of bacterial populations is known as the human microbiome.

In this programme, Paul Evans discovers just what these vast numbers of bacteria and other microscopic organisms are doing inside us, how important they are to our very existence and how they affect our perception of self.

To listen, see: BBC

"When my human body runs for the bus" says Paul "Ten times as many non-human cells hop on too. When I go to sleep, 10 times as many other cells get on with minding my business".

Changes in these communities may be responsible for gum disease, skins diseases, digestive disorders and even obesity and cancer.
But what does all this actually mean and what are the implications for this new found knowledge for what we thought we knew about ourselves . our human self? After all, if we're not all human, then what are we?

With the help of scientists as well as philosophers including Satish Kumar and writer and performer A.L.Kennedy, Paul goes in search of some answers to help understand the human ecology, explore ideas about communities and self, and answer the question, "what am I"? It's a fascinating and unexpected journey which takes him from a busy laboratory in Kings College London Dental Institute to a winter woodland in Devon, and what he discovers is that without our microbes we might not exist at all; we are our microbes. As former Jain Monk, and Fellow of Schumacher College Satish Kumar says "My microbes, therefore I am".

To listen, see: BBC

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (

Saturday, 16 May 2020

Removing the novel coronavirus from the water cycle

Scientists know that coronaviruses, including the SARS-CoV-19 virus responsible for the COVID-19 pandemic, can remain infectious for days -- or even longer -- in sewage and drinking water.

Researchers have called for more testing to determine whether water treatment methods are effective in killing SARS-CoV-19 and coronaviruses in general. The virus can be transported in microscopic water droplets, or aerosols, which enter the air through evaporation or spray.

During a 2003 SARS outbreak in Hong Kong, a sewage leak caused a cluster of cases through aerosolization. Though no known cases of COVID-19 have been caused by sewage leaks, the novel coronavirus is closely related to the one that causes SARS, and infection via this route could be possible.

The novel coronavirus could also colonize biofilms that line drinking water systems, making showerheads a possible source of aerosolized transmission. This transmission pathway is thought to be a major source of exposure to the bacteria that causes Legionnaire's disease, for example.

Fortunately, most water treatment routines are thought to kill or remove coronaviruses effectively in both drinking and wastewater. Oxidation with hypochlorous acid or peracetic acid, and inactivation by ultraviolet irradiation, as well as chlorine, are thought to kill coronaviruses. In wastewater treatment plants that use membrane bioreactors, the synergistic effects of beneficial microorganisms and the physical separation of suspended solids filter out viruses concentrated in the sewage sludge.

The researchers suggest upgrading existing water and wastewater treatment infrastructure in outbreak hot spots, which possibly receive coronavirus from places such as hospitals, community clinics, and nursing homes. For example, energy-efficient, light-emitting, diode-based, ultraviolet point-of-use systems could disinfect water before it enters the public treatment system.

Potable water-reuse systems, which purify wastewater back into tap water, also need thorough investigation for coronavirus removal, and possibly new regulatory standards for disinfection.


Vincenzo Naddeo, Haizhou Liu. Editorial Perspectives: 2019 novel coronavirus (SARS-CoV-2): what is its fate in urban water cycle and how can the water research community respond? Environmental Science: Water Research & Technology, 2020; DOI: 10.1039/d0ew90015j

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (

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