Disclaimer: The information posted here is a summary of current knowledge about this emerging viral pathogen. The state of knowledge will evolve as additional investigation and research is conducted, so continuous review of reputable sources and websites is advised.
Extent of the 2019 Novel Coronavirus Outbreak
This virus is a member of the Coronavirus family. On Feb. 5, 2020, the World Health Organization reported 24,554 cases and 492 deaths in 25 countries worldwide, with the vast majority (24,363 cases and 491 deaths) in China).
The U.S. reported its first confirmed case of person-to-person spread with this virus on Jan. 30, 2020. As of Feb. 5, 2020, there were 11 confirmed cases in the US. The most up-to-date CDC data are available online.
In Canada, five cases of 2019-nCoV have been confirmed as of Feb. 6, 2020. Canadian case numbers are being updated daily by the Public Health Agency of Canada.
Based on the sharp increase in the number of 2019-nCoV infections, on Jan. 30, 2020, the World Health Organization (WHO) declared the current 2019-nCoV outbreak to be a public health emergency of international concern.
Have we seen this virus before? What do we know about its origin?
The 2019-nCoV is a newly identified virus, but it is the seventh Coronavirus known to infect humans. It is in the same Coronavirus family as severe acute respiratory syndrome Coronavirus (SARS-CoV or SARS) and Middle East respiratory syndrome Coronavirus (MERS-CoV or MERS), which caused the two previous Coronavirus outbreaks in 2003 (SARS) and 2012 (MERS).
Since SARS and MERS are from the same family of coronaviruses, they have similar physical and biochemical properties and comparable transmission routes as 2019-nCoV. In the absence of 2019-nCoV specific data, we rely on SARS, MERS, and coronavirus surrogate data to extrapolate, assess, and manage risk. A comparison with these viruses is provided in sections below.
In addition to the seven coronaviruses known to infect humans, many other coronaviruses are known to infect animals. Viruses that infect animals do not normally infect humans and vice versa, but mutations in the viral genetic material can occur naturally and lead to animal-to-person spread, formally known as zoonotic transmission.
Initially, many of the patients in the outbreak in Wuhan reportedly had some link to a large seafood and animal market suggesting animal-to-person spread. Later on, an increasing number of patients with 2019-nCoV had no exposure to animals, indicating person-to-person transmission is occurring.
This has occurred with other Coronaviruses such as SARS and MERS, which originated from animal reservoirs, spread into the human population, and then continued to spread by person-to-person contact. A recent publication links 2019-nCoV to bats. The CDC posts updated information on this topic.
How is 2019-nCoV transmitted, and how contagious is it?
While many questions remain regarding transmission of 2019-nCoV, most often Coronaviruses spread from person-to-person during close contact — about 2 m (6 ft). Person-to-person spread is thought to mainly occur via respiratory droplets produced when an infected person coughs or sneezes, similar to how influenza and other respiratory pathogens spread. These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs. Close contact generally does not include brief interactions, such as walking past a person.
With most respiratory viruses, people are thought to be most contagious when they show symptoms of infection. However, some viruses can be contagious prior to symptoms development, and the 2019-nCoV has been reported to have spread from an asymptomatic infected patient to a close contact.
The rate at which a person can get 2019-nCoV by touching a contaminated surface or object (i.e., fomites) and then touching their own mouth, nose, or possibly their eyes is unclear. We also do not know if viral particles can be aerosolized from water or suspended into the air after settling and remain infective. While such routes can occur for other coronaviruses, current studies of 2019-nCoV transmission routes suggest that spread by respiratory droplets is the primary route, although these studies cannot yet eliminate other routes. These types of studies also suggest that transmission rates of 2019-nCoV currently might be higher than those of SARS and MERS. Scientists have estimated that each person with the new Coronavirus could infect somewhere between 1.5 and 3.5 people without effective containment measures, according to “Early Transmissibility Assessment of a Novel Coronavirus in Wuhan, China,” in the Elsevier SSRN (Social Science Research Network).
Is 2019-nCoV present in wastewater?
Recent information suggests that 2019-nCoV may be transmitted through the fecal-oral route. The virus was detected in patient stool after scientists noticed that some patients infected with the 2019-nCoV virus experienced diarrhea in the early stages of infection instead of a fever, the latter being more common. A recent paper, “First Case of 2019 Novel Coronavirus in the United States,” in the New England Journal of Medicine also confirmed 2019-nCoV detection in feces.
Previous studies investigating persistence of coronavirus surrogates and SARS in wastewater highlight that in the absence of disinfection, the virus can survive in wastewater from hours to days. In 2003, research on SARS had suggested that sewage was implicated in the infection of a cluster of cases in the Amoy Gardens apartment block in Hong Kong.
However, previous work also highlights that SARS can readily be disinfected when chlorine dosing produces a free chlorine residual between 0.2 and 0.5 mg/L for municipal wastewater. While Ebola virus is different, it is reassuring that the article, “Persistence of Ebola Virus in Sterilized Wastewater,” similarly showed that no virus was recovered at doses of 5 and 10 mg/L of chlorine and a 3.5 log reduction was achieved in the presence of free chlorine residual of 0.16 mg/L for 20 seconds. These results imply that standard municipal wastewater system disinfection and hyper (or shock) chlorination practices may be sufficient to eliminate the virus provided utilities monitor free available chlorine during treatment to ensure it has not been depleted.
Chlorine is used extensively in wastewater treatment as a disinfectant due to its effectiveness, low cost, and ease of application. In reality, the chlorine added during treatment has various side reactions and forms chloramines. While researchers have demonstrated reduced microbial inactivation with combined available chlorine compared to free available chlorine, evidence suggests that facilities using a combined chlorine residual of at least 10 mg/L can achieve meaningful coliphage reductions, although these are a virus indicator not specifically coronaviruses. A study examining disinfection of human coronavirus with chloramine T at a concentration of 1,000 mg/L (pH = 8) demonstrated at least 3-log reductions in virus concentrations on surfaces, but additional investigation is needed. Having a robust understanding of treatment facilities’ total, free, and combined chlorine concentrations is crucial for effective control of viral pathogens. Virus inactivation is generally enhanced with ultraviolet (UV) disinfection. Existing disinfection design criteria and regulations were developed to be protective of a broad spectrum of potential pathogens, and the recent coronavirus serves as another example of the importance of this infrastructure for protecting public health.
Wastewater Treatment and 2019-nCoV
Disinfection systems at water resource recovery facilities (WRRFs) and the associated regulatory requirements were developed to be protective of a broad spectrum of potential pathogens. The recent coronavirus serves as another example of the importance of this infrastructure for protecting public health.
On Feb. 5, 2020, the U.S. Occupational Safety and Health Administration (OSHA) released its new wastewater working guidance stating that current disinfection conditions in WRRFs, such as oxidation with hypochlorite or peracetic acid, and inactivation by ultraviolet irradiation, are expected to be sufficient to protect wastewater workers and public health. The recommendation is based on coronavirus disinfection data from healthcare settings and corresponds with OSHA’s position on the susceptibility of coronaviruses to disinfection.
These recommendations are likely to be broadly applicable, although more research may be warranted for disinfectants such as peracetic acid and combined chlorine (chloramines), which have limited data on coronaviruses and which can be less effective against some viruses than bacteria. Although coronaviruses have not been tested, peracetic acid has been found to have some efficacy against other enveloped viruses such as Ebolavirus and Norovirus.
Chlorine is extensively used for wastewater disinfection due to its effectiveness, low cost, and ease of application. It typically reacts with ammonia present in wastewater to form combined chlorine (chloramines), which behaves differently than free chlorine during disinfection; thus, it is important for each facility to understand the chlorine species that are present and their relative abundance within the disinfection process. Evidence suggests that combined chlorine can achieve meaningful coliphage reductions at relatively high doses (10 mg/L) and contact times (2 hours), and that disinfection with ultraviolet (UV) radiation enhances virus inactivation. Additional research could provide reassurance on the effectiveness of wastewater disinfection processes, specifically against coronaviruses and at lower doses and contact times.
Is this virus an occupational health concern to wastewater system workers?
Wastewater treatment and collection system workers are commonly exposed to untreated wastewater that contains disease-causing organisms that could result in an infection. While the risk of infection may increase during some outbreaks, thus requiring additional protective measures for workers, this is not the case for 2019-nCoV based on the new OSHA guidance. These finding are bolstered by what we know about disinfection and persistence of coronaviruses and their surrogates, according to “Efficacy of Various Disinfectants Against SARS Coronavirus.”
WRRF operations should ensure workers follow routine practices to prevent exposure to wastewater, including using the engineering and administrative controls, safe work practices, and PPE normally required for work tasks when handling untreated wastewater. The figure above outlines the hierarchy of controls for wastewater worker protection based on the Occupational Safety and Health Administration (OSHA) recommendations. It is important to communicate that proper PPE use and sound hygiene practices are protective against coronaviruses and other waterborne infectious viruses.
For information specific to protection of workers during infectious disease outbreaks, OSHA has a page dedicated to 2019-nCoV occupational health protection that highlights resources for workers and employers on the evolving Coronavirus situation first identified in Wuhan, China. It also has resources for housekeeping practices that can be helpful and resources for protecting workers during pandemics which apply to office workers.
Should we disinfect surfaces that may have come in contact with untreated wastewater?
For contaminated surfaces to play a role in transmission, respiratory pathogens must be shed into the environment, survive on the surface, be transferred to hands or other objects at concentrations high enough to cause infection (i.e., at an infectious dose) and be transferred to the mouth, nose, or eyes at an infectious dose. Transmission can be interrupted at any of these steps. Therefore, disinfection of PPE, surfaces, and equipment that comes in contact with untreated wastewater can lower risk of infection.
Studies have shown that SARS virus can be inactivated fairly effectively (greater than or equal to 4 log reductions) using common household sanitizers or hand rubs provided recommended contact time and concentrations are used. Similar results were found when investigating common household disinfectants to reduce coronavirus surrogate concentrations. This is consistent with OSHA’s statement on coronaviruses being highly susceptible to inactivation by many commonly used disinfectants.
Resources on Coronavirus
- Hot Topic: Coronavirus
- The Water Professional’s Guide to the 2019 Novel Coronavirus
- How Coronavirus Compares to SARS and MERS?
- Signs and Symptoms of Coronavirus Infection
How Can I Stay Informed?
The organizations below are reputable and reliable sources that are frequently updated.
Occupational Safety and Health Administration (United States Department of Labor)
In an effort to increase transparency and communication, major publishers have created Coronavirus information centers, where relevant and current research is freely available. This includes: Springer Nature, Elsevier and Wiley. Several major journals have done the same, including: The Lancet, New England Journal of Medicine and The British Medical Journal.
How Coronavirus Compares to SARS and MERS
Within the coronavirus family, 2019-nCoV appears to be more easily transmitted but less severe than SARS or MERS.
Like SARS and MERS, 2019-nCoV person to person transmission is not efficient and infects the lower airways making it less transmissible than the flu, which infects the upper respiratory tract and nose.
While 2019-nCoV lab-confirmed case numbers soared from about 50 in China to more than 17,000 in at least 23 countries in 3 weeks, the 9-month SARS outbreak only resulted in 8,098 confirmed cases.
Similarly, MERS had been circulating since 2012 with only about 2,500 known cases. However, the higher number of 2019-nCoV confirmed cases could be due to improved virus detection technologies over recent years.
Although most human Coronavirus infections are typically mild, mortality rates were 10% for SARS and 37% for MERS. In comparison, 2019-nCoV has a much lower estimated mortality rate of 2%, dropping from a high of 4.1 % in Wuhan to approximately 0.17% elsewhere in mainland China. The factors that cause some 2019-nCoV infections to be more severe than others still need to be determined.
How does Coronavirus compare to Ebola?
The Novel Coronavirus is different from the Ebola virus. Ebola virus is a bloodborne, highly infectious, enveloped filovirus. In contrast, SARS and MERS are from the same family of coronaviruses and have similar physical and biochemical properties and comparable transmission routes to 2019-nCoV. In the absence of 2019-nCoV specific data, we rely on SARS, MERS, and other coronavirus surrogate data to extrapolate, assess, and manage risk.
Despite differences between the 2019-nCoV and Ebola, we can adopt many lessons learned from our recent experience with the 2013 to 2016 Ebola outbreak as it relates to risk assessment and risk communication. Table 1 compares what is currently known about the 2019 novel Coronavirus, SARS and Ebola virus.
Table 1. Comparing Ebola, SARS and the novel Coronavirus.
Signs and Symptoms of Coronavirus Infection
A study published by the Lancet reported that as of Jan. 2, 2020 the most common symptoms at the onset of illness were fever [98%], cough [76%], and myalgia, or fatigue [44%]. Less common symptoms were sputum production [28%], headache [8%], haemoptysis (coughing up blood) [5%], and diarrhea [3%].
One distinguishing feature of this Coronavirus infection is dyspnoea or shortness of breath, which has been reported in more than half of patients [55%] (Huang et al., 2020). It can take anywhere from 2 to 14 days for symptoms to develop, according to the U.S. Centers for Disease Control and Prevention.
Treatment or vaccine for the Coronavirus?
There currently are neither vaccines nor direct treatments against the novel Coronavirus. Upon admission to hospitals patients are provided with supportive therapies to help with symptom relief until the immune system can fight the virus.
How can I stay healthy?
Because people of all ages have been infected by 2019-nCoV, the WHO advises everyone to take proper infection control precautions. The best way to prevent infection is to avoid being exposed to this virus. However, as a reminder, CDC always recommends everyday preventive actions to help prevent the spread of respiratory viruses, including:
- Stay informed!
- Wash your hands often with soap and water for at least 20 seconds.
- If soap and water are not available, use an alcohol-based hand sanitizer with at least 60% alcohol content.
- Avoid touching your eyes, nose, and mouth with unwashed hands.
- Avoid close contact with people who are sick.
- Stay home when you are sick.
- Cover your cough or sneeze (ideally with a disposable tissue).
- Clean and disinfect frequently touched objects and surfaces.
- Do not place your personal belongings on the floor or on surfaces that may be contaminated.
What should you do if you think you are infected?
If you feel sick with fever, cough, have difficulty breathing, and have traveled to China or were in close contact with someone with 2019-nCoV in the 14 days before you began to feel sick, seek medical care immediately. Before you go to a doctor’s office or emergency room, call ahead and tell them about your recent travel and your symptoms.
Authors (placed at end of each article before the flipper)
This article was prepared by the WEF Disinfection and Public Health Committee’s (DPHC) Waterborne Infectious Disease Outbreak Control (WIDOC) Working Group. Rasha Maal-Bared is the Senior Microbiologist at EPCOR Water Services Inc. (Edmonton, Canada) and the current chair of the Waterborne Infection Disease Outbreak Control Working Group. Robert Bastian is a senior environmental scientist at the U.S. Environmental Protection Agency. Kyle Bibby is an Associate Professor and the Wanzek Collegiate Chair in the Department of Civil and Environmental Engineering and Earth Sciences at the University of Notre Dame (Notre Dame, IN). Kari Brisolara is the Associate Dean for Academic Affairs and an Associate Professor of Environmental and Occupational Health Sciences at the Louisiana State University Health Sciences Center (New Orleans, LA). Lee Gary is an Adjunct Professor at Tulane University, an instructor with the Basic Academy at the FEMA/Emergency Management Institute (Emmitsburg, Md.) and the owner and CEO of Strategic Management Services (New Orleans). Chuck Gerba is a professor of epidemiology and biostatistics in the Dept of Environmental Science at the University of Arizona and a supporting member of the WIDOC working group. Lola Olabode is a Program Director at the Water Research Foundation and an expert in risk management during outbreaks (Washington, DC). Naoko Munakata is a Supervising Engineer at the Los Angeles County Sanitation Districts. Robert S. Reimers is a Professor Emeritus at Tulane University’s School of Public Health and Tropical Medicine, the Director of Asepticys Inc. (New Orleans). Albert Rubin is a professor emeritus at North Carolina State University in the Dep of Biological and Agricultural Engineering. Scott Schaefer is the Wastewater Practice Leader with AE2S (Saint Joseph, Minn.) and the Chair of the WEF Disinfection and Public Health Committee. Samendra Sherchan is an Assistant Professor at the Tulane School of Public Health and Tropical Medicine (New Orleans, LA). Jay Swift is a Principal Engineer with Gray and Osborne (Seattle, Wash.).
The authors would like to thank Matthew Arduino (CDC, DDID), Christopher K. Brown (OSHA), Matthew Magnuson (U.S. EPA), Jonathan Yoder (CDC, DDID), and Jill Shugart (CDC, NIOSH) for their comments and feedback. (Note: The conclusions, findings, and opinions expressed by the authors contributing to this piece do not reflect the official position of OSHA, the Centers for Disease Control and Prevention, or the authors’ affiliated institutions.)