Meta-Analysis of COVID-19 Spread in Meat Processing Plants and Recommended Practical Actions

Recently, the spread of the coronavirus disease 2019 (COVID-19) has increased among workers of meat processing plants (MPPs) around the world. This study reviewed the possible routes of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission and useful actions against it in slaughterhouses. The results revealed that the main factors for the spread of the virus included low indoor temperature, crowded area, wrong standing along production lines, contamination of high-touch surfaces, difficult education of workers with diverse native languages, low financial income, large MPPs with over 10 million Ib of packed meat per month, higher speed of production lines with 175 birds/minute, temporary contract of the workers, and weak approach of some meat processing companies against COVID-19 infection such as National Beef. COVID-19 transmission rate was 24 times higher among the workers of MPPs than among the population of the US. The practical actions against the spread of the virus were mainly marker using for remembering the previous location, mandatory mask use, especially FFP2/3 masks, and decentralization of large MPPs. By using the results of this study, slaughterhouse managers would be able to significantly control the spread of SARS-CoV-2 and future bio-threats to workers of MPPs and even to society. © 2022 The Author(s);.

Research progress on transmission routes of COVID-19

The COVID-19 (SARS-CoV-2) pandemic has become an urgent issue and attracted extensive attention all over the world due to its strong infectivity and high mortality. The outbreak of COVID-19 has a negative impact on the development of the world economy, brought inconvenience to people's daily life and threatened our health safety. Considering the global spread of COVID-19 disease with the tremendous number of infections and also deaths, understanding the transmission modes of this virus to formulate effective prevention and control strategies is of vital importance. This paper reviews three main transmission routes (contact, droplet and aerosol) and three possible transmission routes (maternal-infant, fecal-oral and cross-species) of COVID-19, which has reference value and guiding significance for the prevention and control of COVID-19 in the future. © 2022 ACM.

Is the virus-laden standing water change the transmission intensity of SARS-CoV-2 after precipitation? A framework for empirical studies.

Understanding the relationship between precipitation and SARS-CoV-2 is significant for combating COVID-19 in the wet season. However, the causes for the variation of SARS-CoV-2 transmission intensity after precipitation is unclear. Starting from "the Zhengzhou event," we found that the virus-laden standing water formed after precipitation might trigger some additional routes for SARS-CoV-2 transmission and thus change the transmission intensity of SARS-CoV-2. Then, we developed an interdisciplinary framework to examine whether the health risk related to the virus-laden standing water needs to be a concern. The framework enables the comparison of the instant and lag effects of precipitation on the transmission intensity of SARS-CoV-2 between city clusters with different formation risks of the virus-laden standing water. Based on the city-level data of China between January 01, 2020, and December 31, 2021, we conducted an empirical study. The result showed that in the cities with a high formation risk of the virus-laden standing water, heavy rain increased the instant transmission intensity of SARS-CoV-2 by 6.2% (95%CI: 4.85-10.2%), while in the other cities, precipitation was uninfluential to SARS-CoV-2 transmission, revealing that the health risk of the virus-laden standing water should not be underestimated during the COVID-19 pandemic. To reduce the relevant risk, virus-laden water control and proper disinfection are feasible response strategies.

Possible transmission of viruses from contaminated human feces and sewage: Implications for SARS-CoV-2.

Humanity has experienced outbreaks by viruses such as severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) in 2003, Eastern respiratory syndrome coronavirus (MERS-CoV) in 2012, Ebola virus in 2014 and nowadays SARS-CoV-2. While clinicians seek for a vaccine to reduce the epidemic outbreak, environmental engineers need to understand consequence of virus entity in sewage given the reported persistency of viruses in human feces and sewage environments for more than days. Herein, we discuss about concerns associated with virus occurrence in human feces and sewage, with attention to the possible SARS-CoV-2 transmission routes, based on the review of recent studies on SARS-CoV-2 as well as the previous pandemic events. Given the reported environmental stability of coronavirus, the feces- and sewage-derived transmission routes may be of importance to prevent unprecedented spread of coronavirus disease 2019 (COVID-19) particularly in developing countries. However, so far, limited number of studies detected infectious SARS-CoV-2 even in human feces, whereas a number of virus RNA copies were identified in both feces and sewage specimens. Therefore, uncertainty remains in the possibility of this transmission pathway, and further investigation is warranted in future studies, for example, by increasing the number of specimens, examining the effectiveness of methods for viral viability test, considering the patient medical history, and so forth.

Construction and stochastic scale-free modelling of empirical, global, index-case SARS-CoV-2 transmission network

First reported in Wuhan, the novel coronavirus disease (COVID-19), caused by severe acute respiratory syndrome 2 (SARS-CoV-2) has astonished health-care systems across the globe due to its rapid and simultaneous spread to the neighbouring and distantly located countries. We constructed the first, global, spatio-temporal, index-case transmission network of SARS-CoV-2 or C19-TraNet consisting of 185 nodes and 196 edges, by manually curating their travel history information that allowed us to map multiple virus invasion routes, both short- as well as long-range, into different geographical locations. To model the growing C19-TraNet, a novel stochastic scale-free (SSF) algorithm is proposed that accounts for stochastic addition of both nodes as well as edges at each time step. C19-TraNet is characterized by a fourth-order polynomial growth of average connectivity having two growth phases, namely, a Chinese and a European wave separated by a stagnation phase that delayed overall growth by 51 days, compared to 1000 corresponding SSF models. Its community structure reveals a heterogeneous grouping of countries, from different WHO regions, suggesting easy invasion of SARS-CoV-2 to susceptible populations through short- as well as long-range transmission. Border control measures initially diminished Chinese wave, however, lack of coordinated actions, multiple transmission routes transported SARS-CoV-2 to remaining countries.

A review on detection of SARS-CoV-2 RNA in wastewater in light of the current knowledge of treatment process for removal of viral fragments.

The entire globe is affected by the novel disease of coronavirus 2019 (COVID-19 or 2019-nCoV), which is formally recognised as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The World Health Organisation (WHO) announced this disease as a global pandemic. The presence of SARS-CoV-2 RNA in unprocessed wastewater has become a cause of worry due to these emerging pathogens in the process of wastewater treatment, as reported in the present study. This analysis intends to interpret the fate, environmental factors and route of transmission of SARS-CoV-2, along with its eradication by treating the wastewater for controlling and preventing its further spread. Different recovery estimations of the virus have been depicted by the detection of SARS-CoV-2 RNA in wastewater through the viral concentration techniques. Most frequently used viral concentration techniques include polyethylene glycol (PEG) precipitation, ultrafiltration, electronegative membrane, and ultracentrifugation, after which the detection and quantification of SARS-CoV-2 RNA are done in wastewater samples through quantitative reverse transcription-polymerase chain reaction (RT-qPCR). The wastewater treatment plant (WWTP) holds the key responsibility of eliminating pathogens prior to the discharge of wastewater into surface water bodies. The removal of SARS-CoV-2 RNA at the treatment stage is dependent on the operations of wastewater treatment systems during the outbreak of the virus; particularly, in the urban and extensively populated regions. Efficient primary, secondary and tertiary methods of wastewater treatment and disinfection can reduce or inactivate SARS-CoV-2 RNA before being drained out. Nonetheless, further studies regarding COVID-19-related disinfectants, environment conditions and viral concentrations in each treatment procedure, implications on the environment and regular monitoring of transmission need to be done urgently. Hence, monitoring the SARS-CoV-2 RNA in samples of wastewater under the procedure of wastewater-based epidemiology (WBE) supplement the real-time data pertaining to the investigation of the COVID-19 pandemic in the community, regional and national levels.

A critical assessment of the potential vertical transmission hypotheses: Implications for research on the early-life infection with COVID-19.

The risk of potential vertical transmission in SARS-CoV-2 infected pregnant women is currently a topic of debate. To explore the correlation between the two, we searched PubMed, Embase®, and Web of Science for studies on vertical transmission of COVID-19. The quality of the studies was evaluated by the Cochrane risk of bias tool. Detailed information of each included case including methods of delivery, protection measures for mothers and neonates at birth, types of specimens, inspection time, results of testing and feeding patterns was collected to assess the possibility of vertical transmission. The results showed that of the 390 neonates reported in 36 studies, 23 were infected with SARS-CoV-2 by potential vertical transmission. From the perspective of virology and pathology, vertical transmission of SARS-CoV-2 was possible via uterus or breastmilk. Some reported potential vertically transmitted neonates could be attributed to horizontal transmission. It is extremely vital to fully elucidate the potential routes of transmission of SARS-CoV-2, implicating clinical practice and nursing to reduce the risk of not only horizontal transmission but also vertical transmission, thus protecting neonates from COVID-19 infection.

A mixed-methods approach to elucidate SARS-CoV-2 transmission routes and clustering in outbreaks in native workers and labour migrants in the fruit and vegetable packaging industry in South Holland, the Netherlands, May to July 2020.

OBJECTIVES: To obtain insight into SARS-CoV-2 clustering and transmission routes during outbreaks in the predominantly migrant workforce of the fruit and vegetable packaging industry of South Holland, the Netherlands, May to July 2020. DESIGN: This mixed-methods study applied direct observation and interviews, epidemiologic investigation, source and contact data analysis and whole-genome sequencing. RESULTS: We detected 46 SARS-CoV-2 cases and 4 outbreaks with a proportional representation of labour migrant and native workers in 6 unrelated facilities. Complete viral genome sequences revealed at least 3 clusters of native workers and labour migrants, 2 within and 1 between facilities. On-site inspections found adequate implementation of preventative measures to which both native workers and labour migrants showed suboptimal adherence. Being a labour migrant was associated with living in shared housing, but not with more contacts or different sources. CONCLUSIONS: The fruit and vegetable packaging industry gave the impression of sufficient preparedness and control. Suboptimal adherence to the facilities' preventative guidelines could have facilitated work floor transmission. Community and household transmission are likely to have contributed to outbreaks. We encourage further research into risk factors for transmission in labour migrants and application of these insights into targeted public health policy.

Estimation of the SARS-CoV-2 transmission probability in confined traffic space and evaluation of the mitigation strategies.

Public transport is a fundamental service for the resumption of work and production, but the enclosed environment and dense population create very favorable conditions for the spread of epidemic infections. Thus, effective public health interventions are urgently introduced. The objective of this paper is to quantitatively estimate the SARS-CoV-2 transmission probability and evaluate the influence of environmental parameters and individual intervention on the epidemic prevention. For this purpose, (1) we estimate the virus emission rate with Diamond Princess Cruise Ship infection data by Monte Carlo simulation and the improved Wells-Riley model, and (2) employ the reproductive number R to quantify diverse mitigation strategies. Different determinants are examined such as the duration of exposure, the number of passengers combined with individual interventions such as mask type and mask-wearing rate. The results show that the SARS-CoV-2 quantum generation rate is 185.63. The R shows a stronger positive correlation with the exposure time comparing to the number of passengers. In this light, reducing the frequency of long-distance journeys on crowded public transportation may be required to reduce the spread of the virus during the pandemic. N95 mask and surgical mask can reduce the transmission risk by 97 and 84%, respectively, and even homemade mask can reduce the risk by 67%, which indicates that it is necessary to advocate wearing masks on public transportation.

Multiple relationships between aerosol and COVID-19: A framework for global studies.

COVID-19 (Corona Virus Disease 2019) is a severe respiratory syndrome currently causing a human global pandemic. The original virus, along with newer variants, is highly transmissible. Aerosols are a multiphase system consisting of the atmosphere with suspended solid and liquid particles, which can carry toxic and harmful substances; especially the liquid components. The degree to which aerosols can carry the virus and cause COVID-19 disease is of significant research importance. In this study, we have discussed aerosol transmission as the pathway of SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2), and the aerosol pollution reduction as a consequence of the COVID-19 lockdown. The aerosol transmission routes of the SARS-CoV-2 can be further subdivided into proximal human-exhaled aerosol transmission and potentially more distal ambient aerosol transmission. The human-exhaled aerosol transmission is a direct dispersion of the SARS-CoV-2. The ambient aerosol transmission is an indirect dispersion of the SARS-CoV-2 in which the aerosol acts as a carrier to spread the virus. This indirect dispersion can also stimulate the up-regulation of the expression of SARS-CoV-2 receptor ACE-2 (Angiotensin Converting Enzyme 2) and protease TMPRSS2 (Transmembrane Serine Protease 2), thereby increasing the incidence and mortality of COVID-19. From the aerosol quality data around the World, it can be seen that often atmospheric pollution has significantly decreased due to factors such as the reduction of traffic, industry, cooking and coal-burning emissions during the COVID-19 lockdown. The airborne transmission potential of SARS-CoV-2, the infectivity of the virus in ambient aerosols, and the reduction of aerosol pollution levels due to the lockdowns are crucial research subjects.

Transmission and prevention of SARS-CoV-2.

The coronavirus disease 2019 (COVID-19), caused by a novel virus of the ß-coronavirus genus (SARS-CoV-2), has been spreading globally. As of July 2020, there have been more than 17 million cases worldwide. Determining multiple transmission routes of SARS-CoV-2 is critical to improving safety practices for the public and stemming the spread of SARS-CoV-2 effectively. This article mainly focuses on published studies on the transmission routes of SARS-CoV-2 including contact transmission, droplet transmission, aerosol transmission and fecal-oral transmission, as well as related research approaches, such as epidemiological investigations, environmental sampling in hospitals and laboratories and animal models. We also provide four specific recommendations for the prevention and control of SARS-CoV-2 that may help reduce the risk of SARS-CoV-2 infection under different environmental conditions. First, social distancing, rational use of face masks and respirators, eye protection, and hand disinfection for medical staff and the general public deserve further attention and promotion. Second, aerodynamic characteristics, such as size distribution, release regularity, aerosol diffusion, survival and decline, infectious dose and spread distance, still require further investigation in order to identify the transmissibility of COVID-19. Third, background monitoring of the distribution of pathogenic microorganisms and environmental disinfection in crowded public places, such as railway stations, schools, hospitals and other densely populated areas, can give early warning of outbreaks and curb the transmission routes of SARS-CoV-2 in those high-risk areas. Forth, establishing novel predictive models can help us to not only assess transmission and impacts in communities, but also better implement corresponding emergency response measures.

Sars-Cov-2 in children - insights and conclusions from the mandatory reporting data in Frankfurt am Main, Germany, March-July 2020.

Introduction: From the beginning of the corona pandemic until August 19, 2020, more than 21,989,366 cases have been reported worldwide - 228,495 in Germany alone, including 12,648 children aged 0-14. In many countries, the proportion of infected children in the total population is comparatively low; in addition, children often have no or milder symptoms and are less likely to transmit the pathogen to adults than the other way round. Based on the registration data in Frankfurt am Main, Germany, the symptoms of children in comparison with adults and the likely routes of transmission are presented below. Materials and methods: The documentation of the mandatory reports includes personal data (name, date of birth, gender, place of residence), disease characteristics (date of report, date of onset of the disease, symptoms), possible contact persons (family, others) and i.a. possible activity or care in children's community facilities. All reports were viewed, especially with regard to likely transmission routes. Results: From March 1 to July 31, 2020, 1,977 infected people were reported, including 138 children between the ages of 0 and 14 years. Children had fewer and milder symptoms than adults. None of the children experienced severe respiratory symptoms or the need for ventilation. 62% of the children had no symptoms at all (19% adults), 5% of the children were hospitalized (24% adults), and none of the children died (3.8% adults). After excluding a cluster of 34 children from refugee accommodations and 14 children from a parish, 78% of the remaining 90 children had been infected by an adult within the family, and only 4% were likely to have a reverse transmission route. In 5.5% of cases, transmission in a community facility was likely. Discussion: The results of the registration data from Frankfurt am Main, Germany confirm the results published in other countries: Children are less likely to become infected, and if infected, their symptoms are less severe than in adults, and they are apparently not the main drivers of virus transmission. Therefore, scientific medical associations strongly recommend reopening schools.

Transmission routes for SARS-CoV-2 infection: review of evidence.

There is no specific treatment for SARS-CoV-2, and all infection control strategies are based on breaking the transmission chain of virus. The high transmission rate of SARS-CoV-2 has raised many questions about the possible routes of infection transmission. Due to uncertainty of the main transmission routes, the infection control policies faced with more challenges. The possible main route of transmission is thought to be the close contact and respiratory droplets. Therefore, it is necessary to maintain physical distance and using the face mask. Another routes of transmission are through contaminated surfaces as well as airborne, fecal-oral transmission.

Managing emerging challenges of Coronavirus disease 2019 (COVID-19) in dentistry.

Dental centers have been referred to as a hub or reservoir for infection, where healthcare professionals and other staff, patients and the public together may potentially spread pathogenic microorganisms. This may occur via saliva, skin or indirectly through air, water, and contaminated surfaces or instruments. Everyone should therefore be considered as potential sources of infection. During a pandemic, limiting unnecessary care has been adopted as a clinical measure for some patient's, to reduce the risk of cross-infection in the short term. However, in order to enable continuation of necessary and qualified care, dental processes need to follow specific infection control strategies in order to prevent transmission of emerging pandemic risks following COVID-19. In this article, we develop a tool with practical recommendations to mitigate infection risks before, during and following pandemics to enable ongoing dental care provision in primary and secondary care based on national and global recommendations.

Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 via Close Contact and Respiratory Droplets Among Human Angiotensin-Converting Enzyme 2 Mice.

We simulated 3 transmission modes, including close-contact, respiratory droplets and aerosol routes, in the laboratory. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be highly transmitted among naive human angiotensin-converting enzyme 2 (hACE2) mice via close contact because 7 of 13 naive hACE2 mice were SARS-CoV-2 antibody seropositive 14 days after being introduced into the same cage with 3 infected-hACE2 mice. For respiratory droplets, SARS-CoV-2 antibodies from 3 of 10 naive hACE2 mice showed seropositivity 14 days after introduction into the same cage with 3 infected-hACE2 mice, separated by grids. In addition, hACE2 mice cannot be experimentally infected via aerosol inoculation until continued up to 25 minutes with high viral concentrations.

Transmission Routes Analysis of SARS-CoV-2: A Systematic Review and Case Report.

The global outbreak of SARS-CoV-2 spread rapidly throughout the world which transmitted among humans through various routes. Asymptomatic (carriers) and possible fecal-oral transmission, resulted into a large-scale spread. These issues pose great challenges to disease diagnosis and epidemic control. We obtained data on 29 cases of COVID-19 patients in Jinan, China, and reported the clinical data of asymptomatic patients confirmed with stool samples positive. Some patients with gastrointestinal infections are secondary to pulmonary infections, and during the patients' recovery period, the virus may still existin the patient's gastrointestinal tract over 7 days. We combined with epidemiological and clinical data of asymptomatic patients to analyze the possible routes of viral transmission and infection, including eyes-nose, hands-eyes, fecal-oral, and eyes-oral, et al., thus first presented the two-way transmission through eyes-oral. Through associating infection symptoms with the transmission routes of virus and the patient course of the disease, we expect to provide guidelines for clinical diagnosis and the basis for suppressing the spread of the virus and antiviral treatment.