Transmission Of SARS-CoV2 Research Articles

Modelling SARS-COV2 Spread in London: Approaches to Lift the Lockdown

ObjectiveTo use mathematical models to predict the epidemiological impact of lifting the lockdown in London, UK, and alternative strategies to help inform policy in the UK. MethodsA mathematical model for the transmission of SARS-CoV2 in London. The model was parametrised using data on notified cases, deaths, contacts, and mobility to analyse the epidemic in the UK capital. We investigated the impact of multiple non pharmaceutical interventions (NPIs) and combinations of these measures on future incidence of COVID-19. ResultsImmediate action at the early stages of an epidemic in the affected districts would have tackled spread. While an extended lockdown is highly effective, other measures such as shielding older populations, universal testing and facemasks can all potentially contribute to a reduction of infections and deaths. However, based on current evidence it seems unlikely they will be as effective as continued lockdown. In order to achieve elimination and lift lockdown within 5 months, the best strategy seems to be a combination of weekly universal testing, contact tracing and use of facemasks, with concurrent lockdown. This approach could potentially reduce deaths by 48% compared with continued lockdown alone. ConclusionsA combination of NPIs such as universal testing, contact tracing and mask use while under lockdown would be associated with least deaths and infections. This approach would require high uptake and sustained local effort but it is potentially feasible as may lead to elimination in a relatively short time scale.

Evidence and possible mechanisms of rare maternal-fetal transmission of SARS-CoV-2.

While SARS-CoV-2 infection has spread rapidly worldwide, data remains scarce about the natural history of infection in pregnant women and the risk of mother-to-fetal transmission. Current data indicates that viral RNA levels in maternal blood are low and there is no evidence of placental infection with SARS-CoV-2. Published reports to date suggest that perinatal transmission of SARSCoV- 2 can occur but is rare. Among 179 newborns tested for SARS-CoV2 at birth from mothers with COVID-19, transmission was suspected in 8 cases, 5 with positive nasopharyngeal SARS-CoV-2 RT-PCR and 3 with SARS-CoV-2 IgM. However, these cases arise from maternal infection close to childbirth and there are no information about exposition during first or second trimester of pregnancy. Welldesigned prospective cohort studies with rigorous judgement criteria are needed to determine the incidence and risk factors for perinatal transmission of SARS-CoV-2.

SARS-CoV-2 detection in patients with influenza-like illness.

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first reported in Wuhan, Hubei Province, China in late December 2019. We re-analysed 640 throat swabs collected from patients in Wuhan with influenza-like-illness from 6 October 2019 to 21 January 2020 and found that 9 of the 640 throat swabs were positive for SARS-CoV-2 RNA by quantitative PCR, suggesting community transmission of SARS-CoV2 in Wuhan in early January 2020.

Airborne Transmission Route of COVID-19: Why 2 Meters/6 Feet of Inter-Personal Distance Could Not Be Enough

The COVID-19 pandemic caused the shutdown of entire nations all over the world. In addition to mobility restrictions of people, the World Health Organization and the Governments have prescribed maintaining an inter-personal distance of 1.5 or 2 m (about 6 feet) from each other in order to minimize the risk of contagion through the droplets that we usually disseminate around us from nose and mouth. However, recently published studies support the hypothesis of virus transmission over a distance of 2 m from an infected person. Researchers have proved the higher aerosol and surface stability of SARS-COV-2 as compared with SARS-COV-1 (with the virus remaining viable and infectious in aerosol for hours) and that airborne transmission of SARS-CoV can occur besides close-distance contacts. Indeed, there is reasonable evidence about the possibility of SARS-COV-2 airborne transmission due to its persistence into aerosol droplets in a viable and infectious form. Based on the available knowledge and epidemiological observations, it is plausible that small particles containing the virus may diffuse in indoor environments covering distances up to 10 m from the emission sources, thus representing a kind of aerosol transmission. On-field studies carried out inside Wuhan Hospitals showed the presence of SARS-COV-2 RNA in air samples collected in the hospitals and also in the surroundings, leading to the conclusion that the airborne route has to be considered an important pathway for viral diffusion. Similar findings are reported in analyses concerning air samples collected at the Nebraska University Hospital. On March 16th, we have released a Position Paper emphasizing the airborne route as a possible additional factor for interpreting the anomalous COVID-19 outbreaks in northern Italy, ranked as one of the most polluted areas in Europe and characterized by high particulate matter (PM) concentrations. The available information on the SARS-COV-2 spreading supports the hypothesis of airborne diffusion of infected droplets from person to person at a distance greater than two meters (6 feet). The inter-personal distance of 2 m can be reasonably considered as an effective protection only if everybody wears face masks in daily life activities.

The Role of Age Distribution and Family Structure on COVID-19 Dynamics: A Preliminary Modeling Assessment for Hubei and Lombardy

As the COVID-19 pandemic continues, formulating targeted policy interventions that are informed by differential SARS-CoV2 transmission dynamics will be of vital importance to national and regional governments. We develop an individual-level model for SARS-CoV2 transmission that accounts for location-dependent distributions of age, household structure, and comorbidities. We use these distributions together with age-stratified contact matrices to instantiate specific models for Hubei, China; Lombardy, Italy; and New York City, United States. Using data on reported deaths to obtain a posterior distribution over unknown parameters, we infer differences in the progression of the epidemic in the three locations. We also examine the role of transmission due to particular age groups on total infections and deaths. The effect of limiting contacts by a particular age group varies by location, indicating that strategies to reduce transmission should be tailored based on population-specific demography and social structure. These findings highlight the role of between-population variation in formulating policy interventions. Across the three populations though, we find that targeted “salutary sheltering" by 50% of a single age group may substantially curtail transmission when combined with the adoption of physical distancing measures by the rest of the population. Code may be found at https://github.com/bwilder0/covid_abm_release.

Coronavirus Disease 2019: Coronaviruses and Blood Safety.

With the outbreak of unknown pneumonia in Wuhan, China, in December 2019, a new coronavirus, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), aroused the attention of the entire world. The current outbreak of infections with SARS-CoV-2 is termed Coronavirus Disease 2019 (COVID-19). The World Health Organization declared COVID-19 in China as a Public Health Emergency of International Concern. Two other coronavirus infections—SARS in 2002-2003 and Middle East Respiratory Syndrome (MERS) in 2012—both caused severe respiratory syndrome in humans. All 3 of these emerging infectious diseases leading to a global spread are caused by β-coronaviruses. Although coronaviruses usually infect the upper or lower respiratory tract, viral shedding in plasma or serum is common. Therefore, there is still a theoretical risk of transmission of coronaviruses through the transfusion of labile blood products. Because more and more asymptomatic infections are being found among COVID-19 cases, considerations of blood safety and coronaviruses have arisen especially in endemic areas. In this review, we detail current evidence and understanding of the transmission of SARS-CoV, MERS–CoV, and SARS-CoV-2 through blood products as of February 10, 2020, and also discuss pathogen inactivation methods on coronaviruses.

Knowledge regarding Infection Prevention and Control guidelines during COVID 19 pandemic among health care workers in tertiary care hospital.

Background The COVID-19 pandemic has taken tragic proportions and has disrupted lives globally. Understanding the risks associated with severe acute respiratory syndrome corona virus 2 SARSCoV-2 transmission during health care delivery and assessing mitigation strategies for hospitals to improve patient safety and access to health care is crucial. Guidelines for triage governmental guidelines for use of personal protective equipment PPE from doctorrsquos point of view precautions to be taken in the OPD and operating room as well as care of various equipments in the meanwhile the role of waste management sector in the hospitals also play an important role in ensuring unusual heaps of waste generated in hospitals during this pandemic thus controlling the spread of COVID19 infection. All these should be assessed to see if standard infection control practices and waste management protocol are being followed properly.Objective To assess knowledge among healthcare workerspostgraduates and interns about infection control in Victoria hospital during COVID-19 pandemic.Methodology It was an online cross-sectional survey among 80 healthcare workers in Victoria hospital in Bengaluru. A pre-tested semi structured self-administered questionnaire was used.Results More than half of the respondents reported being screened daily for temperature monitoring before entering the hospital premises. Only few reported that they were confused about the right sequence of donning and doffing of PPE kit.Conclusion Repeated training of the health care staff is very crucial for proper implementation of infection control practices and biomedical waste management.nbsp

NOVEL CORONAVIRUS: A RECENT OUT BREAK

The novel Coronavirus was recognised as causative pathogen of coronavirus outbreak in 2020. First case reported in Wuhan. Phylogenetic analysis suggests that an animal sold at seafood market is the host of new virus. Thousands of people already contracted with new coronavirus. The WHO declared the outbreak “public health emergency of international concern”. Coronavirus belongs to large family of virus which are zoonotic in nature. Signs of infection by this virus: respiratory diseases, fever, cough, dyspnoea, headache, hypoxemia, pneumonia, sore throat. Mode of transmission of SARS-CoV [2002] & MERS-CoV [2012] was by cat and dromedary camels. Coronavirus is causing severe acute respiratory syndrome indicated by elevated levels of aminotransferase and lymphopenia; alveolar damage can occur. Etiologic agents of respiratory diseases are human coronavirus: HKUI & HCOU-NL63 and for common cold, it is coronavirus OC43 & 229E. Murine coronavirus exhibit various levels of virulence and tropisms. Antibody & cell mediated responses needed for its prevention. Porcine coronavirus are cause of viral enteritis & foetal diarrhoea. The coronavirus spike protein- mediators cell-cell transmission. 1) Spike cleaves by proteases. 2) then enter cells by plasma membrane route. 3) finally replicate to particular cell based on ability to bind with receptors [2019 n-CoV – can bind to ACE-II receptors]. The demographic states: male: female sex ratio is 2.7-1 and age range 1-76 among the infected. Prevention include: regular hand washing, cover mouth while coughing, thoroughly cook meat and egg. The company Reckitt & Benckiser says that Dettol can kill some CoV strains.

Bilio-pancreatic endoscopy during COVID-19 pandemic

On 31 December 2019, the WHO China Country Office was informed of cases of pneumonia of unknown etiology detected in Wuhan (Hubei Province of China). In January 2020, a new coronavirus named SARS-CoV2 was isolated and, since that time, SARS-CoV2 related disease (COVID-19) rapidly spread all over the world becoming pandemic in March 2020. The COVID-19 outbreak dramatically affected the public-health and the health-care facilities organization. Bilio-pancreatic endoscopy is considered a high-risk procedure for cross-contamination and, even though it is not directly involved in COVID-19 diagnosis and management, its reorganization is crucial to guarantee high standards of care minimizing the risk of SARS-CoV2 transmission among patients and health-care providers. Bilio-pancreatic endoscopic procedures often require a short physical distance between the endoscopist and the patient for a long period of time, a frequent exchange of devices, the involvement of a large number of personnel, the use of complex endoscopes difficult to reprocess. On this basis, endoscopic units should take precautions with adjusted management of bilio-pancreatic endoscopy. The aim of this article is to discuss the approach to bilio-pancreatic endoscopy in the COVID-19 era with focus on diagnostic algorithms, indications, management of the endoscopic room, proper use of Personal Protective Equipment and correct reprocessing of instrumentation.

Risk Factors for SARS Transmission from Patients Requiring Intubation: A Multicentre Investigation in Toronto, Canada

BackgroundIn the 2003 Toronto SARS outbreak, SARS-CoV was transmitted in hospitals despite adherence to infection control procedures. Considerable controversy resulted regarding which procedures and behaviours were associated with the greatest risk of SARS-CoV transmission.MethodsA retrospective cohort study was conducted to identify risk factors for transmission of SARS-CoV during intubation from laboratory confirmed SARS patients to HCWs involved in their care. All SARS patients requiring intubation during the Toronto outbreak were identified. All HCWs who provided care to intubated SARS patients during treatment or transportation and who entered a patient room or had direct patient contact from 24 hours before to 4 hours after intubation were eligible for this study. Data was collected on patients by chart review and on HCWs by interviewer-administered questionnaire. Generalized estimating equation (GEE) logistic regression models and classification and regression trees (CART) were used to identify risk factors for SARS transmission.Results45 laboratory-confirmed intubated SARS patients were identified. Of the 697 HCWs involved in their care, 624 (90%) participated in the study. SARS-CoV was transmitted to 26 HCWs from 7 patients; 21 HCWs were infected by 3 patients. In multivariate GEE logistic regression models, presence in the room during fiberoptic intubation (OR = 2.79, p = .004) or ECG (OR = 3.52, p = .002), unprotected eye contact with secretions (OR = 7.34, p = .001), patient APACHE II score ≥20 (OR = 17.05, p = .009) and patient Pa02/Fi02 ratio ≤59 (OR = 8.65, p = .001) were associated with increased risk of transmission of SARS-CoV. In CART analyses, the four covariates which explained the greatest amount of variation in SARS-CoV transmission were covariates representing individual patients.ConclusionClose contact with the airway of severely ill patients and failure of infection control practices to prevent exposure to respiratory secretions were associated with transmission of SARS-CoV. Rates of transmission of SARS-CoV varied widely among patients.

Theoretically estimated risk of severe acute respiratory syndrome transmission through blood transfusion during an epidemic in Shenzhen, Guangdong, China in 2003

Background Severe acute respiratory syndrome (SARS) is a newly recognized infectious disease that caused an outbreak in south China in 2003. The cause of SARS was identified as a novel coronavirus (CoV). The existence of asymptomatic seroconvertors and the detection of the SARS-CoV RNA in plasma during the course of infection all suggest that SARS could, as least theoretically, be transmitted by transfusion. An estimate of the risk of SARS transmission through blood transfusion will contribute to decisions concerning blood safety monitoring and may be useful in the design of strategies to decrease the risk of transfusion-transmitted infections. Study design and methods Case onset dates from the 2003 Shenzhen SARS epidemic and investigational results from Taiwan on viremia in humans are used to estimate the number of cases that were viremic throughout the epidemic. Estimates of the asymptomatic-to-clinically confirmed SARS-CoV infection ratio, the proportion of asymptomatic infections reported in a seroprevalence survey in Hongkong, and the population size of Shenzhen are used to infer the SARS-CoV transfusion–transmission risk. Statistical resampling methods are used. Results Based on data from Shenzhen, Hongkong and Taiwan, the maximum and mean risk (per million) of SARS-CoV transmission from donors in Shenzhen were estimated as 23.57 (95% CI: 6.83–47.69) and 14.11 (95% CI: 11.00–17.22), respectively. The estimated risk peaked on April 02, 2003. Conclusions Although there are currently no confirmed reports of the transmission of SARS-CoV from asymptomatic individuals, recent research data indicate that transfusion-transmitted SARS-CoV is at least theoretically possible. Although the risk is low, with its rapid spread of the disease, appearance of alarmingly high infectivity and high fatality rate, public health authorities need to consider strategies for blood donor recruitment and virus inactivation during an epidemic to further ensure blood safety.

Concentration and detection of SARS coronavirus in sewage from Xiao Tang Shan hospital and the 309th Hospital of the Chinese People's Liberation Army

A worldwide outbreak of severe acute respiratory syndrome (SARS) had been reported. Over 8439 SARS cases and 812 SARS-related deaths were reported to the World Health Organization from 32 countries around the world up to 5 July 2003. The mechanism of transmission of SARS-CoV has been limited only to close contacts with patients. Attention was focused on possible transmission by the sewage system because laboratory studies showed that patients excreted coronavirus RNA in their stools in Amoy Gardens in Hong Kong. To explore whether the stool of SARS patients or the sewage containing the stool of patients would transmit SARS-CoV or not, we used a style of electropositive filter media particle to concentrate the SARS-CoV from the sewage of two hospitals receiving SARS patients in Beijing, as well as cell culture, semi-nested RT-PCR and sequencing of genes to detect and identify the viruses from sewage. There was no live SARS-CoV detected in the sewage in these assays. The nucleic acid of SARS-CoV was found in the sewage before disinfection from both hospitals by PCR. After disinfection, SARS-CoV RNA could be detected from some samples from the 309th Hospital of the Chinese People's Liberation Army, but not from Xiao Tang Shan Hospital after disinfection. In this study, we found that the virus can survive for 14 days in sewage at 4 degrees C, 2 days at 20 degrees C, and its RNA can be detected for 8 days though the virus had been inactivated. In conclusion, this study demonstrates that the RNA of SARS-CoV could be detected from the concentrates of sewage of both hospitals receiving SARS patients before disinfection and occasionally after disinfection though there was no live SARS-CoV; thus much attention should be paid to the treatment of stools of patients and the sewage of hospitals receiving SARS patients.