The risk of COVID-19 transmission upon return to sport: a systematic review.

OBJECTIVES: To evaluate COVID-19 transmission rates in athletes upon return to sport (RTS), as well as the effectiveness of preventive and surveillance measures associated with RTS. METHODS: In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, the PubMed, Embase, and Cochrane Library databases were searched to identify all articles reporting on RTS during COVID-19. Articles were excluded on the basis of the following criteria: (1) non-English text, (2) only abstract available, (3) population not athlete-specific, (4) outcome not RTS-specific, (5) COVID-19 transmission data not quantified, (6) editorial, or (7) review article or meta-analysis. Study characteristics; athlete demographics; COVID-19 preventive, surveillance, and diagnostic measures; COVID-19 transmission outcomes; and RTS recommendations were collected from each included article and analyzed. RESULTS: 10 studies were included in the final analysis, comprising over 97,000 athletes across a wide variety of sports, levels of play, and RTS settings. Of the 10 studies, eight identified low transmission rates and considered RTS to be safe/low risk. Overall, COVID-19 transmission rates were higher in athletes than in contacts, and more prevalent in the greater community than in athletes specifically. The risk of COVID-19 did not appear to be necessarily higher for athletes who played high-contact team sports, shared common facilities, or lived in communities impacted by high transmission rates, provided that rigorous COVID-19 safety and testing protocols were implemented and followed. Mask wearing and physical distancing during active play presented the greatest challenge to athletes. CONCLUSION: Rigorous preventive and surveillance measures can mitigate the risk of COVID-19 transmission in athletes upon RTS. However, the heterogeneity of RTS playing conditions, availability of COVID-19 resources, rise of unforeseen novel variants, and undetermined long-term impact of vaccination on athletes remain a challenge to safe and effective RTS in the era of COVID-19.

A numerical study of COVID-19 epidemic model with vaccination and diffusion.

The coronavirus infectious disease (or COVID-19) is a severe respiratory illness. Although the infection incidence decreased significantly, still it remains a major panic for human health and the global economy. The spatial movement of the population from one region to another remains one of the major causes of the spread of the infection. In the literature, most of the COVID-19 models have been constructed with only temporal effects. In this paper, a vaccinated spatio-temporal COVID-19 mathematical model is developed to study the impact of vaccines and other interventions on the disease dynamics in a spatially heterogeneous environment. Initially, some of the basic mathematical properties including existence, uniqueness, positivity, and boundedness of the diffusive vaccinated models are analyzed. The model equilibria and the basic reproductive number are presented. Further, based upon the uniform and non-uniform initial conditions, the spatio-temporal COVID-19 mathematical model is solved numerically using finite difference operator-splitting scheme. Furthermore, detailed simulation results are presented in order to visualize the impact of vaccination and other model key parameters with and without diffusion on the pandemic incidence. The obtained results reveal that the suggested intervention with diffusion has a significant impact on the disease dynamics and its control.

Prevalence of gastro-intestinal symptoms among COVID-19 patients and the association with disease clinical outcomes.

Aim: This study examined the various manifestations of COVID-19 in people's gastro-intestinal system and how gastro-intestinal involvement relates to the progression and outcome of the disease. Methodology: A questionnaire survey was used to collect data from 561 COVID-19 patients between February 6 and 6 April 2022. Laboratory data and clinical outcomes were obtained from the patients' medical records. Results: 39.9% of patients presented gastro-intestinal symptoms, mainly loss of appetite, nausea, vomiting and diarrhea. Gastro-intestinal symptoms were not linked to poorer outcomes such as mortality, ICU admission or length of hospital stays. Conclusion: gastro-intestinal symptoms were common among patients and may manifest with respiratory symptoms. We recommended clinicians to watch out for gastro-intestinal symptoms as related to COVID-19 infection.

COVID-19 mainly affects the respiratory system. However, it has been previously reported that the disease can impact other organ systems, particularly the gastro-intestinal system. A prospective descriptive study design which involved 561 COVID-19 patients was performed to identify the various manifestations of COVID-19 in people's gastro-intestinal system and how gastro-intestinal involvement influenced the progression and outcome of the disease. Almost 40% of patients presented with gastro-intestinal symptoms, mainly loss of appetite, nausea, vomiting and diarrhea. However, the presence of gastro-intestinal symptoms was not linked to poorer outcomes such as mortality, ICU admission, length of hospital stays and increased mechanical intubation of COVID-19 patients.

Perinatal Transmission of SARS-CoV-2 Infection and Its Clinical Attributes: A Single-Center Study From Western Uttar Pradesh.

Background Globally, severe acute respiratory syndrome coronavirus 2 (SARS­CoV­2) has infected millions of people to date. The morbidity and mortality associated with SARS-CoV-2 are higher in diabetics than those with chronic kidney disease and in the elderly. In pregnant women, it causes an increased risk for preeclampsia/eclampsia, infections, intensive care unit (ICU) admission, maternal mortality, and preterm birth. In neonates, SARS­CoV­2 infection has been found to cause stillbirths, growth retardation, premature delivery, increased neonatal intensive care unit (NICU) admission, and need for oxygen support. The neonate can get infected by vertical or horizontal transmission. As most studies have focussed on transmission at the time of birth only, in this study, we explored both vertical and horizontal transmission along with the clinical attributes of those born to mothers with SARS­CoV­2 infection. Methodology A prospective observational study was conducted in the Department of Pediatrics of a tertiary care hospital over 12 months from October 2020 to October 2021. All reverse transcription-polymerase chain reaction (RT-PCR) SARS-CoV-2-positive pregnant females admitted to the facility during the study duration were included. The enrolled mothers were followed till delivery. The mothers and neonates were managed per standard guidelines. Delivery details and neonatal outcomes were recorded. Coronavirus disease 2019 sampling in newborn babies was done at birth (within 24 hours) using a nasopharyngeal swab sample for RTPCR along with cord blood for SARS-CoV-2 immunoglobulin M (IgM). Complete blood count, C-reactive protein, serum electrolytes, random blood sugar, and chest X-ray were obtained for all babies at birth and thereafter according to requirement. In those roomed in with their mother, RT-PCR was repeated at the time of discharge or if they became symptomatic. Results A total of 44 mother-neonate dyads were included in the study. Cord blood IgM for SARS­CoV­2 was negative for all neonates, while throat swab RT-PCR was positive for two (4.5%) neonates immediately after birth. Overall, 13.6% of the neonates were premature, 27.2% of the neonates had low birth weight (<2,500 g), and 6.8% had very low birth weight (<1,500 g). Among those admitted to the NICU, 18.2% had respiratory distress; 4.5% had fever, lethargy, and poor feeding; and hyperbilirubinemia requiring phototherapy was observed in 11.3% of the neonates. Moreover, 4.5% of the neonates had hypocalcemia on initial investigations. Mortality was seen in 2.2% (1/44) of the neonates. Rooming-in and breastfeeding were seen in 68.2% of the neonates. The horizontal transmission was seen in one (3.3%) roomed-in neonate. Conclusions Perinatal transmission of SARS­CoV­2 infection does occur but its rate is not significant. Furthermore, with proper infection prevention and control measures, the risk of perinatal transmission can be decreased. Breastfeeding and rooming-in do not increase infection transmission if the mother takes all precautions.

Transmission potential of vaccinated and unvaccinated persons infected with the SARS-CoV-2 Delta variant in a federal prison, July-August 2021.

BACKGROUND: The extent to which vaccinated persons who become infected with SARS-CoV-2 contribute to transmission is unclear. During a SARS-CoV-2 Delta variant outbreak among incarcerated persons with high vaccination rates in a federal prison, we assessed markers of viral shedding in vaccinated and unvaccinated persons. METHODS: Consenting incarcerated persons with confirmed SARS-CoV-2 infection provided mid-turbinate nasal specimens daily for 10 consecutive days and reported symptom data via questionnaire. Real-time reverse transcription-polymerase chain reaction (RT-PCR), viral whole genome sequencing, and viral culture was performed on these nasal specimens. Duration of RT-PCR positivity and viral culture positivity was assessed using survival analysis. RESULTS: A total of 957 specimens were provided by 93 participants, of whom 78 (84 %) were vaccinated and 17 (16 %) were unvaccinated. No significant differences were detected in duration of RT-PCR positivity among vaccinated participants (median: 13 days) versus those unvaccinated (median: 13 days; p = 0.50), or in duration of culture positivity (medians: 5 days and 5 days; p = 0.29). Among vaccinated participants, overall duration of culture positivity was shorter among Moderna vaccine recipients versus Pfizer (p = 0.048) or Janssen (p = 0.003) vaccine recipients. In post-hoc analyses, Moderna vaccine recipients demonstrated significantly shorter duration of culture positivity compared to unvaccinated participants (p = 0.02). When restricted to participants without reported prior infection, the difference between Moderna vaccine recipients and unvaccinated participants was more pronounced (medians: 3 days and 6 days, p = 0.002). CONCLUSIONS: Infectious periods for vaccinated and unvaccinated persons who become infected with SARS-CoV-2 are similar and can be highly variable, though some vaccinated persons are likely infectious for shorter durations. These findings are critically important, especially in congregate settings where viral transmission can lead to large outbreaks. In such settings, clinicians and public health practitioners should consider vaccinated, infected persons to be no less infectious than unvaccinated, infected persons.

Geo-epidemiological approach of the COVID-19 pandemic in France and in Europe for public health policies.

The spread of the COVID-19 pandemic has shown great heterogeneity between countries that merits investigation. There is a need to better highlight the variability in the pandemic trajectories in different geographic areas. By using openly available data from 'GitHub' COVID-19 dataset for Europe and from the official dataset of France for the period 2020 to 2021, I present the three COVID-19 waves in France and Europe in maps. The epidemic trends across areas display different evolutions for different time periods. National and European public health authorities will be able to improve allocation of resources for more effective public health measures based on geo-epidemiological analyses.

Modeling COVID-19 contact-tracing using the ratio regression capture-recapture approach.

Contact-tracing is one of the most effective tools in infectious disease outbreak control. A capture-recapture approach based upon ratio regression is suggested to estimate the completeness of case detection. Ratio regression has been recently developed as flexible tool for count data modeling and has proved to be successful in the capture-recapture setting. The methodology is applied here to Covid-19 contact tracing data from Thailand. A simple weighted straight line approach is used which includes the Poisson and geometric distribution as special cases. For the case study data of contact tracing for Thailand, a completeness of 83% could be found with a 95% confidence interval of 74%-93%.

Clinical, Virologic, and Immunologic Evaluation of Symptomatic Coronavirus Disease 2019 Rebound Following Nirmatrelvir/Ritonavir Treatment.

BACKGROUND: Nirmatrelvir/ritonavir, the first severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) protease inhibitor, reduces the risk of hospitalization and death by coronavirus disease 2019 (COVID-19) but has been associated with symptomatic rebound after therapy completion. METHODS: Six individuals with relapse of COVID-19 symptoms after treatment with nirmatrelvir/ritonavir, 2 individuals with rebound symptoms without prior antiviral therapy and 7 patients with acute Omicron infection (controls) were studied. Soluble biomarkers and serum SARS-CoV-2 nucleocapsid protein were measured. Nasal swabs positive for SARS-CoV-2 underwent viral isolation and targeted viral sequencing. SARS-CoV-2 anti-spike, anti-receptor-binding domain, and anti-nucleocapsid antibodies were measured. Surrogate viral neutralization tests against wild-type and Omicron spike protein, as well as T-cell stimulation assays, were performed. RESULTS: High levels of SARS-CoV-2 anti-spike immunoglobulin G (IgG) antibodies were found in all participants. Anti-nucleocapsid IgG and Omicron-specific neutralizing antibodies increased in patients with rebound. Robust SARS-CoV-2-specific T-cell responses were observed, higher in rebound compared with early acute COVID-19 patients. Inflammatory markers mostly decreased during rebound. Two patients sampled longitudinally demonstrated an increase in activated cytokine-producing CD4+ T cells against viral proteins. No characteristic resistance mutations were identified. SARS-CoV-2 was isolated by culture from 1 of 8 rebound patients; Polybrene addition increased this to 5 of 8. CONCLUSIONS: Nirmatrelvir/ritonavir treatment does not impede adaptive immune responses to SARS-CoV-2. Clinical rebound corresponds to development of a robust antibody and T-cell immune response, arguing against a high risk of disease progression. The presence of infectious virus supports the need for isolation and assessment of longer treatment courses. Clinical trials registration. NCT04401436.

The SEIR model incorporating asymptomatic cases, behavioral measures, and lockdowns: Lesson learned from the COVID-19 flow in Sweden.

The Sweden approach is unique in handling the COVID-19 flow, compared to other European countries. While other countries have practiced the full lockdowns, Sweden has practiced the lighter lockdowns or the partial lockdowns as public spaces such as cafes and restaurants are allowed to serve their customers subject to government recommendations. This study aims to develop an SEIR model for Sweden capturing important issues such as the roles of behavioral measures, partial lockdowns, and undocumented cases. The suggested SEIR model is probably the first SEIR model capturing the roles of behavioral measures, partial lockdowns, hospital preparedness, and asymptomatic cases for Sweden. The SEIR model can successfully reproduce similar main observed outputs, namely documented infected cases and documented death cases. This study finds that the effects of partial lockdowns effectively start 52 days after the first confirmed case. Again, behavioral measures and partial lockdowns reduce possible infected cases about 22% and 70% respectively. This study also suggests that the Sweden government should step up to the full lockdowns by conducting public closures so COVID-19 flow can be curtailed significantly. Likewise, owing to airborne transmission, protecting vulnerable people such as senior citizens should be prioritised.

Assessment of SARS-CoV-2 entry in gingival epithelial cells expressing CD147.

SARS-CoV-2, the causative agent of the debilitating COVID-19, is mainly transmitted by first infecting nose and lung epithelial cells. The mouth is also believed to be a viral portal site since certain types of oral epithelial cells were shown to express ACE2 receptor. However, it is unclear whether oral epithelial cells are directly infected by SARS-CoV-2. In this study, we addressed whether epithelial cells of the oral gingiva were susceptible to infection. Interestingly, we found that KRT5+ and KRT18+ gingival epithelial cells do not express ACE2 but highly express TMPRSS2 and Furin as well as CD147, which was proposed to be an alternative receptor for SARS-CoV-2. However, using SARS-CoV-2 pseudoviruses containing the spike protein, we observed that gingival epithelial cells were not susceptible to infection due to the lack of ACE2 expression and the inability of CD147 to mediate viral entry. These results strongly suggest that epithelial cells from the gingiva are not susceptible to SARS-CoV-2 and CD147 is not a receptor for the SARS-CoV-2 virus. The susceptibility of oral cells from other oral structures under healthy and pathological conditions still needs to be confirmed to better understand the role of the oral cavity in COVID-19 infection and transmission.

To open or not to open: the moderating effects of human mobility on the relationship between vaccination and COVID-19 transmission.

COVID-19 vaccination is being used to control SARS-CoV-2 transmission globally, and many countries have relaxed some non-pharmaceutical interventions. It is unclear whether relaxing human mobility restrictions is proper and increases transmission risk. To fill this knowledge gap, we aim to examine if human mobility impairs the role of vaccination on COVID-19 transmission. We apply dynamic panel data models with three lag levels (i.e. 0 day, 7 days, and 14 days) to investigate the relationship between vaccination and COVID-19 transmission and the moderating effects of different kinds of human mobility. Our results show a negative relationship between the percentage of the vaccinated population and daily new COVID-19 cases after controlling for human mobility. We also observe that when people are only vaccinated with one dose, increased human mobility in retail and recreation, grocery and pharmacy, parks, transit stations, and workplaces could impair the role of vaccination on COVID-19 transmission, although their moderating effects appear at different lag levels. However, there are no moderating effects of human mobility in transit stations and workplaces at all lag levels when people are fully vaccinated. This finding does not mean that governments may relax restrictions in these two areas since mobility in transit stations and workplaces could affect COVID-19 transmission by themselves directly. Therefore, we recommend that governments still insist on implementing human mobility control measures from the perspective of transmission risk.

Longitudinal Participatory Surveillance Highlights Association Between Mask-Wearing and Lower COVID-19 Risk - United States, 2020.

What is already known about this topic?: Numerous ecological and laboratory studies suggest face masks are an effective non-pharmaceutical intervention for reducing the spread of coronavirus disease 2019 (COVID-19), but cannot otherwise assess individual-level effects. What is added by this report?: Using a prospective cohort of individuals enrolled in a participatory, syndromic surveillance tool prior to the first case of COVID-19 in the United States, we present a novel longitudinal assessment of the effectiveness of face masks. What are the public health implications for public health practice?: Our analysis demonstrates an association between self-reported mask-wearing behavior and lower individual risk of syndromic COVID-19-like illness while adjusting for confounders at the individual level. Our results also highlight the dual utility of participatory syndromic surveillance systems as both disease trend monitors and tools that can aid in understanding the effectiveness of personal protective measures.

Perceptions of COVID-19 transmission risk and testing readiness in rural Southwest Nigeria.

Although community screening and testing have been recommended by the World Health Organization, the extent of readiness and the associated factors among rural populations remain unknown. We investigated the factors associated with perception of the COVID-19 transmission risk and readiness for testing in rural areas of Southwest Nigeria. Using a multistage cluster sampling technique, cross-sectional data was collected from 922 adults aged 18 years and above who were resident in rural communities selected across three States in the Southwest region between June and August 2020. Descriptive statistics and binary logit models with robust standard errors were utilized for analysis. Mean age of respondents was 37.0 (SD = 15.8) years; 58.6% female; 46.5% had secondary education; and most were traders (33.2%) and artisans (29.9%). Only 149 respondents (16.2%) had a accurate perception of COVID-19 transmission risk. Adjusted logit models showed that independent factors associated with accurate perception of COVID-19 transmission risk include: age 18&19 years (OR = 0.50, CI: 0.34-0.73); exposure to electronic media (OR = 1.84, CI: 1.07-3.18); and being an in-migrant (OR = 3.38, CI: 2.44-4.68). Less than one-third (28.8%) were willing to test for COVID-19. Severe fear of COVID-19 (OR = 3.99, CI: 1.36-11.74) was associated with willingness to undergo COVID-19 testing. Socio-demographic predictors of testing readiness included: male sex (OR = 1.51, CI: 1.36-1.68); traditional religion (OR = 2.81, CI: 1.05-7.53); and exposure to electronic media (OR = 1.31, CI: 1.06-1.62). Awareness campaigns need to be scaled up to improve perception and preparedness to test for COVID-19.