Transmission dynamics of SARS-CoV-2 in a mid-size city of China.

BACKGROUND: An outbreak of pneumonia, COVID-19 associated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan city and then rapidly spread to other cities. Wenzhou is located approximately 900 km from Wuhan, which was experiencing an outbreak that was severe at the time but is considered modest as the epidemic became a pandemic. We described the epidemiological characteristics of SARS-CoV-2 outside of the epicenter to help understand the transmission pattern in a mid-sized Chinese city. METHODS: To investigate the epidemiological and clinical characteristics of the COVID-19, we described case series of 473 patients with confirmed COVID-19 in Wenzhou, China from January 27 to March 16, 2020. We described the public health interventions of COVID-19 and evaluated the effect of interventions by the effective reproduction number (Rt). RESULTS: The median age of all patients was 47.6 years, 48.4% of whom were female. 33.8% of the patients had a history of residence in Wuhan. Fever (71.7%) and cough (43.1%) were the most common symptoms. In addition, three kinds of unconventional cases were observed, namely 4.9% asymptomatic patients, 7.6% confirmed patients who had no link to Wuhan city but contact with individuals from Wuhan without any symptoms at the time of contact, and 12.9% confirmed patients who had an unknown source of transmission. We estimated that the basic reproductive number (R0) was 2.75 (95% CI: 2.37-3.23). The Rt fluctuated within the range of 2.50 to 3.74 from January 11 to January 16 while gradually reached a peak of 3.74 on January 16. Rt gradually decreased after January 16 and decreased to 1.00 on January 30. Rt continually decreased and reached the lowest point (0.03) on February 21, 2020. CONCLUSION: Our study presented the possibility of asymptomatic carriers affected with SARS-CoV-2, and transmission by these three kinds of unconventional patients in Wenzhou may be an important characteristic of SARS-CoV-2 transmission. The evaluation showed that a series of multifaceted interventions proved effective in controlling the epidemic of COVID-19. These findings might provide valuable examples of control policies for countries or areas in combatting the global pandemic of COVID-19.

Prospective analytical performance evaluation of the QuickNavi™-COVID19 Ag for asymptomatic individuals.

INTRODUCTION: Antigen testing may help screen for and detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in asymptomatic individuals. However, limited data regarding the diagnostic performance of antigen tests for this group are available. METHODS: We used clinical samples to prospectively evaluate the analytical and clinical performance of the antigen test QuickNavi™-COVID19 Ag. This study was conducted at a PCR center between October 7, 2020 and January 9, 2021. Two nasopharyngeal samples per patient were obtained with flocked swabs; one was used for the antigen test, and the other for real-time reverse transcription PCR (RT-PCR). The diagnostic performance of the antigen test was compared between asymptomatic and symptomatic patients, and the RT-PCR results were used as a reference. RESULTS: Among the 1934 collected samples, 188 (9.7%) demonstrated detection of SARS-CoV-2 by real-time RT-PCR; 76 (40.4%) of these 188 samples were from asymptomatic individuals, and over half of the total samples were asymptomatic (1073; 55.5%). The sensitivity of the antigen test was significantly lower for the asymptomatic group than for symptomatic patients (67.1% vs. 89.3%, respectively, p < 0.001). The specificity was 100% for both groups, and no false positives were observed among all 1934 samples. The median cycle threshold value for the asymptomatic group was significantly higher than that of the symptomatic group (24 vs. 20, p < 0.001). CONCLUSIONS: The QuickNavi™-COVID19 Ag showed lower sensitivity for the asymptomatic group than for symptomatic patients. However, its specificity was consistently high, and no false positives were found in this study.

Chest Computed Tomography Findings in Asymptomatic Patients with COVID-19.

BACKGROUND: Little is known about the damage to the respiratory system in asymptomatic patients with coronavirus disease (COVID-19). OBJECTIVE: Herein, we evaluate the findings of chest computed tomography (CT) and radiography in patients with COVID-19 who were asymptomatic. METHODS: We retrospectively investigated patients with a confirmed diagnosis of COVID-19 but who did not show any symptoms. Among the 139 patients with COVID-19 who were hospitalized in Yeungnam University Hopistal in Daegu, South Korea, 10 (7.2%) were asymptomatic. Their chest CT and radiographic findings were analyzed. RESULTS: In the results, all patients (100%) had ground-glass opacity (GGO) on chest CT. Further, the GGO lesions were predominantly distributed peripherally and posteriorly in all patients. In 9 (90%) patients, the GGO lesions were combined with reticular opacity. Air bronchogram due to bronchiolectasis surrounded by GGO was observed in 8 patients (80%). Additionally, the lung lesions were dominant on the right side in all patients. CONCLUSIONS: In conclusion, considering our results that the lung is affected in asymptomatic patients, it will be necessary to extend the indications of COVID-19 testing for effective management of COVID-19 during the pandemic.

EDDAMAP: efficient data-dependent approach for monitoring asymptomatic patient.

BACKGROUND: A pandemic affects healthcare delivery and consequently leads to socioeconomic complications. During a pandemic, a community where there lives an asymptomatic patient (AP) becomes a potential endemic zone. Assuming we want to monitor the travel and/or activity of an AP in a community where there is a pandemic. Presently, most monitoring algorithms are relatively less efficient to find a suitable solution as they overlook the continuous mobility instances and activities of the AP over time. Conversely, this paper proposes an EDDAMAP as a compelling data-dependent technique and/or algorithm towards efficient continuous monitoring of the travel and/or activity of an AP. METHODS: In this paper, it is assumed that an AP is infected with a contagious disease in which the EDDAMAP technique exploits a GPS-enabled mobile device by tagging it to the AP along with its travel within a community. The technique further examines the Spatio-temporal trajectory of the AP to infer its spatial time-bounded activity. The technique aims to learn the travels of the AP and correlates them to its activities to derive some classes of point of interests (POIs) in a location. Further, the technique explores the natural occurring POIs via modelling to identify some regular stay places (SP) and present them as endemic zones. The technique adopts concurrent object feature localization and recognition, branch and bound formalism and graph theory to cater for the worst error-guaranteed approximation to obtain a valid and efficient query solution and also experiments with a real-world GeoLife dataset to confirm its performance. RESULTS: The EDDAMAP technique proofs a compelling technique towards efficient monitoring of an AP in case of a pandemic. CONCLUSIONS: The EDDAMAP technique will promote the discovery of endemic zones and hence some public healthcare facilities can rely on it to facilitate the design of patient monitoring system applications to curtail a global pandemic.

Modeling COVID-19 epidemic in Heilongjiang province, China.

The Coronavirus Disease 2019 (COVID-19) surges worldwide. However, massive imported patients especially into Heilongjiang Province in China recently have been an alert for local COVID-19 outbreak. We collected data from January 23 to March 25 from Heilongjiang province and trained an ordinary differential equation model to fit the epidemic data. We extended the simulation using this trained model to characterize the effect of an imported 'escaper'. We showed that an imported 'escaper' was responsible for the newly confirmed COVID-19 infections from Apr 9 to Apr 19 in Heilongjiang province. Stochastic simulations further showed that significantly increased local contacts among imported 'escaper', its epidemiologically associated cases and susceptible populations greatly contributed to the local outbreak of COVID-19. Meanwhile, we further found that the reported number of asymptomatic patients was markedly lower than model predictions implying a large asymptomatic pool which was not identified. We further forecasted the effect of implementing strong interventions immediately to impede COVID-19 outbreak for Heilongjiang province. Implementation of stronger interventions to lower mutual contacts could accelerate the complete recovery from coronavirus infections in Heilongjiang province. Collectively, our model has characterized the epidemic of COVID-19 in Heilongjiang province and implied that strongly controlled measured should be taken for infected and asymptomatic patients to minimize total infections.

Prevalence of Serum IgG Antibodies to Cystic Echinococcus Antigen among Patients in an Uzbekistan Emergency Hospital.

Cystic echinococcosis (CE) is one of the most widespread zoonotic helminthiases, which can last an asymptomatic infection for several years. The purpose of this study was to demonstrate serum antibody prevalence of CE among asymptomatic people in Uzbekistan using ELISA. A total of 2,547 serum samples were collected, 66 from confirmed CE patients and 2,481 of patients with other diseases than CE at a hospital in Tashkent, Uzbekistan. The serum samples were screened for CE specific IgG antibodies by ELISA using cystic fluid antigen obtained from sheep. The serum antibody positive rate was 89.4% (59/66) in CE and 3.6% (89/2,481) in other disease patients. The present ELISA recognized 89.4% sensitivity and 96.4% specificity. The ELISA absorbance of positive samples was distributed 0.271-0.971 for CE and 0.273-0.887 for other disease patients. The other disease patients with high absorbance over 0.3 were 50 (2.0%) who were presumed to be active CE patients. The patients in their 40s showed the highest positive rate of 5.2% (P=0.181), and women were 4.4% while men were 3.1% positive (P=0.136). The data confirmed that there are many asymptomatic patients of CE in Tashkent. It is indicated that CE is an endemic disease of public health importance in Uzbekistan.

Percutaneous Coil Closure of a Large Left Coronary Artery Fistula in an Asymptomatic Child.

Coronary artery fistulas (CAFs) are rare cardiac anomalies characterized by an abnormal connection between the coronary arteries and either a cardiac chamber or a large thoracic vessel. While the majority of CAF cases are asymptomatic, serious cardiac complications can occur, especially with moderate to large fistulas. We describe a case of a large-sized left coronary artery (LCA) fistula in an asymptomatic 11-year-old who was referred for cardiac evaluation due to a systolic murmur. An echocardiogram revealed a hemodynamically significant fistula arising from the LCA draining into the right ventricle. Diagnostic catheterization confirmed the origin and draining site of the fistula, along with aneurysmal dilation at the end of the fistula. The fistula was successfully closed percutaneously using a two-coil occlusive device, with no complication observed.

Early Cytokine Signatures of Hospitalized Mild and Severe COVID-19 Patients: A Prospective Observational Study.

Background: The severe manifestation of coronavirus disease 2019 (COVID-19) is known to be mediated by several cytokines and chemokines. The study aimed to compare the early cytokine profile of mild and severe COVID-19 patients to that with COVID-19-like symptoms and tested negative for Severe Acute Respiratory Syndrome Coronavirus-2 in the Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR) test. Methods: This was a prospective, observational study on COVID-19 patients admitted to King Khalid University Hospital, King Saud University Medical City from June to November 2020. Clinical and biochemical data were collected from hospital charts. Blood samples were collected at the time of hospital admission to measure cytokines. A Cytokine and Growth Factor High-Sensitivity Array was used to quantitatively measure cytokines. Results: The study included 202 RT-PCR-positive individuals and 61 RT-PCR-negative individuals. C-Reactive protein (CRP) and Interleukin-10 (IL-10) levels were found significantly elevated in the RT-PCR positive group compared to the RT-PCR negative group (p=0.001). Patients with severe COVID-19 had significantly longer median hospital stays than those with mild COVID-19 cases (7 vs 6 days). They also had higher CRP and Vascular Endothelial Growth Factor (VEGF) levels and lower Interleukin-4 (IL-4) levels compared to the mild cases. CRP, interleukin-6, IL-10, VEGF, and Monocyte Chemoattractant Protein-1 (MCP-1) levels were significantly elevated in men and IL-10 was significantly higher and interleukin-8 was significantly lower in women compared to negative controls. Elevated Interferon-É£ (IFN-γ) and IL-10 levels were seen in mild COVID-19 cases and elevated level of MCP-1 was seen in severe COVID-19 cases when categorized according to the length of stay in the hospital. Conclusion: CRP and IL-10 levels were elevated in the RT-PCR positive group. People with severe COVID-19 had higher CRP and VEGF levels and lower IL-4 levels. Elevated IFN-γ and IL-10 levels were seen in mild COVID-19 cases and elevated level of MCP-1 was seen in severe COVID-19 cases when categorized according to the length of stay in the hospital.

Characterization of mild or asymptomatic patient admitted with Omicron variant of COVID-19 infection in Tibetan mobile cabin hospital China, August-October 2022.

Background: Prior to August 7, 2022, there had been no positive cases of novel coronavirus in Tibet for 920 consecutive days. However, with the first case of Omicron variant infection, the disease rapidly spread and was prevalent in Tibet for nearly 3 months, from August 7th to November 1st. With the spread of the epidemic, the local government responded quickly and established several mobile cabin hospitals to treat patients with mild and asymptomatic Omicron infection. However, the epidemiological and clinical characteristics of these patients are unknown. Methods: This is a retrospective study including a total of 14,264 mild and asymptomatic cases with Omicron infection in Tibet between August to October, 2022. The clinical data and epidemiological characteristics of COVID-19 cases admitted to Tibet mobile cabin hospitals were collected by using standardized forms from mobile cabin hospital database system, including demographic characteristics, onset symptoms, medication use, past medical history, hospitalization time, and discharge time. In terms of statistical analysis, multivariate Cox regression model was used to analyze the relationship between case characteristics and the length of stay in hospital. Results: Among 14,264 patients infected with Omicron, the average length of hospital stay was six (4-8, Interquartile range) days. Fifty percent of the patients were discharged by the 6th day, and 90% were discharged by the 10th day. Patients of all ages are generally susceptible to COVID-19, and there was no difference in discharge time, but the average length of hospital stay of Tibetan patients with COVID-19 was longer than that of Han patients. According to the statistics of clinical symptoms, sore throat (38.7%) and fever (19.4%) were the most common symptoms, while muscle pain (17.4%), cough (16.6%), and expectoration (13.2%) were also common. In addition, patients with chronic gastritis had significantly longer hospital stays. Conclusion: Based on the experience of Tibet mobile cabin hospitals and data analysis, we believe that patients of all ages are generally susceptible to Omicron. Compared with other novel coronavirus strains, Omicron infected patients had a shorter hospital stay, and treatment of symptoms is expected to shorten the time of nucleic acid negative conversion.

Watchful surgery in asymptomatic mitral valve prolapse.

The most common organic etiology of mitral regurgitation is degenerative and consists of mitral valve prolapse (MVP). Volume overload because of mitral regurgitation is the most common complication of MVP. Advocating surgery before the consequences of volume overload become irreparable restores life expectancy, but carries a risk of mortality in patients who are often asymptomatic. On the other hand, the post-surgical outcome of symptomatic patients is dismal and life expectancy is impaired. In the present article, we aim to bridge the gap between these two therapeutic approaches, unifying the concepts of watchful waiting and early surgery in a "watchful surgery approach".