Mass Testing and Proactiveness Affect Epidemic Spreading.

The detection and management of diseases become quite complicated when pathogens contain asymptomatic phenotypes amongst their ranks, as evident during the recent COVID-19 pandemic. Spreading of diseases has been studied extensively under the paradigm of susceptible-infected-recovered-deceased (SIRD) dynamics. Various game-theoretic approaches have also addressed disease spread, many of which consider S , I , R , and D as strategies rather than as states. Remarkably, most studies from the above approaches do not account for the distinction between the symptomatic or asymptomatic aspect of the disease. It is well-known that precautionary measures like washing hands, wearing masks and social distancing significantly mitigate the spread of many contagious diseases. Herein, we consider the adoption of such precautions as strategies and treat S , I , R , and D as states. We also attempt to capture the differences in epidemic spreading arising from symptomatic and asymptomatic diseases on various network topologies. Through extensive computer simulations, we examine that the cost of maintaining precautionary measures as well as the extent of mass testing in a population affects the final fraction of socially responsible individuals. We observe that the lack of mass testing could potentially lead to a pandemic in case of asymptomatic diseases. Network topology also seems to play an important role. We further observe that the final fraction of proactive individuals depends on the initial fraction of both infected as well as proactive individuals. Additionally, edge density can significantly influence the overall outcome. Our findings are in broad agreement with the lessons learnt from the ongoing COVID-19 pandemic.

Incidentally Detected Asymptomatic Cardiac Myxoma in a Patient With COVID-19.

Primary cardiac tumors, such as myxomas, are rare. About 75% of myxomas occur in the left atrium of the heart. Myxomas can have a broad clinical spectrum. The clinical presentation varies from asymptomatic to sudden cardiac death. Sometimes, a diagnosis is difficult. Cardiac myxoma can cause hemodynamic disturbances in the setting of pneumonia and hypercoagulable state in patients with Coronavirus disease 2019(COVID-19) and make treatment decisions difficult. We present a case of unusually huge left atrial mass discovered incidentally in a patient with COVID-19. Upon workup, an echocardiogram revealed an incidental 7 × 5 cm left atrial myxoma. Preoperatively, the patient was monitored closely in the ICU. After stabilization in the ICU, the patient was taken to surgery and the tumor was successfully removed. Pathohistological results after surgical removal of the tumor confirmed the diagnosis of cardiac myxoma. We consider our case extremely rare due to the asymptomatic course despite the large size of the tumor.

High Prevalence of SARS-CoV-2 in an Indigenous Community of the Colombian Amazon Region.

Introduction. COVID-19 is a pathology caused by the SARS-CoV-2 virus. The World Health Organization (WHO) has reported more than 225 million cases and 4.5 million deaths worldwide. Objective: To describe the seropositivity, spatial distribution, and clinical and sociodemographic variables of SARS-CoV-2 in a community of the Colombian Amazon region. Methods. In December 2020, a cross-sectional observational study was carried out in a population located in the Colombian Amazon in the municipality of Mitú. Sociodemographic and clinical data were taken. Besides, 589 blood samples were taken, and an antibody detection was carried out with an ELISA and a recombinant protein N antigen of SARS-CoV-2. Results. A seropositivity of 57.6% was observed. The highest proportion of the infection is located in inter-municipal transport zones. The bivariate analysis did not show differences in the SARS-CoV-2 infection rate concerning the variables sex, age range, and the presence of comorbidities (p > 0.05). The bivariate and multivariate analysis showed that being symptomatic and presenting neurological manifestations of the upper respiratory tract are clinical variables associated with SARS-CoV-2 infection (p < 0.05). One of the causes of this virus's high spread in this community could be that 53.3% of the people were asymptomatic. Conclusions. Our data showed a high burden and transmission of SARS-CoV-2 in the indigenous community. This could be linked to cultural behaviors and the high infection rate in asymptomatic patients.

COVID-19 in children: clinical and epidemiological spectrum in the community.

Most publications on pediatric COVID-19 in Spain were performed at the beginning of the pandemic when some diagnostic tools were not widely available. This study aims to show the real spectrum of the infection based on wide detection of cases due to symptoms and contact tracing. A descriptive and analytical observational study was performed including pediatric cases (0 to 14 years) from the region of Aragón between May 12 and October 31, 2020. Diagnostics was by PCR detection of viral RNA, rapid antigen detection test, or positive IgG serology. There were 5933 positive children included. Of them, 49.03% were women. The mean age was 7.53 ± 4.28 years. The source of infection could not be determined in 17.8% of cases. As for the rest, was determined to be within the family environment in 67.8%. The percentage of asymptomatic patients was 50.3%. Among symptomatic patients, fever (58.1%) and cough (46.7%) were the most frequent symptoms. Hospitalization was required in 0.52% of infected, intensive care unit admission was on 0.05%, and there was one death (0.02%). Children under the age of one presented some symptoms more frequently (71.6% vs 48.5%; OR 2.68; 95% CI 2.08 to 3.45; p < 0.001) and required more hospitalizations (3.9% vs 0.34%; OR 11.52; 95% CI 5.65 to 23.52; p < 0.001).Conclusion: In our environment, SARS-CoV-2 infection is like other mild respiratory viral infections in the population under the age of 15. The contagion occurs mainly in the family environment, the number of asymptomatic is high, being the symptoms mild and the complications very infrequent. What is Known: • Pediatric infection produced by SARS-CoV-2 has manifested as a mild disease in relation to adult age, although with higher affectation at the youngest ages. • Nearly all studies on epidemiology and clinical spectrum of the disease were conducted with patients diagnosed at the beginning of the pandemic. By then, diagnostic tools were only available in hospitals and in emergency units. What is New: • Once diagnostic means were available in primary care medicine and were used not only for the diagnosis of clinical symptoms of the patient, but for the tracing of case contacts, a much more precise approach to the epidemiology and clinical manifestations of the disease was allowed, as described in this study.

Seroprevalence of anti-SARS-CoV-2 IgG in asymptomatic and pauci-symptomatic people over a 5 month survey in Argentina.

OBJECTIVE: To evaluate the seroprevalence of COVID-19 infection in pauci-symptomatic and asymptomatic people, the associated epidemiological factors, and IgG antibody kinetic over a 5-month period to get a better knowledge of the disease transmissibility and the rate of susceptible persons that might be infected. METHODS: Seroprevalence was evaluated by a cross-sectional study based on the general population of Santa Fe, Argentina (non-probabilistic sample) carried out between July and November 2020. A subgroup of 20 seropositive individuals was followed-up to analyze IgG persistence. For the IgG anti-SARS-CoV-2 antibodies detection, the COVID-AR IgG® ELISA kit was used. RESULTS: 3 000 individuals were included conforming asymptomatic and pauci-symptomatic groups (n=1 500 each). From the total sample, only 8.83% (n=265) presented reactivity for IgG anti-SARS-CoV-2. A significant association was observed between positive anti-SARS-CoV-2 IgG and a history of contact with a confirmed case; the transmission rate within households was approximately 30%. In the pauci-symptomatic group, among the seropositive ones, anosmia and fever presented an OR of 16.8 (95% CI 9.5-29.8) and 2.7 (95% CI 1.6-4.6), respectively (p <0.001). In asymptomatic patients, IgG levels were lower compared to pauci-symptomatic patients, tending to decline after 4 months since the symptoms onset. CONCLUSION: We observed a low seroprevalence, suggestive of a large population susceptible to the infection. Anosmia and fever were independent significant predictors for seropositivity. Asymptomatic patients showed lower levels of antibodies during the 5-month follow-up. IgG antibodies tended to decrease over the end of this period regardless of symptoms.

Analysis of Asymptomatic and Presymptomatic Transmission in SARS-CoV-2 Outbreak, Germany, 2020.

We determined secondary attack rates (SAR) among close contacts of 59 asymptomatic and symptomatic coronavirus disease case-patients by presymptomatic and symptomatic exposure. We observed no transmission from asymptomatic case-patients and highest SAR through presymptomatic exposure. Rapid quarantine of close contacts with or without symptoms is needed to prevent presymptomatic transmission.

A case of aortic dissection with highly suggestive features of COVID-19.

INTRODUCTION: Aortic dissection is a cardiovascular emergency with an overall in-hospital mortality rate of 27.4%, and with every hour without intervention, the mortality rate increases by 1%-2% in the first 48 hours. Thoracic aortic dissection typically presents with tearing chest, back, or abdominal pain. Coronavirus disease 2019 (COVID-19) is a viral disease caused by severe acute respiratory syndrome-coronavirus 2 (SARS-Cov2), which has been declared a pandemic by the World Health Organization (WHO) and usually manifests with respiratory symptoms, including cough, shortness of breath, flu-like symptoms, and fever. This case report highlights an important impact of the COVID-19 pandemic on the identification and management of aortic dissection in the emergency department. CASE REPORT: A 35-year-old Bahraini male, a suspected case of Marfan syndrome, presented with complaints of shortness of breath and worsening productive cough after returning from the United States (U.S). He denied any chest, back, or abdominal pain, dizziness, weakness in any limb, gait disturbance, headache, or change in vision. He was considered high risk for COVID-19 because of the recent travel and respiratory symptoms and was diagnosed incidentally with ascending aortic dissection along with a right lung consolidation. His SARS-Cov2 PCR came negative thrice during hospital stay, and he underwent elective cardiothoracic surgery. CONCLUSION: The COVID-19 pandemic has been a major stressor for the healthcare system worldwide, inflicting serious threats. Aortic dissection is one of the major life-threatening diseases that needs to be identified early on in the emergency department; however, in this case delayed diagnosis raised significant concerns due to underlying evolving triaging system for COVID-19 and atypical and overlapping clinical presentation. Further research is needed to look for COVID-19-associated factors, affecting the standard of care in the emergency department. Improving handover can directly impact patient care; therefore, it should be optimized.