July 6 | Daily COVID-19 LST Report


· A cross-sectional study (n=72,417 from 27 countries) found that elderly people (ages 60-80) reported less compliance with preventative measures against COVID-19 such as mask wearing, despite this population being at highest risk for severe disease and government interventions specifically targeting them. This suggests governments may need to revise their current strategies to promote preventative measures in elderly populations.

· A qualitative focus group in Australia found that community members agree there is a “degree” of responsibility for paramedics to continue working through the COVID-19 pandemic but were ambivalent on if that obligation applies to crisis care beyond routine operations. Several recurring themes include context of obligation, acceptable risk, access to PPE, and legal and ethical guidelines. The authors propose a “Crisis Standards of Care” consensus to define the legal and ethical bounds for healthcare professionals during times of crisis.

· Serial testing of 98 incarcerated or detained individuals with known COVID-19 exposure in a Louisiana correctional facility identified a large number of asymptomatic and presymptomatic cases that were not originally identified through symptom screening. The authors conclude that rapid detection, serial testing, cohorting, and isolation of COVID-19-infected individuals and their close contacts are all important to reduce SARS-CoV-2 transmission in congregated settings and, by extension, the outside community.


· Modeling and mechanism-based research include the following:

o If transmission is highly dependent on those with active symptoms, countries with older populations are likely to have the highest reproductive numbers, while if transmission is equal between symptomatic and asymptomatic cases, countries with younger populations will have the highest reproductive ratios.

o Of the estimated 87,000 excess deaths in the US from COVID-19, only 56,246 were a direct result of disease, while increased death from heart disease (89%), cerebrovascular disease (35%), Alzheimer's (64%), and diabetes (96%) likely represent indirect mechanisms of increased mortality during the pandemic.

o The transition from sub-exponential to exponential transmission occurs eight weeks after the first case cluster, and likely depends on early public health responses, such as limiting spread on public transit in major metropolitan areas.

· A CDC multi-state telephone survey of 350 adult inpatients and outpatients who had a positive SARS-CoV-2 test found inpatients were more likely to be older, minorities, and from lower socioeconomic groups. Also, 46% of participants reported close contact with an infected individual (most commonly a family member [45%] or work colleague [34%]) suggesting that increased screening and contact tracing are necessary to control the R0.

· This ecological study in 38 European nations found a negative association between prevalence of smoking and COVID-19 cases (p<0.0001) and no direct association between smoking prevalence and COVID-19 mortality (p=0.6260

· This retrospective cohort study from 2 academic hospitals in New York City found that COVID-19 patients were more likely to have an acute ischemic stroke than influenza A/B patients (n = 1486) (OR 7.6; 95% CI, 2.3-25.2), further implicating a unique hypercoagulable state in COVID-19 disease.

Understanding the Pathology:

· A study of 6 severely ill and 6 recovering COVID-19 patients in China period found that higher disease severity was associated with increased CD4+ and CD8+ T cells, higher levels of sydecan-1 and interleukin-6 (IL-6), and increased neutralizing antibodies correlated with disease remission.

· In-vitro experiments at Johns Hopkins University detected expression of the ACE-2 receptors in neuronal cells, SARS-CoV-2 presence in neurons, and increased viral replication in neural cell lysate 72 hours post infection suggesting a possible mechanism for direct CNS injury in COVID-19.

Transmission and Prevention:

· A review of COVID-10 vaccine development reports the majority of potential vaccines are intended to induce a neutralizing antibody response against the SARS-CoV-2 spike [S] protein, and the American “Warp Speed” program now has five front-line vaccine candidates based on mRNA or adenovirus vectors. Authors suggest that aggressive timelines due to urgency of need, adequate vaccine trials, and manufacturing and distribution are among the greatest challenges faced in vaccine development.

· A retrospective cohort study of 11,580 contacts of COVID-19 cases in Guangdong, China found that 4.4% of contacts were infected with SARS-COV-2, and risk of infection was highest in children and the 60-69 age range. They also found higher transmission with prolonged exposure during the symptomatic period of disease.


· A review of 12 reports of 90 patients in China who re-tested positive for SARS-CoV-2 via RT-PCR testing after discharge found that these patients were largely asymptomatic and re-tested positive despite proper discharge protocol (i.e. 2 negative results for SARS-CoV-2 RT-PCR 24 hours apart). Although the reasons for this phenomenon remain uncertain, the authors suggest testing respiratory and fecal samples simultaneously when discharging COVID-19 patients and educating patients on post-discharge quarantine, social distancing, and appropriate follow-up protocol.

· A retrospective cohort study conducted from 2 New York hospitals found that of the 38 COVID-19 patients who underwent tracheostomies 55% of patients (n=21) had weaned from ventilators, 18.4% had undergone decannulation (n=7), and 5.3% expired for reasons unrelated to surgery (n=2); no surgeons seroconverted. This suggests tracheostomy may be a safe and effective way to improve outcomes in respiratory failure.

R&D Diagnosis and Treatment:

· A prospectively study of 106 COVID-19 patients in Italy found that the volume of disease on CT was a predictor of short-term outcomes, while CRP better predicted the volume of disease (p<0.001). Therefore, these clinical markers may be useful for patient risk assessment when RT-PCR results cannot be quickly obtained.

· Automated chemiluminescent immunoassays (CLIA) for SARS-CoV-2 were developed and evaluated at 10 Chinese hospitals (972 patients and 586 community donor samples). They found the clinical sensitivity of IgM was 82.54, 92.93, and 84.62% before 7 days, 7-14 days, and after 14 days respectively, since onset of symptoms, and SARS-CoV-2 IgG showed clinical sensitivity of 80.95, 97.98, and 99.15%. This adds another potential diagnostic test for COVID-19 infection that the authors believe can be more accurate than current nucleic acid testing.

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