November 30, 2020
COVID-19
Modeling the impact of school reopening on SARS-CoV-2 transmission using contact structure data from Shanghai. School closures and re-openings have been a subject of heated debate throughout the pandemic. Evidence suggests children under 10-years-old are less susceptible to SARS-CoV-2 and less likely to transmit the virus to adults. Although school closure has severe consequences for children’s support networks and development, it has consisted a widespread measure in response to the pandemic. In this study, researchers used a dataset of contact structures from pre-and post-lockdown to model community transmission under various school scenarios. According to the results, reopening schools for all children would maintain a post-intervention R0 < 1 (compared to a baseline/pre-lockdown R0 of 3.3) if daily contacts among children aged 10-19 were reduced to 33% of baseline. Results remained robust after varying children’s susceptibility to the virus and gradual increases in contacts in the wider community. Researchers concluded that using local contact data in mathematical models can be especially helpful in guiding school re-opening decisions. [BMJ Public Health]
Transmission heterogeneities, kinetics, and controllability of SARS-CoV-2. A team of investigators from China and the US analyzed epidemiological data on 1,178 COVID-19 patients and their 15,648 contacts in Hunan, China, to investigate the role of transmission heterogeneity. The analysis revealed that 80% of secondary infections were connected to 15% of SARS-CoV-2 primary infections, indicating substantial transmission heterogeneities. While the lockdown period was shown to increase household transmission risk, healthcare contacts posed the lowest risk of transmission, reinforcing the importance of adequate protective measures taken in hospitals and healthcare centers. Overall the findings supported the notion that SARS-CoV-2 transmission is facilitated by close proximity, confined environment, and high frequency of contact. Similar to what has been seen in other studies, the infectiousness profile of a typical SARS-CoV-2 patient peaked just before symptom onset, complicating epidemic control efforts and stressing the importance of targeted mitigation strategies and continuous testing. [Science]
County-level predictors of COVID-19 cases and deaths in the united states: what happened, and where do we go from here? Researchers at Pfizer Vaccines conducted a county-level analysis investigating relationships between COVID-19 cases and deaths and sociodemographic factors in the United States. Using negative binomial mixed-effects regression models, they found significant associations between higher case rates and counties that were more urbanized or had more women, 20-49-year-olds, racial and ethnic minorities, and income inequalities among other factors. Higher mortality rates were associated with higher proportions of 20-49-year-olds, suggesting younger people indirectly impact mortality rates via transmission to higher-risk individuals. Results support existing evidence that the pandemic has disproportionately affected minority and vulnerable groups. These groups, as well as women, may make up higher proportions of healthcare and essential workers who are unable to work from home. The authors concluded that ensuring prevention measures and vaccines reach vulnerable communities will be crucial in mitigating the negative effects of the pandemic. [Clinical Infectious Diseases]
Older adults and the mental health effects of COVID-19. In a letter to JAMA, experts summarized evidence on the impact that the COVID-19 pandemic has had on the mental health of older adults. Evidence suggested that despite the fact that older adults have been disproportionately affected by the COVID-19 pandemic, they may be less negatively affected by mental health outcomes than other age groups. A survey from CDC conducted in June 2020 demonstrated that among the 933 participants aged 65 years or older, few reported anxiety disorder (6.2%), depressive disorder (5.8%), or trauma- or stress-related disorder (TSRD) (9.2%), whereas the percentages among 895 participants aged 45 – 64 years, were 16.1%, 14.4%, 17.2%, respectively. In other recent studies, a significant inverse correlation was demonstrated between loneliness and wisdom, and loneliness and empathy, leading the authors to suggest that wisdom and empathy may partially contribute to the resilience enabling the older adults to deal with the adverse effects of the pandemic. However, the authors emphasized that studies on mental health during the COVID-19 pandemic may only deal with short-term outcomes and that findings from population-level studies may not capture heterogeneity at the individual, community or environmental level. [JAMA]
Immunomodulation as treatment for severe COVID-19. In a systematic review on current treatment modalities for severe COVID-19, accumulating evidence indicated that during the course of severe SARS-CoV-2 infection, the viral load peaked early and led to the dysfunction of both innate and adaptive immune systems, which persisted well after viral clearance. The authors underscored that given the heterogeneity in clinical presentation, a personalized treatment approach incorporating both anti-virals and immunomodulators as treatment options should be considered. In this context, the anti-viral drug remdesivir targeting viral RNA polymerase was shown to improve time to recovery, whereas dexamethasone, an anti-inflammatory and immunosuppressant, was shown to reduce mortality among the critically ill receiving mechanical ventilation. Other immunomodulating drugs such as interferons, interleukin receptor blockers, and kinase inhibitors were also used to treat severe COVID-19 patients. However, some of these treatments were associated with increased risks of secondary infectious and other complications, warranting well-designed randomized clinical trials to detail dose, the timing of administration, and any potential benefits. [Clinical Infectious Diseases]
Drug Resistance and Global Health
Effect of antibiotic use within the first 48 hours of life on the preterm infant microbiome. Researchers from the University of Chicago conducted a randomized, double-blinded placebo-controlled trial to investigate any effects that the empiric use of broad-spectrum antibiotics in low-risk infants during the first 48 hours of life may have on the developing microbiome. The study, involving 22 infants with similar clinical characteristics, failed to show that withholding standard intravenous antibiotics immediately after birth, improved the microbiome or clinical outcomes; no significant differences in microbiome diversity (P = 0.22; R2 = 0.064) and species richness (P = 0.38; R2 = 0.025) were detected. While acknowledging the limitations stemming from the small study size, the authors concluded that initial empirical antibiotic therapy in preterm infants may not be harmful to the developing microbiome. [JAMA Pediatrics]
COVID -19, misinformation, and antimicrobial resistance. In an editorial letter to BMJ, researchers expressed their concern on the wide-spread misinformation on antibiotics as a treatment for COVID-19 and its potential impact on antibiotic resistance. Citing a study reporting antibiotic use in 71% of COVID-19 patients when only 4% had bacterial infections, as well as articles and surveys revealing large scale misinformation and overemphasis on the role of antimicrobials for COVID-19 treatment, the authors urge for better communication of scientific evidence to the public and medical professionals. Proper communication on the role of antibiotics on COVID-19 treatment was deemed especially important in low and middle-income countries with an already high burden of multi-resistant organisms. With policymakers and clinicians struggling to keep up with the rapidly evolving evidence on the management of COVID-19, the authors called on big organizations such as WHO and CDC to use their digital platforms to correctly address misinformation and associated myths on antimicrobials as primary treatment for COVID-19. [BMJ]
Predictors and outcomes of HAIs in COVID-19 patients. Critically ill COVID-19 patients are likely to receive catheters and ventilators and have longer hospital stays, and as a result, may be at increased risk of hospital-acquired infections (HAIs). In a retrospective analysis of adult COVID-19 patients at a hospital in Northeast Georgia, researchers used electronic medical records to investigate rates of HAIs, hospital mortality, and explore risk factors. Among 1,565 patients, 59 (3.7%) developed HAIs. Of 140 total HAIs from 73 different organisms, 53 were bacteremia, 67 were pneumonia, and 17 were urinary tract infections. Results of multivariate analyses indicated that higher HAI rates were associated with the use of tocilizumab, steroids, hydroxychloroquine, and acute kidney injury requiring hemodialysis. Length of hospital stay was longer in patients with secondary infections, however, these infections were not associated with increased mortality after multivariate analysis. Despite being a single-center study, findings can inform COVID-19 treatment, specifically the use of therapies shown to increase the risk of HAIs without proven benefits against COVID-19. [International Journal of Infectious Diseases]
Characterization and source investigation of multidrug-resistant Salmonella Anatum from a sustained outbreak, Taiwan. Nontyphoidal Salmonella (NTS) is a major cause of foodborne diseases worldwide. Furthermore, emerging antibiotic resistance has led to increased prevalence, disease severity, and death, requiring treatment with last-line antimicrobial drugs. Researchers in Taiwan investigated a Salmonella enterica serovar Anatum (S.Anatum) outbreak (relatively uncommon for human infections), by examining clinical and laboratory characteristics from 278 patients and Salmonella isolates derived from food samples from various supermarkets and traditional markets. The investigation revealed that pork and poultry were vehicles for transmission and that contaminated meat contributed to high rates of infections among children. Whole-genome sequencing of isolates revealed high similarity between Taiwan and international isolates, implying global dissemination of S.Anatum clone and highlighting the public health value of data sharing in mapping and fighting antimicrobial resistance. [CDC, Emerging Infectious Diseases]
Exploring perspectives on antimicrobial stewardship: a qualitative study of health managers in Kenya. A cross-sectional, qualitative, multicenter study was conducted in three hospitals in Kenya with the objective to understand the perspectives of hospital managers on antimicrobial stewardship (AMS), and identify areas of engagement while addressing potential barriers to change. While the health managers were aware of the fundamental importance of AMS in combating rising antimicrobial resistance, AMS was not found to be well implemented and developed, and this was demonstrated by lack of core AMS components such as hospital antimicrobial formulary, adequate laboratory competency, staff training and communication on antimicrobial audits. The study’s findings underlined the importance of understanding and incorporating the perspectives of health managers on the existing contextual mechanisms that can be leveraged to establish robust AMS programs in the fight against antimicrobial resistance. [BMC]
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