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Center For Disease Dynamics, Economics & Policy

Weekly Digest: Vaccine 2.0: Addressing new coronavirus mutations; Higher SARS-CoV-2 antibody seroprevalence in urban areas in India; The antimicrobial potential of cannabidiol. Procalcitonin and COVID-19 antimicrobial stewardship.


Vaccine 2.0: Moderna and other companies plan tweaks that would protect against new coronavirus mutations. Antibodies triggered by the Moderna vaccine appear less protective against the South African variant of COVID-19 (B.1.351). The company announced it would start developing boosters for new variants. To date, more transmissible variants have been discovered in the UK, Brazil, and South Africa. Preliminary research by Moderna, the US National Institutes of Health, and Columbia University found that the levels of antibodies needed to fight B.1.351 were at least six times higher than levels needed to neutralize a virus expressing the original protein. Moderna says it will commence phase I trials of two booster strategies: one comprising the third dose of its current vaccine and a new one adjusted to incorporate B. 1.351’s mutations. Interviewed scientists agree it is crucial to prepare for new variants as soon as possible and equally important to plan how future boosters will be distributed. [Science]

Higher SARS-CoV-2 antibody seroprevalence in urban areas in India. The second nationwide household serosurvey in India collected 29,082 samples from 700 villages in 70 districts. The key finding was an increase in seroprevalence from 0.73% in May to June to 7.0% in August to September 2020. In other words, one in 15 people aged 10 or older has had a SARS-CoV-2 infection in India as of August 18, 2020. This translates to 74 million cases in total or 26 to 32 infections per confirmed case of COVID-19. Furthermore, urban areas, and in particular urban slums, had higher percentages of seroprevalence. In one example, the urban slums of Mumbai reported 54.1% seroprevalence, much higher than the 16.1% reported for the rest of Mumbai. [The Lancet Global Health]

Increased psychological distress among children and adolescents during the pandemic in China. Researchers conducted a cross-sectional study to assess the mental health of 1199320 children and adolescents in China during the pandemic. The study revealed that 10.5% of students reported psychological distress. Compared with students who wore a face mask frequently, students who never wore a face mask had an increased risk of psychological distress (Odds Ratio, 2.59 [95% CI, 2.41 to 2.79]). Students who spent less than 0.5 hours per day exercising had increased odds of self-reported psychological distress compared with students who spent more than 1-hour exercising (OR, 1.64 [95% CI, 1.61 to 1.67]). Further, high school students had increased risk as compared to primary schoolers. (OR, 1.19 [95% CI, 1.15-1.23]).The researchers concluded that the prevalence of self-reported psychological stress among students during the pandemic was relatively high, making it necessary for governments, schools, and families to pay attention to and take measures to reduce the pandemic’s impact on children’s mental health. [JAMA Network Open] 

Longer persistence of SARS-COV-2 clusters among socioeconomically disadvantaged neighbourhoods. Researchers in Switzerland used a spatiotemporal cluster detection algorithm to monitor SARS-CoV-2 transmission dynamics. They found that SARS-CoV-2 clusters persisted significantly longer in socioeconomically disadvantaged neighbourhoods. The standardized deprivation index was associated with an increased spatial cluster persistence (hazard ratio [HR], 1.43 [95% CI, 1.28–1.59]). The clusters emerged on average 4 days earlier in the most deprived tercile than the moderately deprived and 6 days compared to the least deprived terciles. Further, the neighbourhood-level SARS-CoV-2 incidence rate ranged from 0 cases per 100,000 (interquartile range, IQR = 650) in the least deprived tercile to 465 (IQR = 866) in the most deprived tercile. The researchers concluded that the increased risk of infection among disadvantaged individuals might also be due to community transmission persistence. Highlighting the need for interventions mitigating inequalities in the risk of SARS-CoV-2 infection and, thus, of serious illness and mortality. [Frontiers in Public Health] 

An in-person and telemedicine “hybrid” system to improve cross-border critical care in COVID-19. Researchers from UC San Diego Health System described a hybrid (in-person/Tele-ICU) intervention implemented in three hospitals (one in the US and two in Mexico) in the populous sister city regions of San Diego-Tijuana and El Centro-Mexicali. Many US legal residents cross this border daily, and COVID-19 surges in the spring of 2019 required urgent multi-institutional collaboration. At each site, researchers identified gaps in existing ICU delivery mechanisms, provided recommendations, and launched a Tele-ICU service, in which clinicians presented virtual rounds and discussed the latest research. In interviews with clinicians from all hospitals, qualitative gains included increased confidence with prone positioning and safely extubating patients and increased access to life-saving therapies, such as extracorporeal membrane oxygenation. Survey results indicated that 78% of local healthcare providers felt more confident caring for critically ill COVID-19 patients. Findings from this study are limited due to the speed the crisis necessitated in developing the program. However, observational data illustrate the feasibility and cost-effectiveness of implementing a hybrid critical care program addressing community needs in a multi-cultural context. [Annals of Global Health]



Drug Resistance and Global Health

 The antimicrobial potential of cannabidiolAs the global threat of antimicrobial resistance intensifies, researchers seek alternatives to current antibiotics that face increasing levels of resistance. In Communications Biology, Australian researchers tested cannabidiol (CBD) against various bacterial strains using broth microdilution minimum inhibitory concentration assays. They found that CBD demonstrated a minimum inhibitory concentration (MIC) of 1–4 μg mL−1 against over 20 types of Gram-positive bacteria, including MRSA strains, multidrug-resistant (MDR) Streptococcus pneumoniaeEnterococcus faecalis, and the anaerobic bacteria Clostridioidesdifficile and Cutibacterium acnes. The MIC was also in this range, which indicates a high degree of effectiveness against the bacterium for highly resistant strains, including vancomycin-resistant S. aureus (VRSA), vancomycin-resistant enterococci (VRE), and the hypervirulent ribotype 027 strain of C. difficile. Authors found that CBD was generally inactive against 20 species of Gram-negative bacteria. However, it had selective activity against the World Health Organization (WHO) high priority drug-resistant pathogen N. gonorrhoeae. As CBD products begin to be approved by the United States FDA and other bodies for use as antibacterials, additional research will further explore the potential of CBD as a treatment for a bacterial infection that can minimize antibiotic resistance. [Nature]

One Health drivers of antibacterial resistance. Researchers in Thailand modelled antibiotic use, gut colonization with extended-spectrum beta-lactamase-producing bacteria and transmission, to project a reduction in human antibacterial resistance (ABR) over 20 years for each One Health driver (human, animal, and environmental antibacterial use). The study revealed that human antibacterial use was the most important factor in reducing ABR (65.7 to 99.7% reduction). The National Strategic Plan on AMR was projected to reduce human ABR by 12.2% (95% CI, 6.0 to 18.8%) alone and by 16.7% (95% CI, 8.5 to 24.9%) when supplemented with a 30% reduction in human ABU. The authors concluded that interventions focussed on reducing human ABU in parallel with improved hygiene and sanitation interventions could yield a much higher reduction in ABR. [One Health]

Procalcitonin, a possible antimicrobial stewardship tool and predictor of COVID-19 severity. A prospective cohort study of COVID-19 patients admitted to Austin Health (Melbourne, Australia) revealed that procalcitonin (PCT) levels were significantly associated with antibiotic use (P=0.03), earlier de-escalation to oral therapy (P=0.04), and requirement of supplemental oxygen requirements during admission (P=0.01). Serum PCT levels were also associated with C-reactive protein (P<0.01), lymphocytes (P=<0.01), ferritin (P<0.01) and lactate dehydrogenase (P=0.01). Antibiotic therapy was received by all patients in the high PCT group, by 20% in the medium PCT group and 40% in the low PCT group. Further, high PCT patients received an average of 1.5 additional days of intravenous antibiotics compared to medium and low groups. The study thus indicated that, in COVID-19 patients, the measurement of PCT and other clinical assessments could help develop decision-making algorithms and play an important role in antimicrobial stewardship interventions. [Cambridge University Press]  

Is it cost-effective to use a 2% chlorhexidine wipes bath to reduce central-line associated bloodstream infection? A quasi-experimental study. The cost-effectiveness of employing chlorhexidine (CHG) wipes to reduce central-line associated bloodstream infections (CLABSI) was studied in a single tertiary care hospital in Brazil. Using CHG wipes saw a reduction in CLABSIs from 25 to 4; however, it was not significant due to a lack of statistical power. One exception was Klebsiella pneumoniae, which was the most common CLABSI pathogen in the hospital. Alternatively, the number of CLABSIs per 1000 central days was significantly reduced from 8.69 to 1.83. This decrease resulted in an exponential reduction in the cost of antibiotics employed from US$ 46,114.36 to US$ 4,177.50, which, when accounting for the cost of CHG wipes, resulted in an overall reduction in costs by over US$ 12,000, or 26.6%. While CHG wipes were shown to be cost-effective, more research is necessary on how effectively they reduce CLABSIs, especially with multidrug-resistant pathogens. [Brazilian Journal of Infectious Disease]

Strategies for financing social health insurance schemes for providing universal health care: a comparative analysis of five countries. Although many African countries have made Universal Health Coverage a political priority, they have encountered many barriers. A recent analysis of social health insurance schemes in Ghana, Kenya, Ethiopia, Rwanda, and Tanzania found that existing health insurance schemes vary widely. Ghana’s National Health Insurance Scheme was introduced in 2003 and is intended to cover all citizens, with some segments of the population exempt from paying premiums. Tanzania and Kenya have schemes specifically targeting citizens in the informal sector and programs that cover government and private-sector employees. Ethiopia is scaling up a community-based health insurance scheme, and Rwanda has mandated membership in its health insurance program. The study found that Ghana reported the highest level of out-of-pocket expenditure for health care at 40%, while Rwanda had the lowest level at 6.3%. The authors conclude that health insurance programs should be designed to cover all groups rather than rely on schemes targeted at various segments of populations. [Global Health Action]


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