To determine the impact of a booster dose on the humoral response in individuals inoculated with a complete schedule of any SARS-CoV-2 vaccine, we evaluated the neutralizing antibody (NAb) titres of ...homologous or heterologous booster doses over a 90-days period in CoronaVac vaccinees from 3 centres in Santiago, Chile.
Individuals previously inoculated with 2 doses of CoronaVac (N = 523) were recruited in the context of the REFUERZO clinical trial (NCT04992182) and received either placebo (N = 129), or a booster dose of CoronaVac (N = 134), BNT162b2 (N = 133), or ChAdOx1 (N = 127). Pseudovirus neutralizing antibody titres (pVNT) were determined at baseline (day 0) as well as at days 14, 30, 60, and 90 after booster dose administration.
Inoculating a booster dose increases the pVNTs titres at days 14 and 30 in all groups, (13.5- and 12.0-fold increase for the CoronaVac group; 247.0- and 212.3-fold increase for the BTN162b2 group; and 89.1- and 128.1-fold increase for ChAdOx1 at each time point, respectively) with a decline observed at days 60 and 90. However, although pVNTs remained significantly higher for the BTN162b2 and ChAdOx1 groups at days 60 and 90, NAb titres reached baseline levels in the CoronaVac group at 90 days after inoculation.
A single heterologous booster (BTN162b2 or ChAdOx1) in individuals who completed the CoronaVac primary series resulted in an important increase in NAb titres remaining significantly higher at least for 90 days. These data may directly impact middle- and low-income countries currently using CoronaVac as the main vaccination strategy.
Abstract
Early case detection and isolation of infected individuals are critical to controlling coronavirus disease 2019 (COVID-19). Reverse transcription polymerase chain reaction (RT-PCR) is ...considered the gold standard for the diagnosis of severe acute respiratory syndrome coronavirus 2 infection, but false negatives do occur. We built a user-friendly online tool to estimate the probability of having COVID-19 with negative RT-PCR results and thus avoid preventable transmission.
Abstract
Background
The impact of coronavirus disease 2019 (COVID-19) on antimicrobial use (AU) and resistance has not been well evaluated in South America. These data are critical to inform national ...policies and clinical care.
Methods
At a tertiary hospital in Santiago, Chile, between 2018 and 2022, subdivided into pre- (3/2018–2/2020) and post–COVID-19 onset (3/2020–2/2022), we evaluated intravenous AU and frequency of carbapenem-resistant Enterobacterales (CRE). We grouped monthly AU (defined daily doses DDD/1000 patient-days) into broad-spectrum β-lactams, carbapenems, and colistin and used interrupted time-series analysis to compare AU during pre- and post-pandemic onset. We studied the frequency of carbapenemase-producing (CP) CRE and performed whole-genome sequencing analyses of all carbapenem-resistant (CR) Klebsiella pneumoniae (CRKpn) isolates collected during the study period.
Results
Compared with pre-pandemic, AU (DDD/1000 patient-days) significantly increased after the pandemic onset, from 78.1 to 142.5 (P < .001), 50.9 to 110.1 (P < .001), and 4.1 to 13.3 (P < .001) for broad-spectrum β-lactams, carbapenems, and colistin, respectively. The frequency of CP-CRE increased from 12.8% pre–COVID-19 to 51.9% after pandemic onset (P < .001). The most frequent CRE species in both periods was CRKpn (79.5% and 76.5%, respectively). The expansion of CP-CRE harboring blaNDM was particularly noticeable, increasing from 40% (n = 4/10) before to 73.6% (n = 39/53) after pandemic onset (P < .001). Our phylogenomic analyses revealed the emergence of two distinct genomic lineages of CP-CRKpn: ST45, harboring blaNDM, and ST1161, which carried blaKPC.
Conclusions
AU and the frequency of CP-CRE increased after COVID-19 onset. The increase in CP-CRKpn was driven by the emergence of novel genomic lineages. Our observations highlight the need to strengthen infection prevention and control and antimicrobial stewardship efforts.
The increased usage of carbapenems and broad-spectrum β-lactams during the COVID-19 pandemic was associated with a higher prevalence of carbapenemase-producing Klebsiella pneumoniae in a public hospital in Chile. We observed emergence and spread of blaNDM ST45 during the pandemic.
•We assess COVID-19 lockdowns' effects on Chilean businesses (2020–2021).•Lockdowns reduced sales, affecting MSMEs and select industries.•Vaccination campaign and mobility pass mitigated negative ...effects.•Targeted support needed for MSMEs and vulnerable industries affected by NPIs.•Post-vaccine, easing mobility restrictions improved economic recovery.
This study evaluates the effects of COVID-19 lockdowns, differentiated by their stringency, on the sales of Chilean businesses across various size categories and industries throughout 2020 and 2021. It also explores the role of the vaccination campaign and the implementation of the Mobility Pass in mitigating the negative economic effects of stringent containment measures.
The study uses administrative data from the Chilean Internal Revenue Service (SII), examining sales across different business sizes and industries, from March 2020 to December 2021. Through an econometric analysis, we estimate the effects of lockdowns on business sales during two distinct periods: initial reliance on dynamic non-pharmaceutical interventions (NPIs) pre-vaccine, and a subsequent stage characterized by high vaccine uptake and reduced NPI stringency.
Lockdowns significantly reduced sales across all business sizes and most industries during the first period, with microenterprises and certain service sectors experiencing the highest decline. The national vaccination campaign and the introduction of the Mobility Pass in the second period appears to have mitigated the negative effects of lockdowns, primarily benefiting micro and small firms.
The study highlights the trade-offs between health and economic outcomes during the pandemic, stressing the importance to alleviate mobility restrictions post-vaccine rollout to ease the economic strain on businesses. The findings call for targeted support measures for MSMEs and vulnerable industries affected by NPIs.
Background/Objectives
Patients colonized with toxinogenic strains of
Clostridium difficile
have an increased risk of subsequent infection. Given the potential role of the gut microbiome in increasing ...the risk of
C. difficile
colonization, we assessed the diversity and composition of the gut microbiota among long-term care facility (LTCF) residents with advanced dementia colonized with
C. difficile
.
Design
Retrospective analysis of rectal samples collected during a prospective observational study.
Setting
Thirty-five nursing homes in Boston, Massachusetts.
Participants
Eighty-seven LTCF residents with advanced dementia.
Measurements
Operational taxonomic units were identified using 16S rRNA sequencing. Samples positive for
C. difficile
were matched to negative controls in a 1:3 ratio and assessed for differences in alpha diversity, beta diversity, and differentially abundant features.
Results
Clostridium difficile
sequence variants were identified among 7/87 (8.04%) residents. No patient had evidence of
C. difficile
infection. Demographic characteristics and antimicrobial exposure were similar between the seven cases and 21 controls. The overall biodiversity among cases and controls was reduced with a median Shannon index of 3.2 (interquartile range 2.7–3.9), with no statistically significant differences between groups. The bacterial community structure was significantly different among residents with
C. difficile
colonization versus those without and included a predominance of
Akkermansia
spp.,
Dermabacter
spp.,
Romboutsia
spp.,
Meiothermus
spp.,
Peptoclostridium
spp., and
Ruminococcaceae
UGC 009.
Conclusion
LTCF residents with advanced dementia have substantial dysbiosis of their gut microbiome. Specific taxa characterized
C. difficile
colonization status.
Abstract
Background
Antimicrobial resistance is a global threat, heavily impacting low- and middle-income countries. This study estimated antimicrobial-resistant gram-negative bacteria (GNB) fecal ...colonization prevalence in hospitalized and community-dwelling adults in Chile before the coronavirus disease 2019 pandemic.
Methods
From December 2018 to May 2019, we enrolled hospitalized adults in 4 public hospitals and community dwellers from central Chile, who provided fecal specimens and epidemiological information. Samples were plated onto MacConkey agar with ciprofloxacin or ceftazidime added. All recovered morphotypes were identified and characterized according to the following phenotypes: fluoroquinolone-resistant (FQR), extended-spectrum cephalosporin-resistant (ESCR), carbapenem-resistant (CR), or multidrug-resistant (MDR; as per Centers for Disease Control and Prevention criteria) GNB. Categories were not mutually exclusive.
Results
A total of 775 hospitalized adults and 357 community dwellers were enrolled. Among hospitalized subjects, the prevalence of colonization with FQR, ESCR, CR, or MDR-GNB was 46.4% (95% confidence interval CI, 42.9–50.0), 41.2% (95% CI, 37.7–44.6), 14.5% (95% CI, 12.0–16.9), and 26.3% (95% CI, 23.2–29.4). In the community, the prevalence of FQR, ESCR, CR, and MDR-GNB colonization was 39.5% (95% CI, 34.4–44.6), 28.9% (95% CI, 24.2–33.6), 5.6% (95% CI, 3.2–8.0), and 4.8% (95% CI, 2.6–7.0), respectively.
Conclusions
A high burden of antimicrobial-resistant GNB colonization was observed in this sample of hospitalized and community-dwelling adults, suggesting that the community is a relevant source of antibiotic resistance. Efforts are needed to understand the relatedness between resistant strains circulating in the community and hospitals.
We report a high colonization burden resulting from antimicrobial-resistant Gram-negative bacteria in hospitals and a community in Chile. Strikingly, 29% (95% confidence interval, 24–34) of community-dwelling adults carried extended-spectrum cephalosporin-resistant Enterobacterales, highlighting the magnitude of the community reservoir of antimicrobial resistance.
Background. The emergence and dissemination of multidrug-resistant organisms (MDROs) is a global threat. Characterizing the human microbiome among hospitalized patients and identifying unique ...microbial signatures among those patients who acquire MDROs may identify novel infection prevention strategies. Methods. Adult patients admitted to 5 general medical-surgical floors at a 649-bed, tertiary care center in Boston, Massachusetts, were classified according to in-hospital antimicrobial exposure and MDRO colonization status. Within 48 hours of hospital admission (baseline) and at discharge (follow-up), rectal swab samples were obtained, and compared with samples from an external control group of healthy persons from the community. DNA was extracted from samples, next-generation sequencing performed, and microbial community structure and taxonomic features assessed, comparing those who acquired MDROs and those who had not, and the external controls. Results. Hospitalized patients (n = 44) had reduced microbial diversity and a greater abundance of Escherichia spp. and Enterococcus spp. than healthy controls (n = 26). Among hospitalized patients, 25 had no MDROs at the time of the baseline sample and were also exposed to antimicrobials. Among this group, 7 (28%) acquired ≥1 MDRO; demographic and clinical characteristics were similar between MDRO-acquisition and MDRO-nonacquisition groups. Patients in the nonacquisition group had consistently higher Lactobacillus spp. abundance than those in the acquisition group (linear discriminant score, 3.97; P = .04). Conclusions. The fecal microbiota of the hospitalized subjects had abnormal community composition, and Lactobacillus spp. was associated with lack of MDRO acquisition, consistent with a protective role.
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