Effectiveness of the fourth dose of COVID-19 vaccines against severe COVID-19 among adults 40 years or older in Brazil: a population-based cohort study

Background

The emergence of COVID-19 variants with immune scape and the waning of primary vaccine schemes effectiveness have prompted many countries to indicate first and second booster COVID-19 vaccine doses to prevent severe COVID-19. However, current available evidence on second booster dose effectiveness are mostly limited to high-income countries, older adults, and mRNA-based vaccination schemes scenarios. We aimed to investigate the relative vaccine effectiveness (rVE) of the fourth dose compared to three doses for severe COVID-19 outcomes in Brazil; and compare the rVE of a fourth dose with an mRNA vaccine compared to adenovirus-based product in the same settings.

Methods

We performed a target emulated trial using a population-based cohort of individuals aged 40 years or older who have received a homologous primary scheme of CoronaVac, ChAdOx1, or BNT162b2, and any third dose product and were eligible for the fourth dose in Brazil. The primary outcome was COVID-19 associated hospitalization or death. We built Cohort A matching individuals vaccinated with a fourth dose to individuals who received three doses to estimate the rVE of the fourth dose. We built Cohort B, a subset of Cohort A, matching mRNA-based (mRNA) to adenovirus-based fourth dose vaccinated individuals to compare their relative hazards for severe COVID-19.

Findings

46,693,484 individuals were included in Cohort A and 6,763,016 in Cohort B. 45% of them were aged between 40 and 60 years old, and 48% between 60 and 79 years old. In Cohort A, the most common previous series was a ChAdOx1 two-dose followed by BNT162b2 (44%), and a CoronaVac two-dose followed by a BNT162b2 (36%). Among those fourth dose vaccinated, 36.9% received ChAdOx1, 32.7% Ad26.COV2.S, 25.8% BNT162b2, and 4.7% CoronaVac. In Cohort B, among those who received an adenovirus fourth dose, 53.7% received ChAdOx1 and 46.3% received Ad26.COV2.S. The estimated rVE for the primary outcome of four doses compared to three doses was 44.1% (95% CI 42.3-46.0), with some waning during follow-up (rVE 7-60 days 46.8% [95% CI 44.4-49.1], rVE after 120 days 33.8% [95% CI 18.0-46.6]). Among fourth dose vaccinated individuals, mRNA-based vaccinated individuals had lower hazards for hospitalization or death compared to adenovirus-vaccinated individuals (HR 0.81, 95% CI 0.75-0.87). After 120 days, no difference in hazards between groups was observed (HR 1.35, 95% CI 0.93-1.97). Similar findings were observed for hospitalization and death separately, except no evidence for differences between fourth dose brands for death in Cohort B.

Interpretation

In a heterogeneous scenario of primary and first booster vaccination combinations, a fourth dose provided meaningful and durable protection against severe COVID-19 outcomes. Compared to adenovirus-based booster, a fourth dose wild-type mRNA vaccine was associated with immediate lower hazards of hospitalization or death unsustained after 120 days.

Funding

None.

The Association Between Prepandemic ICU Performance and Mortality Variation in COVID-19: A Multicenter Cohort Study of 35,619 Critically Ill Patients

BACKGROUND

During the COVID-19 pandemic, ICUs remained under stress and observed elevated mortality rates and high variations of outcomes. A knowledge gap exists regarding whether an ICU performing best during nonpandemic times would still perform better when under high pressure compared with the least performing ICUs.

RESEARCH QUESTION

Does prepandemic ICU performance explain the risk-adjusted mortality variability for critically ill patients with COVID-19?

STUDY DESIGN AND METHODS

This study examined a cohort of adults with real-time polymerase chain reaction-confirmed COVID-19 admitted to 156 ICUs in 35 hospitals from February 16, 2020, through December 31, 2021, in Brazil. We evaluated crude and adjusted in-hospital mortality variability of patients with COVID-19 in the ICU during the pandemic. Association of baseline (prepandemic) ICU performance and in-hospital mortality was examined using a variable life-adjusted display (VLAD) during the pandemic and a multivariable mixed regression model adjusted by clinical characteristics, interaction of performance with the year of admission, and mechanical ventilation at admission.

RESULTS

Thirty-five thousand six hundred nineteen patients with confirmed COVID-19 were evaluated. The median age was 52 years, median Simplified Acute Physiology Score 3 was 42, and 18% underwent invasive mechanical ventilation. In-hospital mortality was 13% and 54% for those receiving invasive mechanical ventilation. Adjusted in-hospital mortality ranged from 3.6% to 63.2%. VLAD in the most efficient ICUs was higher than the overall median in 18% of weeks, whereas VLAD was 62% and 84% in the underachieving and least efficient groups, respectively. The least efficient baseline ICU performance group was associated independently with increased mortality (OR, 2.30; 95% CI, 1.45-3.62) after adjusting for patient characteristics, disease severity, and pandemic surge.

INTERPRETATION

ICUs caring for patients with COVID-19 presented substantial variation in risk-adjusted mortality. ICUs with better baseline (prepandemic) performance showed reduced mortality and less variability. Our findings suggest that achieving ICU efficiency by targeting improvement in organizational aspects of ICUs may impact outcomes, and therefore should be a part of the preparedness for future pandemics.

Vaccine coverage and effectiveness against laboratory-confirmed symptomatic and severe Covid-19 in indigenous people in Brazil: a cohort study

BACKGROUND

Indigenous people have historically suffered devastating impacts from epidemics and continue to have lower access to healthcare and be especially vulnerable to respiratory infections. We estimated the coverage and effectiveness of Covid-19 vaccines against laboratory-confirmed Covid-19 cases among indigenous people in Brazil.

METHODS

We linked nationwide Covid-19 vaccination data with flu-like surveillance records and studied a cohort of vaccinated indigenous people aged ≥ 5 years between 18th January 2021 and 1st March 2022. We considered individuals unexposed from the date they received the first dose of vaccine until the 13th day of vaccination, partially vaccinated from the 14th day after the first dose until the 13th day after receiving the second dose, and fully vaccinated onwards. We estimated the Covid-19 vaccination coverage and used Poisson regression to calculate the relative risks (RR) and vaccine effectiveness (VE) of CoronaVac, ChAdOx1, and BNT162b2 against Covid-19 laboratory-confirmed cases incidence, mortality, hospitalisation, and hospital-progression to Intensive Care Unit (ICU) or death. VE was estimated as (1-RR)*100, comparing unexposed to partially or fully vaccinated.

RESULTS

By 1st March 2022, 48.7% (35.0-62.3) of eligible indigenous people vs. 74.8% (57.9-91.8) overall Brazilians had been fully vaccinated for Covid-19. Among fully vaccinated indigenous people, we found a lower risk of symptomatic cases (RR: 0.47, 95%CI: 0.40-0.56) and mortality (RR: 0.47, 95%CI: 0.14-1.56) after the 14th day of the second dose. VE for the three Covid-19 vaccines combined was 53% (95%CI:44-60%) for symptomatic cases, 53% (95%CI:-56-86%) for mortality and 41% (95%CI:-35-75%) for hospitalisation. In our sample, we found that vaccination did not reduce Covid-19 related hospitalisation. However, among hospitalised patients, we found a lower risk of progression to ICU (RR: 0.14, 95%CI: 0.02-0.81; VE: 87%, 95%CI:27-98%) and Covid-19 death (RR: 0.04, 95%CI:0.01-0.10; VE: 96%, 95%CI: 90-99%) after the 14th day of the second dose.

CONCLUSIONS

Lower coverage but similar Covid-19 VE among indigenous people than overall Brazilians suggest the need to expand access, timely vaccination, and urgently offer booster doses to achieve a great level of protection among this group.

What we talk about when we talk about COVID-19 vaccination campaign impact: a narrative review

Background

The lack of precise definitions and terminological consensus about the impact studies of COVID-19 vaccination leads to confusing statements from the scientific community about what a vaccination impact study is.

Objective

The present work presents a narrative review, describing and discussing COVID-19 vaccination impact studies, mapping their relevant characteristics, such as study design, approaches and outcome variables, while analyzing their similarities, distinctions, and main insights.

Methods

The articles screening, regarding title, abstract, and full-text reading, included papers addressing perspectives about the impact of vaccines on population outcomes. The screening process included articles published before June 10, 2022, based on the initial papers' relevance to this study's research topics. The main inclusion criteria were data analyses and study designs based on statistical modelling or comparison of pre- and post-vaccination population.

Results

The review included 18 studies evaluating the vaccine impact in a total of 48 countries, including 32 high-income countries (United States, Israel, and 30 Western European countries) and 16 low- and middle-income countries (Brazil, Colombia, and 14 Eastern European countries). We summarize the main characteristics of the vaccination impact studies analyzed in this narrative review.

Conclusion

Although all studies claim to address the impact of a vaccination program, they differ significantly in their objectives since they adopt different definitions of impact, methodologies, and outcome variables. These and other differences are related to distinct data sources, designs, analysis methods, models, and approaches.

Effect of walnut consumption on neuropsychological development in healthy adolescents: a multi-school randomised controlled trial

Background

Omega-3 fatty acids are critical for neuropsychological functioning. Adolescence is increasingly believed to entail brain vulnerability to dietary intake. The potential benefit on adolescent neurodevelopment of consuming walnuts, a source of omega-3 alpha-linolenic acid (ALA), remains unclear.

Methods

We conducted a 6-month multi-school-based randomised controlled nutrition intervention trial to assess whether walnut consumption has beneficial effects on the neuropsychological and behavioural development of adolescents. The study took place between 04/01/2016 and 06/30/2017 in twelve different high schools in Barcelona, Spain (ClinicalTrials.gov Identifier: NCT02590848). A total of 771 healthy teenagers aged 11-16 years were randomised into two equal groups (intervention or control). The intervention group received 30 g/day of raw walnut kernels to be incorporated into their diet for 6 months. Multiple primary endpoints concerning neuropsychological (working memory, attention, fluid intelligence, and executive function) and behavioural (socio-emotional and attention deficit hyperactivity disorder [ADHD] symptoms) development were assessed at baseline and after intervention. Red blood cell (RBC) ALA status was determined at baseline and 6 months as a measure of compliance. Main analyses were based on intention-to-treat using a linear mixed-effects model. A per-protocol effect of the intervention was analysed using inverse-probability weighting to account for post-randomisation prognostic factors (including adherence) using generalised estimating equations.

Findings

In intention-to-treat analyses, at 6 months there were no statistically significant changes between the intervention and control groups for all primary endpoints. RBC ALA (%) significantly increased only in the intervention group, coefficient = 0.04 (95% Confidence Interval (CI) = 0.03, 0.06; p < 0.0001). The per-protocol (adherence-adjusted) effect on improvement in attention score (hit reaction time variability) was -11.26 ms (95% CI = -19.92, -2.60; p = 0.011) for the intervention group as compared to the control group, improvement in fluid intelligence score was 1.78 (95% CI = 0.90, 2.67; p < 0.0001), and reduction of ADHD symptom score was -2.18 (95% CI = -3.70, -0.67; p = 0.0050).

Interpretation

Our study suggested that being prescribed eating walnuts for 6 months did not improve the neuropsychological function of healthy adolescents. However, improved sustained attention, fluid intelligence, and ADHD symptoms were observed in participants who better complied with the walnut intervention. This study provides a foundation for further clinical and epidemiological research on the effect of walnuts and ALA on neurodevelopment in adolescents.

Funding

This study was supported by Instituto de Salud Carlos III through the projects 'CP14/00108, PI16/00261, PI21/00266' (co-funded by European Union Regional Development Fund 'A way to make Europe'). The California Walnut Commission (CWC) has given support by supplying the walnuts for free for the Walnuts Smart Snack Dietary Intervention Trial.

Effectiveness of a multicomponent intervention to face the COVID-19 pandemic in Rio de Janeiro's favelas: difference-in-differences analysis

INTRODUCTION

Few community-based interventions addressing the transmission control and clinical management of COVID-19 cases have been reported, especially in poor urban communities from low-income and middle-income countries. Here, we analyse the impact of a multicomponent intervention that combines community engagement, mobile surveillance, massive testing and telehealth on COVID-19 cases detection and mortality rates in a large vulnerable community (Complexo da Maré) in Rio de Janeiro, Brazil.

METHODS

We performed a difference-in-differences (DID) analysis to estimate the impact of the multicomponent intervention in Maré, before (March-August 2020) and after the intervention (September 2020 to April 2021), compared with equivalent local vulnerable communities. We applied a negative binomial regression model to estimate the intervention effect in weekly cases and mortality rates in Maré.

RESULTS

Before the intervention, Maré presented lower rates of reported COVID-19 cases compared with the control group (1373 vs 1579 cases/100 000 population), comparable mortality rates (309 vs 287 deaths/100 000 population) and higher case fatality rates (13.7% vs 12.2%). After the intervention, Maré displayed a 154% (95% CI 138.6% to 170.4%) relative increase in reported case rates. Relative changes in reported death rates were -60% (95% CI -69.0% to -47.9%) in Maré and -28% (95% CI -42.0% to -9.8%) in the control group. The case fatality rate was reduced by 77% (95% CI -93.1% to -21.1%) in Maré and 52% (95% CI -81.8% to -29.4%) in the control group. The DID showed a reduction of 46% (95% CI 17% to 65%) of weekly reported deaths and an increased 23% (95% CI 5% to 44%) of reported cases in Maré after intervention onset.

CONCLUSION

An integrated intervention combining communication, surveillance and telehealth, with a strong community engagement component, could reduce COVID-19 mortality and increase case detection in a large vulnerable community in Rio de Janeiro. These findings show that investment in community-based interventions may reduce mortality and improve pandemic control in poor communities from low-income and middle-income countries.

Maré cohort-profile: a prospective cohort study based in a socially vulnerable community during the COVID-19 pandemic in Rio de Janeiro, Brazil

Background: Socially vulnerable populations were vastly affected by the COVID-19 pandemic. The pandemic significantly impacted Brazil, pressuring its healthcare system for several months, with high mortality rates, even among the youngest population. Cohort studies combining disease surveillance are essential for understanding virus circulation in the community, surrogates of protection, vaccine effectiveness, and demand for health resources. Methods: Here, we present the protocol for a community-based prospective cohort study in the largest complex of favelas (slums) in Rio de Janeiro, Brazil (Complexo da Maré). The study participants are residents initially recruited during a massive vaccination campaign in the community. Five waves of data collection at approximately six-month intervals were planned. The first two waves have been completed at the time of writing this study protocol, and the third is underway. The protocol comprises interviews, blood sampling, and records linkage with secondary data to enrich the profiles of cohort participants and community information. We will describe COVID-19 seroprevalence, socio-demographic characteristics, and the burden of COVID-19, followed by estimating the association of socioeconomic factors and the burden of disease with seroprevalence. Discussion: The primary aims of the study are to assess COVID-19 clinical, epidemiological and genomic profiles and outcomes in residents from Maré, including vaccine effectiveness, surrogates of immune protection, virus transmission in households, and the overall burden of the pandemic.

Association between primary or booster COVID-19 mRNA vaccination and Omicron lineage BA.1 SARS-CoV-2 infection in people with a prior SARS-CoV-2 infection: A test-negative case-control analysis

BACKGROUND

The benefit of primary and booster vaccination in people who experienced a prior Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection remains unclear. The objective of this study was to estimate the effectiveness of primary (two-dose series) and booster (third dose) mRNA vaccination against Omicron (lineage BA.1) infection among people with a prior documented infection.

METHODS AND FINDINGS

We conducted a test-negative case-control study of reverse transcription PCRs (RT-PCRs) analyzed with the TaqPath (Thermo Fisher Scientific) assay and recorded in the Yale New Haven Health system from November 1, 2021, to April 30, 2022. Overall, 11,307 cases (positive TaqPath analyzed RT-PCRs with S-gene target failure [SGTF]) and 130,041 controls (negative TaqPath analyzed RT-PCRs) were included (median age: cases: 35 years, controls: 39 years). Among cases and controls, 5.9% and 8.1% had a documented prior infection (positive SARS-CoV-2 test record ≥90 days prior to the included test), respectively. We estimated the effectiveness of primary and booster vaccination relative to SGTF-defined Omicron (lineage BA.1) variant infection using a logistic regression adjusted for date of test, age, sex, race/ethnicity, insurance, comorbidities, social venerability index, municipality, and healthcare utilization. The effectiveness of primary vaccination 14 to 149 days after the second dose was 41.0% (95% confidence interval (CI): 14.1% to 59.4%, p 0.006) and 27.1% (95% CI: 18.7% to 34.6%, p < 0.001) for people with and without a documented prior infection, respectively. The effectiveness of booster vaccination (≥14 days after booster dose) was 47.1% (95% CI: 22.4% to 63.9%, p 0.001) and 54.1% (95% CI: 49.2% to 58.4%, p < 0.001) in people with and without a documented prior infection, respectively. To test whether booster vaccination reduced the risk of infection beyond that of the primary series, we compared the odds of infection among boosted (≥14 days after booster dose) and booster-eligible people (≥150 days after second dose). The odds ratio (OR) comparing boosted and booster-eligible people with a documented prior infection was 0.79 (95% CI: 0.54 to 1.16, p 0.222), whereas the OR comparing boosted and booster-eligible people without a documented prior infection was 0.54 (95% CI: 0.49 to 0.59, p < 0.001). This study's limitations include the risk of residual confounding, the use of data from a single system, and the reliance on TaqPath analyzed RT-PCR results.

CONCLUSIONS

In this study, we observed that primary vaccination provided significant but limited protection against Omicron (lineage BA.1) infection among people with and without a documented prior infection. While booster vaccination was associated with additional protection against Omicron BA.1 infection in people without a documented prior infection, it was not found to be associated with additional protection among people with a documented prior infection. These findings support primary vaccination in people regardless of documented prior infection status but suggest that infection history may impact the relative benefit of booster doses.

Effectiveness of an inactivated Covid-19 vaccine with homologous and heterologous boosters against Omicron in Brazil

The effectiveness of inactivated vaccines (VE) against symptomatic and severe COVID-19 caused by omicron is unknown. We conducted a nationwide, test-negative, case-control study to estimate VE for homologous and heterologous (BNT162b2) booster doses in adults who received two doses of CoronaVac in Brazil in the Omicron context. Analyzing 1,386,544 matched-pairs, VE against symptomatic disease was 8.6% (95% CI, 5.6-11.5) and 56.8% (95% CI, 56.3-57.3) in the period 8-59 days after receiving a homologous and heterologous booster, respectively. During the same interval, VE against severe Covid-19 was 73.6% (95% CI, 63.9-80.7) and 86.0% (95% CI, 84.5-87.4) after receiving a homologous and heterologous booster, respectively. Waning against severe Covid-19 after 120 days was only observed after a homologous booster. Heterologous booster might be preferable to individuals with completed primary series inactivated vaccine.

Association of ambient and household air pollution with lung function in young adults in an peri-urban area of South-India: A cross-sectional study

OBJECTIVE

Although there is evidence for the association between air pollution and decreased lung function in children, evidence for adolescents and young adults is scarce. For a peri-urban area in India, we evaluated the association of ambient PM_2.5 and household air pollution with lung function for young adults who had recently attained their expected maximum lung function.

METHODS

We measured, using a standardized protocol, forced expiratory volume in the first second (FEV₁) and forced vital capacity (FVC) in participants aged 20-26 years from the third follow-up of the population-based APCAPCS cohort (2010-2012) in 28 Indian villages. We estimated annual average PM_2.5outdoors at residence using land-use regression. Biomass cooking fuel (a proxy for levels of household air pollution) was self-reported. We fitted a within-between linear-mixed model with random intercepts by village, adjusting for potential confounders.

RESULTS

We evaluated 1,044 participants with mean age of 22.8 (SD = 1) years (range 20-26 years); 327 participants (31%) were female. Only males reported use of tobacco smoking (9% of all participants, 13% of males). The mean ambient PM_2.5 exposure was 32.9 (SD = 2.8) µg/m³; 76% reported use of biomass as cooking fuel. The adjusted association between 1 µg/m³ increase in PM_2.5 was -27 ml (95% CI, -89 to 34) for FEV₁ and -5 ml (95% CI, -93 to 76) for FVC. The adjusted association between use of biomass was -112 ml (95% CI, -211 to -13) for FEV₁ and -142 ml (95% CI, -285 to 0) for FVC. The adjusted association was of greater magnitude for those with unvented stove (-158 ml, 95% CI, -279 to -36 for FEV₁ and -211 ml, 95% CI, -386 to -36 for FVC).

CONCLUSIONS

We observed negative associations between ambient PM_2.5 and household air pollution and lung function in young adults who had recently attained their maximum lung function.

Use of Recently Vaccinated Individuals to Detect Bias in Test-Negative Case-Control Studies of COVID-19 Vaccine Effectiveness

Postauthorization observational studies play a key role in understanding COVID-19 vaccine effectiveness following the demonstration of efficacy in clinical trials. Although bias due to confounding, selection bias, and misclassification can be mitigated through careful study design, unmeasured confounding is likely to remain in these observational studies. Phase III trials of COVID-19 vaccines have shown that protection from vaccination does not occur immediately, meaning that COVID-19 risk should be similar in recently vaccinated and unvaccinated individuals, in the absence of confounding or other bias. Several studies have used the estimated effectiveness among recently vaccinated individuals as a negative control exposure to detect bias in vaccine effectiveness estimates. In this paper, we introduce a theoretical framework to describe the interpretation of such a bias indicator in test-negative studies, and outline strong assumptions that would allow vaccine effectiveness among recently vaccinated individuals to serve as a negative control exposure.

Change in covid-19 risk over time following vaccination with CoronaVac: test negative case-control study

OBJECTIVE

To estimate the change in odds of covid-19 over time following primary series completion of the inactivated whole virus vaccine CoronaVac (Sinovac Biotech) in São Paulo State, Brazil.

DESIGN

Test negative case-control study.

SETTING

Community testing for covid-19 in São Paulo State, Brazil.

PARTICIPANTS

Adults aged ≥18 years who were residents of São Paulo state, had received two doses of CoronaVac, did not have a laboratory confirmed SARS-CoV-2 infection before vaccination, and underwent reverse transcription polymerase chain reaction (RT-PCR) testing for SARS-CoV-2 from 17 January to 14 December 2021. Cases were matched to test negative controls by age (in 5 year bands), municipality of residence, healthcare worker status, and epidemiological week of RT-PCR test.

MAIN OUTCOME MEASURES

RT-PCR confirmed symptomatic covid-19 and associated hospital admissions and deaths. Conditional logistic regression was adjusted for sex, number of covid-19 associated comorbidities, race, and previous acute respiratory illness.

RESULTS

From 202 741 eligible people, 52 170 cases with symptomatic covid-19 and 69 115 test negative controls with covid-19 symptoms were formed into 43 257 matched sets. Adjusted odds ratios of symptomatic covid-19 increased with time since completion of the vaccination series. The increase in odds was greater in younger people and among healthcare workers, although sensitivity analyses suggested that this was in part due to bias. In addition, the adjusted odds ratios of covid-19 related hospital admission or death significantly increased with time compared with the odds 14-41 days after series completion: from 1.25 (95% confidence interval 1.04 to 1.51) at 70-97 days up to 1.94 (1.41 to 2.67) from 182 days onwards.

CONCLUSIONS

Significant increases in the risk of moderate and severe covid-19 outcomes occurred three months after primary vaccination with CoronaVac among people aged 65 and older. These findings provide supportive evidence for the implementation of vaccine boosters in these populations who received this inactivated vaccine. Studies of waning should include analyses designed to uncover common biases.

Effectiveness of CoronaVac, ChAdOx1 nCoV-19, BNT162b2, and Ad26.COV2.S among individuals with previous SARS-CoV-2 infection in Brazil: a test-negative, case-control study

BACKGROUND

COVID-19 vaccines have proven highly effective among individuals without a previous SARS-CoV-2 infection, but their effectiveness in preventing symptomatic infection and severe outcomes among individuals with previous infection is less clear. We aimed to estimate the effectiveness of four COVID-19 vaccines against symptomatic infection, hospitalisation, and death for individuals with laboratory-confirmed previous SARS-CoV-2 infection.

METHODS

Using national COVID-19 notification, hospitalisation, and vaccination datasets from Brazil, we did a test-negative, case-control study to assess the effectiveness of four vaccines (CoronaVac [Sinovac], ChAdOx1 nCoV-19 [AstraZeneca], Ad26.COV2.S [Janssen], and BNT162b2 [Pfizer-BioNtech]) for individuals with laboratory-confirmed previous SARS-CoV-2 infection. We matched cases with RT-PCR positive, symptomatic COVID-19 with up to ten controls with negative RT-PCR tests who presented with symptomatic illnesses, restricting both groups to tests done at least 90 days after an initial infection. We used multivariable conditional logistic regression to compare the odds of test positivity and the odds of hospitalisation or death due to COVID-19, according to vaccination status and time since first or second dose of vaccines.

FINDINGS

Between Feb 24, 2020, and Nov 11, 2021, we identified 213 457 individuals who had a subsequent, symptomatic illness with RT-PCR testing done at least 90 days after their initial SARS-CoV-2 infection and after the vaccination programme started. Among these, 30 910 (14·5%) had a positive RT-PCR test consistent with reinfection, and we matched 22 566 of these cases with 145 055 negative RT-PCR tests from 68 426 individuals as controls. Among individuals with previous SARS-CoV-2 infection, vaccine effectiveness against symptomatic infection 14 or more days from vaccine series completion was 39·4% (95% CI 36·1-42·6) for CoronaVac, 56·0% (51·4-60·2) for ChAdOx1 nCoV-19, 44·0% (31·5-54·2) for Ad26.COV2.S, and 64·8% (54·9-72·4) for BNT162b2. For the two-dose vaccine series (CoronaVac, ChAdOx1 nCoV-19, and BNT162b2), effectiveness against symptomatic infection was significantly greater after the second dose than after the first dose. Effectiveness against hospitalisation or death 14 or more days from vaccine series completion was 81·3% (75·3-85·8) for CoronaVac, 89·9% (83·5-93·8) for ChAdOx1 nCoV-19, 57·7% (-2·6 to 82·5) for Ad26.COV2.S, and 89·7% (54·3-97·7) for BNT162b2.

INTERPRETATION

All four vaccines conferred additional protection against symptomatic infections and severe outcomes among individuals with previous SARS-CoV-2 infection. The provision of a full vaccine series to individuals after recovery from COVID-19 might reduce morbidity and mortality.

FUNDING

Brazilian National Research Council, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Oswaldo Cruz Foundation, JBS, Instituto de Salud Carlos III, Spanish Ministry of Science and Innovation, and Generalitat de Catalunya.

Change in COVID-19 risk over time following vaccination with CoronaVac: A testnegative case-control study

OBJECTIVE

To estimate the change in odds of covid-19 over time following primary series completion of the inactivated whole virus vaccine, CoronaVac (Sinovac Biotech) in São Paulo state, Brazil.

DESIGN

Test negative case-control study.

SETTING

Community testing for covid-19 in São Paulo state, Brazil.

PARTICIPANTS

Adults aged 18-120 years who were residents of São Paulo state, without a previous laboratory-confirmed covid-19 infection, who received only two doses of CoronaVac, and underwent reverse transcription polymerase chain reaction (RT-PCR) testing for SARS-CoV-2 from 17 January to 30 September 2021.

MAIN OUTCOME MEASURES

RT-PCR-confirmed symptomatic covid-19 and associated hospital admissions and deaths. Cases were pair-matched to test-negative controls by age (in 5-year bands), municipality of residence, healthcare worker (HCW) status, and date of RT-PCR test (±3 days). Conditional logistic regression was adjusted for sex, number of covid-19-associated comorbidities, race, and previous acute respiratory infection.

RESULTS

From 137,820 eligible individuals, 37,929 cases with symptomatic covid-19 and 25,756 test-negative controls with covid-19 symptoms were formed into 37,929 matched pairs. Adjusted odds ratios of symptomatic covid-19 increased with time since series completion, and this increase was greater in younger individuals, and among HCWs compared to non-HCWs. Adjusted odds ratios of covid-19 hospitalisation or death were significantly increased from 98 days since series completion, compared to individuals vaccinated 14-41 days previously: 1.40 (95% confidence interval 1.09 to 1.79) from 98-125 days, 1.55 (1.16 to 2.07) from 126-153 days, 1.56 (1.12 to 2.18) from 154-181 days, and 2.12 (1.39-3.22) from 182 days.

CONCLUSIONS

In the general population of São Paulo state, Brazil, an increase in odds of moderate and severe covid-19 outcomes was observed over time following primary series completion with CoronaVac.

Effectiveness of ChAdOx1 vaccine in older adults during SARS-CoV-2 Gamma variant circulation in São Paulo

A two-dose regimen of the Oxford-AstraZeneca (ChAdOx1) Covid-19 vaccine with an inter-dose interval of three months has been implemented in many countries with restricted vaccine supply. However, there is limited evidence for the effectiveness of ChAdOx1 by dose in elderly populations in countries with high prevalence of the Gamma variant of SARS-CoV-2. Here, we estimate ChAdOx1 effectiveness by dose against the primary endpoint of RT-PCR-confirmed Covid-19, and secondary endpoints of Covid-19 hospitalization and Covid-19-related death, in adults aged ≥60 years during an epidemic with high Gamma variant prevalence in São Paulo state, Brazil using a matched, test-negative case-control study. Starting 28 days after the first dose, effectiveness of a single dose of ChAdOx1 is 33.4% (95% CI, 26.4-39.7) against Covid-19, 55.1% (95% CI, 46.6-62.2) against hospitalization, and 61.8% (95% CI, 48.9-71.4) against death. Starting 14 days after the second dose, effectiveness of the two-dose schedule is 77.9% (95% CI, 69.2-84.2) against Covid-19, 87.6% (95% CI, 78.2-92.9) against hospitalization, and 93.6% (95% CI, 81.9-97.7) against death. Completion of the ChAdOx1 vaccine schedule affords significantly increased protection over a single dose against mild and severe Covid-19 outcomes in elderly individuals during widespread Gamma variant circulation.

Prediction of ventilator-associated pneumonia outcomes according to the early microbiological response: a retrospective observational study

Ventilator-associated pneumonia is a leading infectious cause of morbidity in critically ill patients; yet current guidelines offer no indications for follow-up cultures.We aimed to evaluate the role of follow-up cultures and microbiological response 3 days after diagnosing ventilator-associated pneumonia as predictors of short- and long-term outcomes.We performed a retrospective analysis of a cohort prospectively collected from 2004 to 2017. Ventilator-associated pneumonia was diagnosed based on clinical, radiographic, and microbiological criteria. For microbiological identification, a tracheobronchial aspirate was performed at diagnosis and repeated after 72 h. We defined three groups when comparing the two tracheobronchial aspirate results: persistence, superinfection, and eradication of causative pathogens.One-hundred-fifty-seven patients were enrolled in the study, among whom microbiological persistence, superinfection, and eradication was present in 67 (48%), 25 (16%), and 65 (41%), respectively, after 72hs. Those with superinfection had the highest mortalities in the intensive care unit (p=0.015) and at 90 days (p=0.036), while also having the fewest ventilation-free days (p=0.024). Multivariable analysis revealed shock at VAP diagnosis (odds ratios [OR] 3.43; 95% confidence interval [CI] 1.25 to 9.40), Staphylococcus aureus isolation at VAP diagnosis (OR 2.87; 95%CI 1.06 to 7.75), and hypothermia at VAP diagnosis (OR 0.67; 95%CI 0.48 to 0.95, per +1°C) to be associated with superinfection.Our retrospective analysis suggests that ventilator-associated pneumonia short-term and long-term outcomes may be associated with superinfection in follow-up cultures. Follow-up cultures may help guiding antibiotic therapy and its duration. Further prospective studies are necessary to verify our findings.

Effectiveness of the CoronaVac vaccine in older adults during a gamma variant associated epidemic of covid-19 in Brazil: test negative case-control study

OBJECTIVE

To estimate the effectiveness of the inactivated whole virus vaccine, CoronaVac (Sinovac Biotech), against symptomatic covid-19 in the elderly population of São Paulo state, Brazil during widespread circulation of the gamma variant.

DESIGN

Test negative case-control study.

SETTING

Community testing for covid-19 in São Paulo state, Brazil.

PARTICIPANTS

43 774 adults aged ≥70 years who were residents of São Paulo state and underwent reverse transcription polymerase chain reaction (RT-PCR) testing for SARS-CoV-2 from 17 January to 29 April 2021. 26 433 cases with symptomatic covid-19 and 17 622 test negative controls with covid-19 symptoms were formed into 13 283 matched sets, one case with to up to five controls, according to age, sex, self-reported race, municipality of residence, previous covid-19 status, and date of RT-PCR test (±3 days).

INTERVENTION

Vaccination with a two dose regimen of CoronaVac.

MAIN OUTCOME MEASURES

RT-PCR confirmed symptomatic covid-19 and associated hospital admissions and deaths.

RESULTS

Adjusted vaccine effectiveness against symptomatic covid-19 was 24.7% (95% confidence interval 14.7% to 33.4%) at 0-13 days and 46.8% (38.7% to 53.8%) at ≥14 days after the second dose. Adjusted vaccine effectiveness against hospital admissions was 55.5% (46.5% to 62.9%) and against deaths was 61.2% (48.9% to 70.5%) at ≥14 days after the second dose. Vaccine effectiveness ≥14 days after the second dose was highest for the youngest age group (70-74 years)-59.0% (43.7% to 70.2%) against symptomatic disease, 77.6% (62.5% to 86.7%) against hospital admissions, and 83.9% (59.2% to 93.7%) against deaths-and declined with increasing age.

CONCLUSIONS

Vaccination with CoronaVac was associated with a reduction in symptomatic covid-19, hospital admissions, and deaths in adults aged ≥70 years in a setting with extensive transmission of the gamma variant. Vaccine protection was, however, low until completion of the two dose regimen, and vaccine effectiveness was observe to decline with increasing age among this elderly population.

TELE-critical Care verSus usual Care On ICU PErformance (TELESCOPE): protocol for a cluster-randomised clinical trial on adult general ICUs in Brazil

INTRODUCTION

Daily multidisciplinary rounds (DMRs) consist of systematic patient-centred discussions aiming to establish joint therapeutic goals for the next 24 hours of intensive care unit (ICU) care. The aim of the present study protocol is to evaluate whether an intervention consisting of guided DMRs, supported by a remote specialist and audit/feedback on care performance will reduce ICU length of stay compared with a control group.

METHODS AND ANALYSIS

A multicentre, controlled, cluster-randomised superiority trial including 30 ICUs in Brazil (15 intervention and 15 control), from August 2019 to June 2021. In a parallel assignment, ICUs are randomised to a complex-intervention composed by daily rounds carried out through Tele-ICU by a remote ICU physician; development of local quality indicators dashboards coupled with monthly meetings with local leadership; and dissemination of evidence-based clinical protocols versus usual care. Primary outcome is ICU length of stay. Secondary outcomes include classification of the unit according to the profiles defined by the standardised resource use and the standardised mortality rate, hospital mortality, incidence of healthcare-associated infections, ventilator-free days at 28 days, patient-days receiving oral or enteral feeding, patient-days under light sedation or alert and calm, rate of patients under normoxaemia. All adult patients admitted after the beginning of the study in each participant ICU will be enrolled. Inclusion criteria (clusters): public Brazilian ICUs with a minimum of 8 ICU beds interested/committed to participating in the study. Exclusion criteria (clusters): units with fully established DMRs by an intensivist, specialised or step-down units.

ETHICS AND DISSEMINATION

The study protocol was approved by the institutional review board (IRB) of the coordinator centre, and by IRBs of each enrolled hospital/ICU. Statistical analysis protocol is being prepared for submission before the end of patient's enrolment. Results will be disseminated through conferences, peer-reviewed journals and to each participating unit.

TRIAL REGISTRATION NUMBER

NCT03920501; Pre-results.

Community-acquired pneumonia severity assessment tools in patients hospitalized with COVID-19: a validation and clinical applicability study

Objective

To externally validate community-acquired pneumonia (CAP) tools on patients hospitalized with coronavirus disease 2019 (COVID-19) pneumonia from two distinct countries, and compare their performance with recently developed COVID-19 mortality risk stratification tools.

Methods

We evaluated 11 risk stratification scores in a binational retrospective cohort of patients hospitalized with COVID-19 pneumonia in São Paulo and Barcelona: Pneumonia Severity Index (PSI), CURB, CURB-65, qSOFA, Infectious Disease Society of America and American Thoracic Society Minor Criteria, REA-ICU, SCAP, SMART-COP, CALL, COVID GRAM and 4C. The primary and secondary outcomes were 30-day in-hospital mortality and 7-day intensive care unit (ICU) admission, respectively. We compared their predictive performance using the area under the receiver operating characteristics curve (AUC), sensitivity, specificity, likelihood ratios, calibration plots and decision curve analysis.

Results

Of 1363 patients, the mean (SD) age was 61 (16) years. The 30-day in-hospital mortality rate was 24.6% (228/925) in São Paulo and 21.0% (92/438) in Barcelona. For in-hospital mortality, we found higher AUCs for PSI (0.79, 95% CI 0.77–0.82), 4C (0.78, 95% CI 0.75–0.81), COVID GRAM (0.77, 95% CI 0.75–0.80) and CURB-65 (0.74, 95% CI 0.72–0.77). Results were similar for both countries. For the 1%–20% threshold range in decision curve analysis, PSI would avoid a higher number of unnecessary interventions, followed by the 4C score. All scores had poor performance (AUC <0.65) for 7-day ICU admission.

Conclusions

Recent clinical COVID-19 assessment scores had comparable performance to standard pneumonia prognostic tools. Because it is expected that new scores outperform older ones during development, external validation studies are needed before recommending their use.

Use of dialysis, tracheostomy, and extracorporeal membrane oxygenation among 842,928 patients hospitalized with COVID-19 in the United States

Objective

To estimate the proportion of patients hospitalized with COVID-19 who undergo dialysis, tracheostomy, and extracorporeal membrane oxygenation (ECMO).

Design

A network cohort study.

Setting

Seven databases from the United States containing routinely-collected patient data: HealthVerity, Premier, IQVIA Hospital CDM, IQVIA Open Claims, Optum EHR, Optum SES, and VA-OMOP.

Patients

Patients hospitalized with a clinical diagnosis or a positive test result for COVID-19.

Interventions

Dialysis, tracheostomy, and ECMO.

Measurements and Main Results

842,928 patients hospitalized with COVID-19 were included (22,887 from HealthVerity, 77,853 from IQVIA Hospital CDM, 533,997 from IQVIA Open Claims, 36,717 from Optum EHR, 4,336 from OPTUM SES, 156,187 from Premier, and 10,951 from VA-OMOP). Across the six databases, 35,192 (4.17% [95% CI: 4.13% to 4.22%]) patients received dialysis, 6,950 (0.82% [0.81% to 0.84%]) had a tracheostomy, and 1,568 (0.19% [95% CI: 0.18% to 0.20%]) patients underwent ECMO over the 30 days following hospitalization. Use of ECMO was more common among patients who were younger, male, and with fewer comorbidities. Tracheostomy was broadly used for a similar proportion of patients regardless of age, sex, or comorbidity. While dialysis was generally used for a similar proportion among younger and older patients, it was more frequent among male patients and among those with chronic kidney disease.

Conclusion

Use of dialysis among those hospitalized with COVID-19 is high at around 4%. Although less than one percent of patients undergo tracheostomy and ECMO, the absolute numbers of patients who have undergone these interventions is substantial.

Characterisation of the first 250,000 hospital admissions for COVID-19 in Brazil: a retrospective analysis of nationwide data

Background

Most low-income and middle-income countries (LMICs) have little or no data integrated into a national surveillance system to identify characteristics or outcomes of COVID-19 hospital admissions and the impact of the COVID-19 pandemic on their national health systems. We aimed to analyse characteristics of patients admitted to hospital with COVID-19 in Brazil, and to examine the impact of COVID-19 on health-care resources and in-hospital mortality.

Methods

We did a retrospective analysis of all patients aged 20 years or older with quantitative RT-PCR (RT-qPCR)-confirmed COVID-19 who were admitted to hospital and registered in SIVEP-Gripe, a nationwide surveillance database in Brazil, between Feb 16 and Aug 15, 2020 (epidemiological weeks 8–33). We also examined the progression of the COVID-19 pandemic across three 4-week periods within this timeframe (epidemiological weeks 8–12, 19–22, and 27–30). The primary outcome was in-hospital mortality. We compared the regional burden of hospital admissions stratified by age, intensive care unit (ICU) admission, and respiratory support. We analysed data from the whole country and its five regions: North, Northeast, Central-West, Southeast, and South.

Findings

Between Feb 16 and Aug 15, 2020, 254 288 patients with RT-qPCR-confirmed COVID-19 were admitted to hospital and registered in SIVEP-Gripe. The mean age of patients was 60 (SD 17) years, 119 657 (47%) of 254 288 were aged younger than 60 years, 143 521 (56%) of 254 243 were male, and 14 979 (16%) of 90 829 had no comorbidities. Case numbers increased across the three 4-week periods studied: by epidemiological weeks 19–22, cases were concentrated in the North, Northeast, and Southeast; by weeks 27–30, cases had spread to the Central-West and South regions. 232 036 (91%) of 254 288 patients had a defined hospital outcome when the data were exported; in-hospital mortality was 38% (87 515 of 232 036 patients) overall, 59% (47 002 of 79 687) among patients admitted to the ICU, and 80% (36 046 of 45 205) among those who were mechanically ventilated. The overall burden of ICU admissions per ICU beds was more pronounced in the North, Southeast, and Northeast, than in the Central-West and South. In the Northeast, 1545 (16%) of 9960 patients received invasive mechanical ventilation outside the ICU compared with 431 (8%) of 5388 in the South. In-hospital mortality among patients younger than 60 years was 31% (4204 of 13 468) in the Northeast versus 15% (1694 of 11 196) in the South.

Interpretation

We observed a widespread distribution of COVID-19 across all regions in Brazil, resulting in a high overall disease burden. In-hospital mortality was high, even in patients younger than 60 years, and worsened by existing regional disparities within the health system. The COVID-19 pandemic highlights the need to improve access to high-quality care for critically ill patients admitted to hospital with COVID-19, particularly in LMICs.

Funding

National Council for Scientific and Technological Development (CNPq), Coordinating Agency for Advanced Training of Graduate Personnel (CAPES), Carlos Chagas Filho Foundation for Research Support of the State of Rio de Janeiro (FAPERJ), and Instituto de Salud Carlos III.

Walnuts, Long-Chain Polyunsaturated Fatty Acids, and Adolescent Brain Development: Protocol for the Walnuts Smart Snack Dietary Intervention Trial

Background: Adolescence, when the most complex behaviors are refined to adult sophistication, represents a major window of opportunity and vulnerability for neuropsychological development. To support and protect this complex and active brain growth, different nutritional components considered essential need to be acquired from the diet. For instance, omega-3 fatty acids are mainly obtained from seafood, seeds, and walnuts. Known for their rich lipid profile, walnuts contain sizable amounts of an essential fatty acid, alpha-linolenic acid (ALA), the vegetable omega-3 fatty acid that is the precursor of two longer-chain omega-3 polyunsaturated fatty acids (omega-3 PUFA): docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids. While there is growing evidence of neuropsychological improvements in the young developing brain associated with omega-3 PUFA intake, few studies have examined whether consuming walnuts during adolescence entails similar beneficial effects. There is a need to further explore the ways in which walnuts influence youthful brain function, particularly for the long-term. Thus, we designed the WALNUTs study (WSS), a population-based randomized controlled trial conducted in adolescents in Barcelona, Spain. We hypothesize that walnut intake will increase omega-3 PUFA tissue availability (particularly ALA) to a level that enhances the neuropsychological development during adolescence. Methodology/Design: We conducted a 6-month population-based randomized controlled trial in teenagers (n = 800) and we aimed to determine the effectiveness of the intervention (four walnuts per day, or 30 kernel g, ~1.5g of ALA) in enhancing brain neuropsychological and socio-emotional development compared to a control group with no walnut intervention. Before randomization, different neuropsychological tests were recorded for all participants, and blood samples (in a subsample of participants) were collected to measure omega-3 PUFA levels at baseline, and all again, after randomization and the intervention. The data is now collected and we will conduct linear regression models to assess the effect of the intervention. Discussion: The WALNUTs (WSS) study results will allow us to better understand the role of plant-based omega-3 PUFA intake from regular walnut consumption on neuropsychological development during adolescence. Results could be translated into nutritional public health recommendations targeting teenagers. Trial Registration: ClinicalTrials.gov, U.S. National Library of Medicine, National Institutes of Health # NCT02590848. Retrospectively registered 29/10/2015.

Diagnostic accuracy of Gram staining when predicting staphylococcal hospital-acquired pneumonia and ventilator-associated pneumonia: a systematic review and meta-analysis

BACKGROUND

There is no clear guidance on empirical antibiotic coverage against Staphylococcus aureus for hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP).

OBJECTIVE

To evaluate whether the presence of clusters of Gram-positive cocci in Gram staining of respiratory samples predicts S. aureus as HAP/VAP pathogen.

METHODS

Data sources were MEDLINE, PubMed, Embase, Scielo, CINAHL and Scopus, from inception to 15/07/2017 (update on 31/10/2019), and original data from a single-centre database (PROSPERO: CRD42017072138). We included studies reporting the diagnostic accuracy of a Gram-staining evaluation suggestive of Staphylococcus compared with a positive culture for S. aureus in any type of lower respiratory tract sample. Participants were adult patients with HAP/VAP. The index test was morphological evaluation of Gram staining of respiratory samples. We followed PRISMA guidelines and assessed risk of bias and applicability with the QUADAS-2 tool. We conducted a meta-analysis using a bivariate random effects model.

RESULTS

We selected five studies that included only VAP and data from a single-centre database including VAP and HAP. We pooled six studies for VAP and analysed 1665 respiratory samples. Pooled sensitivity was 68% (95%CI 49-83 and specificity 95% (95%CI 86-98). The pooled positive likelihood ratio was 12.7 (95%CI 5.1-31.6), negative likelihood ratio 0.34 (95%CI 0.20-0.57), diagnostic odds ratio 38 (95%CI 13-106) and area under the summary receiver operating curve (SROC) 0.91 (95%CI 0.88-0.93). There was great heterogeneity between sensitivity and specificity. In scenarios in which the prevalence of S. aureus was between 5% and 20%, the positive and negative predictive values were 62% (95%CI 47-77) and 95% (95%CI 82-100), respectively.

CONCLUSIONS

Detection of Gram-positive cocci in clusters in respiratory samples of patients with VAP has the potential to guide risk assessments of S. aureus for more personalized antibiotic coverage. Randomized clinical trials with patient-centred outcomes are needed for strong clinical recommendations.

Zoonotic Tuberculosis in Humans: Control, Surveillance, and the One Health Approach

Zoonotic tuberculosis is a reemerging infectious disease in high-income countries and a neglected one in low- and middle-income countries. Despite major advances in its control as a result of milk pasteurization, its global burden is unknown, especially due the lack of surveillance data. Additionally, very little is known about control strategies. The purpose of this review was to contextualize the current knowledge about the epidemiology of zoonotic tuberculosis and to describe the available evidence regarding surveillance and control strategies in high-, middle-, and low-income countries. We conducted this review enriched by a One Health perspective, encompassing its inherent multifaceted characteristics. We found that the burden of zoonotic tuberculosis is likely to be underreported worldwide, with higher incidence in low-income countries, where the surveillance systems are even more fragile. Together with the lack of specific political commitment, surveillance data is affected by lack of a case definition and limitations of diagnostic methods. Control measures were dependent on risk factors and varied greatly between countries. This review supports the claim that a One Health approach is the most valuable concept to build capable surveillance systems, resulting in effective control measures. The disease characteristics and suggestions to implement surveillance and control programs are discussed.

Personal exposure to particulate air pollution and vascular damage in peri-urban South India

OBJECTIVE

Air pollution is a leading preventable risk factor for cardiovascular diseases. Previous studies mostly relied on concentrations at residence, which might not represent personal exposure. Personal air pollution exposure has a greater variability compared with levels of ambient air pollution, facilitating evaluation of exposure-response functions and vascular pathophysiology. We aimed to evaluate the association between predicted annual personal exposure to PM2.5 and black carbon (BC) and three vascular damage markers in peri-urban South India.

METHODS

We analyzed the third wave of the APCAPS cohort (2010-2012), which recruited participants from 28 villages. We used predicted personal exposure to PM2.5 and BC derived from 610 participant-days of 24 h average gravimetric PM2.5 and BC measurements and predictors related to usual time-activity. Outcomes included carotid intima-media thickness (CIMT), carotid-femoral pulse wave velocity (cf-PWV) and augmentation index (AIx). We fit linear mixed models, adjusting for potential confounders and accounting for the clustered data structure. We evaluated nonlinear associations using generalized additive mixed models.

RESULTS

Of the 3017 participants (mean age 38 years), 1453 (48%) were women. The average PM2.5 exposure was 51 µg/m3 (range 13-85) for men, and 61 µg/m3 (range 40-120) for women, while the average BC was 4 µg/m3 (range 3-7) for men and 8 µg/m3 (range 3-22) for women. A 10 μg/m3 increase of PM2.5 was positively associated with CIMT (0.026 mm, 95% CI 0.014, 0.037), cf-PWV (0.069 m/s, 95% CI 0.008, 0.131) and AIx (0.8%, 95% CI 0.3, 1.3) among men. The exposure-response function for PM2.5 and AIx among men showed non-linearity, particularly within the exposure range dominated by tobacco smoking and occupational exposures. Both PM2.5 and BC were positively associated with AIx among women (0.6%, 95% CI 0.2, 1.0, per 10 μg/m3 PM2.5; 0.5%, 95% CI 0.1, 0.8, per 2 μg/m3 BC).

CONCLUSIONS

Personal exposure to particulate matter was associated with vascular damage in a peri-urban population in South India. Personal exposure to particulate matter appears to have gender-specific effects on the type of vascular damage, potentially reflecting differences in sources of personal exposure by gender.

Association between ambient and household air pollution with carotid intima-media thickness in peri-urban South India: CHAI-Project

BACKGROUND

Evidence linking ambient air pollution with atherosclerosis is lacking from low- and middle-income countries. Additionally, evidence regarding the association between household air pollution and atherosclerosis is limited. We evaluated the association between ambient fine particulate matter [particulate matter with an aerodynamic diameter of ≤2.5 µm (PM2.5)] and biomass fuel use on carotid intima-media thickness (CIMT), a surrogate of atherosclerosis, in India.

METHODS

We analysed the third follow-up of the Andhra Pradesh Children and Parent Study cohort (2010-2012), which recruited participants from 28 peri-urban villages. Our primary outcome was mean CIMT, measured using a standardized protocol. We estimated annual average PM2.5 outdoors at residence using land-use regression. Biomass cooking fuel was self-reported. We fitted a within-between linear-mixed model adjusting for potential confounders.

RESULTS

Among 3278 participants (48% women, mean age 38 years), mean PM2.5 was 32.7 [range 24.4-38.2] µg/m3, and 60% used biomass. After confounder adjustment, we observed positive associations between within-village variation in PM2.5 and CIMT in all participants [1.79%, 95% confidence interval (CI), -0.31 to 3.90 per 1  µg/m3 of PM2.5] and in men (2.98%, 95% CI, 0.23-5.72, per 1  µg/m3 of PM2.5). Use of biomass cooking fuel was associated with CIMT in all participants (1.60%, 95% CI, -0.46 to 3.65), especially in women with an unvented stove (6.14%, 95% CI, 1.40-10.89). The point-estimate for the PM2.5 association was larger in sub-groups with higher cardiometabolic risk profile.

CONCLUSIONS

Ambient and household air pollution were positively associated with CIMT in a peri-urban population of India, although with limited precision for some estimates. We observed differences in the association between ambient and household air pollution and CIMT by gender.

Association of Ambient and Household Air Pollution With Bone Mineral Content Among Adults in Peri-urban South India

IMPORTANCE

Air pollution is a major threat to global health. Osteoporosis is responsible for a substantial burden of disease globally and is expected to increase in prevalence because of population aging. Few studies have investigated the association between air pollution and bone health, and their findings were inconclusive.

OBJECTIVE

To quantify the association between ambient and household air pollution and bone mass in a sample of the general population in peri-urban India.

DESIGN, SETTING, AND PARTICIPANTS

This was a population-based cross-sectional analysis of the Andhra Pradesh Children and Parents Study cohort, which recruited participants from 28 villages near Hyderabad, South India, during 2009 to 2012. Separate linear mixed models were fitted with nested random intercepts (household within villages) for each exposure-outcome pair and were sequentially adjusted for potential confounders. Data analysis was conducted between April 2019 and July 2019.

EXPOSURES

Annual mean ambient particulate matter air pollution less than 2.5 µm in aerodynamic diameter (PM2.5) and black carbon (BC) levels at the residence estimated by land-use regression and self-reported use of biomass cooking fuel.

MAIN OUTCOMES AND MEASURES

The primary outcome was bone mineral content (BMC) measured in grams, corrected by bone area at the lumbar spine and left hip, as measured by dual-energy x-ray absorptiometry. The secondary outcome was bone mineral density measured in grams per centimeters squared.

RESULTS

A total of 3717 participants were analyzed (mean [SD] age, 35.7 [14.0] years; 1711 [46.0%] women). The annual mean (SD) PM2.5 exposure was 32.8 (2.5) μg/m3, and the annual mean (SD) BC exposure was 2.5 (0.2) μg/m3; 57.8% of participants used biomass cooking fuels. In fully adjusted models, PM2.5 was associated with lower BMC in the spine (mean difference, -0.57 g per 3 μg/m3 increase in PM2.5; 95% CI, -1.06 to -0.07 g per 3 μg/m3 increase in PM2.5) and hip (mean difference, -0.13 g per 3 μg/m3 increase in PM2.5; 95% CI, -0.3 to 0.03 g per 3 μg/m3 increase in PM2.5). After confounder adjustment, exposure to PM2.5 was also associated with lower bone mineral density in the spine (mean difference, -0.011 g/cm2 per 3 μg/m3 increase in PM2.5; 95% CI, -0.021 to 0 g/cm2 per 3 μg/m3 increase in PM2.5) and hip (mean difference, -0.004 g/cm2 per 3 μg/m3 increase in PM2.5; 95% CI, -0.008 to 0.001 g/cm2 per 3 μg/m3 increase in PM2.5). Exposure to BC was associated with lower BMC in the spine (mean difference, -1.13 g per 1 μg/m3 increase in BC; 95% CI, -2.81 to 0.54 g per 1 μg/m3 increase in BC) and hip (mean difference, -0.35 g per 1 μg/m3 increase in BC; 95% CI, -0.96 to 0.25 g per 1 μg/m3 increase in BC), although the confidence intervals were wider. There was no association between biomass fuel use and spine BMC (mean difference, 0.12 g; 95% CI, -0.45 to 0.68 g).

CONCLUSIONS AND RELEVANCE

In a cross-sectional analysis of a population-based cohort, ambient air pollution was associated with lower BMC in a young adult population in a peri-urban area of South India.

Long-term survival and cause-specific mortality of patients newly diagnosed with tuberculosis in São Paulo state, Brazil, 2010-15: a population-based, longitudinal study

BACKGROUND

Long-term survival and cause-specific mortality of patients who start tuberculosis treatment is rarely described. We aimed to assess the long-term survival of these patients and evaluate the association between vulnerable conditions (social, health behaviours, and comorbidities) and cause-specific mortality in a country with a high burden of tuberculosis.

METHODS

In this population-based, longitudinal study in São Paulo state, Brazil, we described the 5-year survival of patients who were newly diagnosed with tuberculosis in 2010. We included patients with newly-diagnosed tuberculosis, aged 15 years or older, and notified to the São Paulo State Tuberculosis Program in 2010. We excluded patients whose diagnosis had changed during follow-up (ie, they did not have tuberculosis) and patients who had multidrug-resistant (MDR) tuberculosis. We selected our population with tuberculosis from the dedicated electronic system TBweb. Our primary objective was to estimate the excess mortality over 5 years and within the group who survived the first year, compared with the general São Paulo state population. We also estimated the association between social vulnerability (imprisonment and homelessness), health behaviours (alcohol and drug use), and comorbidities (diabetes and mental disorders) with all-cause and cause-specific mortality. We used the competing risk analysis framework, estimating cause-specific hazard ratios (HRs) adjusted for potential confounding factors.

FINDINGS

In 2010, there were 19 252 notifications of tuberculosis cases. We excluded 550 cases as patients were younger than 15 years, 556 cases that were not tuberculosis, 2597 retreatments, and 48 cases of MDR tuberculosis, resulting in a final cohort of 15 501 patients with tuberculosis. Over a period of 5 years from tuberculosis diagnosis, 2660 (17%) of 15 501 patients died. Compared with the source population, matched by age, sex, and calendar year, the standardised mortality ratio was 6·47 (95% CI 6·22-6·73) over 5 years and 3·93 (3·71-4·17) among those who survived the first year. 1197 (45%) of 2660 deaths were due to infection. Homelessness and alcohol and drug use were associated with death from infection (adjusted cause-specific HR 1·60, 95% CI 1·39-1·85), cardiovascular (1·43, 1·06-1·95), and external or ill-defined causes of death (1·80, 1·37-2·36). Diabetes was associated with deaths from cardiovascular causes (1·70, 1·23-2·35).

INTERPRETATION

Patients newly diagnosed with tuberculosis were at a higher risk of death than were the source population, even after tuberculosis treatment. Post-tuberculosis sequelae and vulnerability are associated with excess mortality and must be addressed to mitigate the tuberculosis burden worldwide.

FUNDING

Wellcome Trust.

Lymphocytopenia as a Predictor of Mortality in Patients with ICU-Acquired Pneumonia

BACKGROUND

Intensive care unit-acquired pneumonia (ICU-AP) is a severe complication in patients admitted to the ICU. Lymphocytopenia is a marker of poor prognosis in patients with community-acquired pneumonia, but its impact on ICU-AP prognosis is unknown. We aimed to evaluate whether lymphocytopenia is an independent risk factor for mortality in non-immunocompromised patients with ICU-AP.

METHODS

Prospective observational cohort study of patients from six ICUs of an 800-bed tertiary teaching hospital (2005 to 2016).

RESULTS

Of the 473 patients included, 277 (59%) had ventilator-associated pneumonia (VAP). Receiver operating characteristic (ROC) analysis of the lymphocyte counts at diagnosis showed that 595 cells/mm³ was the best cut-off for discriminating two groups of patients at risk: lymphocytopenic group (lymphocyte count <595 cells/mm³, 141 patients (30%)) and non-lymphocytopenic group (lymphocyte count ≥595 cells/mm³, 332 patients (70%)). Patients with lymphocytopenia presented more comorbidities and a higher sequential organ failure assessment (SOFA) score at the moment of pneumonia diagnosis. Also, 28-day mortality and 90-day mortality were higher in patients with lymphocytopenia (28-day: 38 (27%) versus 59 (18%), 90-day: 74 (53%) versus 111 (34%)). In the multivariable model, <595 cells/mm³ resulted to be an independent predictor for 90-day mortality (Hazard Ratio 1.41; 95% Confidence Interval 1.02 to 1.94).

CONCLUSION

Lymphocytopenia is an independent predictor of 90-day mortality in non-immunocompromised patients with ICU-AP.

In-vitro analysis of a novel 'add-on' silicone cuff to improve sealing properties of tracheal tubes

Leakage of colonised oropharyngeal secretions across the tracheal tube cuff may cause iatrogenic pulmonary infection. We studied a novel 'add-on' cuff, which can be inserted over an existing tracheal tube and advanced into the subglottic region. The physical properties of the novel silicone cuff (BronchoGuard, Ciel Medical, USA) were evaluated in comparison with the Hi-Lo^® tracheal tube. In a bench study, we identified saline inflation volumes required to transmit pressures between 15 and 30 cmH₂ O against artificial tracheas of 18, 20 and 22 mm internal diameter. We computed cuff compliance, and minimal inflation volume to achieve air sealing during mechanical ventilation. Finally, we compared the leakage flow rate of artificial saliva across the novel cuff. On average, the mean (SD) inflation volumes necessary to transmit tracheal pressures of 15, 20, 25 and 30 cmH₂ O were 4.1 (2.2), 4.4 (2.3), 4.6 (2.4) and 4.8 (2.4) ml for the novel cuff and 7.7 (2.5), 8.0 (2.6), 8.4 (2.6) and 8.7 (2.7) ml for the Hi-Lo tube, respectively (p < 0.001). The minimal inflation volumes to achieve air sealing were 3.8 (0.9) and 10.5 (2.1) ml (p < 0.001), which resulted in transmitted tracheal pressures of 8.3 (9.8) and 27.6 (34.8) cmH₂ O (p < 0.001). Compliance was 0.026 (0.004) and 0.616 (0.324) ml.cmH₂ 0^-1 , respectively (p < 0.001). Although massive leak was found when the novel cuff transmitted pressures ≤ 20 cmH₂ O against the trachea, leakage was avoided with pressures ≥ 25 cmH₂ O, owing to optimal contact between the cuff and the tracheal wall. In contrast, the standard cuff consistently leaked irrespective of the pressure. We conclude that the novel cuff has advantageous properties that warrant clinical corroboration.

Invasive and non-invasive diagnostic approaches for microbiological diagnosis of hospital-acquired pneumonia

Background

Data on the methods used for microbiological diagnosis of hospital-acquired pneumonia (HAP) are mainly extrapolated from ventilator-associated pneumonia. HAP poses additional challenges for respiratory sampling, and the utility of sputum or distal sampling in HAP has not been comprehensively evaluated, particularly in HAP admitted to the ICU.

Methods

We analyzed 200 patients with HAP from six ICUs in a teaching hospital in Barcelona, Spain. The respiratory sampling methods used were divided into non-invasive [sputum and endotracheal aspirate (EAT)] and invasive [fiberoptic-bronchoscopy aspirate (FBAS), and bronchoalveolar lavage (BAL)].

Results

A median of three diagnostic methods were applied [range 2–4]. At least one respiratory sampling method was applied in 93% of patients, and two or more were applied in 40%. Microbiological diagnosis was achieved in 99 (50%) patients, 69 (70%) by only one method (42% FBAS, 23% EAT, 15% sputum, 9% BAL, 7% blood culture, and 4% urinary antigen). Seventy-eight (39%) patients underwent a fiberoptic-bronchoscopy when not receiving mechanical ventilation. Higher rates of microbiological diagnosis were observed in the invasive group (56 vs. 39%, p = 0.018). Patients with microbiological diagnosis more frequently presented changes in their empirical antibiotic scheme, mainly de-escalation.

Conclusions

A comprehensive approach might be undertaken for microbiological diagnosis in critically ill nonventilated HAP. Sputum sampling determined one third of microbiological diagnosis in HAP patients who were not subsequently intubated. Invasive methods were associated with higher rates of microbiological diagnosis.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2348-2) contains supplementary material, which is available to authorized users.

A decision-aid tool for ICU admission triage is associated with a reduction in potentially inappropriate intensive care unit admissions

PURPOSE

Intensive care unit (ICU) admission triage occurs frequently and often involves highly subjective decisions that may lead to potentially inappropriate ICU admissions. In this study, we evaluated the effect of implementing a decision-aid tool for ICU triage on ICU admission decisions.

METHODS

This was a prospective, before-after study. Urgent ICU referrals to ten ICUs in a tertiary hospital in Brazil were assessed before and after the implementation of the decision-aid tool. Our primary outcome was the proportion of potentially inappropriate ICU referrals (defined as priority 4B or 5 referrals, accordingly to the Society of Critical Care Medicine guidelines of 1999 and 2016, respectively) admitted to the ICU within 48 h. We conducted multivariate analyses to adjust for potential confounders and evaluated the interaction between phase and triage priority.

RESULTS

Of the 2201 patients analyzed, 1184 (53.8%) patients were admitted to the ICU. After adjustment for confounders, implementation of the decision-aid tool was associated with a reduction in potentially inappropriate ICU admissions using either the 1999 [adjOR (95% CI) = 0.36 (0.13-0.97)] or 2016 [adjOR (95%CI) = 0.35 (0.13-0.96)] definitions.

CONCLUSION

Implementation of a decision-aid tool for ICU triage was associated with a reduction in potentially inappropriate ICU admissions.

Effect of Combined β-Lactam/Macrolide Therapy on Mortality According to the Microbial Etiology and Inflammatory Status of Patients With Community-Acquired Pneumonia

BACKGROUND

Antibiotic combinations that include macrolides have shown lower mortality rates than β-lactams in monotherapy or combined with fluoroquinolones in patients with community-acquired pneumonia (CAP). However, this effect has not been studied according to the levels of C-reactive protein in CAP with identified microbial cause. In patients with CAP and known microbial cause we aimed to evaluate 30-day mortality of a β-lactam plus macrolide (BL + M) compared with a fluoroquinolone alone or with a β-lactam (FQ ± BL).

METHODS

We analyzed a prospective observational cohort of patients with CAP admitted to the Hospital Clinic of Barcelona between 1996 and 2016. We included only patients with known microbial cause.

RESULTS

Of 1,715 patients (29%) with known etiology, a total of 932 patients (54%) received BL + M. Despite lower crude mortality in the BL + M group in the overall population (BL + M, 5% vs FQ ± BL, 8%; P = .015), after adjustment by a propensity score and baseline characteristics, the combination of BL + M had a protective effect on mortality only in patients with high inflammatory response (C-reactive protein, > 15 mg/dL) and pneumococcal CAP (adjusted OR, 0.28; 95% CI, 0.09-0.93). No benefits on mortality were observed for the population without high inflammatory response and pneumococcal CAP or with other etiologies.

CONCLUSIONS

The combination of a β-lactam with a macrolide was associated with decreased mortality in patients with pneumococcal CAP and in patients with high systemic inflammatory response. When both factors occurred together, BL + M was protective for mortality in the multivariate analysis.

Appraisal of systemic inflammation and diagnostic markers in a porcine model of VAP: secondary analysis from a study on novel preventive strategies

Background

We previously evaluated the efficacy of a ventilatory strategy to achieve expiratory flow bias and positive end-expiratory pressure (EFB + PEEP) or the Trendelenburg position (TP) for the prevention of ventilator-associated pneumonia (VAP). These preventive measures were aimed at improving mucus clearance and reducing pulmonary aspiration of bacteria-laden oropharyngeal secretions. This secondary analysis is aimed at evaluating the effects of aforementioned interventions on systemic inflammation and to substantiate the value of clinical parameters and cytokines in the diagnosis of VAP.

Methods

Twenty female pigs were randomized to be positioned in the semirecumbent/prone position, and ventilated with duty cycle 0.33 and without PEEP (control); positioned as in the control group, PEEP 5 cmH₂O, and duty cycle to achieve expiratory flow bias (EFB+PEEP); ventilated as in the control group, but in the Trendelenburg position (Trendelenburg). Following randomization, P. aeruginosa was instilled into the oropharynx. Systemic cytokines and tracheal secretions P. aeruginosa concentration were quantified every 24h. Lung biopsies were collected for microbiological confirmation of VAP.

Results

In the control, EFB + PEEP, and Trendelenburg groups, lung tissue Pseudomonas aeruginosa concentration was 2.4 ± 1.5, 1.9 ± 2.1, and 0.3 ± 0.6 log cfu/mL, respectively (p = 0.020). Whereas, it was 2.4 ± 1.9 and 0.6 ± 0.9 log cfu/mL in animals with or without VAP (p < 0.001). Lower levels of interleukin (IL)-1β (p = 0.021), IL-1RA (p < 0.001), IL-4 (p = 0.005), IL-8 (p = 0.008), and IL-18 (p = 0.050) were found in Trendelenburg animals. VAP increased IL-10 (p = 0.035), tumor necrosis factor-α (p = 0.041), and endotracheal aspirate (ETA) P. aeruginosa concentration (p = 0.024). A model comprising ETA bacterial burden, IL-10, and TNF-α yielded moderate discrimination for the diagnosis of VAP (area of the receiver operating curve 0.82, 95% CI 0.61–1.00).

Conclusions

Our findings demonstrate anti-inflammatory effects associated with the Trendelenburg position. In this reliable model of VAP, ETA culture showed good diagnostic accuracy, whereas systemic IL-10 and TNF-α marginally improved accuracy. Further clinical studies will be necessary to confirm clinical value of the Trendelenburg position as a measure to hinder inflammation during mechanical ventilation and significance of systemic IL-10 and TNF-α in the diagnosis of VAP.