Significant Rise in SARS-CoV-2 Reinfection Rate in Vaccinated Hospital Workers during the Omicron Wave: A Prospective Cohort Study.

Background: Relatively low SARS-CoV-2 reinfection rates have been reported in vaccinated individuals, but updates considering the Omicron variant are lacking. Objectives: The objective of the study was to provide a current estimate of the SARS-CoV-2 reinfection rate in a highly immunized population. Methods: A prospective cohort of Mexican hospital workers was followed (March 2020-February 2022). Reinfection was defined as the occurrence of two or more episodes of COVID-19 separated by a period of ≥ 90 days without symptoms. The reinfection rate was calculated as the number of reinfection episodes per 100,000 persons per day. Results: A total of 3732 medical consultations were provided to 2700 workers, of whom 1388 (51.4%) were confirmed COVID-19 cases. A total of 73 reinfection cases were identified, of whom 71 (97.3%) had completed their primary vaccination series and 22 (30.1%) had had a booster dose before the second episode. The overall reinfection rate was 23.1 per 100,000 persons per day (as compared to a rate of 1.9 per 100,000 persons per day before the Omicron wave). Conclusions: The SARS-CoV-2 reinfection rate rose significantly during the Omicron wave despite a high primary vaccination coverage rate. Almost one-third of reinfected workers had a vaccine booster ≥ 14 days before the last COVID-19 episode.

Efectividad de las vacunas contra SARS-CoV-2 en hospitalizados con fallas vacunales en 10 hospitales de la CCINSHAE.

OBJETIVO: Evaluar la efectividad de las vacunas contra SARS-CoV-2 para evitar muerte e intubación en pacientes hospitalizados con Covid-19. Material y métodos. Se presentó un análisis de 3 565 hospitalizaciones por SARS-CoV-2 de personas mayores de 20 años de edad, reportadas con fines de salud pública por 10 hospitales de especialidad. Se comparó a los egresados por mejoría (2 094) con los fallecidos (1 471) en modelos mixtos de regresión logística ajustados por edad, sexo, número de comorbilidades y el hospital como variable aleatoria. RESULTADOS: Un esquema completo de vacunación, con cinco tipos de vacunas disponi-bles, tuvo un efecto protector para muerte o intubación (RM: 0.67, IC95%: 0.54,0.83, 33% de protección); y para muerte (RM: 0.80, IC95%: 0.64,0.99, 20% de protección) estos datos se compararon con los que no habían sido vacunados. Todas las vacunas aplicadas mostraron un efecto protector con un RM<0.8, con intervalos de confianza variables. Conclusio-nes. El antecedente de vacunación reduce los riesgos de ser intubado y morir, aun en pacientes previamente vacunados y hospitalizados con Covid-19 grave.

Correction: In-hospital mortality from severe COVID-19 in a tertiary care center in Mexico City; causes of death, risk factors and the impact of hospital saturation.

[This corrects the article DOI: 10.1371/journal.pone.0245772.].

Seroepidemiology of SARS-CoV-2 in healthcare personnel working at the largest tertiary COVID-19 referral hospitals in Mexico City.

INTRODUCTION: We performed a longitudinal SARS-CoV-2 seroepidemiological study in healthcare personnel of the two largest tertiary COVID-19 referral hospitals in Mexico City. METHODS: All healthcare personnel, including staff physicians, physicians in training, nurses, laboratory technicians, researchers, students, housekeeping, maintenance, security, and administrative staff were invited to voluntarily participate, after written informed consent. Participants answered a computer-assisted self-administered interview and donated blood samples for antibody testing every three weeks from October 2020 to June 2021. RESULTS: A total of 883 participants (out of 3639 registered employees) contributed with at least one blood sample. The median age was 36 years (interquartile range: 28-46) and 70% were women. The most common occupations were nurse (28%), physician (24%), and administrative staff (22%). Two hundred and ninety participants (32.8%) had a positive-test result in any of the visits, yielding an overall adjusted prevalence of 33.5% for the whole study-period. Two hundred and thirty-five positive tests were identified at the baseline visit (prevalent cases), the remaining 55 positive tests were incident cases. Prevalent cases showed associations with both occupational (institution 2 vs. 1: adjusted odds ratio [aOR] = 2.24, 95% confidence interval [CI]: 1.54-3.25; laboratory technician vs. physician: aOR = 4.38, 95% CI: 1.75-10.93) and community (municipality of residence Xochimilco vs. Tlalpan: aOR = 2.03, 95% CI: 1.09-3.79) risk-factors. The incidence rate was 3.0 cases per 100 person-months. Incident cases were associated with community-acquired risk, due to contact with suspect/confirmed COVID-19 cases (HR = 2.45, 95% CI: 1.21-5.00). CONCLUSIONS: We observed that between October 2020 and June 2021, healthcare workers of the two largest tertiary COVID-19 referral centers in Mexico City had similar level of exposure to SARS-CoV-2 than the general population. Most variables associated with exposure in this setting pointed toward community rather than occupational risk. Our observations are consistent with successful occupational medicine programs for SARS-CoV-2 infection control in the participating institutions but suggest the need to strengthen mitigation strategies in the community.

Epicardial adipose tissue thickness is associated with increased COVID-19 severity and mortality.

BACKGROUND: Increased adiposity and visceral obesity have been linked to adverse COVID-19 outcomes. The amount of epicardial adipose tissue (EAT) may have relevant implications given its proximity to the heart and lungs. Here, we explored the role of EAT in increasing the risk for COVID-19 adverse outcomes. METHODS: We included 748 patients with COVID-19 attending a reference center in Mexico City. EAT thickness, sub-thoracic and extra-pericardial fat were measured using thoracic CT scans. We explored the association of each thoracic adipose tissue compartment with COVID-19 mortality and severe COVID-19 (defined as mortality and need for invasive mechanical ventilation), according to the presence or absence of obesity. Mediation analyses evaluated the role of EAT in facilitating the effect of age, body mass index and cardiac troponin levels with COVID-19 outcomes. RESULTS: EAT thickness was associated with increased risk of COVID-19 mortality (HR 1.18, 95% CI 1.01-1.39) independent of age, gender, comorbid conditions and BMI. Increased EAT was associated with lower SpO2 and PaFi index and higher levels of cardiac troponins, D-dimer, fibrinogen, C-reactive protein, and 4 C severity score, independent of obesity. EAT mediated 13.1% (95% CI 3.67-28.0%) and 5.1% (95% CI 0.19-14.0%) of the effect of age and 19.4% (95% CI 4.67-63.0%) and 12.8% (95% CI 0.03-46.0%) of the effect of BMI on requirement for intubation and mortality, respectively. EAT also mediated the effect of increased cardiac troponins on myocardial infarction during COVID-19. CONCLUSION: EAT is an independent risk factor for severe COVID-19 and mortality independent of obesity. EAT partly mediates the effect of age and BMI and increased cardiac troponins on adverse COVID-19 outcomes.

Outbreak of NDM-1-Producing Escherichia coli in a Coronavirus Disease 2019 Intensive Care Unit in a Mexican Tertiary Care Center.

Emergency department areas were repurposed as intensive care units (ICUs) for patients with acute respiratory distress syndrome during the initial months of the coronavirus disease 2019 (COVID-19) pandemic. We describe an outbreak of New Delhi metallo-ß-lactamase 1 (NDM-1)-producing Escherichia coli infections in critically ill COVID-19 patients admitted to one of the repurposed units. Seven patients developed infections (6 ventilator-associated pneumonia [VAP] and 1 urinary tract infection [UTI]) due to carbapenem-resistant E. coli, and only two survived. Five of the affected patients and four additional patients had rectal carriage of carbapenem-resistant E. coli. The E. coli strain from the affected patients corresponded to a single sequence type. Rectal screening identified isolates of two other sequence types bearing blaNDM-1. Isolates of all three sequence types harbored an IncFII plasmid. The plasmid was confirmed to carry blaNDM-1 through conjugation. An outbreak of clonal NDM-1-producing E. coli isolates and subsequent dissemination of NDM-1 through mobile elements to other E. coli strains occurred after hospital conversion during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. This emphasizes the need for infection control practices in surge scenarios. IMPORTANCE The SARS-CoV-2 pandemic has resulted in a surge of critically ill patients. Hospitals have had to adapt to the demand by repurposing areas as intensive care units. This has resulted in high workload and disruption of usual hospital workflows. Surge capacity guidelines and pandemic response plans do not contemplate how to limit collateral damage from issues like hospital-acquired infections. It is vital to ensure quality of care in surge scenarios.

SARS-CoV-2 Infection Rate in Patients With Cancer and Health Care Workers in a Chemoradiotherapy Unit During the Pandemic: A Prospective Cohort in Mexico.

PURPOSE: Cancer treatment during the COVID-19 pandemic represents a challenge. Hospital visits to receive treatment and interaction with health care workers (HCW) represent potential contagious events. We aimed to determine SARS-CoV-2 infection rate among patients with cancer and HCW of a chemoradiotherapy unit localized in a center designated as a COVID-19 priority facility in Mexico City. We also determined the diagnostic performance of a clinical questionnaire (CQ) as a screening tool and anti-SARS-CoV-2 antibody seroconversion rate. METHODS: HCW and patients with solid tumors attending the chemoradiotherapy unit signed informed consent. To determine SARS-CoV-2 infection rate prospectively, a nasopharyngeal swab for SARS-CoV-2 real-time quantitative reverse transcriptase polymerase chain reaction (RT-qPCR) was performed every 2 weeks in asymptomatics. An electronic CQ interrogating COVID-19-related symptoms was sent daily. Anti-SARS-CoV-2 immunoglobulin G (IgG) antibodies were measured at baseline and at the end of the study period. RESULTS: From June to September 2020, we included 130 asymptomatic participants, 44.6% HCW and 55.4% patients with cancer. During a median follow-up of 85 days, 634 nasopharyngeal swabs were performed. Average SARS-CoV-2 monthly incidence was 4.6% (3.15%-7.47%), and cumulative infection rate was 13.8% (18 of 130). Cases were mostly asymptomatic (66%), and no hospitalizations or deaths were recorded. The CQ as a screening tool provided a sensitivity of 27.7%, a positive predictive value of 26.3%, and a positive likelihood ratio of 12. SARS-CoV-2 IgG seroconversion rate was 27.7% among those with a positive RT-PCR. CONCLUSION: Patients with cancer on treatment can have uncomplicated COVID-19 outcomes. Biweekly RT-qPCR testing detects asymptomatic infections, prevents transmission, and should be implemented in units to increase patient safety. CQ increase RT-qPCR diagnostic yield and may prioritize testing in resource-deprived settings. Post-infection IgG seroconversion is unreliable.

Surge in Ventilator-Associated Pneumonias and Bloodstream Infections in An Academic Referral Center Converted to Treat COVID-19 Patients.

BACKGROUND: Healthcare-associated infections (HAIs) are important adverse events that must be prevented. OBJECTIVE: The objective of the study was to report and study possible changes in HAI rates as well as their causes after the COVID-19 hospital surge capacity response (HSCR) in an academic referral center. METHODS: This was a before-after observational study. The Infection Prevention and Control (IPC) program (prospective surveillance, prevention bundles, antibiotic stewardship, continuing education, and feedback) was transiently disrupted after the start of HSCR (March 2020). HAI rates were compared before (January 2019-February 2020) and after (April-July 2020) HSCR, and plausible predisposing factors in affected patients were compared. RESULTS: An increase in the HAI rate from 6.2 to 11.8 cases/1000 patient-days was noted between periods due to increases in ventilator-associated pneumonia and bloodstream infection (BSI) rates. More critically ill patients were admitted during HSCR, and use of invasive devices increased. Prone positioning and infusion of muscle relaxants became commonplace. The nurse-to-patient ratio in the intensive care unit decreased, and 4 h shifts were introduced to avoid fatigue. The BSI rate decreased after the IPC program with additional measures was reintroduced in May 2020. CONCLUSIONS: The strain on the workforce and modifications to the IPC program very possibly underlay the findings. IPC programs continue to be essential during the pandemic.

Factors Associated with COVID-19 and Asymptomatic Carriage in Healthcare Workers of a COVID-19 Hospital.

BACKGROUND: Risk factors for coronavirus disease (COVID-19) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) asymptomatic carriage (AC) in healthcare workers (HCWs) have been scarcely characterized. OBJECTIVE: The objective of the study was to study factors associated with COVID-19 and AC in HCWs of a COVID-19 academic medical center. METHODS: This is a case-control study. Cases were either symptomatic or asymptomatic HCWs with a positive SARS-CoV-2 polymerase chain reaction (PCR) test result between March 16 and May 21 of 2020. Adjusted odds ratios (aOR) were calculated by means of multivariable logistic regression. In addition, each subject was followed for 14 days to inform outcomes. RESULTS: One hundred thirty of 249 (52.2%) symptomatic HCWs had COVID-19; 10 were hospitalized but none died. Of 987 asymptomatic HCWs,37 (3.7%) were AC; 6 of the remaining 950 asymptomatic HCWs with a negative PCR test result were found to be presymptomatic COVID-19 cases the following 14 days. Nurses were more frequently present in the COVID-19 group (51.5% vs. 37.0%), but multivariable analysis rendered non-significant results. After adjustment for age, comorbidities, and working place, factors found to be associated with AC were: working in wards as a nurse (aOR = 9.19, 95% confidence interval [CI] = 1.05-80.22, p = 0.045), kitchen personnel (aOR = 4.09, 95% CI = 1.55-10.83, p = 0.005), and being a physician (aOR = 0.12, 95% CI = 0.03-0.54, p = 0.006). CONCLUSIONS: HCW category was the predominant factor associated with AC of SARS-CoV-2 in this study.

Antimicrobial Resistance Patterns and Antibiotic Use during Hospital Conversion in the COVID-19 Pandemic.

OBJECTIVE: To describe empirical antimicrobial prescription on admission in patients with severe COVID-19, the prevalence of Hospital-Acquired Infections, and the susceptibility patterns of the causing organisms. METHODS: In this prospective cohort study in a tertiary care center in Mexico City, we included consecutive patients admitted with severe COVID-19 between March 20th and June 10th and evaluated empirical antimicrobial prescription and the occurrence of HAI. RESULTS: 794 patients with severe COVID-19 were admitted during the study period. Empiric antibiotic treatment was started in 92% of patients (731/794); the most frequent regimes were amoxicillin-clavulanate plus atypical coverage in 341 (46.6%) and ceftriaxone plus atypical coverage in 213 (29.1%). We identified 110 HAI episodes in 74/656 patients (11.3%). Ventilator-associated pneumonia (VAP) was the most frequent HAI, in 56/110 (50.9%), followed by bloodstream infections (BSI), in 32/110 (29.1%). The most frequent cause of VAP were Enterobacteriaceae in 48/69 (69.6%), followed by non-fermenter gram-negative bacilli in 18/69 (26.1%). The most frequent cause of BSI was coagulase negative staphylococci, in 14/35 (40.0%), followed by Enterobacter complex in 7/35 (20%). Death occurred in 30/74 (40.5%) patients with one or more HAI episodes and in 193/584 (33.0%) patients without any HAI episode (p < 0.05). CONCLUSION: A high frequency of empiric antibiotic treatment in patients admitted with COVID-19 was seen. VAP and BSI were the most frequent hospital-acquired infections, due to Enterobacteriaceae and coagulase negative staphylococci, respectively.

Substantial reduction of healthcare facility-onset Clostridioides difficile infection (HO-CDI) rates after conversion of a hospital for exclusive treatment of COVID-19 patients.

Healthcare facility-onset Clostridioides difficile infection rates substantially dropped in a Mexican hospital after its conversion to a full COVID-19 setting, despite heavy contamination of the environment the previous year. Better adherence to hand hygiene and contact precautions may help explain this finding.

CLINICAL AND EPIDEMIOLOGICAL CHARACTERISTICS OF PATIENTS DIAGNOSED WITH COVID-19 IN A TERTIARY CARE CENTER IN MEXICO CITY: A PROSPECTIVE COHORT STUDY.

BACKGROUND: Regional information regarding the characteristics of patients with coronavirus disease (COVID)-19 is needed for a better understanding of the pandemic. OBJECTIVE: The objective of the study to describe the clinical features of COVID-19 patients diagnosed in a tertiary-care center in Mexico City and to assess differences according to the treatment setting (ambulatory vs. hospital) and to the need of intensive care (IC). METHODS: We conducted a prospective cohort, including consecutive patients with COVID-19 from February 26, 2020 to April 11, 2020. RESULTS: We identified 309 patients (140 inpatients and 169 outpatients). The median age was 43 years (interquartile range, 33-54), 59.2% men, and 18.6% healthcare workers (12.3% from our center). The median body mass index (BMI) was 29.00 kg/m2 and 39.6% had obesity. Compared to outpatients, inpatients were older, had comorbidities, cough, and dyspnea more frequently. Twenty-nine (20.7%) inpatients required treatment in the IC unit (ICU). History of diabetes (type 1 or 2) and abdominal pain were more common in ICU patients compared to non-ICU patients. ICU patients had higher BMIs, higher respiratory rates, and lower room-air capillary oxygen saturations. ICU patients showed a more severe inflammatory response as assessed by white blood cell count, neutrophil and platelet count, C-reactive protein, ferritin, procalcitonin, and albumin levels. By the end of the study period, 65 inpatients had been discharged because of improvement, 70 continued hospitalized, and five had died. CONCLUSIONS: Patients with comorbidities, either middle-age obese or elderly complaining of fever, cough, or dyspnea, were more likely to be admitted. At admission, patients with diabetes, high BMI, and clinical or laboratory findings consistent with a severe inflammatory state were more likely to require IC.

The SARS-CoV-2 (COVID-19) coronavirus pandemic: current situation and implications for Mexico.

The Coronavirus pandemic (COVID-19) is one of the most devastating in this century. It originated in China in December 2019 caused by the SARS-Cov-2 virus, and in less than a month it had been classified as an "International Public Health Emergency". To date there are nearly 3 million people infected and more than 250,000 deaths caused by the disease worldwide. Initially it affects the respiratory tract with atypical pneumonia and in severe cases it produces systemic inflammation with cytokine storm that can cause rapid deterioration with circulatory and respiratory failure, coagulopathy and a lethality rate of approximately 7%. In Mexico, the first case was detected in February 2020, and to date there are 26,616 confirmed cases and 2,961 deaths throughout the country. The low number of diagnostic tests conducted in our country clearly underestimates the real incidence and impact of the disease. The most affected groups are those with risk factors such as age over 60, presence of hypertension, diabetes or cardiovascular disease. Of the confirmed cases, 15% are healthcare workers. There is no specific treatment or vaccine yet, so it is important to have hygiene, social isolation and personal protection measures. Health, social and economic consequences could have great impact in the near future.

La pandemia del Coronavirus (COVID-19) es una de las más devastadoras de este siglo. Originada en China en diciembre de 2019 y causada por el virus SARS-CoV-2, en menos de 1 mes ya había sido catalogada como "Emergencia de Salud Pública de Alcance Internacional". A la fecha hay cerca de 3 millones de personas con infección confirmada y ha provocado más de 250,000 fallecimientos en el mundo. Inicialmente afecta las vías respiratorias con neumonías atípica y en casos graves provoca inflamación sistémica con liberación de citoquinas que pueden provocar un rápido deterioro, insuficiencia circulatoria, respiratoria y alteraciones de coagulación con una letalidad cercana al 7%. En México, el primer caso se detectó en febrero del 2020, y a la fecha de esta publicación se cuenta con 29,616 casos confirmados y 2,961 fallecimientos en toda la extensión de país. La baja tasa de muestreo diagnóstico en nuestro país claramente subestima la incidencia e impacto de esta enfermedad. Los grupos mas afectados son aquéllos con factores de riesgo como lo son la edad mayor a 60 años, hipertensión, diabetes o historia de enfermedad cardiovascular. De los casos confirmados, 15% son trabajadores del sector salud. No existe hasta ahora un tratamiento específico o vacuna, de tal manera que es importante contar con las medidas de higiene, aislamiento social y protección personal. Las consecuencias en salud, sociales y económicas podrían ser de gran impacto en los tiempos por venir.