Influenza Incidence and Vaccine Effectiveness During the Southern Hemisphere Influenza Season - Chile, 2022.

The COVID-19 pandemic has affected influenza virus transmission, with historically low activity, atypical timing, or altered duration of influenza seasons during 2020-22 (1,2). Community mitigation measures implemented since 2020, including physical distancing and face mask use, have, in part, been credited for low influenza detections globally during the pandemic, compared with those during prepandemic seasons (1). Reduced population exposure to natural influenza infections during 2020-21 and relaxed community mitigation measures after introduction of COVID-19 vaccines could increase the possibility of severe influenza epidemics. Partners in Chile and the United States assessed Southern Hemisphere influenza activity and estimated age-group-specific rates of influenza-attributable hospitalizations and vaccine effectiveness (VE) in Chile in 2022. Chile's most recent influenza season began in January 2022, which was earlier than during prepandemic seasons and was associated predominantly with influenza A(H3N2) virus, clade 3C.2a1b.2a.2. The cumulative incidence of influenza-attributable pneumonia and influenza (P&I) hospitalizations was 5.1 per 100,000 person-years during 2022, which was higher than that during 2020-21 but lower than incidence during the 2017-19 influenza seasons. Adjusted VE against influenza A(H3N2)-associated hospitalization was 49%. These findings indicate that influenza activity continues to be disrupted after emergence of SARS-CoV-2 in 2020. Northern Hemisphere countries might benefit from preparing for an atypical influenza season, which could include early influenza activity with potentially severe disease during the 2022-23 season, especially in the absence of prevention measures, including vaccination. Health authorities should encourage all eligible persons to seek influenza vaccination and take precautions to reduce transmission of influenza (e.g., avoiding close contact with persons who are ill).

Reductions in Childhood Pneumonia Mortality After Vaccination in the United States.

BACKGROUND: We aim to estimate the magnitude of the reduction in pneumococcal pneumonia and meningitis mortality after the mass introduction of pneumococcal conjugate vaccine (PCV)7 and PCV13 in children in the United States. METHODS: We assessed the trends in mortality rates from pneumococcal pneumonia and meningitis, in the United States between 1994 and 2017. We fitted an interrupted time-series negative binomial regression model (adjusted by trend, seasonality, PCV7/PCV13 coverage, and H. influenzae type b vaccine coverage) to estimate the counterfactual rates without vaccination. We reported a percent reduction in mortality estimates relative to the projected no-vaccination scenario, using the formula 1 minus the incidence risk ratio, with 95% confidence intervals (CIs). RESULTS: Between 1994 and 1999 (the prevaccination period), the all-cause pneumonia mortality rate for 0-1-month-old children was 2.55 per 100,00 pop., whereas for 2-11 months-old children, this rate was 0.82 deaths per 100,000 pop. During the PCV7-period in 0-59-month-old children in the United States, the adjusted reduction of all-cause pneumonia was 13% (95% CI: 4-21) and 19% (95% CI: 0-33) of all-cause meningitis For PCV13, the reductions in this age group were 21% (95% CI: 4-35) for all-cause pneumonia mortality and 22% (95% CI: -19 to 48) for all-cause meningitis mortality. PCV13 had greater reductions of all-cause pneumonia than PCV13 in 6-11-month-old infants. CONCLUSIONS: The universal introduction of PCV7, and later PCV13, for children 0-59 months old in the United States was associated with decreases in mortality due to all-cause pneumonia.

Description of the first global outbreak of mpox: an analysis of global surveillance data.

BACKGROUND: In May 2022, several countries with no history of sustained community transmission of mpox (formerly known as monkeypox) notified WHO of new mpox cases. These cases were soon followed by a large-scale outbreak, which unfolded across the world, driven by local, in-country transmission within previously unaffected countries. On July 23, 2022, WHO declared the outbreak a Public Health Emergency of International Concern. Here, we aim to describe the main epidemiological features of this outbreak, the largest reported to date. METHODS: In this analysis of global surveillance data we analysed data for all confirmed mpox cases reported by WHO Member States through the global surveillance system from Jan 1, 2022, to Jan 29, 2023. Data included daily aggregated numbers of mpox cases by country and a case reporting form (CRF) containing information on demographics, clinical presentation, epidemiological exposure factors, and laboratory testing. We used the data to (1) describe the key epidemiological and clinical features of cases; (2) analyse risk factors for hospitalisation (by multivariable mixed-effects binary logistic regression); and (3) retrospectively analyse transmission trends. Sequencing data from GISAID and GenBank were used to analyse monkeypox virus (MPXV) genetic diversity. FINDINGS: Data from 82 807 cases with submitted CRFs were included in the analysis. Cases were primarily due to clade IIb MPXV (mainly lineage B.1, followed by lineage A.2). The outbreak was driven by transmission among males (73 560 [96·4%] of 76 293 cases) who self-identify as men who have sex with men (25 938 [86·9%] of 29 854 cases). The most common reported route of transmission was sexual contact (14 941 [68·7%] of 21 749). 3927 (7·3%) of 54 117 cases were hospitalised, with increased odds for those aged younger than 5 years (adjusted odds ratio 2·12 [95% CI 1·32-3·40], p=0·0020), aged 65 years and older (1·54 [1·05-2·25], p=0·026), female cases (1·61 [1·35-1·91], p<0·0001), and for cases who are immunosuppressed either due to being HIV positive and immunosuppressed (2·00 [1·68-2·37], p<0·0001), or other immunocompromising conditions (3·47 [1·84-6·54], p=0·0001). INTERPRETATION: Continued global surveillance allowed WHO to monitor the epidemic, identify risk factors, and inform the public health response. The outbreak can be attributed to clade IIb MPXV spread by newly described modes of transmission. FUNDING: WHO Contingency Fund for Emergencies. TRANSLATIONS: For the French and Spanish translations of the abstract see Supplementary Materials section.

North to south gradient and local waves of influenza in Chile.

Influenza seasonality is caused by complex interactions between environmental factors, viral mutations, population crowding, and human travel. To date, no studies have estimated the seasonality and latitudinal patterns of seasonal influenza in Chile. We obtained influenza-like illness (ILI) surveillance data from 29 Chilean public health networks to evaluate seasonality using wavelet analysis. We assessed the relationship between the start, peak, and latitude of the ILI epidemics using linear and piecewise regression. To estimate the presence of incoming and outgoing traveling waves (timing vs distance) between networks and to assess the association with population size, we used linear and logistic regression. We found a north to south gradient of influenza and traveling waves that were present in the central, densely populated region of Chile. Our findings suggest that larger populations in central Chile drive seasonal influenza epidemics.

Diarrheal Deaths After the Introduction of Rotavirus Vaccination in 4 Countries.

BACKGROUND: We aim in our analysis to estimate the reduction of diarrhea-related mortality rates after introduction of a rotavirus vaccine in subregions of 4 Latin American countries. METHODS: We selected diarrhea-related deaths from individual-level data from death certificates in Brazil, Colombia, Ecuador, and Mexico. Counts were aggregated by region, year and month, and age group for each country. We ran an interrupted time-series analysis using Poisson regression to obtain seasonal and trend-adjusted estimates of impact. Results are reported as percentages (1 - mortality rate ratio). RESULTS: We found a reduction in diarrhea-related mortality in children <5 years old of 18% (95% confidence interval [CI], 15 to 20) for Mexico, 39% (95% CI, 35 to 44) for Colombia, 19 (95% CI, 17 to 22) for Brazil, and -26% (95% CI, -40 to -14) for Ecuador. Using wavelet analyses, we found a reduction of 6- and 12-month seasonality in Brazil, Colombia, and Mexico. We also found that the increased reduction of diarrhea-related deaths was larger with greater prevaccine burden of diarrhea in infants. CONCLUSIONS: Our findings and available evidence support the recommendation from the World Health Organization for the monovalent and/or pentavalent rotavirus vaccine in countries worldwide. We found an increased benefit in those settings with a higher burden of infant diarrhea-related deaths.

Trastornos Musculoesqueléticos de espalda lumbar en trabajadores de la salud de la comuna rural de Til Til / Musculo-skeletal disorders of the lower back, in health workers of the rural district of Til-Til

Se realizó estudio de prevalencia de trastornos de la espalda lumbar entre los trabajadores del Hospital de Til Til y del Departamento de Salud de la Municipalidad de Til Til en el mes de enero del año 2004. Se utilizó el Cuestionario Nórdico Estandarizado específico para estos trastornos. Un 60 por ciento de los trabajadores sufrieron un o más TME de espalda lumbar en los últimos 12 meses; 62 por ciento mujeres y 54 por ciento hombres. El 7.7 por ciento han tenido que variar sus labores a causa de éstos problemas. La duración de los síntomas fue, en su mayoría de 1 a 7 días con un 42 por ciento. Once trabajadores (48 por ciento) se vieron forzados a reducir su actividad en el trabajo y 10 (43 por ciento) en su tiempo libre. Tan solo 3 (13 por ciento) encuestadosconsultaron a un profesional de la salud a causa de TME de espalda lumbar.