Heterogeneity in influenza seasonality and vaccine effectiveness in Australia, Chile, New Zealand and South Africa: early estimates of the 2019 influenza season.

We compared 2019 influenza seasonality and vaccine effectiveness (VE) in four southern hemisphere countries: Australia, Chile, New Zealand and South Africa. Influenza seasons differed in timing, duration, intensity and predominant circulating viruses. VE estimates were also heterogeneous, with all-ages point estimates ranging from 7-70% (I2: 33%) for A(H1N1)pdm09, 4-57% (I2: 49%) for A(H3N2) and 29-66% (I2: 0%) for B. Caution should be applied when attempting to use southern hemisphere data to predict the northern hemisphere influenza season.

Good health indicators in children with Down syndrome: High frequency of exclusive breastfeeding at 6 months. / Buenos indicadores de salud en niños con síndrome de Down: Alta frecuencia de lactancia materna exclusiva a los 6 meses.

AIM: To describe the frequency of exclusive breastfeeding at 6 months in binomial of mother and in fants with Down Syndrome (DS) attending at the Health net UC CHRISTUS (PSSPSD-UC), and iden tify the main factors associated with exclusive breastfeeding cessation. PATIENTS AND METHODS: Prevalence study of exclusively breastfeeding at 6 months of age that includes mother-child binomial of Chilean infants with (DS) aged 6-24 months, who attend the PSSPSD-UC. An on-line questionnaire was conducted, which included demographic data, child's background and experience in breastfee ding. RESULTS: The total sample consisted of 73 binomials. Forty-six percent (34/73) of the mothers exclusively breastfed until 6 months or longer, 67.1% (49/73) of the infants had a disease or malfor mation that interfere with breast feeding. Among the 39 mothers who did not exclusively breastfeed until 6 months, 25 (64.1%) referred child factors. Hospitalization during the first 6 months was the most significant factor affecting the cessation of breastfeeding (OR = 6,13). CONCLUSIONS: First study in Chile that describes the frequency of exclusive breastfeeding at 6 months of age in children with DS, which shows a large rate of exclusively breastfeeding in the studied sample. The adequate support and education in breastfeeding could allow to achieve a better rate of exclusive breastfeeding in this vulnerable group.

[Risk matrix for estimating imported outbreaks of measles or rubella in ChileMatriz de risco para estimar surtos importados de sarampo ou rubéola aplicada ao Chile]. / Matriz de riesgo para estimar brotes importados de sarampión o rubéola aplicada a Chile.

OBJECTIVE: Develop a risk matrix to evaluate the ongoing risk of measles and rubella outbreaks associated with imported cases in Chile. METHODS: The risk assessment tools were developed in the following stages: preparation and approval of biological, programmatic, and demographic variables; weighting of the selected variables by a panel of experts; calculation of the risk index; specialization; and knowledge transfer. RESULTS: Of the 346 Chilean communes analyzed, 34% were in the high-risk interval for experiencing a measles and rubella outbreak with the introduction of the virus, 59%, in the average-risk interval, and 3%, in the low-risk interval. The remaining percentage corresponded to communes lacking data in at least one of the 13 variables required for calculating the risk index. CONCLUSION: Use of this tool will enable subnational teams to use their own data to evaluate the risk of outbreaks in their area and take corrective action for a rapid response to any importation of these viruses in the post-elimination phase.

OBJETIVO: Desenvolver uma matriz de risco para avaliar o risco contínuo de surtos de sarampo e rubéola associados com a importação de casos no Chile. MÉTODOS: As ferramentas de avaliação de riscos foram desenvolvidas nas seguintes etapas: preparação e aprovação das variáveis biológicas, programáticas e demográficas, consideração das variáveis selecionadas por painel de especialistas, cálculo do índice de risco, especialização e transferência de conhecimento. RESULTADOS: Das 346 comunidades analisadas, 34% estavam dentro da faixa de alto risco de ter um surto de sarampo e rubéola com a introdução do vírus, 59% na faixa de risco intermediário e 3% na faixa de baixo risco. O percentual restante correspondeu a comunidades com dados insuficientes em pelo menos uma das 13 variáveis necessárias ao cálculo do índice de risco. CONCLUSÃO: A utilização desta ferramenta permitirá às equipes subnacionais lançar mão de dados próprios para avaliar o risco de surtos e realizar medidas corretivas para responder rapidamente a qualquer importação de vírus na fase posterior à eliminação.

Nowcasting methods to improve the performance of respiratory sentinel surveillance: lessons from the COVID-19 pandemic.

Respiratory diseases, including influenza and coronaviruses, pose recurrent global threats. This study delves into the respiratory surveillance systems, focusing on the effectiveness of SARI sentinel surveillance for total and severe cases incidence estimation. Leveraging data from the COVID-19 pandemic in Chile, we examined 2020-2023 data (a 159-week period) comparing census surveillance results of confirmed cases and hospitalizations, with sentinel surveillance. Our analyses revealed a consistent underestimation of total cases and an overestimation of severe cases of sentinel surveillance. To address these limitations, we introduce a nowcasting model, improving the precision and accuracy of incidence estimates. Furthermore, the integration of genomic surveillance data significantly enhances model predictions. While our findings are primarily focused on COVID-19, they have implications for respiratory virus surveillance and early detection of respiratory epidemics. The nowcasting model offers real-time insights into an outbreak for public health decision-making, using the same surveillance data that is routinely collected. This approach enhances preparedness for emerging respiratory diseases by the development of practical solutions with applications in public health.

H105A peptide eye drops promote photoreceptor survival in murine and human models of retinal degeneration.

Photoreceptor death causes blinding inheritable retinal diseases, such as retinitis pigmentosa (RP). As disease progression often outpaces therapeutic advances, finding effective treatments is urgent. This study focuses on developing a targeted approach by evaluating the efficacy of small peptides derived from pigment epithelium-derived factor (PEDF), known to restrict common cell death pathways associated with retinal diseases. Peptides with affinity for the PEDF receptor, PEDF-R, (17-mer and H105A) delivered via eye drops reached the retina, efficiently promoted photoreceptor survival, and improved retinal function in RP mouse models based on both the rd10 mutation and the rhodopsin P23H mutation. Additionally, intravitreal delivery of AAV-H105A vectors delayed photoreceptor degeneration in the latter RP mouse model. Furthermore, peptide H105A specifically prevented photoreceptor death induced by oxidative stress, a contributing factor to RP progression, in human retinal organoids. This promising approach for peptide eye drop delivery holds significant potential as a therapeutic for preventing photoreceptor death in retinal disorders, offering a high safety profile, low invasiveness and multiple delivery options.

[Clinical characterization of cases with meningococcal disease by W135 group in Chile, 2012]. / Caracterización clínica de los casos de enfermedad meningocóccica por serogrupo W135 confirmados durante el año 2012 en Chile.

BACKGROUND: During 2012 in Chile, there were 60 cases of serogroup W135 meningococcal disease, which accounts for 57.7% of identified serogroup cases. AIM: To describe main clinical features of patients with serogroup W135 meningococcal disease confirmed in 2012. MATERIAL AND METHODS: Descriptive study of case series based on retrospective review of medical records. RESULTS: Male patients represented 61.7% and 46.7% were children under 5 years. At first clinical attention, 3.4% of patients were suspected of meningococcal disease, while 83.3% had meningococcemia as final diagnosis. Also at first attention, the most common symptoms or clinical signs were fever ≥ 38.0° C (60.3%), cold symptoms (52.5%), and nausea or vomiting (46.7%). Meningeal signs had a low frequency (8.7%). Diarrhea was the second most common symptom found among deceased patients (55.6%) and statistically higher than survivors (26.8%; p = 0.034). Six cases reported with sequelae: limb amputation, hearing loss or neurological damage, and mortality was 31.7%. DISCUSSION: In 2012, serogroup W135 meningococcal disease reported high mortality, atypical clinical presentation, low initial meningococcal disease diagnosis, and a high number of cases with poor clinical course.

End-of-season influenza vaccine effectiveness during the Southern Hemisphere 2022 influenza season - Chile, Paraguay, and Uruguay.

OBJECTIVES: This study estimated the 2022 end-of-season influenza vaccine effectiveness (VE) against severe acute respiratory illness (SARI) hospitalization in Chile, Paraguay, and Uruguay. METHODS: We pooled surveillance data from SARI cases in 18 sentinel surveillance hospitals in Chile (n = 9), Paraguay (n = 2), and Uruguay (n = 7) from March 16-November 30, 2022. VE was estimated using a test-negative design and logistic regression models adjusted for country, age, sex, presence of ≥1 comorbidity, and week of illness onset. VE estimates were stratified by influenza virus type and subtype (when available) and influenza vaccine target population, categorized as children, individuals with comorbidities, and older adults, defined per countries' national immunization policies. RESULTS: Among the 3147 SARI cases, there were 382 (12.1%) influenza test-positive case patients; 328 (85.9%) influenza case patients were in Chile, 33 (8.6%) were in Paraguay, and 21 (5.5%) were in Uruguay. In all countries, the predominant subtype was influenza A(H3N2) (92.6% of influenza cases). Adjusted VE against any influenza-associated SARI hospitalization was 33.8% (95% confidence interval: 15.3%, 48.2%); VE against influenza A(H3N2)-associated SARI hospitalization was 30.4% (95% confidence interval: 10.1%, 46.0%). VE estimates were similar across target populations. CONCLUSION: During the 2022 influenza season, influenza vaccination reduced the odds of hospitalization among those vaccinated by one-third. Health officials should encourage influenza vaccination in accordance with national recommendations.

Severity of influenza illness by seasonal influenza vaccination status among hospitalised patients in four South American countries, 2013-19: a surveillance-based cohort study.

BACKGROUND: Although several studies have reported attenuated influenza illness following influenza vaccination, results have been inconsistent and have focused predominantly on adults in the USA. This study aimed to evaluate the severity of influenza illness by vaccination status in a broad range of influenza vaccine target groups across multiple South American countries. METHODS: We analysed data from four South American countries (Argentina, Brazil, Chile, and Paraguay) participating in REVELAC-i, a multicentre, test-negative design, vaccine effectiveness network including 41 sentinel hospitals. Individuals hospitalised at one of these centres with severe acute respiratory infection were tested for influenza by real-time RT-PCR, and were included in the analysis if they had complete information about their vaccination status and outcomes of their hospital stay. We used multivariable logistic regression weighted by inverse probability of vaccination and adjusted for antiviral use, duration of illness before admission, and calendar week, to calculate the adjusted odds ratios (aORs) of intensive care unit (ICU) admission and in-hospital death (and combinations of these outcomes) among influenza-positive patients by vaccination status for three target groups: young children (aged 6-24 months), adults (aged 18-64 years) with pre-existing health conditions, and older adults (aged ≥65 years). Survival curves were used to compare length of hospital stay by vaccination status in each target group. FINDINGS: 2747 patients hospitalised with PCR-confirmed influenza virus infection between Jan 1, 2013, and Dec 8, 2019, were included in the study: 649 children (70 [10·8%] fully vaccinated, 193 [29·7%] partially vaccinated) of whom 87 (13·4%) were admitted to ICU and 12 (1·8%) died in hospital; 520 adults with pre-existing medical conditions (118 [22·7%] vaccinated), of whom 139 (26·7%) were admitted to ICU and 55 (10·6%) died in hospital; and 1578 older adults (609 [38·6%] vaccinated), of whom 271 (17·2%) were admitted to ICU and 220 (13·9%) died in hospital. We observed earlier discharge among partially vaccinated children (adjusted hazard ratio 1·14 [95% CI 1·01-1·29]), fully vaccinated children (1·24 [1·04-1·47]), and vaccinated adults with pre-existing medical conditions (1·78 [1·18-2·69]) compared with their unvaccinated counterparts, but not among vaccinated older adults (0·82 [0·65-1·04]). Compared with unvaccinated individuals, lower odds of ICU admission were found for partially vaccinated children (aOR 0·64 [95% CI 0·44-0·92]) and fully vaccinated children (0·52 [0·28-0·98]), but not for adults with pre-existing conditions (1·25 [0·93-1·67]) or older adults (0·88 [0·72-1·08]). Lower odds of in-hospital death (0·62 [0·50-0·78]) were found in vaccinated versus unvaccinated older adults, with or without ICU admission, but did not differ significantly in partially vaccinated (1·35 [0·57-3·20]) or fully vaccinated young children (0·88 [0·16-4·82]) or adults with pre-existing medical conditions (1·09 [0·73-1·63]) compared with the respective unvaccinated patient groups. INTERPRETATION: Influenza vaccination was associated with illness attenuation among those hospitalised with influenza, although results differed by vaccine target group. These findings might suggest that attenuation of disease severity might be specific to certain target groups, seasons, or settings. FUNDING: US Centers for Disease Control and Prevention. TRANSLATIONS: For the Spanish and Portuguese translations of the abstract see Supplementary Materials section.

[Epidemiological and clinical characteristics of influenza A (H1N1) 2009 at San Felipe, Valparaiso Region, Chile: June-August 2009]. / Caracterización epidemiológica y clínica de la infección por influenza A (H1N1) 2009 en San Felipe, Región de Valparaíso, Chile: Junio a agosto 2009.

In order to understand the clinical and epidemiological aspects of infection with the AH1N1 influenza virus in Chile, a prospective study in the city of San Felipe was undertaken. It analyses the trends in consultations for respiratory causes in three primary care centers and hospital discharges by comparing data from years 2008 and 2009 until epidemiological week 37.It also includes a study of cases of ILI / SARI (influenza like disease/severe acute respiratory disease) in which viruses were detected by direct immunofluorescence (DIF) of nasopharyngeal aspirates and by real-time polymerase chain reaction in the case of influenza A (H1N1) 2009. A household survey was conducted in those cases with confirmed A (H1N1) infection, to identify contacts and history related to influenza virus transmission. The results indicate that the behavior of the pandemic was similar to that observed in the rest of the country, with an increase in emergency room visits for ILI. The most affected age group was from 5 to 14 years (26.5 per thousand inhabitants) and the least affected 60 years or older (1.2 per thousand). A 2.78% of the cases corresponded to SARI and the fatality rate was 0.11%.

[Molecular detection of gastrointestinal pathogens among children under 5 years old with diarrhea in a hospital center for rotavirus sentinel surveillance in Chile]. / Detección molecular de patógenos entéricos en niños con diarrea en un hospital centinela de vigilancia de rotavirus en Chile.

BACKGROUND: Infectious diarrhea is still a major problem in public health, especially in children under 5 years of age. The identification of the etiologic agent is important for the clinical management of the diarrhea episode and, from the epidemiological point of view, to implement control measures. AIM: To determine the presence of gastrointestinal pathogens in children under five years of age with diarrhea in a Chilean rotavirus surveillance center. METHODS: Observational study in children under five years of age who were hospitalized for diarrhea at the Dr. Luis Calvo Mackenna Hospital from December 2015 to December 2019. Molecular detection was performed using the FilmArray gastrointestinal (FilmArray GI®) panel. RESULTS: We analyzed 493 diarrheal stool samples of children, 427 samples (87%) were positive and 66 samples (13%) were negative. Of positive samples, 174 samples (41%) and 253 samples (59%) were positive for one or more pathogen, respectively. In children under one year and the group between one and four years there was a predominance of infections caused by enteric virus. Rotavirus and norovirus were the most common virus in both age groups. The most frequent bacteria were EPEC (27%), C. difficile (17%), EAEC (14%) and Campylobacter (9%). In parasites, Giardia lamblia and Cryptosporidium were identified, in 3% and 1% of the total samples, respectively. CONCLUSIONS: The molecular detection system used allowed an increase in the detection of enteropathogens in children under five years of age. The information generated by this type of surveillance could help to characterize the episodes of diarrhea in the population and might be a tool to technically advise the authorities in the decision-making process for the implementation of control measures.