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.

Global burden of acute lower respiratory infection associated with human parainfluenza virus in children younger than 5 years for 2018: a systematic review and meta-analysis.

BACKGROUND: Human parainfluenza virus (hPIV) is a common virus in childhood acute lower respiratory infections (ALRI). However, no estimates have been made to quantify the global burden of hPIV in childhood ALRI. We aimed to estimate the global and regional hPIV-associated and hPIV-attributable ALRI incidence, hospital admissions, and mortality for children younger than 5 years and stratified by 0-5 months, 6-11 months, and 12-59 months of age. METHODS: We did a systematic review of hPIV-associated ALRI burden studies published between Jan 1, 1995, and Dec 31, 2020, found in MEDLINE, Embase, Global Health, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Global Health Library, three Chinese databases, and Google search, and also identified a further 41 high-quality unpublished studies through an international research network. We included studies reporting community incidence of ALRI with laboratory-confirmed hPIV; hospital admission rates of ALRI or ALRI with hypoxaemia in children with laboratory-confirmed hPIV; proportions of patients with ALRI admitted to hospital with laboratory-confirmed hPIV; or in-hospital case-fatality ratios (hCFRs) of ALRI with laboratory-confirmed hPIV. We used a modified Newcastle-Ottawa Scale to assess risk of bias. We analysed incidence, hospital admission rates, and hCFRs of hPIV-associated ALRI using a generalised linear mixed model. Adjustment was made to account for the non-detection of hPIV-4. We estimated hPIV-associated ALRI cases, hospital admissions, and in-hospital deaths using adjusted incidence, hospital admission rates, and hCFRs. We estimated the overall hPIV-associated ALRI mortality (both in-hospital and out-hospital mortality) on the basis of the number of in-hospital deaths and care-seeking for child pneumonia. We estimated hPIV-attributable ALRI burden by accounting for attributable fractions for hPIV in laboratory-confirmed hPIV cases and deaths. Sensitivity analyses were done to validate the estimates of overall hPIV-associated ALRI mortality and hPIV-attributable ALRI mortality. The systematic review protocol was registered on PROSPERO (CRD42019148570). FINDINGS: 203 studies were identified, including 162 hPIV-associated ALRI burden studies and a further 41 high-quality unpublished studies. Globally in 2018, an estimated 18·8 million (uncertainty range 12·8-28·9) ALRI cases, 725 000 (433 000-1 260 000) ALRI hospital admissions, and 34 400 (16 400-73 800) ALRI deaths were attributable to hPIVs among children younger than 5 years. The age-stratified and region-stratified analyses suggested that about 61% (35% for infants aged 0-5 months and 26% for 6-11 months) of the hospital admissions and 66% (42% for infants aged 0-5 months and 24% for 6-11 months) of the in-hospital deaths were in infants, and 70% of the in-hospital deaths were in low-income and lower-middle-income countries. Between 73% and 100% (varying by outcome) of the data had a low risk in study design; the proportion was 46-65% for the adjustment for health-care use, 59-77% for patient groups excluded, 54-93% for case definition, 42-93% for sampling strategy, and 67-77% for test methods. Heterogeneity in estimates was found between studies for each outcome. INTERPRETATION: We report the first global burden estimates of hPIV-associated and hPIV-attributable ALRI in young children. Globally, approximately 13% of ALRI cases, 4-14% of ALRI hospital admissions, and 4% of childhood ALRI mortality were attributable to hPIV. These numbers indicate a potentially notable burden of hPIV in ALRI morbidity and mortality in young children. These estimates should encourage and inform investment to accelerate the development of targeted interventions. FUNDING: Bill & Melinda Gates Foundation.

National Seroprevalence of Coxiella burnetii in Chile, 2016-2017.

Coxiella burnetii is an intracellular bacterium and the cause of the zoonotic infection, Q fever. National surveillance data on C. burnetii seroprevalence is currently not available for any South American country, making efforts of public health to implement strategies to mitigate infections in different at-risk groups within the population extremely challenging. In the current study, we used two commercial anti-C. burnetii immunoassays to screen sera collected from a sample of the Chilean population as part of a 2016-2017 national health survey (n = 5166), nationwide and age-standardized. The seroprevalence for C. burnetii for persons ≥ 15 years was estimated to be 3.0% (95% CI 2.2-4.0), a level similar to national surveys from The Netherlands (2.4%) and USA (3.1%), but lower than Australia (5.6%). A linear increase of C. burnetii seropositivity was associated with an individual's age, with the peak seroprevalence 5.6% (95% CI 3.6-8.6) observed in the ≥65 years' group. C. burnetii seropositivity was significantly higher in the southern macro-zone 6.0% (95% CI 3.3-10.6) compared to metropolitan region 1.8% (95% CI 0.9-3.3), the former region being home to significant livestock industries, particularly dairy farming. These data will be useful to inform targeted strategies for the prevention of Q fever in at-risk populations in Chile.

[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.

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

INTRODUCCIÓN: Las diarreas de causa infecciosa son un problema de salud pública, especialmente en niños bajo los cinco años. La identificación de los agentes etiológicos puede ser relevante para el manejo del cuadro clínico y, desde el punto de vista epidemiológico, para la implementación de medidas de control. OBJETIVO: Determinar la presencia de patógenos entéricos en niños bajo los cinco años que se hospitalizaron por diarrea aguda en uno de los centros centinelas de la red de vigilancia de rotavirus en Chile. PACIENTES Y MÉTODOS: Estudio observacional en niños menores de cinco años que se internaron por cuadros de diarrea en el Hospital Dr. Luis Calvo Mackenna, durante diciembre del 2015 a diciembre del 2019, el que forma parte de la red de vigilancia de rotavirus del Ministerio de Salud de Chile. Las muestras fecales se analizaron mediante un test molecular, FilmArray GI® panel, que permite la detección de 22 patógenos entéricos virales, bacterianos y parasitarios. RESULTADOS: Se analizaron 493 muestras fecales de niños con episodios de diarrea infecciosa, detectando al menos un patógeno en 427 muestras (87%). De estas muestras positivas, se detectó solo un patógeno en 174 muestras (41%) y dos o más patógenos en 253 muestras (59%). En el grupo de niños bajo un año y el grupo entre uno y cuatro años hubo un predominio de infecciones causadas por virus gastroentéricos, siendo rotavirus y norovirus los virus más detectados en ambos grupos de edad. Las bacterias más frecuentes fueron EPEC (27%), C. difficile (17%), EAEC (14%) y Campylobacter (9%). Respecto a los parásitos, se identificó Giardia lamblia y Cryptosporidium, en el 3 y 1% del total de las muestras, respectivamente. CONCLUSIÓN: La detección molecular utilizada permitió detectar un alto número de enteropatógenos en niños bajo los cinco años. La información generada por este tipo de vigilancia, podría ayudar a caracterizar en la población los episodios de diarrea causados por los principales patógenos entéricos y podría ser una herramienta para asesorar técnicamente a las autoridades en la toma de decisión para la implementación de medidas de control contra estos patógenos.

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.

Mother-to-Child Transmission of Andes Virus through Breast Milk, Chile1.

Andes virus (ANDV) is the only hantavirus transmitted between humans through close contact. We detected the genome and proteins of ANDV in breast milk cells from an infected mother in Chile who transmitted the virus to her child, suggesting gastrointestinal infection through breast milk as a route of ANDV person-to-person transmission.

Global burden of respiratory infections associated with seasonal influenza in children under 5 years in 2018: a systematic review and modelling study.

BACKGROUND: Seasonal influenza virus is a common cause of acute lower respiratory infection (ALRI) in young children. In 2008, we estimated that 20 million influenza-virus-associated ALRI and 1 million influenza-virus-associated severe ALRI occurred in children under 5 years globally. Despite this substantial burden, only a few low-income and middle-income countries have adopted routine influenza vaccination policies for children and, where present, these have achieved only low or unknown levels of vaccine uptake. Moreover, the influenza burden might have changed due to the emergence and circulation of influenza A/H1N1pdm09. We aimed to incorporate new data to update estimates of the global number of cases, hospital admissions, and mortality from influenza-virus-associated respiratory infections in children under 5 years in 2018. METHODS: We estimated the regional and global burden of influenza-associated respiratory infections in children under 5 years from a systematic review of 100 studies published between Jan 1, 1995, and Dec 31, 2018, and a further 57 high-quality unpublished studies. We adapted the Newcastle-Ottawa Scale to assess the risk of bias. We estimated incidence and hospitalisation rates of influenza-virus-associated respiratory infections by severity, case ascertainment, region, and age. We estimated in-hospital deaths from influenza virus ALRI by combining hospital admissions and in-hospital case-fatality ratios of influenza virus ALRI. We estimated the upper bound of influenza virus-associated ALRI deaths based on the number of in-hospital deaths, US paediatric influenza-associated death data, and population-based childhood all-cause pneumonia mortality data in six sites in low-income and lower-middle-income countries. FINDINGS: In 2018, among children under 5 years globally, there were an estimated 109·5 million influenza virus episodes (uncertainty range [UR] 63·1-190·6), 10·1 million influenza-virus-associated ALRI cases (6·8-15·1); 870 000 influenza-virus-associated ALRI hospital admissions (543 000-1 415 000), 15 300 in-hospital deaths (5800-43 800), and up to 34 800 (13 200-97 200) overall influenza-virus-associated ALRI deaths. Influenza virus accounted for 7% of ALRI cases, 5% of ALRI hospital admissions, and 4% of ALRI deaths in children under 5 years. About 23% of the hospital admissions and 36% of the in-hospital deaths were in infants under 6 months. About 82% of the in-hospital deaths occurred in low-income and lower-middle-income countries. INTERPRETATION: A large proportion of the influenza-associated burden occurs among young infants and in low-income and lower middle-income countries. Our findings provide new and important evidence for maternal and paediatric influenza immunisation, and should inform future immunisation policy particularly in low-income and middle-income countries. FUNDING: WHO; Bill & Melinda Gates Foundation.

Host characteristics predict outcome among adult patients admitted by severe acute respiratory infection.

BACKGROUND: Except for influenza pandemics, different observational studies have failed to demonstrate differences in mortality between various etiologies in adult patients hospitalized for respiratory infections. AIM: To compare clinical and mortality differences between different viral pathogens associated with severe acute respiratory infections (SARI) in hospitalized adults. MATERIAL AND METHODS: One-year prospective study in a sentinel center. We included 132 patients with SARI hospitalized for any of the nine viruses under study by PCR. Clinical variables were compared, excluding cases of coinfection. RESULTS: A viral coinfection was identified in 12% and influenza infection in 56% of cases. Eighty percent of patients were aged ≥ 65 years, with a high frequency of comorbidities, 27% were bedridden. Twenty four percent were admitted to critical care units, 20% required ventilatory assistance and 16% died. Cases occurred throughout the year, with an expected seasonal peak between autumn and spring and a predominance of infections not associated with influenza during summer months. In the multivariate analysis, only being bedridden was significantly associated with mortality at discharge (Odds ratio 23.46; 95% confidence intervals 3.33-165.12, p < 0.01), without association with age, comorbidity, viral pathogen involved, laboratory parameters, clinical presentation or CURB65 score. No major clinical dissimilarities were found between different viral pathogens. CONCLUSIONS: In our series of patients, mostly elderly, only bedridden status was significantly associated with mortality at discharge in patients hospitalized for SARI. Viral pathogens were not relevant.

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.

Burden of influenza-associated respiratory hospitalizations in the Americas, 2010-2015.

BACKGROUND: Despite having influenza vaccination policies and programs, countries in the Americas underutilize seasonal influenza vaccine, in part because of insufficient evidence about severe influenza burden. We aimed to estimate the annual burden of influenza-associated respiratory hospitalizations in the Americas. METHODS: Thirty-five countries in the Americas with national influenza surveillance were invited to provide monthly laboratory data and hospital discharges for respiratory illness (International Classification of Diseases 10th edition J codes 0-99) during 2010-2015. In three age-strata (<5, 5-64, and ≥65 years), we estimated the influenza-associated hospitalizations rate by multiplying the monthly number of respiratory hospitalizations by the monthly proportion of influenza-positive samples and dividing by the census population. We used random effects meta-analyses to pool age-group specific rates and extrapolated to countries that did not contribute data, using pooled rates stratified by age group and country characteristics found to be associated with rates. RESULTS: Sixteen of 35 countries (46%) contributed primary data to the analyses, representing 79% of the America's population. The average pooled rate of influenza-associated respiratory hospitalization was 90/100,000 population (95% confidence interval 61-132) among children aged <5 years, 21/100,000 population (13-32) among persons aged 5-64 years, and 141/100,000 population (95-211) among persons aged ≥65 years. We estimated the average annual number of influenza-associated respiratory hospitalizations in the Americas to be 772,000 (95% credible interval 716,000-829,000). CONCLUSIONS: Influenza-associated respiratory hospitalizations impose a heavy burden on health systems in the Americas. Countries in the Americas should use this information to justify investments in seasonal influenza vaccination-especially among young children and the elderly.

Patterns of influenza B circulation in Latin America and the Caribbean, 2010-2017.

OBJECTIVE: There are limited published data about the circulation of influenza B/Victoria and B/Yamagata in Latin America and the Caribbean (LAC) and most countries have a vaccine policy that includes the use of the trivalent influenza vaccine. We analyzed influenza surveillance data to inform decision-making in LAC about prevention strategies, such as the use of the quadrivalent influenza vaccine. METHODS: There are a total of 28 reference laboratories and National Influenza Centers in LAC that conduct influenza virologic surveillance according to global standards, and on a weekly basis upload their surveillance data to the open-access World Health Organization (WHO) platform FluNet. These data include the number of specimens tested for influenza and the number of specimens positive for influenza by type, subtype and lineage, all by the epidemiologic week of specimen collection. We invited these laboratories to provide additional epidemiologic data about the hospitalized influenza B cases. We conducted descriptive analyses of patterns of influenza circulation and characteristics of hospitalized cases. We compared the predominant B lineage each season to the lineage in the vaccine applied, to determine vaccine mismatch. A Chi-square and Wilcoxan statistic were used to assess the statistical significance of differences in proportions and medians at the P<0.05 level. FINDINGS: During 2010-2017, the annual number of influenza B cases in LAC was ~4500 to 7000 cases. Since 2011, among the LAC-laboratories reporting influenza B lineage using molecular methods, both B/Victoria and B/Yamagata were detected annually. Among the hospitalized influenza B cases, there were statistically significant differences observed between B/Victoria and B/Yamagata cases when comparing age and the proportion with underlying co-morbid conditions and with history of oseltamivir treatment (P<0.001). The proportion deceased among B/Victoria and B/Yamagata hospitalized cases did not differ significantly. When comparing the predominant influenza B lineage detected, as part of surveillance activities during 63 seasons among 19 countries, to the lineage of the influenza B virus included in the trivalent influenza vaccine used during that season, there was a vaccine mismatch noted during 32% of the seasons analyzed. CONCLUSIONS: Influenza B is important in LAC with both B/Victoria and B/Yamagata circulating annually in all sub regions. During approximately one-third of the seasons, an influenza B vaccine mismatch was identified. Further analyses are needed to better characterize the medical and economic burden of each influenza B lineage, to examine the potential cross-protection of one vaccine lineage against the other circulating virus lineage, and to determine the potential impact and cost-effectiveness of using the quadrivalent vaccine rather than the trivalent influenza vaccine.

Host characteristics predict outcome among adult patients admitted by severe acute respiratory infection / Características del huésped predicen el desenlace en adultos hospitalizados por infección respiratoria aguda grave

Background: Except for influenza pandemics, different observational studies have failed to demonstrate differences in mortality between various etiologies in adult patients hospitalized for respiratory infections. Aim: To compare clinical and mortality differences between different viral pathogens associated with severe acute respiratory infections (SARI) in hospitalized adults. Material and Methods: One-year prospective study in a sentinel center. We included 132 patients with SARI hospitalized for any of the nine viruses under study by PCR. Clinical variables were compared, excluding cases of coinfection. Results: A viral coinfection was identified in 12% and influenza infection in 56% of cases. Eighty percent of patients were aged ≥ 65 years, with a high frequency of comorbidities, 27% were bedridden. Twenty four percent were admitted to critical care units, 20% required ventilatory assistance and 16% died. Cases occurred throughout the year, with an expected seasonal peak between autumn and spring and a predominance of infections not associated with influenza during summer months. In the multivariate analysis, only being bedridden was significantly associated with mortality at discharge (Odds ratio 23.46; 95% confidence intervals 3.33-165.12, p < 0.01), without association with age, comorbidity, viral pathogen involved, laboratory parameters, clinical presentation or CURB65 score. No major clinical dissimilarities were found between different viral pathogens. Conclusions: In our series of patients, mostly elderly, only bedridden status was significantly associated with mortality at discharge in patients hospitalized for SARI. Viral pathogens were not relevant.

Los factores del huésped son más importantes que el tipo viral para predecir el desenlace en pacientes hospitalizados por infecciones respiratoria aguda grave. Exceptuando las pandemias de influenza, diferentes estudios observacionales no han logrado demostrar diferencias en mortalidad entre diferentes patógenos en pacientes adultos hospitalizados por infecciones respiratorias. Objetivo: Comparar diferencias clínicas y en mortalidad entre diferentes patógenos virales asociados a infección respiratoria aguda grave (IRAG) en adultos hospitalizados. Método: Estudio prospectivo durante un año en un centro centinela. Se incluyeron casos de IRAG hospitalizados por alguno de los 9 virus bajo estudio por RCP. Se compararon variables clínicas y desenlace. Resultados: Ingresaron 132 pacientes con IRAG. Se identificó coinfección viral en 12,1% e infección por influenza en 56,1%. La mayor parte era de la tercera edad (80,3%) con una alta frecuencia de comorbilidad y 27,3% estaba postrado. Veintitres coma cinco por ciento ingresó a unidad de cuidados críticos, 19,7% requirió asistencia ventilatoria y 15,9% fallecieron. Los casos ocurrieron todo el año, con un aumento estacional esperado entre otoño y primavera y predominio de infecciones no asociadas a influenza en verano. En el análisis multivariado, sólo la postración se asoció significativamente a mortalidad al egreso (ORa 23,46 IC95 3,33-165,12, p = 0,002), sin asociación con la edad, comorbilidad, patógeno viral involucrado, parámetros de laboratorio, presentación clínica o puntuación CURB65. No se encontraron discordancias clínicas mayores entre diferentes agentes virales. Conclusiones: En nuestra serie de pacientes, mayoritariamente de la tercera edad, sólo la postración se asoció significativamente a mortalidad al egreso en pacientes hospitalizados por IRAG. El patógeno viral no resultó ser relevante.

Severe acute respiratory infections (SARI) from influenza in adult patients in Chile: the experience of a sentinel hospital.

OBJECTIVE: To 1) describe clinical characteristics of adult patients in Chile with severe acute respiratory infections (SARI) associated with influenza viruses, and 2) analyze virus subtypes identified in specimens collected from those patients, hospital resources used in clinical management, clinical evolution, and risk factors associated with a fatal outcome, using observational data from the SARI surveillance network (SARInet). METHODS: Adults hospitalized from 1 July 2011 to 31 December 2015 with influenza-associated SARI at a SARI sentinel surveillance hospital in Santiago were identified and the presence of influenza in all cases confirmed by reverse transcription polymerase chain reaction (RT-PCR), using respiratory samples. RESULTS: A total of 221 patients (mean age: 74.1 years) were hospitalized with influenza-associated SARI during the study period. Of this study cohort, 91.4% had risk factors for complications and 34.3% had been vaccinated during the most recent campaign. Pneumonia was the most frequent clinical manifestation, occurring in 57.0% of the cohort; other manifestations included influenza-like illness, exacerbated chronic bronchitis, decompensated heart failure, and asthmatic crisis. Cases occurred year-round, with an epidemic peak during autumn-winter. Both influenza A (H1N1pdm09 and H3N2) and B virus co-circulated. Critical care beds were required for 26.7% of the cohort, and 19.5% needed ventilatory assistance. Multivariate analysis identified four significant factors associated with in-hospital mortality: 1) being bedridden (adjusted odds ratio (aOR): 22.3; 95% confidence interval (CI): 3.0-164); 2) admission to critical care unit (aOR: 8.9; CI: 1.44-55); 3) Pa02/Fi02 ratio < 250 (aOR: 5.8; CI: 1.02-33); and 4) increased serum creatinine concentration (> 1 mg/dL) (aOR: 5.47; CI: 1.20-24). Seasonal influenza vaccine was identified as a significant protective factor (aOR: 0.14; CI: 0.021-0.90). CONCLUSIONS: Influenza-associated SARI affected mainly elderly patients with underlying conditions. Most patients evolved to respiratory failure and more than one-quarter required critical care beds. Clinical presentation was variable. Death was associated with host characteristics and disease-associated conditions, and vaccine was protective. Virus type did not influence outcome.

Severe acute respiratory infections (SARI) from influenza in adult patients in Chile: the experience of a sentinel hospital

[ABSTRACT]. Objective. To 1) describe clinical characteristics of adult patients in Chile with severe acute respiratory infections (SARI) associated with influenza viruses, and 2) analyze virus subtypes identified in specimens collected from those patients, hospital resources used in clinical management, clinical evolution, and risk factors associated with a fatal outcome, using observational data from the SARI surveillance network (SARInet). Methods. Adults hospitalized from 1 July 2011 to 31 December 2015 with influenza-associated SARI at a SARI sentinel surveillance hospital in Santiago were identified and the presence of influenza in all cases confirmed by reverse transcription polymerase chain reaction (RT-PCR), using respiratory samples. Results. A total of 221 patients (mean age: 74.1 years) were hospitalized with influenza-associated SARI during the study period. Of this study cohort, 91.4% had risk factors for complications and 34.3% had been vaccinated during the most recent campaign. Pneumonia was the most frequent clinical manifestation, occurring in 57.0% of the cohort; other manifestations included influenza-like illness, exacerbated chronic bronchitis, decompensated heart failure, and asthmatic crisis. Cases occurred year-round, with an epidemic peak during autumn–winter. Both influenza A (H1N1pdm09 and H3N2) and B virus co-circulated. Critical care beds were required for 26.7% of the cohort, and 19.5% needed ventilatory assistance. Multivariate analysis identified four significant factors associated with in-hospital mortality: 1) being bedridden (adjusted odds ratio (aOR): 22.3; 95% confidence interval (CI): 3.0–164); 2) admission to critical care unit (aOR: 8.9; CI: 1.44–55); 3) Pa02/Fi02 ratio < 250 (aOR: 5.8; CI: 1.02–33); and 4) increased serum creatinine concentration (> 1 mg/dL) (aOR: 5.47; CI: 1.20–24). Seasonal influenza vaccine was identified as a significant protective factor (aOR: 0.14; CI: 0.021–0.90). Conclusions. Influenza-associated SARI affected mainly elderly patients with underlying conditions. Most patients evolved to respiratory failure and more than one-quarter required critical care beds. Clinical presentation was variable. Death was associated with host characteristics and disease-associated conditions, and vaccine was protective. Virus type did not influence outcome.

[RESUMEN]. Objetivos. 1) Describir las características clínicas de los pacientes adultos con infección respiratoria aguda grave relacionada con virus gripales en Chile, y 2) analizar los subtipos de los virus identificados en las muestras recogidas de estos pacientes, los recursos hospitalarios empleados en el tratamiento clínico, la evolución clínica y los factores de riesgo asociados a un desenlace mortal, mediante los datos de observación de la red de vigilancia de las infecciones respiratorias agudas graves (SARInet). Métodos. Se identificaron los adultos hospitalizados entre el 1 de julio del 2011 y el 31 de diciembre del 2015 con infección respiratoria aguda grave relacionada con la gripe en un hospital de vigilancia centinela de esta afección en Santiago y se confirmó la presencia de gripe en todos los casos por medio de la reacción en cadena de la polimerasa con transcriptasa inversa realizada en muestras de las vías respiratorias Resultados. Un total de 221 pacientes (con una media de edad de 74,1 años) fueron hospitalizados con infección respiratoria aguda grave relacionada con la gripe durante el período de estudio. En esta cohorte de estudio, 91,4 % presentó factores de riesgo de complicaciones y 34,3 % había recibido la vacuna en la campaña más reciente. La neumonía fue la manifestación clínica más frecuente y afectó a 57,0 % de la cohorte; otras manifestaciones fueron el síndrome gripal, la bronquitis crónica exacerbada, la insuficiencia cardíaca descompensada y la crisis asmática. Los casos se presentaron durante todo el año y alcanzaron un pico epidémico durante el otoño y el invierno. Tanto el virus de la gripe de tipo A (H1N1pdm09 y H3N2) y tipo B circularon simultáneamente. En 26,7 % de la cohorte se precisaron cuidados intensivos y en 19,5 % fue necesario recurrir a la respiración asistida. El análisis multifactorial detectó cuatro factores fundamentales relacionados con la mortalidad hospitalaria: 1) la postración (razón de posibilidades ajustada [ORA]: 22,3; intervalo de confianza [IC] de 95 %: 3,0–164); 2) la admisión en la unidad de cuidados intensivos (ORA: 8,9; IC: 1,4 4–55); 3) un coeficiente Pa02/Fi02 inferior a 250 (ORA: 5,8; IC: 1,02–33), y 4) una mayor concentración de creatinina sérica (> 1 mg/dL) (ORA: 5,47; IC: 1,20–24). Se determinó que la vacuna contra la gripe estacional era un factor protector significativo (ORA: 0,14; IC: 0,021–0,90). Conclusiones. La infección respiratoria aguda grave asociada a la gripe afectó a pacientes predominantemente ancianos con afecciones subyacentes. La mayoría de los pacientes evolucionó en una insuficiencia respiratoria y más de una cuarta parte precisó cuidados intensivos. El cuadro clínico fue variable. La mortalidad estuvo relacionada con las características del huésped y los trastornos relacionados con la enfermedad, y la vacuna tuvo un efecto protector. El tipo vírico no influyó en los desenlaces.

[RESUMO]. Objetivo. Descrever as características clínicas de pacientes adultos com infecção respiratória aguda grave (SARI) associada ao vírus da influenza e analisar os subtipos virais identificados em amostras coletadas destes pacientes, os recursos hospitalares empregados no tratamento clínico, a evolução clínica e os fatores de risco clínicos associados a um desfecho fatal, a partir de dados observacionais da rede de vigilância de SARI (SARInet) no Chile. Métodos. Foram identificados os adultos hospitalizados com SARI associada a influenza em um hospital-sentinela de vigilância de SARI, em Santiago, de 1o de julho de 2011 a 31 de dezembro de 2015. A ocorrência de influenza foi confirmada em amostras respiratórias em todos os casos com a reação em cadeia da polimerase via transcriptase reversa (RT-RCP). Resultados. Ao todo, 221 pacientes (idade média de 74,1 anos) foram hospitalizados com SARI associada a influenza no período de estudo. Nesta coorte, 91,4% apresentavam fatores de risco para complicação e 34,3% haviam sido vacinados na última campanha de vacinação. Pneumonia foi a manifestação clínica mais frequente, ocorrendo em 57,0% da coorte. Outras manifestações foram doença gripal, bronquite crônica exacerbada, insuficiência cardíaca descompensada e crise asmática. Os casos estiveram distribuídos ao longo do ano, com pico epidêmico no outono–inverno. Houve circulação simultânea dos vírus da influenza A (H1N1pdm09 e H3N2) e B. Leitos de terapia intensiva foram necessários em 26,7% da coorte e suporte ventilatório, em 19,5%. Na análise multivariada, quatro fatores importantes associados à mortalidade hospitalar foram identificados: estar restrito ao leito (odds ratio ajustado [ORaj] 22.3; intervalo de confiança de 95% [IC 95%] 3.0–164); ser admitido na unidade de terapia intensiva (ORaj 8.9, IC 95% 1.4 4–55); relação Pa02/Fi02 <250 (ORaj 5.8; IC 95% 1.02–33) e aumento da creatinina sérica (>1 mg/dl) (ORaj 5.47; IC 95% 1.20–24). A vacinação sazonal contra influenza foi identificada como importante fator de proteção (ORaj 0.14; IC 95% 0.021–0.90). Conclusões. A SARI associada a influenza acometeu sobretudo pacientes idosos com doenças preexistentes. A maioria dos pacientes evoluiu com insuficiência respiratória e mais de um quarto precisou de cuidados intensivos. O quadro clínico foi variável. Morte foi associada às características do hospedeiro e problemas relacionados à doença. A vacinação teve efeito protetor e o tipo viral não influiu no desfecho.

Factores de riesgo asociados al diagnóstico de alergia al huevo IgE mediada en Pediatría

Introducción: La prevalencia de alergias alimentarias se ha incrementado, lo que representa un problema de salud pública. Las guías alimentarias recomendaban retrasar la introducción de alimentos de manera a prevenir alergias alimentarias sin real evidencia. Objetivos: Describir el perfil clínico del paciente pediátrico que acude a consulta con el diagnóstico de alergia al huevo. Materiales y métodos: Estudio de observacional retrospectivo descriptivo de. Ingresaron al estudio pacientes con sospecha de alergia al huevo que tuvieron estudio de RAST. Se estudio datos demográficos, lactancia materna, inicio de alimentación solida incluyendo el huevo, presencia de manisfestaciones de alergia. Se realizo comparación entre los grupo con RAST positivo y aquellos con resultados negativo. Los datos fueron procesados en Microsoft Excell y se utilizó variables descriptivas. Resultados: ingresaron 156 pacientes ,58 en cada grupo con prueba positiva y negativa. Los pacientes alérgicos al huevo se presentaron con un predominio de sexo masculino, con antecedentes personales de atopia, peso y tallas normales, duración de la lactancia materna promedio de 10,5 meses, introducción de sólidos a los 5,7 meses, edad de ingesta de huevo a los 9,2 meses, similar al grupo con test negativo. Los síntomas predominantes fueron los gastrointestinales Como manifestación de atopia concomitante tuvieron mayor porcentaje de Alergia a las proteínas de leche de vaca y dermatitis atópica en comparación con el grupo con test negativo. Conclusiones: No hubo diferencias demograficas ni de habitos alimentarios entre los grupos con RAST postivo y negativo Hubo concomitancia de otras manisfestaciones de alergia en el grupo RAST postivo.

Introduction: The prevalence of food allergies has increased, representing a public health problem. Current dietary guidelines recommend delaying the introduction of food in order to prevent food allergies, but supporting evidence for this is lacking. Objectives: To describe the clinical profile of pediatric patients presenting with a diagnosis of egg allergy. Materials and methods: This was a descriptive, retrospective, observational study. We included patients with a suspected egg allergy who had a RAST study. We evaluated demographic data, breastfeeding, introduction of solid foods, including egg, and the presence of allergy manifestations. A comparison was made between the groups with positive RAST and those with negative results. The data was processed in Microsoft Excel and descriptive variables were used. Results: 156 patients were included in the study, 58 in each group with positive and negative tests. Egg-allergic patients were predominantly male, with a personal history of atopy, normal weight and size, an average breastfeeding duration of 10.5 months, introduction of solids at 5.7 months, age of intake of egg at 9.2 months, which was similar to the group with negative testing. The predominant symptoms were gastrointestinal. Concomitant atopy manifestations included a higher percentage of cow's milk protein allergy and atopic dermatitis compared to the group with a negative testing. Conclusions: There were no demographic or dietary differences between the groups with positive and negative RAST. There was concomitance of other allergic manifestations in the positive RAST group.

Severe acute respiratory infections (SARI) from influenza in adult patients in Chile: the experience of a sentinel hospital / La infección respiratoria aguda grave asociada a la gripe en pacientes adultos en Chile: experiencia de un hospital centinela / Infecção respiratória aguda grave (SARI) decorrente da influenza em pacientes adultos no Chile: experiência de um hospital-sentinela

ABSTRACT Objective To 1) describe clinical characteristics of adult patients in Chile with severe acute respiratory infections (SARI) associated with influenza viruses, and 2) analyze virus subtypes identified in specimens collected from those patients, hospital resources used in clinical management, clinical evolution, and risk factors associated with a fatal outcome, using observational data from the SARI surveillance network (SARInet). Methods Adults hospitalized from 1 July 2011 to 31 December 2015 with influenza-associated SARI at a SARI sentinel surveillance hospital in Santiago were identified and the presence of influenza in all cases confirmed by reverse transcription polymerase chain reaction (RT-PCR), using respiratory samples. Results A total of 221 patients (mean age: 74.1 years) were hospitalized with influenza-associated SARI during the study period. Of this study cohort, 91.4% had risk factors for complications and 34.3% had been vaccinated during the most recent campaign. Pneumonia was the most frequent clinical manifestation, occurring in 57.0% of the cohort; other manifestations included influenza-like illness, exacerbated chronic bronchitis, decompensated heart failure, and asthmatic crisis. Cases occurred year-round, with an epidemic peak during autumn-winter. Both influenza A (H1N1pdm09 and H3N2) and B virus co-circulated. Critical care beds were required for 26.7% of the cohort, and 19.5% needed ventilatory assistance. Multivariate analysis identified four significant factors associated with in-hospital mortality: 1) being bedridden (adjusted odds ratio (aOR): 22.3; 95% confidence interval (CI): 3.0-164); 2) admission to critical care unit (aOR: 8.9; CI: 1.44-55); 3) Pa02/Fi02 ratio < 250 (aOR: 5.8; CI: 1.02-33); and 4) increased serum creatinine concentration (> 1 mg/dL) (aOR: 5.47; CI: 1.20-24). Seasonal influenza vaccine was identified as a significant protective factor (aOR: 0.14; CI: 0.021-0.90). Conclusions Influenza-associated SARI affected mainly elderly patients with underlying conditions. Most patients evolved to respiratory failure and more than one-quarter required critical care beds. Clinical presentation was variable. Death was associated with host characteristics and disease-associated conditions, and vaccine was protective. Virus type did not influence outcome.

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RESUMO Objetivo Descrever as características clínicas de pacientes adultos com infecção respiratória aguda grave (SARI) associada ao vírus da influenza e analisar os subtipos virais identificados em amostras coletadas destes pacientes, os recursos hospitalares empregados no tratamento clínico, a evolução clínica e os fatores de risco clínicos associados a um desfecho fatal, a partir de dados observacionais da rede de vigilância de SARI (SARInet) no Chile. Métodos Foram identificados os adultos hospitalizados com SARI associada a influenza em um hospital-sentinela de vigilância de SARI, em Santiago, de 1o de julho de 2011 a 31 de dezembro de 2015. A ocorrência de influenza foi confirmada em amostras respiratórias em todos os casos com a reação em cadeia da polimerase via transcriptase reversa (RT-RCP). Resultados Ao todo, 221 pacientes (idade média de 74,1 anos) foram hospitalizados com SARI associada a influenza no período de estudo. Nesta coorte, 91,4% apresentavam fatores de risco para complicação e 34,3% haviam sido vacinados na última campanha de vacinação. Pneumonia foi a manifestação clínica mais frequente, ocorrendo em 57,0% da coorte. Outras manifestações foram doença gripal, bronquite crônica exacerbada, insuficiência cardíaca descompensada e crise asmática. Os casos estiveram distribuídos ao longo do ano, com pico epidêmico no outono-inverno. Houve circulação simultânea dos vírus da influenza A (H1N1pdm09 e H3N2) e B. Leitos de terapia intensiva foram necessários em 26,7% da coorte e suporte ventilatório, em 19,5%. Na análise multivariada, quatro fatores importantes associados à mortalidade hospitalar foram identificados: estar restrito ao leito (odds ratio ajustado [ORaj] 22.3; intervalo de confiança de 95% [IC 95%] 3.0-164); ser admitido na unidade de terapia intensiva (ORaj 8.9, IC 95% 1.4 4-55); relação Pa02/Fi02 <250 (ORaj 5.8; IC 95% 1.02-33) e aumento da creatinina sérica (>1 mg/dl) (ORaj 5.47; IC 95% 1.20-24). A vacinação sazonal contra influenza foi identificada como importante fator de proteção (ORaj 0.14; IC 95% 0.021-0.90). Conclusões A SARI associada a influenza acometeu sobretudo pacientes idosos com doenças preexistentes. A maioria dos pacientes evoluiu com insuficiência respiratória e mais de um quarto precisou de cuidados intensivos. O quadro clínico foi variável. Morte foi associada às características do hospedeiro e problemas relacionados à doença. A vacinação teve efeito protetor e o tipo viral não influiu no desfecho.

Estimating the burden of influenza-associated hospitalizations and deaths in Chile during 2012-2014.

BACKGROUND: Influenza is a vaccine preventable disease that causes important morbidity and mortality worldwide. Estimating the burden of influenza disease is difficult. However, there are some methods based in surveillance data and laboratory testing that can be used for this purpose. OBJECTIVES: Estimating the burden of serious illness from influenza by means of hospitalization and death records during the period between 2012 and 2014, and using information from Severe Acute Respiratory Illness (SARI) surveillance. METHODS: To estimate the Chilean rate of influenza-associated hospitalizations and deaths, we applied the influenza positivity of respiratory samples tested in six SARI surveillance sentinel hospitals to the hospitalizations and deaths from the records with ICD-10 codes from influenza and pneumonia. RESULTS: Annually, 5320 people are hospitalized for influenza and 447 die for this cause. The annual influenza-associated hospitalization rate for the period was 71.5/100 000 person-year for <5 years old, 11.8/100 000 person-year for people between 5 and 64 years old; and 156.0/100 000 person-year for ≥65 years. The annual mortality rate for the period was 0.08/100 000 person-year for <5 years; 0.3/100 000 person-year for people between 5 and 64 years; and 22.8/100 000 person-year for ≥65 years. CONCLUSIONS: This is the first study of influenza burden in Chile. Every year an important quantity of hospitalizations and deaths result from influenza infection. In countries in temperate zones, it is important to know the burden of influenza in order to prepare the health care network and to assess preventive intervention currently in practice and the new ones to implementing.

Estudio comparativo de morbimortalidad del prematuro tardío y el recién nacido de termino. Hospital de Clínicas. Asunción, Paraguay

Introducción: Comparado con el recién nacido a término, la tasa de morbimortalidad en el prematuro tardío es mayor a causa de las características específicas limítrofes que presentan en sus diferentes órganos. Objetivos: Describir las causas, las características clínicas y determinar la incidencia y la tasa de mortalidad de prematuros tardíos en comparación con los recién nacidos de término en un Departamento de Neonatología. Materiales y Métodos: Estudio observacional analítico retrospectivo, muestreo no probabilístico de casos consecutivos de recién nacidos prematuros tardíos, así como el siguiente recién nacido de término, de las fichas clínicas para una relación 1/1. Resultados: Durante el año 2012 nacieron 2741 RN vivos, 210 fueron RN prematuros tardíos (7,6%). El 61% de los nacimientos fue por parto normal en RN de término, y por cesárea 60% en RN pretérmino tardío (p=0,003). Presentaron alguna complicación posterior al nacimiento 95/210 de los RN pretérmino tardíos (45%), y 11/210 de los RN de término (5%) con un OR de 14,9 (IC= 7-29, P < 0.0001). La complicación más frecuente fue la dificultad respiratoria en 54/210 RN pretérmino tardíos y así como en 8/210 RNT, requerimiento de luminoterapia en 41/210 RN pretérmino tardíos y en 8/210 RNT. Se encontraron diferencias significativas en la presencia de dificultad respiratoria OR 8,74, requerimiento de luminoterapia OR 6, de antibioticoterapia OR 6 y de ingreso a terapia intensiva 9,6. No se detectó diferencias significativas en cuanto al óbito de los pacientes (p=0.29). Conclusiones: Los RN pretérminos tardíos presentan mayor morbilidad que los nacidos a término. La incidencia de RN pretérmino tardíos fue similar a lo encontrado a nivel mundial. La causa más frecuentemente asociada fue el elevado número de cesáreas. En comparación con los de término, presentaron mayor número de complicaciones como dificultad respiratoria y requerimiento de luminoterapia, y mayor tiempo de hospitalización.

Introduction: Compared with term newborns, the morbidity and mortality rate in late prematurity is higher because of the specific borderline development of the different organ systems. Objectives: To describe the causes, clinical characteristics and determine the incidence and mortality rate of late preterm infants compared with term infants in a Neonatology Department. Materials and Methods: This was a retrospective analytical observational study, with non-probabilistic sampling of consecutive cases of late preterm infants, as well as the following term newborn, as obtained from clinical records for a 1/1 ratio. Results: During 2012, 2741 live births were born, 210 were premature newborns (7.6%). 61% of births were due to normal delivery in term newborns, and 60% in late preterm newborns (p = 0.003). There were 95/210 complications of late preterm infants (45%) and 11/210 of term infants (5%) with an OR of 14.9 (CI = 7-29, P <0.0001) . The most frequent complication was respiratory distress in 54/210 late preterm infants, as well as in 8/210 in term newborns; luminotherapy in 41/210 late preterm infants and 8/210 in term newborns. Significant differences were found in the presence of respiratory distress, OR 8.74, luminotherapy, OR 6, antibiotic therapy, OR 6, and admission to intensive care unit, OR 9,6. There were no significant differences in patient deaths (p = 0.29). Conclusions: Late preterm infants present higher morbidity than those born at term. The incidence of late preterm newborns was similar to that found worldwide. The most frequent associated cause was a high number of cesarean sections. Compared with term newborns, late preterm newborns developed a greater number of complications such as respiratory distress and light therapy requirements, and longer hospitalization time.

Rates of influenza-like illness and winter school breaks, Chile, 2004-2010.

To determine effects of school breaks on influenza virus transmission in the Southern Hemisphere, we analyzed 2004-2010 influenza-like-illness surveillance data from Chile. Winter breaks were significantly associated with a two-thirds temporary incidence reduction among schoolchildren, which supports use of school closure to temporarily reduce illness, especially among schoolchildren, in the Southern Hemisphere.

Emergencia de la cepa W135 causante de enfermedad meningocócica invasora en Chile 2012 / Emergence of W135 meningococcal serogroup in Chile during 2012

The epidemiologic behavior of the Invasive Meningococcal Disease (IMD) in Chile has changed. At the end of 2011, the W135 serogroup belonging to the hypervirulent clone ST-11 emerged. It affected diverse countries of the world, after the Mecca pilgrimage in 2000. In Chile, there have been 133 IMD cases during 2012. These figures represent an incidence of 0.7 per 100,000 inhabitants, which is 30% higher than expected. Eighty eight percent of cases were confirmed by the National Reference Laboratory at the Chilean Public Health Institute. The serogroup was determined in 103 strains and 58% belonged to the W135 serogroup, surpassing for the first time the B serogroup (37%). The Metropolitan Region concentrated 80% of these cases, and the remaining 20% affected other seven regions of the country. Forty seven percent of cases corresponded to children less than 5 years of age. The predominant clinical presentation of the W135 serogroup was a sepsis in 67% of cases. The fatality ratio of IDM during 2012 was 27%, the highest in the past 20 years. With this information, the Chilean Ministry of Health decreed a sanitary alert and implemented an integrated approach to control and prevent W-135 IDM, denominated "W-135 Action Plan".