COVID-19 Vaccination Hesitancy in Mexico City among Healthy Adults and Adults with Chronic Diseases: A Survey of Complacency, Confidence, and Convenience Challenges in the Transition to Endemic Control.

Background. Monitoring of SARS-COV-2 vaccine hesitancy is important for epidemic control. We measured vaccine hesitancy among healthy adults and adults with chronic diseases after they had been offered the first dose of the vaccine in Mexico City. Methods. An observational cross-sectional study was undertaken among 185 healthy adults and 175 adults living with chronic diseases. Differences in means of variables for confidence, complacency, and convenience were analyzed. Aggregate indicators were constructed and their association with socioeconomic and demographic conditions and vaccination acceptance analyzed using multivariate analysis of variance and multivariate logistic analysis. Results. Up to 16.8% of healthy adults and 10.3% of sick adults reported not having received the SARS-COV-2 vaccine. Healthy adults were more complacent about COVID-19 risks than adults with chronic diseases, while no differences were found between the two groups regarding other hesitancy aggregate indicators. Among adults with chronic diseases, those with more education and enrolled with a social insurance institution were less complacent of COVID-19, while education was positively associated with convenience across both groups. Less complacency with COVID-19 and more confidence in the vaccine were associated with higher vaccine acceptance across both groups. Among adults living with chronic diseases, the odds ratios of vaccine acceptance were higher for less complacency (OR = 2.4, p = 0.007) than for confidence (OR = 2.0, p = 0.001). Odds ratios of vaccine acceptance in these two hesitancy indicators were similar among healthy adults (OR = 3.3, p = <0.005) and higher than for adults with comorbidities. Conclusions. Confidence in the vaccine and complacency regarding COVID-19 risks play an important role for vaccine acceptance in Mexico City, particularly among healthy adults. The perception of risk regarding COVID-19 is more important than confidence in vaccine safety and effectiveness. Promotion of COVID-19 vaccines needs to focus on decreasing complacency with COVID-19 and increasing vaccine confidence, particularly among healthy adults.

Barriers and facilitators to influenza vaccination observed by officers of national immunization programs in South America countries with contrasting coverage rates.

Influenza is a severe, vaccine-preventable disease. Vaccination programs across Latin American countries show contrasting coverage rates, from 29% in Paraguay to 89% in Brazil. This study explores how national influenza vaccination programs in the chosen South American countries address vaccine confidence and convenience, as well as complacency toward the disease. Barriers and facilitators to influenza vaccination programs in their relation to vaccine hesitancy were observed by documentary analysis and interviews with 38 national immunization program officers in high- (Brazil and Chile) and low-performing (Paraguay, Peru, and Uruguay) countries. Influenza vaccination policies, financing, purchasing, coordination, and accessibility are considered good or acceptable. National communication strategies focus on vaccine availability during campaigns. In Chile, Paraguay, and Uruguay, anti-vaccine propaganda was mentioned as a problem. Programming and implementation face human resource shortages across most countries. Statistical information, health information systems, and nominal risk-group records are available, with limitations in Peru and Paraguay. Health promotion, supervision, monitoring, and evaluation are perceived as opportunities to address confidence and complacency. Influenza vaccination programs identify and act on most barriers and facilitators affecting influenza vaccine hesitancy via supply-side strategies which mostly address vaccine convenience. Confidence and complacency are insufficiently addressed, except for Uruguay. Programs have the opportunity to develop integral supply and demand-side approaches.

Barriers and facilitators to influenza vaccination observed by officers of national immunization programs in South America countries with contrasting coverage rates / Barreras y facilitadores de la vacuna contra la gripe observados por funcionarios de los programas nacionales de inmunización en países de Suramérica con niveles de cobertura contrastantes / Barreiras e facilitadores da vacinação contra influenza observados por funcionários dos programas nacionais de imunização em países Sul-Americanos com diferentes níveis de cobertura

Influenza is a severe, vaccine-preventable disease. Vaccination programs across Latin American countries show contrasting coverage rates, from 29% in Paraguay to 89% in Brazil. This study explores how national influenza vaccination programs in the chosen South American countries address vaccine confidence and convenience, as well as complacency toward the disease. Barriers and facilitators to influenza vaccination programs in their relation to vaccine hesitancy were observed by documentary analysis and interviews with 38 national immunization program officers in high- (Brazil and Chile) and low-performing (Paraguay, Peru, and Uruguay) countries. Influenza vaccination policies, financing, purchasing, coordination, and accessibility are considered good or acceptable. National communication strategies focus on vaccine availability during campaigns. In Chile, Paraguay, and Uruguay, anti-vaccine propaganda was mentioned as a problem. Programming and implementation face human resource shortages across most countries. Statistical information, health information systems, and nominal risk-group records are available, with limitations in Peru and Paraguay. Health promotion, supervision, monitoring, and evaluation are perceived as opportunities to address confidence and complacency. Influenza vaccination programs identify and act on most barriers and facilitators affecting influenza vaccine hesitancy via supply-side strategies which mostly address vaccine convenience. Confidence and complacency are insufficiently addressed, except for Uruguay. Programs have the opportunity to develop integral supply and demand-side approaches.

La gripe es una enfermedad grave, prevenible mediante vacunas con sus correspondientes programas en países latinoamericanos, informando sobre tasas contrastadas de cobertura, desde el 29% en Paraguay al 89% en Brasil. Este artículo investiga cómo los programas nacionales contra la gripe en países seleccionados de Suramérica abordan la confianza en la vacuna y su conveniencia, así como también la complacencia hacia la enfermedad. Las barreras y facilitadores del programa de vacunación de la gripe, en su relación con la vacilación hacia la vacuna, se observaron mediante análisis documental y entrevistas a 38 a cargo de los programas nacionales de inmunización en países con alto (Brasil y Chile) y bajo desempeño (Paraguay, Perú y Uruguay). Políticas de vacunación contra la gripe, financiamiento, compras coordinación y accesibilidad fueron consideradas como buenas o aceptables. Las estrategias nacionales de comunicación se centran en la disponibilidad de la vacuna durante las campañas. En Chile, Paraguay y Uruguay la propaganda antivacunas fue mencionada como un problema. La planificación e implementación enfrentan escasez de recursos humanos en la mayoría de países a través de la mayoría de países. Los sistemas de información en salud, estadísticas y registros nominales por grupos de riesgo se encuentran disponibles con limitaciones en Perú y Paraguay. La promoción de la salud, supervisión, monitoreo y evaluación son percibidos como oportunidades para abordar la confianza y complacencia. Los programas de vacunación contra la gripe actúan principalmente sobre las barreras y facilitadores que afectan la vacilación a vacunarse mediante estrategias del lado de la demanda, las cuales en su mayor parte van dirigidas a contrarestar la conveniencia. La confianza y complacencia son insuficientemente abordadas en todos los países, excepto en Uruguay. Los programas tienen la oportunidad de desarrollar estrategias que aborden tanto el lado de la oferta como de la demanda.

A influenza é uma doença grave, imunoprevenível, para a qual os programas de vacinação nos países latino-americanos apresentam taxas de cobertura contrastantes, desde 29% no Paraguai até 89% no Brasil. O artigo explora de que maneira os programas nacionais de influenza em países selecionados da América do Sul lidam com a confiança e a conveniência da vacina, assim como, a acomodação em relação à doença. As barreiras e facilitadores dos programas de vacinação contra influenza foram observados em relação à hesitação vacinal, através de análise documental e entrevistas com 38 autoridades de programas nacionais de imunização em países com desempenho alto (Brasil e Chile) e baixo (Paraguai, Peru e Uruguai). As políticas de vacinação contra influenza, financiamento da compra de vacinas, coordenação e acessibilidade são consideradas boas ou aceitáveis. As estratégias nacionais de comunicação estão concentradas na disponibilidade durante campanhas. No Chile, Paraguai e Uruguay, a propaganda antivacina foi mencionada enquanto problema. A programação e a implementação enfrentam escassez de recursos humanos na maioria dos países. Dados estatísticos, sistemas de informação em saúde e registros nominais de grupos de risco estão disponíveis, com limitações no Peru e no Paraguai. A promoção da saúde, supervisão, monitoramento e avaliação foram percebidas como oportunidades para tratar da confiança e da acomodação. Os programas de vacinação contra influenza identificam e agem sobre a maioria das barreiras e facilitadores que afetam a hesitação vacinal através de estratégias do lado da oferta, tratando principalmente da conveniência da vacina. A confiança e a acomodação não são tratadas de maneira suficiente, com exceção notável do Uruguai. Os programas têm a oportunidade de desenvolver abordagens que integram os lados da oferta e da procura.

Influenza and morbidity and mortality risk in patients in Mexico with systemic arterial hypertension alone or with comorbidities: a retrospective, observational, cross-sectional study from 2014 to 2020.

OBJECTIVES: In Mexico, patients with systemic arterial hypertension (SAH) are excluded from the influenza vaccination programme despite their risk of cardiovascular events as influenza-related complications. We investigated the impact of influenza on morbidity and mortality in patients with SAH. DESIGN: This was a retrospective cross-sectional study that analysed data from early 2014 to mid-2020. SETTING: Data were obtained from the Influenza Epidemiological Surveillance System in Mexico database. PARTICIPANTS: 32 663 cases of influenza in people aged ≥20 years with a confirmed case of influenza-like illness, severe respiratory infection and/or influenza death were investigated. PRIMARY AND SECONDARY OUTCOME MEASURES: Influenza deaths, hospitalisation frequency and the impact on hospitalisation and/or death due to influenza by the SAH variate alone and in combination with diabetes, obesity, chronic obstructive pulmonary disease, cardiovascular disease and/or smoking, and by vaccination status were assessed. RESULTS: The hospitalisation frequency increased with age. Notably, 46.0% (15 033/32 663) of confirmed influenza cases had at least one comorbidity, with SAH (19.2%; 6260/32 663) and obesity (18.7%; 6106/32 663) being the most prevalent. Most confirmed SAH cases (80.8%; 5057/6260) were in those who had not been vaccinated against influenza. There were 3496 deaths due to influenza (mortality rate, 0.69×1 00 000 inhabitants), with the highest rates seen in those aged ≥80 years (80-89 years, 2.0%; ≥90 years, 3.6%). The case fatality rate due to influenza and SAH was significantly higher than those due to influenza without SAH in those aged <50 years, but not in the other age groups (20-29 years, 9.8%, p<0.0005; 30-39 years, 8.2%, p<0.035; 40-49 years, 17.8%, p<0.0005; vs 15.1%-20.0%, p=0.31-0.99 for those aged ≥50 years). CONCLUSIONS: Our findings support the need to include SAH in public policies of influenza vaccination as a secondary prevention measure to avoid fatal outcomes.

Influenza vaccination hesitancy in large urban centers in South America. Qualitative analysis of confidence, complacency and convenience across risk groups.

Influenza vaccination coverage in countries of Latin America is low among priority risk groups, ranging from 5 to 75% among older people. This paper aims to describe and analyze the determinants of influenza vaccination hesitancy through the lens of the 3C model of confidence, complacency and convenience among middle-class, urban risk group populations in Brazil, Chile, Paraguay, Peru, Uruguay, countries in South America with contrasting vaccination coverage. Focus groups were conducted among four risk groups: pregnant women, mothers of children aged <6 years, adults with risk factors, and adults aged ≥60 years in samples of urban residents. Adults with risk factors expressed the most detailed perceptions about confidence in the vaccine. A wide range of perceptions regarding complacency were expressed across risk groups and countries, with pregnant women and mothers showing greater concerns while convenience had a narrower and generally more positive range of perceptions. Participants from Chile and Paraguay expressed the most contrasts regarding confidence and complacency. Information and communication strategies need to be tailored for risk groups while confidence and complacency should be addressed in synergy.

The importance of confidence, complacency, and convenience for influenza vaccination among key risk groups in large urban areas of Peru.

Influenza vaccination has been available under Peru's national immunization program since 2008, but vaccination coverage has decreased lately. Surveys and focus groups were conducted among four risk groups (pregnant women, mothers of children aged <6 years, adults with risk factors, and adults aged ≥65 years) to identify factors affecting influenza vaccine hesitancy in Peru. The 3Cs model (Confidence, Complacency, and Convenience) was used as a conceptual framework for the study. Most pregnant women and mothers of young children (70.0%), but less than half (46.3%) of older adults and adults with risk factors were vaccinated against influenza. Vaccine confidence and complacency were positively associated with educational level. Complacency was the most deficient of the 3Cs. Pregnant women and mothers were the most informed and least complacent among risk groups. Focus groups revealed the misconceptions behind the high level of complacency observed, including the perception of influenza risk and the role assigned to vaccination in preventing the disease. Interviews with officials identified that most strategies are directed to vaccination availability and hence to convenience, with opportunities for strategies to improve vaccination uptake and community engagement. The results highlight the importance of implementing in Peru communication strategies to increase perceptions of vaccine safety and effectiveness thus improving confidence and reducing complacency. The establishment of explicit incentives should also be considered to increase vaccination uptake, particularly to health personnel.

Influenza vaccination hesitancy in five countries of South America. Confidence, complacency and convenience as determinants of immunization rates.

INTRODUCTION: Influenza morbidity and mortality are significant in the countries of South America, yet influenza vaccination is as low as 56.7% among pregnant women, reaching 76.7% of adults with chronic diseases. This article measures the relative values for the vaccination hesitancy indicators of confidence, complacency and convenience by risk-groups in urban areas of five countries of South America with contrasting vaccination rates, analyzing their association with sociodemographic variables and self-reported immunization status. METHODS: An exit survey was applied to 640 individuals per country in Brazil, Chile, Paraguay, Peru and Uruguay, distributed equally across risk groups of older adults, adults with risk factors, children ≤6 and pregnant women. Indicators were constructed for vaccine confidence, complacency and convenience. Analysis of variance and multiple logistic analysis was undertaken. RESULTS: Adults with risk factors are somewhat more confident of the influenza vaccine yet also more complacent. Convenience is higher for mothers of minors. Children and older adults report higher levels of vaccination. The 3Cs are more different across countries than across risk groups, with values for Chile higher for confidence and those for Uruguay the lowest. Complacency is lower in Brazil and higher in Uruguay. Results suggest that confidence and complacency affect vaccination rates across risk groups and countries. CONCLUSIONS: Influenza vaccine confidence, complacency and convenience have to be bolstered to improve effective coverage across all risk groups in the urban areas of the countries studied. The role played by country contextual and national vaccination programs has to be further researched in relation to effective coverage of influenza vaccine.

Force-of-infection of Taenia solium porcine cysticercosis: a modelling analysis to assess global incidence and prevalence trends.

The World Health Organization (WHO) called, in 2012, for a validated strategy towards Taenia solium taeniasis/cysticercosis control and elimination. Estimating pig force-of-infection (FoI, the average rate at which susceptible pigs become infected) across geographical settings will help understand local epidemiology and inform effective intervention design. Porcine cysticercosis (PCC) age-prevalence data (from 15 studies in Latin America, Africa and Asia) were identified through systematic review. Catalytic models were fitted to the data using Bayesian methods, incorporating uncertainty in diagnostic performance, to estimate rates of antibody seroconversion, viable metacestode acquisition, and seroreversion/infection loss. There was evidence of antibody seroreversion across 5 studies, and of infection loss in 6 studies measured by antigen or necropsy, indicating transient serological responses and natural resolution of infection. Concerted efforts should be made to collect robust data using improved diagnostics to better understand geographical heterogeneities in T. solium transmission to support post-2020 WHO targets.

Pertussis in Latin America and the Hispanic Caribbean: a systematic review.

Introduction: Pertussis in Latin America continues to cause periodic epidemics with substantial morbidity particularly among young children. The disease has persisted despite long-standing vaccination programs in the region. Areas covered: We conducted a systematic review to characterize the recent epidemiology of pertussis in Latin America and Hispanic Caribbean. We undertook a holistic approach and attempted to include all available data concerning pertussis that may explain the changing dynamics of the disease. Expert opinion: There are wide disparities in the reported annual incidence rates of pertussis both within and between countries in the region. General trends in pertussis incidence are difficult to ascertain due to the heterogeneity in the epidemiological data. Available data suggests that the disease burden has changed over the years such that now it predominantly affects those <1 year. Coverage with three doses of the pertussis vaccine has been highly variable, and very few countries have consistently achieved ≥90% coverage annually since 2000. There remain inequalities in vaccination coverage in some regions/localities and specific groups, which sustains the risk of pertussis dissemination. The WHO considers that maternal pertussis immunization provides protection to infants too young to be vaccinated; >10 Latin American countries currently recommend vaccination of pregnant women.

Incidence rates of neurotropic-like and viscerotropic-like disease in three dengue-endemic countries: Mexico, Brazil, and Malaysia.

BACKGROUND: The background incidence of viscerotropic- (VLD) and neurotropic-like disease (NLD) unrelated to immunization in dengue-endemic countries is currently unknown. METHODS: This retrospective population-based analysis estimated crude and standardized incidences of VLD and NLD in twelve hospitals in Brazil (n = 3), Mexico (n = 3), and Malaysia (n = 6) over a 1-year period before the introduction of the tetravalent dengue vaccine. Catchment areas were estimated using publicly available population census information and administrative data. The denominator population for incidence rates was calculated, and sensitivity analyses assessed the impact of important assumptions. RESULTS: Total cases adjudicated as definite VLD were 5, 57, and 56 in Brazil, Mexico, and Malaysia, respectively. Total cases adjudicated as definite NLD were 103, 29, and 26 in Brazil, Mexico, and Malaysia, respectively. Crude incidence rates of cases adjudicated as definite VLD in Brazil, Mexico, and Malaysia were 1.17, 2.60, and 1.48 per 100,000 person-years, respectively. Crude incidence rates of cases adjudicated as definite NLD in Brazil, Mexico, and Malaysia were 4.45, 1.32, and 0.69 per 100,000 person-years, respectively. CONCLUSIONS: Background incidence estimates of VLD and NLD obtained in Mexico, Brazil, and Malaysia could provide context for cases occurring after the introduction of the tetravalent dengue vaccine.

Seroprevalence of dengue in school children in Mexico ages 6-17 years, 2016.

Background: Dengue is the most important arboviral disease in the world. Seroprevalence has been proposed as a marker of endemicity, however, studies are scarce. Methods: We conducted a cross-sectional, stratified cluster, random sample study to measure the seroprevalence of antibodies to dengue virus (DENV) in Mexico. The target population was school children ages 6-17 y from 22 endemic states in Mexico, clustered in four regions: Pacific, South-Central, Southeast and Low. Results: A total of 2134 subjects provided blood samples for immunoglobulin G antibody detection in serum by enzyme-linked immunosorbent assay. Overall, the seroprevalence of antibodies against DENV was 33.5% (95% confidence interval [CI] 27.5 to 40.1). The Southeast had the highest regional seroprevalence, reaching 70.9% (95% CI 60.3 to 79.7). Seroprevalence was higher in older children in the Southeast region: 62.1% (95% CI 46.9 to 75.2) in children 6-8 y and 82.6% (95% CI 73.8 to 88.9) in 13-17 years old (y). However, this was not consistent in all regions. Seroprevalence was associated with dengue incidence. Conclusions: DENV seroprevalence in Mexico was found to be heterogeneous at the country, regional and state levels. Seroprevalence was linked to long-term exposure and did not adequately reflect recent patterns of transmission, suggesting that utilization of a single epidemiological indicator to define endemic regions should be avoided.

Epidemiological Characteristics of Dengue Disease in Latin America and in the Caribbean: A Systematic Review of the Literature.

Dengue, an important mosquito-borne virus transmitted mainly by Aedes aegypti, is a major public health issue in Latin America and the Caribbean. National epidemiological surveillance systems, usually based on passive detection of symptomatic cases, while underestimating the true burden of dengue disease, can provide valuable insight into disease trends and excess reporting and potential outbreaks. We carried out a systematic review of the literature to characterize the recent epidemiology of dengue disease in Latin America and the English-speaking and Hispanic Caribbean Islands. We identified 530 articles, 60 of which met criteria for inclusion. In general, dengue seropositivity across the region was high and increased with age. All four virus serotypes were reported to circulate in the region. These observations varied considerably between and within countries and over time, potentially due to climatic factors (temperature, rainfall, and relative humidity) and their effect on mosquito densities and differences in socioeconomic factors. This review provides important insight into the major epidemiological characteristics of dengue in distinct regions of Latin America and the Caribbean, allowing gaps in current knowledge and future research needs to be identified.

Dengue in Latin America: Systematic Review of Molecular Epidemiological Trends.

Dengue, the predominant arthropod-borne viral disease affecting humans, is caused by one of four distinct serotypes (DENV-1, -2, -3 or -4). A literature analysis and review was undertaken to describe the molecular epidemiological trends in dengue disease and the knowledge generated in specific molecular topics in Latin America, including the Caribbean islands, from 2000 to 2013 in the context of regional trends in order to identify gaps in molecular epidemiological knowledge and future research needs. Searches of literature published between 1 January 2000 and 30 November 2013 were conducted using specific search strategies for each electronic database that was reviewed. A total of 396 relevant citations were identified, 57 of which fulfilled the inclusion criteria. All four dengue virus serotypes were present and co-circulated in many countries over the review period (with the predominance of individual serotypes varying by country and year). The number of countries in which more than one serotype circulated steadily increased during the period under review. Molecular epidemiology data were found for Argentina, Bolivia, Brazil, the Caribbean region, Colombia, Ecuador, Mexico and Central America, Paraguay, Peru and Venezuela. Distinct lineages with different dynamics were found in each country, with co-existence, extinction and replacement of lineages occurring over the review period. Despite some gaps in the literature limiting the possibility for comparison, our review has described the molecular epidemiological trends of dengue infection. However, several gaps in molecular epidemiological information across Latin America and the Caribbean were identified that provide avenues for future research; in particular, sequence determination of the dengue virus genome is important for more precise phylogenetic classification and correlation with clinical outcome and disease severity.

Age and regional differences in clinical presentation and risk of hospitalization for dengue in Brazil, 2000-2014.

OBJECTIVES: Dengue cases range from asymptomatic to severe, eventually leading to hospitalization and death. Timely and appropriate management is critical to reduce morbidity. Since 1980, dengue has spread throughout Brazil, affecting an increasing number of individuals. This paper describes age and regional differences in dengue's clinical presentation and associated risk of hospitalization based on more than 5 million cases reported to the Brazilian Ministry of Health from 2000-2014. METHODS: We performed a retrospective analysis of ∼5,450,000 dengue cases, relating clinical manifestations and the risk of hospitalization to age, gender, previous infection by dengue, dengue virus serotype, years of formal education, delay to first attendance and the occurrence of dengue during outbreaks and in different Brazilian regions. RESULTS: Complicated forms of dengue occurred more frequently among those younger than 10 years (3.12% vs 1.92%) and those with dengue virus 2 infection (7.65% vs 2.42%), with a delay to first attendance >2 days (3.18% vs 0.82%) and with ≤4 years of formal education (2.02% vs 1.46%). The risk of hospitalization was higher among those aged 6-10 years old (OR 4.57; 95% CI 1.43-29.96) and those who were infected by dengue virus 2 (OR 6.36; 95% CI 2.52-16.06), who lived in the Northeast region (OR 1.38; 95% CI 1.11-2.10) and who delayed first attendance by >5 days (composite OR 3.15; 95% CI 1.33-8.9). CONCLUSIONS: In Brazil, the occurrence of severe dengue and related hospitalization is associated with being younger than 10 years old, being infected by dengue virus 2 or 3, living in the Northeast region (the poorest and the second most populated) and delaying first attendance for more than 2 days.

Age and regional differences in clinical presentation and risk of hospitalization for dengue in Brazil, 2000-2014

OBJECTIVES: Dengue cases range from asymptomatic to severe, eventually leading to hospitalization and death. Timely and appropriate management is critical to reduce morbidity. Since 1980, dengue has spread throughout Brazil, affecting an increasing number of individuals. This paper describes age and regional differences in dengue’s clinical presentation and associated risk of hospitalization based on more than 5 million cases reported to the Brazilian Ministry of Health from 2000-2014. METHODS: We performed a retrospective analysis of ∼5,450,000 dengue cases, relating clinical manifestations and the risk of hospitalization to age, gender, previous infection by dengue, dengue virus serotype, years of formal education, delay to first attendance and the occurrence of dengue during outbreaks and in different Brazilian regions. RESULTS: Complicated forms of dengue occurred more frequently among those younger than 10 years (3.12% vs 1.92%) and those with dengue virus 2 infection (7.65% vs 2.42%), with a delay to first attendance >2 days (3.18% vs 0.82%) and with ≤4 years of formal education (2.02% vs 1.46%). The risk of hospitalization was higher among those aged 6-10 years old (OR 4.57; 95% CI 1.43-29.96) and those who were infected by dengue virus 2 (OR 6.36; 95% CI 2.52-16.06), who lived in the Northeast region (OR 1.38; 95% CI 1.11-2.10) and who delayed first attendance by >5 days (composite OR 3.15; 95% CI 1.33-8.9). CONCLUSIONS: In Brazil, the occurrence of severe dengue and related hospitalization is associated with being younger than 10 years old, being infected by dengue virus 2 or 3, living in the Northeast region (the poorest and the second most populated) and delaying first attendance for more than 2 days.

Symptomatic Dengue in Children in 10 Asian and Latin American Countries.

BACKGROUND: The control groups in two phase 3 trials of dengue vaccine efficacy included two large regional cohorts that were followed up for dengue infection. These cohorts provided a sample for epidemiologic analyses of symptomatic dengue in children across 10 countries in Southeast Asia and Latin America in which dengue is endemic. METHODS: We monitored acute febrile illness and virologically confirmed dengue (VCD) in 3424 healthy children, 2 to 16 years of age, in Asia (Indonesia, Malaysia, the Philippines, Thailand, and Vietnam) from June 2011 through December 2013 and in 6939 children, 9 to 18 years of age, in Latin America (Brazil, Colombia, Honduras, Mexico, and Puerto Rico) from June 2011 through April 2014. Acute febrile episodes were determined to be VCD by means of a nonstructural protein 1 antigen immunoassay and reverse-transcriptase-polymerase-chain-reaction assays. Dengue hemorrhagic fever was defined according to 1997 World Health Organization criteria. RESULTS: Approximately 10% of the febrile episodes in each cohort were confirmed to be VCD, with 319 VCD episodes (4.6 episodes per 100 person-years) occurring in the Asian cohort and 389 VCD episodes (2.9 episodes per 100 person-years) occurring in the Latin American cohort; no trend according to age group was observed. The incidence of dengue hemorrhagic fever was less than 0.3 episodes per 100 person-years in each cohort. The percentage of VCD episodes requiring hospitalization was 19.1% in the Asian cohort and 11.1% in the Latin American cohort. In comparable age groups (9 to 12 years and 13 to 16 years), the burden of dengue was higher in Asia than in Latin America. CONCLUSIONS: The burdens of dengue were substantial in the two regions and in all age groups. Burdens varied widely according to country, but the rates were generally higher and the disease more frequently severe in Asian countries than in Latin American countries. (Funded by Sanofi Pasteur; CYD14 and CYD15 ClinicalTrials.gov numbers, NCT01373281 and NCT01374516.).

A comparative study on active and passive epidemiological surveillance for dengue in five countries of Latin America.

BACKGROUND: Dengue is a notifiable infectious disease in many countries, but under-reporting of cases to National Epidemiological Surveillance Systems (NESSs) conceals the true extent of the disease burden. The incidence of dengue identified in a cohort study was compared with those reported to NESSs. METHODS: A randomized, placebo-controlled study was undertaken in Brazil, Colombia, Honduras, Mexico, and Puerto Rico to assess the efficacy of a tetravalent dengue vaccine (CYD-TDV) in children aged 9-16 years. The incidence of dengue in the placebo group was compared with that reported to NESSs in a similar age group (10-19 years) from June 2011 to April 2014. RESULTS: Three thousand six hundred and fifteen suspected dengue cases were identified in the study over 13527 person-years of observation. The overall incidence of confirmed dengue was 2.9 per 100 person-years (range 1.5 to 4.1 per 100 person-years). In the NESSs combined, over 3.2 million suspected dengue cases were reported during the same period, corresponding to over 1 billion person-years of observation. The incidence of confirmed dengue reported by the NESSs in the same locality where the study took place was 0.286 per 100 person-years across Brazil, Colombia, and Mexico (range 0.180 to 0.734 per 100 person-years). The incidence of confirmed dengue was 10.0-fold higher in the study than that reported to NESSs in the same localities (range 3.5- to 19.4-fold higher). CONCLUSIONS: There is a substantial under-reporting of dengue in the NESSs. Understanding the level of under-reporting would allow more accurate estimates of the dengue burden in Latin America.

Dengue Awareness in Latin American Populations: A Questionnaire Study.

INTRODUCTION: Dengue is an escalating public health concern in Latin American Countries with a dramatic increase of cases reported during the past decade. The objectives of this study were to identify and provide insights into current management and attitudes toward dengue and to understand attitudes to vaccination and current behaviors to prevent dengue in Mexico and Colombia. METHODS: This was a community-based, cross-sectional, descriptive study conducted in urban and rural areas in endemic and non-endemic regions. The interviews were conducted face-to-face using a structured questionnaire containing 58 questions. A quota sampling approach was used to obtain a nationally representative sample of the adult population. All data were weighted to correct for differences between the samples surveyed in each country relative to their general population. RESULTS: A total of 1978 participants completed the survey. Two percent and 10% of participants in Mexico and Colombia, respectively, had experienced dengue fever, with just under one-third of adults and almost two-thirds of their children hospitalized as a result of the illness. Awareness of dengue was similar in Colombia (76%) and Mexico (68%), with awareness higher in endemic regions than in non-endemic regions. Colombia had a higher proportion of participants (84%) who considered dengue to be a common disease in their country, compared with Mexico (56%). In Mexico and Colombia, 55% and 54% in endemic areas, and 28% and 46% in non-endemic areas believed that everyone was at risk of contracting dengue. In both countries, the most common action undertaken by participants to prevent dengue infection was removal of standing water. At least 70% of participants believe their government could do more to prevent dengue in their country. CONCLUSIONS: Dengue was identified as a severe and common disease in Mexico and Colombia. Most participants recognized the need to reduce the risk of dengue infection by removal of standing water. Awareness was similar in Colombia and Mexico.

Epidemiological trends of dengue disease in Colombia (2000-2011): a systematic review.

A systematic literature review was conducted to describe the epidemiology of dengue disease in Colombia. Searches of published literature in epidemiological studies of dengue disease encompassing the terms "dengue", "epidemiology," and "Colombia" were conducted. Studies in English or Spanish published between 1 January 2000 and 23 February 2012 were included. The searches identified 225 relevant citations, 30 of which fulfilled the inclusion criteria defined in the review protocol. The epidemiology of dengue disease in Colombia was characterized by a stable "baseline" annual number of dengue fever cases, with major outbreaks in 2001-2003 and 2010. The geographical spread of dengue disease cases showed a steady increase, with most of the country affected by the 2010 outbreak. The majority of dengue disease recorded during the review period was among those <15 years of age. Gaps identified in epidemiological knowledge regarding dengue disease in Colombia may provide several avenues for future research, namely studies of asymptomatic dengue virus infection, primary versus secondary infections, and under-reporting of the disease. Improved understanding of the factors that determine disease expression and enable improvement in disease control and management is also important.

Epidemiological trends of dengue disease in Mexico (2000-2011): a systematic literature search and analysis.

This systematic literature review describes the epidemiology of dengue disease in Mexico (2000-2011). The annual number of uncomplicated dengue cases reported increased from 1,714 in 2000 to 15,424 in 2011 (incidence rates of 1.72 and 14.12 per 100,000 population, respectively). Peaks were observed in 2002, 2007, and 2009. Coastal states were most affected by dengue disease. The age distribution pattern showed an increasing number of cases during childhood, a peak at 10-20 years, and a gradual decline during adulthood. All four dengue virus serotypes were detected. Although national surveillance is in place, there are knowledge gaps relating to asymptomatic cases, primary/secondary infections, and seroprevalence rates of infection in all age strata. Under-reporting of the clinical spectrum of the disease is also problematic. Dengue disease remains a serious public health problem in Mexico.