RESUMO

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.

Assuntos

Vacinas contra Influenza , Influenza Humana , Criança , Humanos , Pré-Escolar , Idoso , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Estações do Ano , Estudos de Coortes , Mortalidade Hospitalar , Hospitalização , Vacinação , Brasil/epidemiologia

RESUMO

Background: Respiratory viruses remain a key cause of early childhood illness, hospitalization, and death globally.The recent pandemic has rekindled interest in the control of respiratory viruses among paediatric populations. We estimate the burden of such viruses among children <2 years. Methods: Enrolled neonates were followed until two years of age. Weekly active symptom monitoring for the development of acute respiratory illnesses (ARI) defined as cough, rhinorrhoea, difficulty breathing, asthenia, anorexia, irritability, or vomiting was conducted. When the child had ARI and fever, nasopharyngeal swabbing was performed, and samples were tested through singleplex RT-PCR. Incidence of respiratory viruses was calculated by dividing the number of laboratory-confirmed detections by the person-time accrued during weeks when that virus was detectable through national surveillance then corrected for under-ascertainment among untested children. Findings: During December 2014-November 2017, 1567 enrolled neonates contributed 2,186.9 person-years (py). Six in ten (64·4%) children developed ARI (total 2493 episodes). Among children <2 years, incidence of respiratory syncytial virus (RSV)-associated ARI episodes (21·0, 95%CI 19·3-22·8, per 100py) and rhinovirus-associated (20·5, 95%CI 20·4-20·7) were similar and higher than parainfluenza 1-3-associated (14·2, 95%CI 12·2-16·1), human metapneumovirus-associated (9·2, 95%CI 7·7-10·8), influenza-associated (5·9, 95%CI 4·4-7·5), and adenovirus-associated ARI episodes (5·1, 95%CI 5·0-5·2). Children aged <3 months had the highest rates of RSV ARI (49·1, 95%CI 44·0-54·1 per 100py) followed by children aged 3-5 (25·1, 95%CI 20·1-30·0), 6-11 (17·6, 95%CI 13·2-21·9), and 12-23 months (11·9, 95%CI 10·8-12·9). One in ten children with RSV was referred to the hospital (2·5, 95%CI 2·1-2·8, per 100py). Interpretation: Children frequently developed viral ARI and a substantive proportion required hospital care. Such findings suggest the importance of exploring the value of new interventions and increasing uptake of existing prevention measures to mitigate burden of epidemic-prone respiratory viruses. Funding: The study was supported by the Centers for Disease Control and Prevention.

RESUMO

The World Health Organization (WHO) has established a target to eliminate mother-to-child-transmission (EMTCT) of hepatitis B virus (HBV), defined as a prevalence of hepatitis B surface antigen (HBsAg) of ≤0.1% among children, by 2030. Using nationally representative serosurveys to verify achievement of this target requires large sample sizes and significant resources. We assessed the feasibility of a potentially more efficient two-phase method to verify EMTCT of HBV in Colombia. In the first phase, we conducted a risk assessment to identify municipalities at the highest risk of ongoing HBV transmission. We ranked the 1122 municipalities of Colombia based on the reports of HBV infection in pregnant women per 1000 population. Municipalities with ≥0.3 reports per 1000 persons (equating to the top quartile) were further assessed based on health facility birth rates, coverage with three doses of hepatitis B vaccine (HepB3) and seroprevalence data. Hepatitis B risk was considered to be further increased for municipalities with HepB3 coverage or health facility birth rate <90%. In the second phase, we conducted a multistage household serosurvey of children aged 5-10 years in 36 municipalities with the highest assessed HBV risk. HBsAg was not detected in any of 3203 children tested, yielding a 90% upper confidence bound of <0.1% prevalence. Coverage with HepB3 and hepatitis B birth dose was high at 97.5% and 95.6%, respectively. These results support the conclusion that Colombia has likely achieved EMTCT of HBV.

Assuntos

Hepatite B , Transmissão Vertical de Doenças Infecciosas , Colômbia/epidemiologia , Feminino , Hepatite B/epidemiologia , Hepatite B/prevenção & controle , Antígenos de Superfície da Hepatite B , Vacinas contra Hepatite B , Vírus da Hepatite B , Humanos , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Gravidez , Prevalência , Estudos Soroepidemiológicos

RESUMO

BACKGROUND: Ecuador annually has handwashing and respiratory hygiene campaigns and seasonal influenza vaccination to prevent respiratory virus illnesses but has yet to quantify disease burden and determine epidemic timing. METHODS: To identify respiratory virus burden and assess months with epidemic activity, we followed a birth cohort in northwest Ecuador during 2011-2014. Mothers brought children to the study clinic for routine checkups at ages 1, 2, 3, 5, and 8 years or if children experienced any acute respiratory illness symptoms (e.g., cough, fever, or difficulty breathing); clinical care was provided free of charge. Those with medically attended acute respiratory infections (MAARIs) were tested for common respiratory viruses via real-time reverse-transcription polymerase chain reaction (rRT-PCR). RESULTS: In 2011, 2376 children aged 1-4 years (median 35 months) were enrolled in the respiratory cohort and monitored for 7017.5 child-years (cy). The incidence of respiratory syncytial virus (RSV) was 23.9 (95% CI 17.3-30.5), influenza 10.6 (2.4-18.8), adenoviruses 6.7 (4.6-28.0), parainfluenzas 5.0 (2.3-10.5), and rhinoviruses, bocaviruses, human metapneumoviruses, seasonal coronaviruses, and enteroviruses <3/100 cy among children aged 12-23 months and declined with age. Most (75%) influenza detections occurred April-September. CONCLUSION: Cohort children frequently had MAARIs, and while the incidence decreased rapidly among older children, more than one in five children aged 12-23 months tested positive for RSV, and one in 10 tested positive for influenza. Our findings suggest this substantial burden of influenza occurred more commonly during the winter Southern Hemisphere influenza season.

Assuntos

Influenza Humana , Infecções por Vírus Respiratório Sincicial , Vírus Sincicial Respiratório Humano , Infecções Respiratórias , Vírus , Coorte de Nascimento , Criança , Pré-Escolar , Equador/epidemiologia , Humanos , Incidência , Lactente , Influenza Humana/epidemiologia , Infecções por Vírus Respiratório Sincicial/epidemiologia , Estações do Ano , Vírus/genética

RESUMO

BACKGROUND: Antenatal care providers have a key role in providing appropriate information and immunization recommendations to improve pregnant women's vaccine uptake. The objective of this study is to describe health care providers' perspectives and experience regarding the implementation of maternal immunization programs in Latin America. METHODS: We conducted 33 in-depth interviews of health care providers from Argentina, Brazil, Honduras, Mexico, and Peru (6-7 per country). Qualitative data analysis was conducted using a combination of both manual techniques and the computer software program NVivo. We identified and coded main themes related to maternal immunization. RESULTS: The main themes identified in this analysis were practices related to maternal immunization, knowledge and training, resource availability and interactions with pregnant women. Healthcare providers knew that recommendations exists but some did not know their content; they expressed concerns about insufficient training. Providers from all five countries expressed the need for additional human resources and supplies. They also expressed a desire for women to be more proactive and ask more questions during the health visits. CONCLUSION: This is the first multi-country study assessing the perspectives of health care providers about maternal immunization practices at the facility level in Latin America. Recommendations based on the results from this study include implementing additional trainings around maternal immunization, especially targeting obstetricians and midwives. These trainings should be conducted in coordination with improvements to supply chain and other structural issues.

Assuntos

Pessoal de Saúde , Imunização , Argentina , Brasil , Feminino , Honduras , Humanos , América Latina , México , Peru , Gravidez , Cuidado Pré-Natal

RESUMO

OBJECTIVE: To determine rates and results of maternal Group B streptococcus (GBS) screening during pregnancy and identify sociodemographic characteristics associated with GBS screening in Latin American countries. BACKGROUND: GBS is a primary cause of morbidity and mortality in neonates and is prevented by screening pregnant women for GBS before delivery and intrapartum antibiotic treatment. Yet, data regarding national GBS screening practices and the epidemiology of maternal GBS colonization in Latin America are limited. METHODS: We conducted a retrospective observational study using de-identified records of pregnant women in six Latin American countries from a regional database. 460,328 collected from January 1, 2009 through December 31, 2012 met study criteria and were included. Maternal screening rates for GBS were determined, association of demographic variables (ethnicity, age, education level, and civil status) with maternal GBS screening was determined using logistic regression, odds ratios were calculated comparing incidence of adverse neonatal outcomes (sepsis, pneumonia, and meningitis) between countries with high and low rates of GBS screening, maternal GBS colonization prevalence was determined by year and association of demographic variables with maternal GBS colonization was determined using logistic regression. RESULTS: Maternal GBS screening was less than 15% in each country, except Uruguay which screened greater than 65% of women. The final regression model examining maternal screening rates and demographic variables included the covariates ethnicity, maternal age group, education level and civil status. Countries with lower rates of maternal GBS screening had increased odds of neonatal sepsis [OR 23.3; 95% CI (15.2-35.9)] and pneumonia [OR 19.9; 95% CI (12.1-32.6)]. In Uruguay, GBS prevalence over the study period was 18.5%. Black women, older women and women without a primary education had higher rates of GBS colonization (21.3%, 20.4% and 21.9% respectively). CONCLUSIONS: Our study highlights the need for national policy and investments to increase maternal GBS screening and better understand the prevalence of maternal GBS colonization in Latin America. Further research on the burden of neonatal GBS disease within Latin America is needed to inform the introduction of a maternal GBS vaccine, when available.

Assuntos

Complicações Infecciosas na Gravidez , Infecções Estreptocócicas , Idoso , Feminino , Humanos , Recém-Nascido , América Latina/epidemiologia , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Complicações Infecciosas na Gravidez/epidemiologia , Infecções Estreptocócicas/diagnóstico , Infecções Estreptocócicas/epidemiologia , Streptococcus agalactiae , Uruguai/epidemiologia

RESUMO

INTRODUCTION: The World Health Organization (WHO) recommends that countries prioritize pregnant women for influenza vaccination, yet few low- or middle-income countries (LMICs) have implemented maternal influenza immunization programs. To inform vaccine decision-making and operational planning in LMICs, there is a need to document and share experiences from countries that provide seasonal influenza vaccine to pregnant women, particularly those with high coverage, like El Salvador. METHODS: In 2015 and 2016, PATH and country researchers conducted a mixed-methods study to document the experience and lessons learned from maternal influenza immunization delivery and acceptance in El Salvador as part of a collaborative effort between WHO and PATH. Researchers conducted focus group discussions, semi-structured interviews, antenatal clinic exit interviews, and key informant interviews with 326 participants from two municipalities in each of the country's three regions. Respondents included pregnant and recently pregnant women, family members, community leaders, health personnel, public health managers and partners, and policymakers. RESULTS: Factors perceived as positively influencing maternal influenza immunization delivery and acceptance in El Salvador include the use of multiple vaccine delivery strategies, targeted education and community engagement efforts, and a high degree of trust between the community and health care providers. Influenza vaccine acceptance by pregnant women is high and has improved over time, largely attributed to education targeting health care advisors. Perceived challenges to pregnant women receiving health care and vaccination include the need for permission to attend services and limited access to health services in insecure areas related to the presence of criminal gang activity. CONCLUSIONS: We identified approaches and barriers perceived to affect maternal influenza vaccine delivery in El Salvador. This information will be useful to public health decision-makers and implementers in El Salvador and other countries considering introduction of new maternal vaccines or striving to increase coverage of vaccines currently provided.

Assuntos

Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Aceitação pelo Paciente de Cuidados de Saúde , Complicações Infecciosas na Gravidez/prevenção & controle , Cobertura Vacinal , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , El Salvador , Feminino , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Gravidez , Adulto Jovem

RESUMO

BACKGROUND: Nicaragua implemented an influenza vaccination program for pregnant women with high-risk obstetric conditions in 2007. In 2014, the recommendation of influenza vaccination expanded to include all pregnant women. Given the expansion in the recommendation of vaccination, we evaluated knowledge, attitudes and practices of pregnant women and their healthcare providers towards influenza vaccination and its recommendation. METHODS: We conducted surveys among pregnant women and their healthcare providers from June to August 2016 at two hospitals and 140 health facilities in Managua. The questions were adapted from the U.S. national CDC influenza survey and related to knowledge, attitudes and practices about influenza vaccination and barriers to vaccination. We analyzed reasons for not receiving vaccination among pregnant women as well as receipt of vaccination recommendation and offer by their healthcare providers. RESULTS: Of 1,303 pregnant women enrolled, 42% (5 4 5) reported receiving influenza vaccination in the 2016 season. Of those who reported not receiving vaccination, 46% indicated barriers to vaccination. Pregnant women who were vaccinated were more likely to be aware of the recommendation for vaccination and the risks of influenza illness during pregnancy and to perceive the vaccine as safe and effective, compared to unvaccinated pregnant women (p-values < 0.001). Of the 619 health workers enrolled, over 89% recalled recommending influenza vaccination to all pregnant women, regardless of obstetric risk. Of the 1,223 women who had a prenatal visit between the start date of the influenza vaccination and the time of interview, 44% recalled receiving a recommendation for influenza vaccination and 43% were offered vaccination. Vaccination rates were higher for those receiving a recommendation and offer of vaccination compared with those who received neither (95% vs 5%, p-value < 0.001). CONCLUSION: Pregnant women in Managua had positive perceptions of influenza vaccine and were receptive to receiving influenza vaccination, especially after the offer and recommendation by their healthcare providers.

Assuntos

Conhecimentos, Atitudes e Prática em Saúde , Pessoal de Saúde/psicologia , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Complicações Infecciosas na Gravidez/prevenção & controle , Vacinação/estatística & dados numéricos , Adulto , Feminino , Pessoal de Saúde/ética , Inquéritos Epidemiológicos , Hospitais , Humanos , Programas de Imunização , Influenza Humana/imunologia , Influenza Humana/virologia , Nicarágua , Gravidez , Complicações Infecciosas na Gravidez/imunologia , Complicações Infecciosas na Gravidez/virologia , Encaminhamento e Consulta/estatística & dados numéricos , Vacinação/psicologia

RESUMO

BACKGROUND: Studies have shown that influenza vaccination during pregnancy reduces the risk of influenza disease in pregnant women and their offspring. Some have proposed that maternal vaccination may also have beneficial effects on birth outcomes. In 2014, we conducted an observational study to test this hypothesis using data from two large hospitals in Managua, Nicaragua. METHODS: We conducted a retrospective cohort study to evaluate associations between influenza vaccination and birth outcomes. We carried out interviews and reviewed medical records post-partum to collect data on demographics, influenza vaccination during pregnancy, birth outcomes and other risk factors associated with adverse neonatal outcomes. We used influenza surveillance data to adjust for timing of influenza circulation. We assessed self-reports of influenza vaccination status by further reviewing medical records of those who self-reported but did not have readily available evidence of vaccination status. We performed multiple logistic regression (MLR) and propensity score matching (PSM). RESULTS: A total of 3268 women were included in the final analysis. Of these, 55% had received influenza vaccination in 2014. Overall, we did not observe statistically significant associations between influenza vaccination and birth outcomes after adjusting for risk factors, with either MLR or PSM. With PSM, after adjusting for risk factors, we observed protective associations between influenza vaccination in the second and third trimester and preterm birth (aOR: 0.87; 95% confidence interval (CI): 0.75-0.99 and aOR: 0.66; 95% CI: 0.45-0.96, respectively) and between influenza vaccination in the second trimester and low birth weight (aOR: 0.80; 95% CI: 0.64-0.97). CONCLUSIONS: We found evidence to support an association between influenza vaccination and birth outcomes by trimester of receipt with data from an urban population in Nicaragua. The study had significant selection and recall biases. Prospective studies are needed to minimize these biases.

Assuntos

Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Complicações Infecciosas na Gravidez/prevenção & controle , Resultado da Gravidez , Adolescente , Adulto , Estudos de Coortes , Feminino , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Modelos Logísticos , Prontuários Médicos , Nicarágua/epidemiologia , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Trimestres da Gravidez , Nascimento Prematuro/epidemiologia , Pontuação de Propensão , Estudos Retrospectivos , População Urbana/estatística & dados numéricos , Vacinação , Adulto Jovem

RESUMO

BACKGROUND: Pregnant women are at risk of severe influenza disease and are a priority group for influenza vaccination programs. Nicaragua expanded recommendations to include influenza vaccination to all pregnant women in the municipality of Managua in 2013. METHODS: We carried out a survey among 1,807 pregnant women who delivered at public hospitals in the municipality of Managua to evaluate the uptake of influenza vaccination and factors associated with vaccination. RESULTS: We observed a high (71%) uptake of influenza vaccination among this population, with no differences observed by age, education or parity of the women. Having four antenatal visits and five or more visits were associated with receipt of influenza vaccination (AORs: 2.58; 95% CI: 1.15, 5.81, and 2.37; 95% CI: 1.12, 5.0, respectively). Also, receipt of influenza vaccination recommendation from a health care provider was positively associated with receipt of influenza vaccination (AOR: 14.22; 95% CI: 10.45, 19.33). CONCLUSIONS: The successful expansion of influenza vaccination among pregnant women in the municipality of Managua may be due to ready access to free medical care and health care providers' recommendation for vaccination at health care clinics that received influenza vaccine.

Assuntos

Programas de Imunização , Vacinas contra Influenza/uso terapêutico , Influenza Humana/prevenção & controle , Vacinação/estatística & dados numéricos , Adolescente , Adulto , Feminino , Hospitais Públicos , Humanos , Nicarágua , Gravidez , Gestantes , Cuidado Pré-Natal , Adulto Jovem

RESUMO

Five suspected cases of yellow fever vaccine-associated viscerotropic disease (YEL-AVD) clustered in space and time following a vaccination campaign in Ica, Peru in 2007. All five people received the same lot of 17DD live attenuated yellow fever vaccine before their illness; four of the five died of confirmed YEL-AVD. The surviving case was classified as probable YEL-AVD. Intensive investigation yielded no abnormalities of the implicated vaccine lot and no common risk factors. This is the first described space-time cluster of yellow fever viscerotropic disease involving more than two cases. Mass yellow fever vaccination should be avoided in areas that present extremely low risk of yellow fever.

Assuntos

Vacinação/efeitos adversos , Vacina contra Febre Amarela/efeitos adversos , Febre Amarela/prevenção & controle , Adulto , Idoso , Evolução Fatal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Peru , Fatores de Risco , Vacinas Atenuadas/efeitos adversos , Adulto Jovem