Family-Based WhatsApp Intervention to Promote Healthy Eating Behaviors Among Amazonian School Children: Protocol for a Randomized Controlled Trial.

BACKGROUND: Stunting and micronutrient deficiencies have persistently affected children in the Brazilian Amazon for decades. However, in recent years, a notable increase in childhood overweight prevalence has been observed, particularly in the context of heightened food insecurity exacerbated by the COVID-19 pandemic. Despite the limited number of effective solutions proposed to tackle this problem, digital interventions have shown great promise worldwide in preventing obesity and promoting healthy diets. OBJECTIVE: This study aims to describe the protocol of a family-based WhatsApp intervention, specifically designed to investigate the efficacy of multimedia messaging in preventing excessive weight gain and improving healthy eating practices among school-aged children in the Amazon region. METHODS: This study protocol outlines a theory-driven randomized controlled trial based on the cognitive theory of multimedia learning and the social cognitive theory. A total of 240 parents or caregivers of children enrolled in the Maternal and Child Health and Nutrition Cohort Study in Acre (MINA-Brazil) will be recruited by phone and social media. The intervention group will receive persuasive multimedia messages through WhatsApp over 19 weeks, while the waitlist control group will remain in the usual care. The primary outcome is a change in children's BMI in z score. Secondary outcomes are changes in dietary intake and biochemical indicators of the children. Outcome measures will be assessed at baseline and 5 months after randomization in comparison to usual care. The analysis will use an intent-to-treat approach and will be conducted using the statistical package Stata (version 18.0), with a significance level set at P<.05. Paired and unpaired 2-tailed t tests will be applied to compare mean changes in the outcomes. RESULTS: Data collection started in June 2023, and final measurements are scheduled to be completed in December 2023. The results of the main analysis are expected to be available in 2024. CONCLUSIONS: This innovative multimedia message intervention holds significant potential for fostering behavioral changes among Amazonian children. TRIAL REGISTRATION: Brazilian Clinical Trials Registry RBR-5zdnw6t; https://ensaiosclinicos.gov.br/rg/RBR-5zdnw6t. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/54446.

Birth-to-childhood tracking of linear growth and weight gain in the MINA-Brazil Study.

OBJECTIVE: To investigate birth-to-childhood tracking of linear growth and weight gain across the distribution of length/height and weight for age z-scores and according to household wealth. METHODS: Data from 614 children from the MINA-Brazil Study with repeated anthropometric measurements at birth and up to age five years were used. Z-scores were calculated for length/height (HAZ) and weight (WAZ) according to international standards. Birth-to-childhood tracking was separately estimated using quantile regression models for HAZ and WAZ, extracting coefficients and 95% confidence intervals (95%CI) at the 25th, 50th, and 75th quantiles. In a subgroup analysis, we estimated tracking between birth and age two years, and between ages two and five years. To investigate disparities in tracking, interaction terms between household wealth indexes (at birth and age five years) and newborn size z-scores were included in the models. RESULTS: Tracking coefficients were significant and had similar magnitude across the distribution of anthropometric indices at age five years (HAZ, 50th quantile: 0.23, 95%CI: 0.11 to 0.35; WAZ, 50th quantile: 0.31, 95%CI: 0.19 to 0.43). Greater tracking was observed between ages two and five years, with coefficients above 0.82. Significantly higher tracking of linear growth was observed among children from wealthier households, both at birth, at the lower bounds of HAZ distribution (25th quantile: 0.30, 95%CI: 0.13 to 0.56), and during childhood, in the entire HAZ distribution at five years. For weight gain, stronger tracking was observed at the upper bounds of WAZ distribution at age five years among children from wealthier households at birth (75th quantile: 0.59, 95%CI: 0.35 to 0.83) and during childhood (75th quantile: 0.54, 95%CI: 0.15 to 0.93). CONCLUSION: There was significant tracking of HAZ and WAZ since birth, with indication of substantial stability of nutritional status between ages two and five years. Differential tracking according to household wealth should be considered for planning early interventions for preventing malnutrition.

Adolescent pregnancy in Cruzeiro do Sul, Acre, Brazil: socioeconomic characteristics, prenatal and obstetric care. / Parturientes adolescentes em Cruzeiro do Sul, Acre, Brasil: características socioeconômicas e obstétricas.

The present study aimed to investigate the socioeconomic and obstetric characteristics of adolescent mothers and the complications they cause to maternal and neonatal health. This baseline data analysis of the MINA-Brazil birth cohort was conducted in the municipality of Cruzeiro do Sul, state of Acre, Brazil. The chi-square test was used to compare characteristics of adolescent and adult postpartum women, and multiple Poisson regression models with robust variance were used to assess associated factors. Among the postpartum women, 26.2% (95%CI: 24.0-28.4) were adolescents. Factors associated with childbirth in adolescence included: nine years or less of schooling (adjPR:1.36; 95%CI: 1.14-1.61), belongs to the lowest quartiles of the wealth index (1st quartile: adjPR:1.40; 95%CI: 1.08-1.80) (2nd quartile: adjPR:1.37; 95%CI: 1.08-1.74), primigravidae (adjPR:3.69; 95%CI: 2.98-4.57), low pre-pregnancy BMI (adjPR:1.28; CI95%: 1.04-1.57), urinary tract infection during pregnancy (adjPR:1.25; CI95%: 1.07-1.46) and less than six prenatal consultations (adjPR:1.42; 95%CI: 1.21-1.66). Poverty, little schooling, primigravidae, low pre-pregnancy BMI, urinary tract infection during pregnancy and few prenatal consultations were associated with childbirth during adolescence in a municipality in the Northern region of Brazil.

O objetivo do estudo foi investigar as características socioeconômicas e obstétricas de parturientes adolescentes e suas complicações sobre a saúde materna e neonatal. Trata-se de uma análise de dados da linha de base da coorte de nascimentos MINA-Brasil conduzida no município de Cruzeiro do Sul, estado do Acre. Utilizou-se teste qui-quadrado para comparar características das puérperas adolescentes com as adultas e modelos múltiplos de regressão de Poisson com variância robusta para avaliar fatores associados. Entre as puérperas estudadas, 26,2% (IC95%: 24,0-28,4) eram adolescentes. Os fatores associados ao parto na adolescência foram ter nove anos ou menos de estudo (RPaj:1,36; IC95%: 1,14-1,61), pertencer aos menores quartis do índice de riqueza (1° quartil: RPaj:1,40; IC95%: 1,08-1,80) (2° quartil: RPaj:1,37; IC95%: 1,08-1,74), ser primigesta (RPaj:3,69; IC95%: 2,98-4,57), baixo IMC pré-gestacional (RPaj:1,28; IC95%: 1,04-1,57), infecção urinária na gravidez (RPaj:1,25; IC95%: 1,07-1,46) e menos de seis consultas de pré-natal (RPaj:1,42; IC95%: 1,21-1,66). Pobreza, baixa escolaridade, primigestação, baixo IMC pré-gestacional, infecção urinária na gestação e menor número de consultas de pré-natal foram associados ao parto na adolescência em município da região Norte do Brasil.

Parturientes adolescentes em Cruzeiro do Sul, Acre, Brasil: características socioeconômicas e obstétricas / Adolescent pregnancy in Cruzeiro do Sul, Acre, Brazil: socioeconomic characteristics, prenatal and obstetric care

Resumo O objetivo do estudo foi investigar as características socioeconômicas e obstétricas de parturientes adolescentes e suas complicações sobre a saúde materna e neonatal. Trata-se de uma análise de dados da linha de base da coorte de nascimentos MINA-Brasil conduzida no município de Cruzeiro do Sul, estado do Acre. Utilizou-se teste qui-quadrado para comparar características das puérperas adolescentes com as adultas e modelos múltiplos de regressão de Poisson com variância robusta para avaliar fatores associados. Entre as puérperas estudadas, 26,2% (IC95%: 24,0-28,4) eram adolescentes. Os fatores associados ao parto na adolescência foram ter nove anos ou menos de estudo (RPaj:1,36; IC95%: 1,14-1,61), pertencer aos menores quartis do índice de riqueza (1° quartil: RPaj:1,40; IC95%: 1,08-1,80) (2° quartil: RPaj:1,37; IC95%: 1,08-1,74), ser primigesta (RPaj:3,69; IC95%: 2,98-4,57), baixo IMC pré-gestacional (RPaj:1,28; IC95%: 1,04-1,57), infecção urinária na gravidez (RPaj:1,25; IC95%: 1,07-1,46) e menos de seis consultas de pré-natal (RPaj:1,42; IC95%: 1,21-1,66). Pobreza, baixa escolaridade, primigestação, baixo IMC pré-gestacional, infecção urinária na gestação e menor número de consultas de pré-natal foram associados ao parto na adolescência em município da região Norte do Brasil.

Abstract The present study aimed to investigate the socioeconomic and obstetric characteristics of adolescent mothers and the complications they cause to maternal and neonatal health. This baseline data analysis of the MINA-Brazil birth cohort was conducted in the municipality of Cruzeiro do Sul, state of Acre, Brazil. The chi-square test was used to compare characteristics of adolescent and adult postpartum women, and multiple Poisson regression models with robust variance were used to assess associated factors. Among the postpartum women, 26.2% (95%CI: 24.0-28.4) were adolescents. Factors associated with childbirth in adolescence included: nine years or less of schooling (adjPR:1.36; 95%CI: 1.14-1.61), belongs to the lowest quartiles of the wealth index (1st quartile: adjPR:1.40; 95%CI: 1.08-1.80) (2nd quartile: adjPR:1.37; 95%CI: 1.08-1.74), primigravidae (adjPR:3.69; 95%CI: 2.98-4.57), low pre-pregnancy BMI (adjPR:1.28; CI95%: 1.04-1.57), urinary tract infection during pregnancy (adjPR:1.25; CI95%: 1.07-1.46) and less than six prenatal consultations (adjPR:1.42; 95%CI: 1.21-1.66). Poverty, little schooling, primigravidae, low pre-pregnancy BMI, urinary tract infection during pregnancy and few prenatal consultations were associated with childbirth during adolescence in a municipality in the Northern region of Brazil.

Hypertensive disorders of pregnancy in Western Brazilian Amazon: Associated factors and neonatal outcomes.

OBJECTIVE: Hypertensive disorders of pregnancy (HDP) are responsible for several maternal and fetal complications. This study investigated the occurrence of HDP, associated factors, and neonatal complications in women living in the Western Brazilian Amazon. METHODS: This is a population-based cross-sectional study with 1521 mother-child pairs enrolled in the Maternal and Child Health and Nutrition in Acre birth cohort (MINA-Brazil study). All parturients with HDP (registered in the medical records) were identified. Crude and adjusted prevalence ratios were calculated in Poisson regression models with robust variance. RESULTS: The prevalence of HDP was 11.0% (95% CI: 9.5-12.7). Factors associated with the prevalence of HDP were maternal age ≥ 35 years (PR: 1.9; 95% CI: 1.3-3.0), primigravida status (PR: 2.0; 95% CI: 1.5-2.7), pre-pregnancy obesity (PR: 2.7; 95% CI: 1.9-4.0), higher gestational weight gain (highest quartile RP: 2.5; 95% CI: 1.6-3.8), chronic hypertension (RP: 3.6; 95% CI: 2.7-4.9), and diabetes in pregnancy (RP: 1.9; 95% CI: 1.1-3.2). HDP was associated with risk for caesarean delivery (PR: 1.8; 95% CI: 1.6-2.0) and prematurity (PR: 2.0; 95% CI: 1.3-3.2). Gestational malaria was not associated with HDP in Amazonian pregnant women. CONCLUSIONS: Evaluating risk factors before pregnancy and during the prenatal period is essential for reducing adverse maternal and neonatal outcomes.

Breastfeeding practices and head circumference in young children: a systematic review.

OBJECTIVE: To review observational studies on the association between breastfeeding (BF) practices and head circumference (HC) of children < 2 years old. METHODS: A systematic review was conducted using the following electronic databases of health sciences: PubMed, Latin American and Caribbean Literature in Health Sciences (Lilacs), Web of Science and Scopus. We selected observational studies published in any language from January 01, 2010 to November 19, 2021, from different populations that investigated the association between BF practice and HC among healthy children < 2 years old. Titles and abstracts were screened independently by two evaluators. RESULTS: From the 4,229 articles identified, 24 were included in this review: 6 cross-sectional, 17 longitudinal, and 1 case-control. The studies varied in their definition of the variables for BF and in reporting its practice, frequency, duration, and feeding method. Regarding HC, the authors analyzed the mean differences, abnormal values (z-score above + 2SD or below -2SD according to the World Health Organization (WHO) growth standards, 2007), and longitudinal growth parameters. The findings of this review suggest that BF may have a positive relationship with HC at the beginning of life. CONCLUSIONS: Our findings suggest that BF, especially exclusive BF, may play a protective role against abnormal HC values in young children. However, more robust evidence with standardized BF indicators and WHO growth standards (2007) are required.

Exposure to ultra-processed foods during pregnancy and ultrasound fetal growth parameters.

Periconceptional maternal ultra-processed food (UPF) consumption impairs embryonic growth. Impacts of exposure to UPF on distinct components of fetal growth in late pregnancy are unknown. We investigated the influence of frequency of UPF consumption during pregnancy on fetal head circumference (HC), abdominal circumference (AC) and femur length (FL). This study included 417 live-born singleton pregnancies prospectively followed-up since the antenatal period in the MINA-Brazil Study, with an available ultrasound scan at >24 gestational weeks. Frequency of food groups consumption in the previous month was categorised as no/monthly, weekly or daily. Ultrasound scans were conducted at 27·8 (sd: 1·7) gestational weeks. HC, AC and FL z-scores were calculated for gestational age using the INTERGROWTH-21st Project standards. Simultaneous-quantile regression models were fitted at the 10th, 50th and 90th percentiles of the distribution of each ultrasound parameter according to UPF consumption, with adjustment for potential confounders. Participants were aged on average 24·7 (sd: 6·5) years, 44·8 % were primiparous, and 26·9 % and 24·9 %, respectively, had weekly and daily UPF consumption. Compared with no/monthly intake, daily UPF consumption impaired HC across its distribution, with significant effect sizes varying from -0·24 to -0·40 z-score. Weekly UPF consumption decreased HC at the 90th percentile by -0·39 z-score (95 % CI: -0·78, -0·01) and FL at the 50th percentile by -0·32 z-score (95 % CI: -0·60, -0·04). No association was noted with AC. Frequency of UPF consumption was negatively associated with skeletal components of fetal growth in late pregnancy. Infant body composition may benefit from healthy food practices since pregnancy.

Factors associated with incomplete vaccination and negative antibody test results for measles, mumps, and hepatitis A among children followed in the MINA-BRAZIL cohort.

Vaccination coverage has been dropping in Brazil and other countries. In addition, immune responses after vaccination may not be homogeneous, varying according to sociodemographic and clinical factors. Understanding the determinants of incomplete vaccination and negative antibody test results may contribute to the development of strategies to improve vaccination effectiveness. In this study, we aimed to investigate the frequency of vaccine adherence, factors associated with incomplete vaccination for measles, mumps, rubella (MMR) and hepatitis A, and factors associated with the seronegative test results for measles, mumps and hepatitis A at 2 years of age. This was a population-based cohort that addressed health conditions and mother/infant nutrition in Cruzeiro do Sul city, Brazil. Vaccination data were obtained from official certificates of immunization. The children underwent blood collection at the two-year-old follow-up visit; the samples were analyzed using commercially available kits to measure seropositivity for measles, mumps, and hepatitis A. We used modified Poisson regression models adjusted for covariates to identify factors associated with incomplete vaccination and negative serology after vaccination. Out of the 825 children included in the study, adherence to the vaccine was 90.6% for MMR, 76.7% for the MMRV (MMR + varicella), and 74.9% for the hepatitis A vaccine. For MMR, after the adjustment for covariates, factors associated with incomplete vaccination included: white-skinned mother; paid maternity leave; raising more than one child; lower number of antenatal consultations; and attending childcare. For hepatitis A, the factors included: white-skinned mother and not having a cohabiting partner. The factors with statistically significant association with a negative antibody test result included: receiving Bolsa Familia allowance for measles and mumps; incomplete vaccination for measles; and vitamin A deficiency for mumps. Strategies to improve the efficiency of vaccine programs are urgently needed. These include improvements in communication about vaccine safety and efficacy, and amplification of access to primary care facilities, prioritizing children exposed to the sociodemographic factors identified in this study. Additionally, sociodemographic factors and vitamin A deficiency may impact the immune responses to vaccines, leading to an increased risk of potentially severe and preventable diseases.

Maternal pre-pregnancy body mass index, gestational weight gain and child weight during the first 2 years of life in an Amazonian birth cohort.

BACKGROUND: In socially vulnerable populations, evidence is needed regarding the role of maternal nutritional status on child weight during the first 2 years of life. OBJECTIVES: We aimed to assess the association of pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) with offspring BMI-for-age z-scores (BAZs) during the first 2 years of life. METHODS: A population-based birth cohort study was conducted with 900 mother-child pairs. Pre-pregnancy weight and weight at delivery were collected from medical records, and anthropometric data were measured at birth and at 6-month, 1-year and 2-year follow-up visits. Linear regression and linear mixed-effect models assessed associations with pre-pregnancy BMI, GWG and BAZ during the first 2 years of life. RESULTS: Pre-pregnancy overweight and obesity and excessive GWG were positively associated with BAZ at birth and at 1- and 2-year follow-up visits. There were no significant additional BAZ changes per year based on the exposures up to age 2 years. CONCLUSIONS: Elevated maternal pre-pregnancy BMI and GWG were associated with a child's higher BAZ at birth, and these differences remained constant throughout the first 2 years of life in Amazonian children. These findings highlight the importance of promoting adequate maternal weight before pregnancy and during prenatal care also in socially vulnerable populations.

Gestational weight gain and breastfeeding practices in relation to offspring body mass index among Amazonian young children.

OBJECTIVE: Excessive weight gain during childhood has been considered an early life risk factor for chronic disease in the long term. We examined the role of excessive gestational weight gain (GWG) and breastfeeding (BF) practices with the offspring's body mass index-for-age z-score (zBMI) at 2 years. METHODS: Data from 743 Amazonian young children of the MINA-Brazil population-based birth cohort study were used. Linear regression models were run to estimate the associations between excessive GWG and BF practices (exclusive breastfeeding, EBF <3 months of age and BF <1 year) with zBMI. RESULTS: Excessive GWG and BF <1 year were associated with an adjusted 0.24 units (95% CI: 0.08, 0.41) and 0.28 units (95% CI: 0.12, 0.44) higher zBMI at age 2 years, respectively. CONCLUSIONS: Gain excessive weight during pregnancy and shorter BF duration (<1y) were associated with a higher body mass index at 2 years of age among Brazilian Amazonian children.

Breastfeeding practices and head circumference in young children: a systematic review

ABSTRACT OBJECTIVE To review observational studies on the association between breastfeeding (BF) practices and head circumference (HC) of children < 2 years old. METHODS A systematic review was conducted using the following electronic databases of health sciences: PubMed, Latin American and Caribbean Literature in Health Sciences (Lilacs), Web of Science and Scopus. We selected observational studies published in any language from January 01, 2010 to November 19, 2021, from different populations that investigated the association between BF practice and HC among healthy children < 2 years old. Titles and abstracts were screened independently by two evaluators. RESULTS From the 4,229 articles identified, 24 were included in this review: 6 cross-sectional, 17 longitudinal, and 1 case-control. The studies varied in their definition of the variables for BF and in reporting its practice, frequency, duration, and feeding method. Regarding HC, the authors analyzed the mean differences, abnormal values (z-score above + 2SD or below -2SD according to the World Health Organization (WHO) growth standards, 2007), and longitudinal growth parameters. The findings of this review suggest that BF may have a positive relationship with HC at the beginning of life. CONCLUSIONS Our findings suggest that BF, especially exclusive BF, may play a protective role against abnormal HC values in young children. However, more robust evidence with standardized BF indicators and WHO growth standards (2007) are required.

Birth-to-childhood tracking of linear growth and weight gain in the MINA-Brazil Study / Autocorrelação do crescimento linear e ganho de peso do nascimento à infância no Estudo MINA-Brasil

ABSTRACT OBJECTIVE: To investigate birth-to-childhood tracking of linear growth and weight gain across the distribution of length/height and weight for age z-scores and according to household wealth. METHODS: Data from 614 children from the MINA-Brazil Study with repeated anthropometric measurements at birth and up to age five years were used. Z-scores were calculated for length/height (HAZ) and weight (WAZ) according to international standards. Birth-to-childhood tracking was separately estimated using quantile regression models for HAZ and WAZ, extracting coefficients and 95% confidence intervals (95%CI) at the 25th, 50th, and 75th quantiles. In a subgroup analysis, we estimated tracking between birth and age two years, and between ages two and five years. To investigate disparities in tracking, interaction terms between household wealth indexes (at birth and age five years) and newborn size z-scores were included in the models. RESULTS: Tracking coefficients were significant and had similar magnitude across the distribution of anthropometric indices at age five years (HAZ, 50th quantile: 0.23, 95%CI: 0.11 to 0.35; WAZ, 50th quantile: 0.31, 95%CI: 0.19 to 0.43). Greater tracking was observed between ages two and five years, with coefficients above 0.82. Significantly higher tracking of linear growth was observed among children from wealthier households, both at birth, at the lower bounds of HAZ distribution (25th quantile: 0.30, 95%CI: 0.13 to 0.56), and during childhood, in the entire HAZ distribution at five years. For weight gain, stronger tracking was observed at the upper bounds of WAZ distribution at age five years among children from wealthier households at birth (75th quantile: 0.59, 95%CI: 0.35 to 0.83) and during childhood (75th quantile: 0.54, 95%CI: 0.15 to 0.93). CONCLUSION: There was significant tracking of HAZ and WAZ since birth, with indication of substantial stability of nutritional status between ages two and five years. Differential tracking according to household wealth should be considered for planning early interventions for preventing malnutrition.

RESUMO OBJETIVO: Investigar a autocorrelação do crescimento linear e ganho de peso do nascimento até a infância considerando a distribuição de escores z de comprimento/estatura e peso por idade e de acordo com a riqueza domiciliar. MÉTODOS: Foram utilizados dados de 614 crianças do Estudo MINA-Brasil com medições antropométricas realizadas do nascimento até os cinco anos de idade. Escores z foram calculados para comprimento/estatura (HAZ) e peso (WAZ) seguindo padrões internacionais. A autocorrelação ou estabilidade da adequação do estado nutricional do nascimento à infância foi estimada por meio de modelos de regressão quantílica para HAZ e WAZ, separadamente, extraindo-se coeficientes e intervalos de confiança de 95% (IC95%) nos quantis 25, 50 e 75. Em uma análise de subgrupo, estimou-se a autocorrelação entre o nascimento até os dois anos de idade, e entre dois e cinco anos de idade. Para investigar disparidades na autocorrelação, termos de interação entre índices de riqueza familiar (ao nascer e aos cinco anos de idade) e escores z de tamanho do recém-nascido foram incluídos nos modelos. RESULTADOS: Os coeficientes de autocorrelação foram significantes e tiveram magnitude semelhante ao longo da distribuição dos índices antropométricos aos cinco anos de idade (HAZ, quantil 50: 0,23, IC95%: 0,11 a 0,35; WAZ, quantil 50: 0,31, IC95%: 0,19 a 0,43). Maior estabilidade do estado nutricional foi observada entre dois e cinco anos, com coeficientes acima de 0,82. Autocorrelação significantemente maior do crescimento linear foi observada entre as crianças de domicílios mais ricos, tanto ao nascer, nos limites inferiores da distribuição HAZ (quantil 25: 0,30, IC95%: 0,13 a 0,56) e durante a infância, em toda a distribuição HAZ aos cinco anos. Para o ganho de peso, observou-se uma autocorrelação mais forte nos limites superiores da distribuição do WAZ aos cinco anos de idade entre as crianças de domicílios mais ricos ao nascer (quantil 75: 0,59, IC95%: 0,35 a 0,83) e durante a infância (quantil 75: 0,54, IC95%: 0,15 a 0,93). CONCLUSÃO: Houve autocorrelação significante de HAZ e WAZ desde o nascimento, com indicação de substancial estabilidade do estado nutricional entre os dois e cinco anos de idade. A autocorrelação diferencial de acordo com a riqueza domiciliar deve ser considerada para o planejamento de intervenções precoces para prevenir a má nutrição.

Factors associated with incomplete vaccination and negative antibody test results for measles, mumps, and hepatitis A among children followed in the MINA-BRAZIL cohort

ABSTRACT Vaccination coverage has been dropping in Brazil and other countries. In addition, immune responses after vaccination may not be homogeneous, varying according to sociodemographic and clinical factors. Understanding the determinants of incomplete vaccination and negative antibody test results may contribute to the development of strategies to improve vaccination effectiveness. In this study, we aimed to investigate the frequency of vaccine adherence, factors associated with incomplete vaccination for measles, mumps, rubella (MMR) and hepatitis A, and factors associated with the seronegative test results for measles, mumps and hepatitis A at 2 years of age. This was a population-based cohort that addressed health conditions and mother/infant nutrition in Cruzeiro do Sul city, Brazil. Vaccination data were obtained from official certificates of immunization. The children underwent blood collection at the two-year-old follow-up visit; the samples were analyzed using commercially available kits to measure seropositivity for measles, mumps, and hepatitis A. We used modified Poisson regression models adjusted for covariates to identify factors associated with incomplete vaccination and negative serology after vaccination. Out of the 825 children included in the study, adherence to the vaccine was 90.6% for MMR, 76.7% for the MMRV (MMR + varicella), and 74.9% for the hepatitis A vaccine. For MMR, after the adjustment for covariates, factors associated with incomplete vaccination included: white-skinned mother; paid maternity leave; raising more than one child; lower number of antenatal consultations; and attending childcare. For hepatitis A, the factors included: white-skinned mother and not having a cohabiting partner. The factors with statistically significant association with a negative antibody test result included: receiving Bolsa Familia allowance for measles and mumps; incomplete vaccination for measles; and vitamin A deficiency for mumps. Strategies to improve the efficiency of vaccine programs are urgently needed. These include improvements in communication about vaccine safety and efficacy, and amplification of access to primary care facilities, prioritizing children exposed to the sociodemographic factors identified in this study. Additionally, sociodemographic factors and vitamin A deficiency may impact the immune responses to vaccines, leading to an increased risk of potentially severe and preventable diseases.

Clinically silent Plasmodium vivax infections in native Amazonians of northwestern Brazil: acquired immunity or low parasite virulence?

BACKGROUND: Malaria remains common among native Amazonians, challenging Brazil's elimination efforts. OBJECTIVES: We examined the epidemiology of malaria in riverine populations of the country's main hotspot - the upper Juruá Valley in Acre state, close to the Brazil-Peru border, where Plasmodium vivax accounts for > 80% of cases. METHODS: Participants (n = 262) from 10 villages along the Azul River were screened for malaria parasites by microscopy and genus-specific, cytochrome b (cytb) gene-based polymerase chain reaction. Positive samples were further tested with quantitative TaqMan assays targeting P. vivax- and P. falciparum-specific cytb domains. We used multiple logistic regression analysis to identify independent correlates of P. vivax infection. FINDINGS: Microscopy detected only one P. vivax and two P. falciparum infections. TaqMan assays detected 33 P. vivax infections (prevalence, 11.1%), 78.1% of which asymptomatic, with a median parasitaemia of 34/mL. Increasing age, male sex and use of insecticide-treated bed nets were significant predictors of elevated P. vivax malaria risk. Children and adults were similarly likely to remain asymptomatic once infected. MAIN CONCLUSIONS: Our findings are at odds with the hypothesis of age-related clinical immunity in native Amazonians. The low virulence of local parasites is suggested as an alternative explanation for subclinical infections in isolated populations.

Oficina educativa para profissionais da Atenção Primária à Saúde como estratégia para promover alimentação complementar saudável no Acre, Amazônia brasileira / Educational workshop for Primary Health Care professionals as a strategy to promote healthy complementary feeding in Acre, Brazilian Amazon

RESUMO A alimentação adequada e saudável é crucial para o desenvolvimento infantil, principalmente nos primeiros mil dias de vida. Sendo a alimentação não saudável um fator de risco modificável para doenças e desnutrição, ações que promovam as orientações do 'Guia alimentar para crianças brasileiras menores de 2 anos' são necessárias. O presente relato compartilha o processo de planejamento, construção, divulgação, oferecimento e avaliação de uma oficina virtual para profissionais da Atenção Primária à Saúde no Acre, Amazônia Ocidental brasileira, com destaque para os desafios encontrados e as lições aprendidas. A oficina contou com 170 inscritos e foi assíncrona para facilitar o acesso dos participantes diante da baixa disponibilidade de tempo e instabilidade do sinal de internet na região. O uso de diferentes ferramentas virtuais favoreceu o diálogo entre os participantes e as coordenadoras da oficina. Participantes relataram preferir vídeos curtos com animações, e os conteúdos considerados mais importantes abordaram avaliação antropométrica, processamento e classificação de alimentos e desafios da alimentação. Ressalta-se a importância das parcerias com secretarias de saúde para o adequado planejamento e divulgação da oficina, e da colaboração de pesquisadoras e profissionais da área para a definição e elaboração de conteúdo relevante.

ABSTRACT Adequate and healthy nutrition is crucial for child development, especially in the first 1,000 days of life. Since unhealthy eating is a modifiable risk factor for diseases and malnutrition, actions that promote the guidelines of the 'Food guide for Brazilian children under 2 years old' are necessary. This report shares the process of planning, building, disseminating, offering, and evaluating a virtual workshop for professionals in Primary Health Care in Acre, Western Brazilian Amazon, highlighting the challenges encountered and lessons learned. The workshop had 170 participants and was asynchronous to facilitate access for participants given the low availability of time and instability of the internet signal in the region. The use of different virtual tools favored dialogue between the participants and the workshop coordinators. Participants reported preferring short videos with animations, and the content considered most important addressed anthropometric assessment, food processing and classification, and food challenges. The importance of partnerships with health departments is highlighted for the adequate planning and dissemination of the workshop, and the collaboration of researchers and professionals in the field for the definition and elaboration of relevant content.