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1.
JMIR Public Health Surveill ; 10: e48060, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38592761

RESUMO

BACKGROUND: The decline in global child mortality is an important public health achievement, yet child mortality remains disproportionally high in many low-income countries like Guinea-Bissau. The persisting high mortality rates necessitate targeted research to identify vulnerable subgroups of children and formulate effective interventions. OBJECTIVE: This study aimed to discover subgroups of children at an elevated risk of mortality in the urban setting of Bissau, Guinea-Bissau, West Africa. By identifying these groups, we intend to provide a foundation for developing targeted health interventions and inform public health policy. METHODS: We used data from the health and demographic surveillance site, Bandim Health Project, covering 2003 to 2019. We identified baseline variables recorded before children reached the age of 6 weeks. The focus was on determining factors consistently linked with increased mortality up to the age of 3 years. Our multifaceted methodological approach incorporated spatial analysis for visualizing geographical variations in mortality risk, causally adjusted regression analysis to single out specific risk factors, and machine learning techniques for identifying clusters of multifactorial risk factors. To ensure robustness and validity, we divided the data set temporally, assessing the persistence of identified subgroups over different periods. The reassessment of mortality risk used the targeted maximum likelihood estimation (TMLE) method to achieve more robust causal modeling. RESULTS: We analyzed data from 21,005 children. The mortality risk (6 weeks to 3 years of age) was 5.2% (95% CI 4.8%-5.6%) for children born between 2003 and 2011, and 2.9% (95% CI 2.5%-3.3%) for children born between 2012 and 2016. Our findings revealed 3 distinct high-risk subgroups with notably higher mortality rates, children residing in a specific urban area (adjusted mortality risk difference of 3.4%, 95% CI 0.3%-6.5%), children born to mothers with no prenatal consultations (adjusted mortality risk difference of 5.8%, 95% CI 2.6%-8.9%), and children from polygamous families born during the dry season (adjusted mortality risk difference of 1.7%, 95% CI 0.4%-2.9%). These subgroups, though small, showed a consistent pattern of higher mortality risk over time. Common social and economic factors were linked to a larger share of the total child deaths. CONCLUSIONS: The study's results underscore the need for targeted interventions to address the specific risks faced by these identified high-risk subgroups. These interventions should be designed to work to complement broader public health strategies, creating a comprehensive approach to reducing child mortality. We suggest future research that focuses on developing, testing, and comparing targeted intervention strategies unraveling the proposed hypotheses found in this study. The ultimate aim is to optimize health outcomes for all children in high-mortality settings, leveraging a strategic mix of targeted and general health interventions to address the varied needs of different child subgroups.


Assuntos
Aprendizado de Máquina , Saúde Pública , Criança , Humanos , Lactente , Pré-Escolar , Guiné-Bissau/epidemiologia , Estudos de Coortes , Geografia
2.
BMJ Glob Health ; 9(2)2024 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-38350670

RESUMO

OBJECTIVE: To assess the effect of providing BCG and oral polio vaccine (OPV) at an early home visit after delivery. DESIGN: Cluster-randomised trial, randomising 92 geographically defined clusters 1:1 to intervention/control arms. SETTING: Bandim Health Project Health and Demographic Surveillance System, Guinea-Bissau. PARTICIPANTS: 2226 newborns enrolled between July 2016 and August 2019. INTERVENTIONS: In both arms, newborns received a home visit within 72 hours after birth. In intervention clusters (n=46), BCG and OPV were provided at the home visit. MAIN OUTCOME MEASURE: Rates of non-accidental mortality were compared in Cox proportional hazards models from (last of) day 1 or enrolment, until (first of) day 60 or registration of non-trial vaccines. RESULTS: A total of 35 deaths (intervention: 7, control: 28) were registered during the trial. Providing BCG and OPV reduced non-accidental early infant mortality by 59% (8-82%). The intervention also reduced non-accidental hospital admissions. The intervention had little impact on growth and BCG scarring and tended to increase the risk of consultations. CONCLUSIONS: The trial was stopped early due to lower-than-expected enrolment and event rates when 33% of the planned number of newborns had been enrolled. Despite the small size of the trial, the results support that early BCG and OPV vaccinations are beneficial and reduce early child mortality and morbidity. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT02504203).


Assuntos
Vacina BCG , Mortalidade Infantil , Lactente , Criança , Humanos , Recém-Nascido , Guiné-Bissau/epidemiologia , Japão , Vacinação , Vacina Antipólio Oral
3.
PLOS Glob Public Health ; 4(2): e0002901, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38349910

RESUMO

Facemasks have been employed to mitigate the spread of SARS-CoV-2. The community effect of providing cloth facemasks on COVID-19 morbidity and mortality is unknown. In a cluster randomised trial in urban Bissau, Guinea-Bissau, clusters (geographical areas with an average of 19 houses), were randomised to an intervention or control arm using computer-generated random numbers. Between 20 July 2020 and 22 January 2021, trial participants (aged 10+ years) living in intervention clusters (n = 90) received two 2-layer cloth facemasks, while facemasks were only distributed later in control clusters (n = 91). All participants received information on COVID-19 prevention. Trial participants were followed through a telephone interview for COVID-19-like illness (3+ symptoms), care seeking, and mortality for 4 months. End-of-study home visits ensured full mortality information and distribution of facemasks to the control group. Individual level information on outcomes by trial arm was compared in logistic regression models with generalised estimating equation-based correction for cluster. Facemasks use was mandated. Facemask use in public areas was assessed by direct observation. We enrolled 39,574 trial participants among whom 95% reported exposure to groups of >20 persons and 99% reported facemasks use, with no difference between trial arms. Observed use was substantially lower (~40%) with a 3%, 95%CI: 0-6% absolute difference between control and intervention clusters. Half of those wearing a facemask wore it correctly. Few participants (532, 1.6%) reported COVID-19-like illness; proportions did not differ by trial arm: Odds Ratio (OR) = 0.81, 95%CI: 0.57-1.15. 177 (0.6%) participants reported consultations and COVID-19-like illness (OR = 0.83, 95%CI: 0.56-1.24); 89 participants (0.2%) died (OR = 1.34, 95%CI: 0.89-2.02). Hence, though trial participants were exposed to many people, facemasks were mostly not worn or not worn correctly. Providing facemasks and messages about correct use did not substantially increase their use and had limited impact on morbidity and mortality. Trial registration: clinicaltrials.gov: NCT04471766.

4.
Hum Vaccin Immunother ; 19(3): 2288297, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38054431

RESUMO

Vaccines may alter the ability to combat infections unrelated to the target disease, i.e. have "nonspecific effects." The non-live Diphtheria-Tetanus-Pertussis vaccine (DTP) has been associated with increased child mortality, especially for females. In 2008, the DTP-containing Pentavalent vaccine replaced DTP vaccine in Guinea-Bissau. We investigate female relative to male mortality after Penta vaccination. In Guinea-Bissau, Bandim Health Project (BHP) registered children's vaccination and vital status at biannual village visits and provided vaccines. Among children Penta-vaccinated by BHP, we compared mortality of males and females in Cox proportional hazards models. Children aged 6 weeks to 8 months entered the analysis at the date of vaccination and were followed for up to 6 months. Between September 2008 and December 2017, 33,989 children aged 6 weeks to 8 months were under surveillance. Of these 12,753 (females: 6,363; males: 6,390) received Penta by the BHP and entered the study contributing with 19,667 observations. The mortality rate following Penta vaccination was 25.2 per 1,000 person years for females and 26.6 for males, resulting in an adjusted Female/Male mortality rate ratio of (F/M aMRR) 1.01 (0.82-1.25). The association between sex and mortality differed by timeliness of vaccination, F/M aMRR: 0.62 (0.41-0.93) for children vaccinated below median age, and F/M aMRR: 1.38 (0.90-2.13) for children vaccinated above median age. We did not find higher overall mortality in females than males after Penta vaccination. Our findings suggest that mortality differences between males and females following Penta vaccination may depend on timeliness of Penta vaccination.


Assuntos
Vacina contra Difteria, Tétano e Coqueluche , Vacinas Anti-Haemophilus , Vacinas contra Hepatite B , Feminino , Humanos , Lactente , Masculino , Mortalidade da Criança , Vacina contra Difteria, Tétano e Coqueluche/efeitos adversos , Vacinas Anti-Haemophilus/efeitos adversos , Vacinação , Vacinas contra Hepatite B/efeitos adversos , Vacinas Combinadas/efeitos adversos , Fatores Sexuais
5.
J Glob Health ; 13: 04086, 2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37590896

RESUMO

Background: Approximately 4.4 million children die peripartum annually, primarily in low- and middle-income countries. Accurate mortality tracking is essential to prioritising prevention efforts but is undermined by misclassification between stillbirths (SBs) and early neonatal deaths (ENNDs) in household surveys, which serve as key data sources. We explored and quantified associations between peripartum provider-mother interactions and misclassification of SBs and ENNDs in Guinea-Bissau. Methods: Using a case-control design, we followed up on women who had reported a SB or ENND in a retrospective household survey nested in the Bandim Health Project's Health and Demographic Surveillance Systems (HDSS). Using prospective HDSS registration as the reference standard, we linked the survey-reported deaths to the corresponding HDSS records and cross-tabulated SB/ENND classification to identify cases (discordant classification between survey and HDSS) and controls (concordant classification). We further interviewed cases and controls on peripartum provider-mother interactions and analysed data using descriptive statistics and logistic regressions. Results: We interviewed 278 women (cases: 63 (23%); controls: 215 (77%)). Most cases were SBs misclassified as ENNDs (n/N = 49/63 (78%)). Three-fourths of the interviewed women reported having received no updates on the progress of labour and baby's health intrapartum, and less than one-fourth inquired about this information. In comparison with births where women did inquire for information, misclassification was less likely when women did not inquire and recalled no doubts about progress of labour (odds ratio (OR) = 0.51; 95% confidence interval (CI) = 0.28-0.91), or baby's health (OR = 0.54; 95% CI = 0.30-0.97). Most women reported that service providers' death notifications lasted <5 minutes (cases: 23/27 (85%); controls: 61/71 (86%)), and most often encompassed neither events leading to the death (cases: 19/27 (70%); controls: 55/71 (77%)) nor causes of death (cases: 20/27 (74%); controls: 54/71 (76%)). Misclassification was more likely if communication lasted <1 compared to 1-4 minutes (OR = 1.83; 95% CI = 1.10-3.06) and if a formal service provider had informed the mother of the death compared to a family member (OR = 1.57; 95% CI = 1.04-2.36). Conclusions: Peripartum provider-mother interactions are limited in Guinea-Bissau and associated with birth outcome misclassifications in retrospective household surveys. In our study population, misclassification led to overestimated neonatal mortality.


Assuntos
Família , Morte Perinatal , Lactente , Criança , Recém-Nascido , Gravidez , Humanos , Feminino , Estudos de Casos e Controles , Estudos Retrospectivos , Guiné-Bissau/epidemiologia , Estudos Prospectivos , Natimorto
6.
Trop Med Int Health ; 28(7): 562-570, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37269131

RESUMO

OBJECTIVE: Child mortality and stillbirth rates (SBR) remain high in low-income countries but may be underestimated due to incomplete reporting of child deaths in retrospective pregnancy/birth histories. The aim of this study is to compare stillbirth and mortality estimates derived using two different methods: the method assuming full information and the prospective method. METHODS: Bandim Health Project's Health and Demographic Surveillance Systems (HDSS) follows women of reproductive age and children under five through routine home visits every 1, 2 or 6 months. Between 2012 and 2020, we estimated and compared early neonatal (ENMR, <7 days), neonatal (NMR, <28 days), and infant mortality (IMR, <1 year) per 1000 live births and SBR per 1000 births. Risk time for children born to registered women was calculated from birth (the method assuming full information) versus date of first observation in the HDSS (the prospective method), either at birth (for pregnancy registration) or registration. Rates were calculated using the Kaplan-Meier estimator and compared in generalised linear models allowing for within-child correlation obtaining relative risks (RR). RESULTS: We registered and followed 29,413 infants (1380 deaths; 1459 stillbirths) prospectively. An additional 164 infant deaths and 129 stillbirths were registered retrospectively and included in the method assuming full information. The ENMR was 24.5 (95%CI: 22.6-26.4) for the method assuming full information and 25.8 (23.7-27.8) for the prospective method, RR = 0.96 (0.93-0.99). Differences were smaller for the NMRs and IMRs. For SBRs, the estimates were 53.5 (50.9-56.0) and 58.6 (55.7-61.5); RR = 0.91 (0.90-0.93). The difference between methods became more pronounced when the analysis was limited to areas visited every 6 months: RR for ENMR: 0.91 (0.86-0.96) and RR for SBR: 0.85 (0.83-0.87). CONCLUSIONS: Assuming full information underestimates SBR and ENMR. Accounting for omissions of stillbirths and early neonatal deaths may lead to more accurate estimates and improved ability to monitor mortality.


Assuntos
Mortalidade Infantil , Natimorto , Lactente , Recém-Nascido , Gravidez , Feminino , Humanos , Natimorto/epidemiologia , Estudos Retrospectivos , Mortalidade da Criança , Risco
7.
Int J Infect Dis ; 134: 23-30, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37182547

RESUMO

OBJECTIVES: Campaigns with measles vaccine (C-MV) are conducted to eradicate measles, but prior studies indicate that MV reduces non-measles mortality and hospital admissions too. We hypothesized that C-MV reduces death/hospital admission by 30%. METHODS: Between 2016-2019, we conducted a non-blinded cluster-randomized trial randomizing village clusters in rural Guinea-Bissau to a C-MV targeting children aged 9-59 months. In Cox proportional hazards models, we assessed the effect of C-MV, obtaining hazard ratios (HR) for the composite outcome (death/hospital admission). We also examined potential effect modifiers. RESULTS: Among 18,411 children (9636 in 111 intervention clusters/8775 in 110 control clusters), 379 events occurred (208 intervention/171 control) during a median follow-up period of 22 months. C-MV did not reduce the composite outcome (HR 1.12, 95% confidence interval 0.88-1.41). Mortality among enrolled children (5.3 intervention and 4.6 control, per 1000 person-years) was approximately half the pre-trial mortality rate (11.1 intervention and 8.9 control, per 1000 person-years). Neither planned nor explorative analyses of potential effect modifiers explained the contrasting results to prior studies. CONCLUSION: C-MV did not reduce overall mortality or hospital admission. This might be explained by changes in disease patterns, baseline differences in health status, and/or modifying effects of other campaigns during follow-up.


Assuntos
Vacina contra Sarampo , Sarampo , Humanos , Criança , Lactente , Guiné-Bissau/epidemiologia , Esquemas de Imunização , Sarampo/prevenção & controle , Hospitais
8.
Environ Res ; 228: 115784, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-37011795

RESUMO

BACKGROUND: Knowledge about PFAS exposure in Africa is limited. We have previously detected six types of PFAS in the serum of infants from Guinea-Bissau, West Africa. The aim of this study was to identify predictors of the infant serum-PFAS concentrations. METHODS: This cross-sectional study was based on a subset of data from a randomized controlled trial of early measles vaccination performed in 2012-2015 in three rural regions of Guinea-Bissau. Blood samples were obtained from 237 children aged 4-to-7 months, and six types of PFAS were quantified in serum. Location of residence was recorded, and information about predictors related to socioeconomic status as well as maternal and child characteristics were obtained through structured interviews with the mothers through routine surveillance. Associations between potential predictors and infant serum-PFAS concentrations were examined in linear regression models while adjusting for potential confounding and mediating factors as identified in a directed acyclic graph. RESULTS: Infants from the Cacheu region had the lowest concentrations of perfluorooctanoic acid (PFOA), while infants from the Oio region had the lowest concentrations of all other PFAS. Compared to infants from Oio, infant serum-perfluorooctane sulfonic acid (PFOS) concentrations were 94.1% (95% CI: 52.4, 147.1%) and 81.9% (95% CI: 45.7, 127.1%) higher in Cacheu and Biombo, respectively. Higher maternal age and lower parity were associated with slightly higher child-serum perfluorohexane sulfonic acid (PFHxS) concentrations, while infants with higher socioeconomic status and infants breastfed without supplementary solid foods at inclusion had higher average concentrations of most PFAS, although the confidence intervals were wide and overlapped zero. DISCUSSION: Location of residence was the most important determinant of serum-PFAS concentrations among Guinea-Bissau infants, indicating a potential role of diet as affected by the global spread of PFAS, but future studies should explore reasons for the regional differences in PFAS exposure.


Assuntos
Ácidos Alcanossulfônicos , Poluentes Ambientais , Fluorocarbonos , Gravidez , Feminino , Humanos , Lactente , Exposição Ambiental , Guiné-Bissau/epidemiologia , Estudos Transversais , África Ocidental
10.
BMJ Open ; 12(11): e063872, 2022 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-36410811

RESUMO

INTRODUCTION: Increasing evidence suggests that the BCG vaccine has non-specific effects, altering the susceptibility to non-tuberculous infections. Thus, early BCG vaccination may reduce mortality. BCG is recommended at birth but is often delayed. Vaccination opportunities are missed due to multidose vials not being opened for a few children. We will assess the effect of making BCG available at the first health-facility contact on early infant mortality and morbidity in a rural setting in Guinea-Bissau. METHODS AND ANALYSIS: In a cluster-randomised crossover trial, we randomise 23 health centres to two different treatment groups. In half of the health centres, BCG is provided as per current practice; in the remaining health centres, we make BCG available everyday to allow opening a vial of BCG if there is just one eligible child present. The randomisation of centres will be crossed over after 12 months and enrolment will continue for another 12 months.We will use logistic regression models with adjustment for village to assess the effect of making BCG available at the first health-facility contact. The main outcome is non-accidental mortality between day 1 and day 42 after birth. We will adjust for sex, health centre, period (before/after crossover) and level of surveillance (level 1 or level 2). Further analyses include assessment of the effect on hospital admission and a cost-effectiveness evaluation. ETHICS AND DISSEMINATION: If BCG vaccination reduces early infant mortality, missed opportunities and delays of vaccinations expose infants in several low-income countries to unnecessary excess mortality risk. The present trial will provide information on the effect of implementing a feasible intervention, where all children receive BCG at their first health-facility contact. Consent is obtained from all pregnant women registered as part of the trial. The results of the study will be published and communicated to the National Institute of Public Health in Guinea-Bissau. TRIAL REGISTRATION NUMBER: NCT04658680; Clinicaltrials.gov.


Assuntos
Vacina BCG , Mortalidade Infantil , Gravidez , Lactente , Recém-Nascido , Criança , Humanos , Feminino , Vacinação/métodos , Instalações de Saúde , População Rural , Ensaios Clínicos Controlados Aleatórios como Assunto
11.
Front Microbiol ; 13: 1016220, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36386704

RESUMO

After the eradication of polio infection, the plan is to phase-out the live-attenuated oral polio vaccine (OPV). Considering the protective non-specific effects (NSE) of OPV on unrelated pathogens, the withdrawal may impact child health negatively. Within a cluster-randomized trial, we carried out 16S rRNA deep sequencing analysis of fecal and nasopharyngeal microbial content of Bissau-Guinean infants aged 4-8 months, before and after 2 months of OPV revaccination (revaccinated infants = 47) vs. no OPV revaccination (control infants = 47). The aim was to address changes in the gut and upper respiratory bacterial microbiotas due to revaccination. Alpha-diversity for both microbiotas increased similarly over time in OPV-revaccinated infants and controls, whereas greater changes over time in the bacterial composition of gut (p adjusted < 0.001) and upper respiratory microbiotas (p adjusted = 0.018) were observed in the former. Taxonomic analysis of gut bacterial microbiota revealed a decrease over time in the median proportion of Bifidobacterium longum for all infants (25-14.3%, p = 0.0006 in OPV-revaccinated infants and 25.3-11.6%, p = 0.01 in controls), compatible with the reported weaning. Also, it showed a restricted increase in the median proportion of Prevotella_9 genus in controls (1.4-7.1%, p = 0.02), whereas in OPV revaccinated infants an increase over time in Prevotellaceae family (7.2-17.4%, p = 0.005) together with a reduction in median proportion of potentially pathogenic/opportunistic genera such as Escherichia/Shigella (5.8-3.4%, p = 0.01) were observed. Taxonomic analysis of upper respiratory bacterial microbiota revealed an increase over time in median proportions of potentially pathogenic/opportunistic genera in controls, such as Streptococcus (2.9-11.8%, p = 0.001 and Hemophilus (11.3-20.5%, p = 0.03), not observed in OPV revaccinated infants. In conclusion, OPV revaccination was associated with a healthier microbiome composition 2 months after revaccination, based on a more abundant and diversified bacterial community of Prevotellaceae and fewer pathogenic/opportunistic organisms. Further information on species-level differentiation and functional analysis of microbiome content are warranted to elucidate the impact of OPV-associated changes in bacterial microbiota on child health.

12.
Open Forum Infect Dis ; 9(9): ofac470, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36193229

RESUMO

Background: Oral polio vaccine (OPV) may improve resistance to non-polio-infections. We tested whether OPV reduced the risk of illness and mortality before coronavirus disease 2019 (COVID-19) vaccines were available. Methods: During the early COVID-19 pandemic, houses in urban Guinea-Bissau were randomized 1:1 to intervention or control. Residents aged 50+ years were invited to participate. Participants received bivalent OPV (single dose) or nothing. Rates of mortality, admissions, and consultation for infections (primary composite outcome) during 6 months of follow-up were compared in Cox proportional hazards models adjusted for age and residential area. Secondary outcomes included mortality, admissions, consultations, and symptoms of infection. Results: We followed 3726 participants (OPV, 1580; control, 2146) and registered 66 deaths, 97 admissions, and 298 consultations for infections. OPV did not reduce the risk of the composite outcome overall (hazard ratio [HR] = 0.97; 95% confidence interval [CI], .79-1.18). OPV reduced the risk in males (HR = 0.71; 95% CI, .51-.98) but not in females (HR = 1.18; 95% CI, .91-1.52) (P for same effect = .02). OPV also reduced the risk in Bacillus Calmette-Guérin scar-positive (HR = 0.70; 95% CI, .49-.99) but not in scar-negative participants (HR = 1.13; 95% CI, .89-1.45) (P = .03). OPV had no overall significant effect on mortality (HR = 0.96; 95% CI, .59-1.55), admissions (HR = 0.76; 95% CI, .49-1.17) or recorded consultations (HR = 0.99; 95% CI, .79-1.25), but the OPV group reported more episodes with symptoms of infection (6050 episodes; HR = 1.10 [95% CI, 1.03-1.17]). Conclusions: In line with previous studies, OPV had beneficial nonspecific effects in males.

13.
Open Forum Infect Dis ; 9(8): ofac340, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35937644

RESUMO

Background: The live vaccines bacille Calmette-Guérin (BCG) and measles vaccine have beneficial nonspecific effects (NSEs) reducing mortality, more than can be explained by prevention of tuberculosis or measles infection. Live oral polio vaccine (OPV) will be stopped after polio eradication; we therefore reviewed the potential NSEs of OPV. Methods: OPV has been provided in 3 contexts: (1) coadministration of OPV and diphtheria-tetanus-pertussis (DTP) vaccine at 6, 10, and 14 weeks of age; (2) at birth (OPV0) with BCG; and (3) in OPV campaigns (C-OPVs) initiated to eradicate polio infection. We searched PubMed and Embase for studies of OPV with mortality as an outcome. We used meta-analysis to obtain the combined relative risk (RR) of mortality associated with different uses of OPV. Results: First, in natural experiments when DTP was missing, OPV-only compared with DTP + OPV was associated with 3-fold lower mortality in community studies (RR, 0.33 [95% confidence interval {CI}, .14-.75]) and a hospital study (RR, 0.29 [95% CI, .11-.77]). Conversely, when OPV was missing, DTP-only was associated with 3-fold higher mortality than DTP + OPV (RR, 3.23 [95% CI, 1.27-8.21]). Second, in a randomized controlled trial, BCG + OPV0 vs BCG + no OPV0 was associated with 32% (95% CI, 0-55%) lower infant mortality. Beneficial NSEs were stronger with early use of OPV0. Third, in 5 population-based studies from Guinea-Bissau and Bangladesh, the mortality rate was 24% (95% CI, 17%-31%) lower after C-OPVs than before C-OPVs. Conclusions: There have been few clinical polio cases reported in this century, and no confounding factors or bias would explain all these patterns. The only consistent interpretation is that OPV has beneficial NSEs, reducing nonpolio child mortality.

14.
EClinicalMedicine ; 49: 101467, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35747181

RESUMO

Background: Early 2-dose measles vaccine (MV) at 4 and 9 months of age vs. the WHO strategy of MV at 9 months of age reduced all-cause child mortality in a previous trial. We aimed to test two hypotheses: 1) a 2-dose strategy reduces child mortality between 4 and 60 months of age by 30%; 2) receiving early MV at 4 months in the presence versus absence of maternal measles antibodies (MatAb) reduces child mortality by 35%. Methods: Single-centre open-label community-based randomised controlled trial in Guinea-Bissau, with 2:1 block-randomisation by sex to a 2-dose (4 + 9 months) vs. 1-dose (9 months) MV strategy. Healthy children were eligible 4 weeks after the 3rd diphtheria-tetanus-pertussis-containing vaccine. Before randomisation a blood sample was collected to determine MatAb level. The primary outcome was all-cause mortality. Hazard ratios (HR) were derived from Cox regression in the per protocol population. We tested for interactions with national campaigns with oral polio vaccine (C-OPV). Trial registration: NCT01486355. Findings: Between August 2011-April 17th 2015, 6,636 children were enroled, 6,598[n2-dose=4,397; n1-dose=2,201] were included in the analysis of the primary outcome, The HR(2-dose/1-dose) between 4 and 60 months was 1.38 (95%CI: 0.92-2.06) [deaths: n2-dose=90; n1-dose=33]. Before the 9-month MV and the HR(1-dose/no dose) was 0.94 (0.45-1.96) [deaths: n2-dose=21; n1-dose=11]. The HR(2-dose/1-dose) was 0.81 (0.29-2.22) for children, who received no C-OPV [deaths/children: n2-dose=10/2,801; n1-dose=6/1,365], and 4.73 (1.44-15.6) for children, who received C-OPV before and after enrolment (p for interaction=0.027) [deaths/children: n2-dose=27/1,602; n1-dose=3/837]. In the 2-dose group receiving early MV at 4 months, mortality was 50% (20-68%) lower for those vaccinated in the presence of MatAb vs. the absence of MatAb [deaths/children: nMatAb=51/3,132; nnoMatAb=31/1,028]. Interpretation: The main result contrasts with previous findings but may, though based on a small number of events, be explained by frequent OPV campaigns that reduced the mortality rate, but apparently interacted negatively with early MV. The beneficial non-specific effects of MV in the presence of MatAb should be investigated further. Funding: ERC, Danish National Research Foundation, the Danish Council for Development Research, Ministry of Foreign Affairs, Novo Nordisk Foundation, European Union and the Lundbeck Foundation.

15.
Int J Epidemiol ; 51(5): 1522-1532, 2022 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-35640034

RESUMO

BACKGROUND: Malnutrition is considered an important contributing factor to child mortality, and the mid-upper arm circumference (MUAC) is regarded as one of the better anthropometric predictors of child mortality. We explored whether the decline in child mortality over recent decades could be explained by changes in children's MUAC. METHODS: This prospective study analysed individual-level data from 47 731 children from the capital of Guinea-Bissau followed from 3 months until 36 months of age over 2003 to 2016. We used standardization to compare the mortality rate as if only the MUAC distribution had changed between an early period (2003-05) and a late period (2014-16). We adjusted the analyses for age, sex, socioeconomic-related possessions and maternal education. RESULTS: A total of 949 deaths were included in the analysis. The adjusted mortality rate was 18.9 [95% confidence interval (CI) 14.3-23.3] deaths per 1000 person-years (pyrs) in the early period and declined to 4.4 (95% CI 2.9-6.0) deaths per 1000 pyrs in the late period, a 77% (95% CI 71-83%) reduction in the mortality rate. At all calendar years, the MUAC distribution in the population was close to the WHO reference population. MUAC below -1 z-score was associated with increased child mortality. The change in MUAC distribution from the early period to the late period (in the early period mortality standardization) corresponded to 1.5 (95% CI 1.0-2.2) fewer deaths per 1000 pyrs, equivalent to 11% (95% CI 7-14%) of the observed change in child mortality. CONCLUSIONS: From 2003 to 2016, child mortality in urban Guinea-Bissau declined considerably but, though a low MUAC was associated with increased mortality, changes in the MUAC distribution in the population explained little of the decline. Understanding the driving factors of child mortality decline can help scope tomorrow's interventions.


Assuntos
Braço , Estado Nutricional , Antropometria , Braço/anatomia & histologia , Criança , Guiné-Bissau/epidemiologia , Humanos , Lactente , Estudos Prospectivos
16.
Trials ; 23(1): 349, 2022 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-35461287

RESUMO

BACKGROUND: Measles vaccination coverage in Guinea-Bissau is low; fewer than 80% of children are currently measles vaccinated before 12 months of age. The low coverage hampers control of measles. Furthermore, accumulating evidence indicates that measles vaccine has beneficial non-specific effects, strengthening the resistance towards other infections. Thus, even if children are not exposed to measles virus, measles-unvaccinated children may be worse off. To increase vaccination coverage, WHO recommends that contacts with the health system for mild illness are utilised to vaccinate. Currently, in Guinea-Bissau, curative health system contacts are not utilised. METHODS: Bandim Health Project registers out-patient consultations and admissions at the paediatric ward of the National Hospital in Guinea-Bissau. Measles-unvaccinated children aged 9-59 months consulting for milder illness or being discharged from the paediatric ward will be invited to participate in a randomised trial. Among 5400 children, randomised 1:1 to receive standard measles vaccine or a saline placebo, we will test the hypothesis that providing a measles vaccine at discharge lowers the risk of admission/mortality (composite outcome) during the subsequent 6 months by 25%. All enrolled children are followed through the Bandim Health Project registration system and through telephone follow-up. The first 1000 enrolled children are furthermore followed through interviews on days 2, 4, 7 and 14 after enrolment. DISCUSSION: Utilising missed vaccination opportunities can increase vaccination coverage and may improve child health. However, without further evidence for the safety and potential benefits of measles vaccination, these curative contacts are unlikely to be used for vaccination in Guinea-Bissau. TRIAL REGISTRATION: www. CLINICALTRIALS: gov NCT04220671 . Registered on 5 January 2020.


Assuntos
Vacina contra Sarampo , Sarampo , Criança , Guiné-Bissau , Hospitais , Humanos , Lactente , Sarampo/prevenção & controle , Vacina contra Sarampo/efeitos adversos , Vacinação
17.
BMC Pregnancy Childbirth ; 22(1): 292, 2022 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35387593

RESUMO

BACKGROUND: Globally, approximately 6,700 newborn deaths and 5,400 stillbirths occur daily. The true figure is likely higher, with under reporting of adverse pregnancy outcomes (APOs) noted. Decision-making in health is influenced by various factors, including one's social networks. We sought to understand APOs disclosure within social networks in Uganda, Ghana, Guinea-Bissau and Bangladesh and how this could improve formal reporting of APOs in surveys.  METHODS: A qualitative, exploratory multi-country study was conducted within four health and demographic surveillance system sites. 16 focus group discussions were held with 147 women aged 15-49 years, who had participated in a recent household survey. Thematic analysis, with both deductive and inductive elements, using three pre-defined themes of Sender, Message and Receiver was done using NVivo software. RESULTS: Disclosure of APOs was a community concern, with news often shared with people around the bereaved for different reasons, including making sense of what happened and decision-making roles of receivers. Social networks responded with comfort, providing emotional, in-kind and financial support. Key decision makers included men, spiritual and traditional leaders. Non-disclosure was usually to avoid rumors in cases of induced abortions, or after a previous bad experience with health workers, who were frequently excluded from disclosure, except for instances where a woman sought advice on APOs. CONCLUSIONS: Communities must understand why they should report APOs and to whom. Efforts to improve APOs reporting could be guided by diffusion of innovation theory, for instance for community entry and sensitization before the survey, since it highlights how information can be disseminated through community role models. In this case, these gatekeepers we identified could promote reporting of APOs. The stage at which a person is in decision-making, what kind of adopter they are and their take on the benefits and other attributes of reporting are important. In moving beyond survey reporting to getting better routine data, the theory would be applicable too. Health workers should demonstrate a more comforting and supportive response to APOs as the social networks do, which could encourage more bereaved women to inform them and seek care.


Assuntos
Revelação , Resultado da Gravidez , Adolescente , Adulto , Feminino , Humanos , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Gravidez , Pesquisa Qualitativa , Rede Social , Inquéritos e Questionários , Adulto Jovem
18.
Vaccines (Basel) ; 9(12)2021 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-34960198

RESUMO

The recommendation to provide inactivated influenza vaccine (IIV) to pregnant women is based on observed protection against influenza-related morbidity in mother and infant. Non-live vaccines may have non-specific effects (NSEs), increasing the risk of non-targeted infections in females. We reviewed the evidence from available randomised controlled trials (RCTs) of IIV to pregnant women, to assess whether IIV may have NSEs. Four RCTs, all conducted in low- and middle-income settings, were identified. We extracted information on all-cause and infectious mortality and adverse events in women and their infants. We conducted meta-analyses providing risk ratios (RR). The meta-analysis for maternal all-cause mortality provided a RR of 1.48 (95% CI = 0.52-4.16). The estimates for miscarriage/stillbirth and infant all-cause mortality up to 6 months of age were 1.06 (0.78-1.44) and 1.11 (0.87-1.41), respectively. IIV was associated with a higher risk of non-influenza infectious adverse events, with meta-estimates of 2.01 (1.15-3.50) in women and 1.36 (1.12-1.67) in infants up to 6 months of age. Thus, following a pattern seen for other non-live vaccines, IIV was associated with a higher risk of non-influenza infectious adverse events. To ensure that scarce resources are used well, and no harm is inflicted, further RCTs are warranted.

19.
BMJ Glob Health ; 6(8)2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34344667

RESUMO

OBJECTIVE: BCG vaccination is frequently delayed in low-income countries. Restrictive vial-opening policies, where a vial of BCG vaccine is not opened for few children, are a major reason for delay. During delays, children are unprotected against tuberculosis (TB) and deprived of non-specific effects of BCG. We assessed the potential effect and cost-effectiveness of disregarding the restrictive vial-opening policy, on TB and all-cause mortality, in children aged 0-4 years in Guinea-Bissau. METHODS: Using static mathematical models, we estimated the absolute and percentage change in TB and all-cause deaths, in children aged 0-4 years, between the current BCG vaccine restrictive-opening policy scenario, and a non-restrictive policy scenario where all children were vaccinated in the first health-facility contact. Incremental cost-effectiveness was estimated by integration of vaccine and treatment costs. FINDINGS: Disregarding the restrictive BCG vial-opening policy was estimated to reduce TB deaths by 11.0% (95% uncertainty range (UR):0.5%-28.8%), corresponding to 4 (UR:0-15) TB deaths averted per birth cohort in Guinea-Bissau, resulting in incremental cost-effectiveness of US$ 911 per discounted life-year gained (LYG) (UR:145-9142). For all-cause deaths, the estimated reduction was 8.1% (UR: 3.3%-12.7%) corresponding to 392 (UR:158-624) fewer all-cause deaths and an incremental cost-effectiveness of US$ 9 (UR:5-23) per discounted LYG. CONCLUSIONS: Disregarding the restrictive BCG vial-opening policy was associated with reductions in TB deaths and all-cause deaths and low cost-effectiveness ratios. Our results suggest that it would be cost-effective to disregard the restrictive vial-opening policy. Other settings with similar practice are also likely to gain from disregarding this policy.


Assuntos
Vacina BCG , Tuberculose , Criança , Análise Custo-Benefício , Guiné-Bissau/epidemiologia , Humanos , Políticas , Tuberculose/prevenção & controle
20.
BMC Public Health ; 21(1): 1164, 2021 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-34140010

RESUMO

BACKGROUND: Low birthweight (LBW) is associated with higher mortality and morbidity, but there is limited data on the prevalence of LBW in rural Africa, where many births occur at home. The Bacillus Calmette-Guérin (BCG) vaccine has non-specific effects. Studies suggest that maternal BCG-vaccination may affect the health of the child. METHODS: The present study is nested within a randomised trial in rural Guinea-Bissau: Pregnancies were registered at two-monthly village visits, where information on BCG scar status and other background factors were obtained. Children were enrolled in the trial and weighed at home within 72 h after birth. In this prospective observational study, we assessed factors associated with adverse pregnancy outcomes and birthweight in binomial and linear regression models. RESULTS: Among 1320 women who had their BCG scar status assessed, 848 (64%) had a scar, 472 (36%) had no scar. The risk of adverse pregnancy outcomes (miscarriages, stillbirths, early neonatal deaths) tended to be higher among BCG scar-negative women (13%) than among women with a BCG scar (10%), adjusted prevalence ratio = 1.29 (0.99-1.68). Birthweight was assessed for 628 (50%) of the 1232 live born children. The mean birthweight was 2.89 kg (SD 0.43) and the proportion of LBW children was 17% (104/628). Sex, twinning, region of birth, maternal age, maternal mid-upper arm circumference (MUAC), antenatal consultations, parity and possession of a mobile phone were associated with birthweight, while maternal BCG scar status was not. CONCLUSIONS: This study provides the first birthweight data for home-born children in rural Guinea-Bissau, with a mean birthweight of 2.89 kg (SD 0.43) and a LBW prevalence of 17%. We found a tendency for higher risk of adverse pregnancy outcomes among BCG scar-negative women. Birthweight was similar in children of mothers with and without BCG scar.


Assuntos
Vacina BCG , Resultado da Gravidez , África , Peso ao Nascer , Criança , Feminino , Guiné-Bissau/epidemiologia , Humanos , Recém-Nascido , Gravidez , Resultado da Gravidez/epidemiologia
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