Gates Open Research最新文献

There is a scarcity of prospective longitudinal research targeted at early postnatal life which maps developmental pathways of early-stage processing and brain specialisation in the context of early adversity. Follow up from infancy into the one-five year age range is key, as it constitutes a critical gap between infant and early childhood studies. Availability of portable neuroimaging (functional near infrared spectroscopy (fNIRS) and electroencephalography (EEG)) has enabled access to rural settings increasing the diversity of our sampling and broadening developmental research to include previously underrepresented ethnic-racial and geographical groups in low- and middle- income countries (LMICs). The primary objective of the Brain Imaging for Global Health (BRIGHT) project was to establish brain function - using longitudinal data from mother - for-age reference curves infant dyads living in the UK and rural Gambia and investigate the association between context-associated moderators and developmental trajectories across the first two years of life in The Gambia. In total, 265 participating families were seen during pregnancy, at 7-14 days, 1-, 5-, 8-, 12-, 18- and 24-months post-partum. An additional visit is now underway at 3-5 years to assess pre-school outcomes. The majority of our Gambian cohort live in poverty, but while resource-poor in many factors they commonly experience a rich and beneficial family and caregiving context with multigenerational care and a close-knit supportive community. Understanding the impact of different factors at play in such an environment ( i.e., detrimental undernutrition versus beneficial multigenerational family support) will (i) improve the representativeness of models of general cognitive developmental pathways from birth, (ii) identify causal pathways of altered trajectories associated with early adversity at both individual and group level, and (iii) identify the context-associated moderators ( i.e. social context) that protect development despite the presence of poverty-associated challenges. This will in turn contribute to the development of targeted interventions.

Background: Previous studies of infants born to HIV-positive mothers have linked HIV exposure to poor outcomes from gastrointestinal and respiratory illnesses, and to overall increased mortality rates. The mechanism behind this is unknown, but it is possible that differences in the nasopharyngeal (NP) microbiome between infants who are HIV-unexposed or HIV-exposed could play a role in perpetuating some outcomes.

Methods: We conducted a longitudinal analysis of 170 NP swabs of healthy infants who are HIV-exposed (n=10) infants and their HIV(+) mothers, and infants who are HIV-unexposed, uninfected (HUU; n=10) .and their HIV(-) mothers. These swabs were identified from a sample library collected in Lusaka, Zambia between 2015 and 2016. Using 16S rRNA gene sequencing, we characterized the maturation of the microbiome over the first 14 weeks of life to determine what quantifiable differences exist between HIV-exposed and HUU infants, and what patterns are reflected in the mothers' NP microbiomes.

Results: In both HIV-exposed and HUU infants, Staphylococcus and Corynebacterium began as primary colonizers of the NP microbiome but were in time replaced by Dolosigranulum, Streptococcus, Moraxella and Haemophilus. When evaluating the interaction between HIV exposure status and time of sampling among infants, the microbe Staphylococcus haemolyticus showed a distinctive high association with HIV exposure at birth. When comparing infants to their mothers with paired analyses, HIV-exposed infants' NP microbiome composition was only slightly different from their HIV(+) mothers at birth or 14 weeks, including in their carriage of S. pneumoniae, H. influenzae, and S. haemolyticus.

Conclusions: Our analyses indicate that the HIV-exposed infants in our study exhibit subtle differences in the NP microbial composition throughout the sampling interval. Given our results and the sampling limitations of our study, we believe that further research must be conducted in order to confidently understand the relationship between HIV exposure and infants' NP microbiomes.

Background: Calcium intake is below recommendations in several parts of the world. Improving calcium intake has benefits not only for bone health but also helps to prevent pregnancy hypertension disorders. Calcium concentration of tap water is usually low The aim of the present study was to determine the maximum amount of calcium that can be added to tap water while complying with drinking water Argentine regulations.

Methods: Tap water samples were collected from the Province of Buenos Aires (Argentina). Physicochemical properties and saturation index were measured. Different incremental concentrations of calcium chloride were added to the experimental aliquots.

Results: Baseline water had a mean calcium concentration of 22.00 ± 2.54 mg/L, water hardness of 89.9 ± 6.4 mg/L CaCO ₃, and a saturation index of -1.50 ± 0.11. After the addition of 0.4554 ± 0.0071 g of salt, water hard-ness reached 355.0 ± 7.1 mg/L CaCO ₃, a calcium concentration of 140.50 ± 2.12 mg/L, and a saturation index -0.53 ± 0.02.

Conclusions: This study shows that at laboratory level it is feasible to increase calcium concentration of drinking water by adding calcium chloride while complying with national standards. Calcium concentration of drinking tap water could be evaluated and minimum calcium concentration of tap water regulated so as to improve calcium intake in populations with low calcium intake.

Background: Recent trials have confirmed the effectiveness of promising dengue control technologies - two vaccines and Wolbachia. These would generally be applied at the municipal level. To help local officials decide which, if any, control strategy to implement, they need affordable, timely, and accurate data on dengue burden. Building on our previous work in Mexico, Indonesia, and Thailand, we developed a streamlined prospective method to estimate dengue burden at the municipal level quickly, accurately, and efficiently.

Methods: The method entails enrolling and repeatedly interviewing 100 patients with laboratory-confirmed dengue. They will be selected after screening and testing about 1,000 patients with clinical dengue. The method will capture both acute and chronic effects relating to disease, economic burden, and psychological impacts (presenteeism). The total time requirements are 1.5 years, comprised of 0.25 years for planning and approvals, 1 year for data collection (a full dengue cycle), and 0 .25 years for data cleaning and analysis. A collaboration with municipal and academic colleagues in the city of Semarang, Central Java, Indonesia shows how the method could be readily applied in Indonesia's eighth largest city (population 1.8 million).

Conclusions: Many surveillance studies gather only information on numbers of cases. This proposed method will provide a comprehensive picture of the dengue burden to the health system, payers, and households at the local level.

Background: Maternal and perinatal health is often directly and indirectly affected during infectious disease epidemics. Yet, a lack of evidence on epidemics' impact on women and their offspring delays informed decision-making for healthcare providers, pregnant women, women in the post-pregnancy period and policy-makers. To rapidly generate evidence in these circumstances, we aim to develop a Core Outcome Set (COS) for maternal and perinatal health research and surveillance in light of emerging and ongoing epidemic threats.

Methods: We will conduct a Systematic Review and a four-stage modified Delphi expert consensus. The systematic literature will aim to inform experts on outcomes reported in maternal and perinatal research and surveillance during previous epidemics. The expert consensus will involve two individual, anonymous online surveys to rate outcomes' importance and suggest new ones, one virtual meeting to discuss disagreements, and one in-person meeting to agree on the final COS, outcomes definitions and measurement methods. Four panels will be established to participate in the modified Delphi with expertise in (a) maternal and perinatal health, (b) neonatal health, (c) public health and emergency response, and (d) representation of civil society. We will recruit at least 20 international experts for each stakeholder group, with diverse backgrounds and gender, professional, and geographic balance. Only highly-rated outcomes (with at least 80% of ratings being 7-9 on a 9-point Likert scale) and no more than 10% of low ratings (1-3) will be included in the final COS.

Conclusions: Implementing this COS in future maternal and perinatal research and surveillance, especially in the context of emerging and ongoing epidemic threats, will facilitate the rapid and systematic generation of evidence. It will also enhance the ability of policy-makers, healthcare providers, pregnant women and women in the post-pregnancy period and their families to make well-informed choices in challenging circumstances.

Background: The prevalence of contraception among married women, evaluated at 23%, is low in Cameroon. Maternal death rates, estimated at 782 deaths per 100,000 live births, are very worrying. The National Strategic Plan for Reproductive, Maternal, Newborn and Child Health (2015-2020) and the Health Sector Strategy (2016-2027) focuses on increasing modern contraceptive prevalence as a means to reduce maternal death. This paper identifies women's bargaining power as a factor that may stimulate contraceptive use. The objective of this study is to analyze the association between women's bargaining power within couples and modern contraceptive use.

Methods: The data used come from the fifth Demographic and Health Survey (DHS) conducted in 2018. Women's bargaining power within couple is measured by a Woman Bargaining Power Composite Index (WBPCI) built through a multiple correspondence analysis. The logistic regression model was used to analyze the relationship between WBPCI and modern contraceptive use.

Results: The results of the descriptive statistics show that women's bargaining power is higher among women who use contraception than for those who do not. The results of the logistic regression model show that an increase of WBPCI was significantly associated with higher chances of using a modern contraceptive method (OR = 1.352; 95% CI: 1.257, 1.454; p <0.01). The education of women is also a key determinant since educated women were at least two times more likely to use a modern contraceptive method than uneducated women.

Conclusions: To reduce high maternal death rates in Cameroon, public health policies should not only focus on the health system itself, but should also focus on social policies to empower women in the household.

Background: The COVID-19 pandemic affected global access to health services, including contraception We sought to explore effects of the pandemic on family planning (FP) service provision and use in South Africa and Zambia, including on implant and intrauterine device (IUD) users' desire and ability to obtain removal.

Methods: Between August 2020 and April 2021, we conducted surveys with 537 women participating in an ongoing longitudinal contraceptive continuation study. We also carried out in-depth interviews with 39 of the survey participants and 36 key informants involved in FP provision. We conducted descriptive analysis of survey responses and thematic analysis of interviews.

Results: Contraceptive use changed minimally in this sample with the emergence of COVID-19. Fewer than half of women (n=220) reported that they tried to access FP since the start of the pandemic. The vast majority of those seeking services were using short-acting methods and 95% were able to obtain their preferred method. The proportion of women not using a method before and after the start of the pandemic did not change in Zambia (31%), and increased from 8% to 10% in South Africa. Less than 7% of implant or IUD users in either country reported wanting removal. Among the 22 who sought removal, 10 in Zambia and 6 in South Africa successfully obtained removal. In qualitative interviews, those reporting challenges to service access specifically mentioned long queues, deprioritization of contraceptive services, lack of transportation, stock-outs, and fear of contracting COVID-19 at a facility. Key informants reported stock-outs, especially of injectables, and staff shortages as barriers.

Conclusions: We did not find a substantial impact of COVID-19 on contraceptive access and use among this sample; however, providers and others involved in service provision identified risks to continuity of care. As the COVID-19 pandemic wanes, it continues to be important to monitor people's ability to access their preferred contraceptive methods.

Label-free techniques including Surface Plasmon Resonance (SPR) and Biolayer Interferometry (BLI) are biophysical tools widely used to collect binding kinetics data of bimolecular interactions. To efficiently analyze SPR and BLI binding kinetics data, we have built a new high throughput analysis tool named the TitrationAnalysis. It can be used as a package in the Mathematica scripting environment and ultilize the non-linear curve-fitting module of Mathematica for its core function. This tool can fit the binding time course data and estimate association and dissociation rate constants ( k _a and k _d respectively) for determining apparent dissociation constant ( K _D ) values. The high throughput fitting process is automatic, requires minimal knowledge on Mathematica scripting and can be applied to data from multiple label-free platforms. We demonstrate that the TitrationAnalysis is optimal to analyze antibody-antigen binding data acquired on Biacore T200 (SPR), Carterra LSA (SPR imaging) and ForteBio Octet Red384 (BLI) platforms. The k _a , k _d and K _D values derived using TitrationAnalysis very closely matched the results from the commercial analysis software provided specifically for these instruments. Additionally, the TitrationAnalysis tool generates user-directed customizable results output that can be readily used in downstream Data Quality Control associated with Good Clinical Laboratory Practice operations. With the versatility in source of data input source and options of analysis result output, the TitrationAnalysis high throughput analysis tool offers investigators a powerful alternative in biomolecular interaction characterization.

Background: Although global mortality rates in children under 5 years have decreased substantially in the last 30 years, there remain around 2.6 million stillbirths and 2.9 million neonatal deaths each year. The majority of these deaths occur in Africa and South Asia. To reduce perinatal deaths in East Africa, knowledge of the burden, but also the risk factors and causes of perinatal deaths are crucial. To the best of our knowledge, reviews have previously focused on the burden of perinatal deaths; here we aim to synthesize evidence on the burden, causes, and risk factors for perinatal mortality in East Africa.

Methods: We will conduct a systematic literature search in Medline, Web of Science, EMBASE, Global Health, SCOPUS, Cochrane Library, CINAHL, HINARI, African Index Medicus, African Journals Online (AJOL), and WHO African Regional Office (AFRO) Library. The study population includes all fetuses and newborns from ≥22 weeks of gestation (birth weight ≥500gm) to 7 days after birth, with reported causes or/and determinants as exposure, and perinatal mortality (stillbirths and/or early neonatal deaths) as an outcome. We will include studies from 2010 to 2022, and to facilitate the inclusion of up-to-date data, we will request recent data from ongoing surveillance in the region. To assess the quality of included studies, we will use the Joanna Briggs Institute quality assessment tool for observational and trial studies. We will analyze the data using STATA version 17 statistical software and assess heterogeneity and publication bias by Higgins' I ² and funnel plot, respectively.

Conclusions: This systematic review will search for published studies, and seek unpublished data, on the burden, causes, and risk factors of perinatal mortality in East Africa. Findings will be reported, and gaps in the evidence base identified, with recommendations, with the ultimate aim of reducing perinatal deaths.

Protocol registration: PROSPERO-CRD42021291719.

Background: South-South learning exchange (SSLE) refers to an interactive learning process where peers exchange knowledge and experience to work towards a beneficial change. Despite organizations having recently increased the opportunity to run SSLEs, the SSLE support mechanisms and processes are not well documented in the scientific literature. This study explored experts' perspectives on SSLEs, strengths, weaknesses and mechanisms leading to sustainable outcomes.

Methods: We conducted a qualitative study using semi-structured interviews on experiences of participants and organizers of SSLEs. Data were collected between 1st September 2021 to 26th November 2021. All data were digitally recorded, transcribed verbatim, and analysed. In the analysis, we adopted an inductive approach derived from thematic analysis.

Results: Sixteen experts, who have participated in or facilitated one or more SSLE, were interviewed. The experts' accounts demonstrated an appreciation of participants' empowerment, positive peer-to-peer "mind change" and convincing and powerful hands-on learning of this approach as strengths in the implementation of the SSLE. Being resource heavy, participant and donor reluctance and absence of a validated methodology emerged as main weaknesses of the South-South learning approach, which could impair the effectiveness of this scheme.

Conclusions: The strengths of SSLEs are anchored in the theories of experiential and social learning, highlighting SSLE's potential to create an environment that enhances knowledge exchange. the study highlights the challenges SSLE initiatives face. In particular, these include limited commitment and funds, limited evidence of impact, disparate approaches, and the absence of standardized guidelines and evaluation practices.