Geospatial analysis and impact of targeted development of breast cancer care in The Gambia: a cross-sectional study.

BACKGROUND: The Gambia has one of the lowest survival rates for breast cancer in Africa. Contributing factors are late presentation, delays within the healthcare system, and decreased availability of resources. We aimed to characterize the capacity and geographic location of healthcare facilities in the country and calculate the proportion of the population with access to breast cancer care. METHODS: A facility-based assessment tool was administered to secondary and tertiary healthcare facilities and private medical centers and clinics in The Gambia. GPS coordinates were obtained, and proximity of service availability and population analysis were performed. Distance thresholds of 10, 20, and 45 km were chosen to determine access to screening, pathologic diagnosis, and surgical management. An additional population analysis was performed to observe the potential impact of targeted development of resources for breast cancer care. RESULTS: All 102 secondary and tertiary healthcare facilities and private medical centers and clinics in The Gambia were included. Breast cancer screening is mainly performed through clinical breast examination and is available in 52 facilities. Seven facilities provide pathologic diagnosis and surgical management of breast cancer. The proportion of the Gambian population with access to screening, pathologic diagnosis, and surgical management is 72, 53, and 62%, respectively. A hypothetical targeted expansion of resources would increase the covered population to 95, 62, and 84%. CONCLUSIONS: Almost half of the Gambian population does not have access to pathologic diagnosis and surgical management of breast cancer within the distance threshold utilized in the study. Mapping and population analysis can identify areas for targeted development of resources to increase access to breast cancer care.

A novel nutritional supplement to reduce plasma homocysteine in nonpregnant women: A randomised controlled trial in The Gambia.

BACKGROUND: Infant DNA methylation profiles are associated with their mother's periconceptional nutritional status. DNA methylation relies on nutritional inputs for one-carbon metabolic pathways, including the efficient recycling of homocysteine. This randomised controlled trial in nonpregnant women in rural Gambia tests the efficacy of a novel nutritional supplement designed to improve one-carbon-related nutrient status by reducing plasma homocysteine, and assesses its potential future use in preconception trials. METHODS AND FINDINGS: We designed a novel drink powder based on determinants of plasma homocysteine in the target population and tested it in a three-arm, randomised, controlled trial. Nonpregnant women aged between 18 and 45 from the West Kiang region of The Gambia were randomised in a 1:1:1 allocation to 12 weeks daily supplementation of either (a) a novel drink powder (4 g betaine, 800 µg folic acid, 5.2 µg vitamin B12, and 2.8 mg vitamin B2), (b) a widely used multiple micronutrient tablet (United Nations Multiple Micronutrient Preparation [UNIMMAP]) containing 15 micronutrients, or (c) no intervention. The trial was conducted between March and July 2018. Supplementation was observed daily. Fasted venepuncture samples were collected at baseline, midline (week 5), and endline (week 12) to measure plasma homocysteine. We used linear regression models to determine the difference in homocysteine between pairs of trial arms at midline and endline, adjusted for baseline homocysteine, age, and body mass index (BMI). Blood pressure and pulse were measured as secondary outcomes. Two hundred and ninety-eight eligible women were enrolled and randomised. Compliance was >97.8% for both interventions. At endline (our primary endpoint), the drink powder and UNIMMAP reduced mean plasma homocysteine by 23.6% (-29.5 to -17.1) and 15.5% (-21.2 to -9.4), respectively (both p < 0.001), compared with the controls. Compared with UNIMMAP, the drink powder reduced mean homocysteine by 8.8% (-15.8 to -1.2; p = 0.025). The effects were stronger at midline. There was no effect of either intervention on blood pressure or pulse compared with the control at endline. Self-reported adverse events (AEs) were similar in both intervention arms. There were two serious AEs reported over the trial duration, both in the drink powder arm, but judged to be unrelated to the intervention. Limitations of the study include the use of a single targeted metabolic outcome, homocysteine. CONCLUSIONS: The trial confirms that dietary supplements can influence metabolic pathways that we have shown in previous studies to predict offspring DNA methylation. Both supplements reduced homocysteine effectively and remain potential candidates for future epigenetic trials in pregnancy in rural Gambia. TRIAL REGISTRATION: Clinicaltrials.gov Reference NCT03431597.

Haematological and biochemical reference values of Gambian infants.

OBJECTIVE: To establish haematological and biological reference values for Gambian infants. METHODS: Basic haematological and biochemical indices were analysed in blood samples obtained from healthy infants from Sukuta in the Western Division of The Gambia. The 2.5 and the 97.5 centiles for these indices were estimated. RESULTS: Reference ranges for haematological and biochemical indices were determined. Haemoglobin, total white cell count (WBC) and platelet levels decreased with age (P < 0.001), whereas most of the white cell count subsets except monocytes did not vary with age. Potassium and alkaline phosphatase fell significantly with increasing age (P < 0.001; P < 0.001), whereas urea and creatinine rose with increasing age (P = 0.002; P < 0.001, respectively). CONCLUSION: Our set of haematological and biochemical reference values for healthy infants in The Gambia differs from values in other settings, thus underscoring the importance of establishing region-specific paediatric reference ranges to ensure optimal patient management and evaluate the impact of interventions in clinical research.

Directly observed social contact patterns among school children in rural Gambia.

INTRODUCTION: School-aged children play a major role in the transmission of many respiratory pathogens due to high rate of close contacts in schools. The validity and accuracy of proxy-reported contact data may be limited, particularly for children when attending school. We observed social contacts within schools and assessed the accuracy of proxy-reported versus observed physical contact data among students in rural Gambia. METHODS: We enrolled school children who had also been recruited to a survey of Streptococcus pneumoniae carriage and social contacts. We visited participants at school and observed their contact patterns within and outside the classroom for two hours. We recorded the contact type, gender and approximate age of the contactee, and class size. We calculated age-stratified contact matrices to determine in-school contact patterns. We compared proxy-reported estimated physical contacts for the subset of participants (18 %) randomised to be observed on the same day for which the parent or caregiver reported the school contacts. RESULTS: We recorded 3822 contacts for 219 participants from 114 schools. The median number of contacts was 15 (IQR: 11-20). Contact patterns were strongly age-assortative, and mainly involved physical touch (67.5 %). Those aged 5-9 years had the highest mean number of contacts [19.0 (95 %CI: 16.7-21.3)] while the ≥ 15-year age group had fewer contacts [12.8 (95 %CI: 10.9-14.7)]. Forty (18 %) participants had their school-observed contact data collected on the same day as their caregiver reported their estimated physical contacts at school; only 22.5 % had agreement within ±2 contacts between the observed and reported contacts. Fifty-eight percent of proxy-reported contacts were under-estimates. CONCLUSIONS: Social contact rates observed among pupils at schools in rural Gambia were high, strongly age-assortative, and physical. Reporting of school contacts by proxies may underestimate the effect of school-age children in modelling studies of transmission of infections. New approaches are needed to quantify contacts within schools.

SARS-CoV-2 seroprevalence in pregnant women during the first three COVID-19 waves in The Gambia.

OBJECTIVES: SARS-CoV-2 transmission in sub-Saharan Africa has probably been underestimated. Population-based seroprevalence studies are needed to determine the extent of transmission in the continent. METHODS: Blood samples from a cohort of Gambian pregnant women were tested for SARS-CoV-2 total receptor binding domain (RBD) immunoglobulin (Ig) M/IgG before (Pre-pandemic: October-December 2019) and during the pandemic (Pre-wave 1: February-June 2020; Post-wave 1: October-December 2020, Post-wave 2: May-June 2021; and Post-wave 3: October-December 2021). Samples reactive for SARS-CoV-2 total RBD IgM/IgG were tested in specific S1- and nucleocapsid (NCP) IgG assays. RESULTS: SARS-CoV-2 total RBD IgM/IgG seroprevalence was 0.9% 95% confidence interval (0.2, 4.9) in Pre-pandemic; 4.1% (1.4, 11.4) in Pre-wave 1; 31.1% (25.2, 37.7) in Post-wave 1; 62.5% (55.8, 68.8) in Post-wave 2 and 90.0% (85.1, 93.5) in Post-wave 3. S-protein IgG and NCP-protein IgG seroprevalence also increased at each Post-wave period. Although S-protein IgG and NCP-protein IgG seroprevalence was similar at Post-wave 1, S-protein IgG seroprevalence was higher at Post-wave 2 and Post-wave 3, (prevalence difference 13.5 [0.1, 26.8] and prevalence ratio 1.5 [1.0, 2.3] in Post-wave 2; and 22.9 [9.2, 36.6] and 1.4 [1.1, 1.8] in Post-wave 3 respectively, P <0.001). CONCLUSION: SARS-CoV-2 transmission in The Gambia during the first 3 COVID-19 waves was high, differing significantly from official numbers of COVID-19 cases reported. Our findings are important for policy makers in managing the near-endemic COVID-19.

A novel nano-iron supplement versus standard treatment for iron deficiency anaemia in children 6-35 months (IHAT-GUT trial): a double-blind, randomised, placebo-controlled non-inferiority phase II trial in The Gambia.

Background: Iron deficiency anaemia (IDA) is the leading cause of years lost to disability in most sub-Saharan African countries and is especially common in young children. The IHAT-GUT trial assessed the efficacy and safety of a novel nano iron supplement, which is a dietary ferritin analogue termed iron hydroxide adipate tartrate (IHAT), for the treatment of IDA in children under 3 years of age. Methods: In this single-country, randomised, double-blind, parallel, placebo-controlled, non-inferiority Phase II study in The Gambia, children 6-35 months with IDA (7≤Hb < 11 g/dL and ferritin<30 µg/L) were randomly assigned (1:1:1) to receive either IHAT, ferrous sulphate (FeSO4) or placebo daily for 3 months (85 days). The daily iron dose was 12.5 mg Fe equivalent for FeSO4 and the estimated dose with comparable iron-bioavailability for IHAT (20 mg Fe). The primary efficacy endpoint was the composite of haemoglobin response at day 85 and correction of iron deficiency. The non-inferiority margin was 0.1 absolute difference in response probability. The primary safety endpoint was moderate-severe diarrhoea analysed as incidence density and prevalence over the 3 months intervention. Secondary endpoints reported herein include hospitalisation, acute respiratory infection, malaria, treatment failures, iron handling markers, inflammatory markers, longitudinal prevalence of diarrhoea and incidence density of bloody diarrhoea. Main analyses were per-protocol (PP) and intention-to-treat (ITT) analyses. This trial is registered with clinicaltrials.gov (NCT02941081). Findings: Between Nov 2017 and Nov 2018, 642 children were randomised into the study (214 per group) and included in the ITT analysis, the PP population included 582 children. A total of 50/177 (28.2%) children in the IHAT group achieved the primary efficacy endpoint, as compared with 42/190 (22.1%) in the FeSO4 group (OR 1.39, 80% CI 1.01-1.91, PP population) and with 2/186 (1.1%) in the placebo group. Diarrhoea prevalence was similar between groups, with 40/189 (21.2%) children in the IHAT group developing at least one episode of moderate-severe diarrhoea over the 85 days intervention, compared with 47/198 (23.7%) in the FeSO4 group (OR 1.18, 80% CI 0.86-1.62) and 40/195 (20.5%) in the placebo group (OR 0.96, 80% CI 0.7-1.33, PP population). Incidence density of moderate-severe diarrhoea was 2.66 in the IHAT group and 3.42 in the FeSO4 group (RR 0.76, 80% CI 0.59-0.99, CC-ITT population).There were 143/211 (67.8%) children with adverse events (AEs) in the IHAT group, 146/212 (68.9%) in the FeSO4 group and 143/214 (66.8%) in the placebo group. There were overall 213 diarrhoea-related AEs; 35 (28.5%) cases reported in the IHAT group compared with 51 (41.5%) cases in the FeSO4 group and 37 (30.1%) cases in the placebo group. Interpretation: In this first Phase II study conducted in young children with IDA, IHAT showed sufficient non-inferiority compared to standard-of-care FeSO4, in terms of ID correction and haemoglobin response, to warrant a definitive Phase III trial. In addition, IHAT had lower incidence of moderate-severe diarrhoea than FeSO4, with no increased adverse events in comparison with placebo. Funding: The Bill & Melinda Gates Foundation (OPP1140952).

Quantifying excess mortality during the COVID-19 pandemic in 2020 in The Gambia: a time-series analysis of three health and demographic surveillance systems.

OBJECTIVES: Estimates for COVID-19-related excess mortality for African populations using local data are needed to design and implement effective control policies. METHODS: We applied time-series analysis using data from three health and demographic surveillance systems in The Gambia (Basse, Farafenni, and Keneba) to examine pandemic-related excess mortality during 2020, when the first SARS-CoV-2 wave was observed, compared to the pre-pandemic period (2016-2019). RESULTS: Across the three sites, average mortality during the pre-pandemic period and the total deaths during 2020 were 1512 and 1634, respectively (Basse: 1099 vs 1179, Farafenni: 316 vs 351, Keneba: 98 vs 104). The overall annual crude mortality rates per 100,000 (95% CI) were 589 (559, 619) and 599 (571, 629) for the pre-pandemic and 2020 periods, respectively. The adjusted excess mortality rate was 8.8 (-34.3, 67.6) per 100,000 person-month with the adjusted rate ratio (aRR) = 1.01 (0.94,1.11). The age-stratified analysis showed excess mortality in Basse for infants (aRR = 1.22 [1.04, 1.46]) and in Farafenni for the 65+ years age group (aRR = 1.19 [1, 1.44]). CONCLUSION: We did not find significant excess overall mortality in 2020 in The Gambia. However, some age groups may have been at risk of excess death. Public health response in countries with weak health systems needs to consider vulnerable age groups and the potential for collateral damage.

Circulation of respiratory viruses during the COVID-19 pandemic in The Gambia.

Background: In many countries, non-pharmaceutical interventions to limit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission resulted in significant reductions in other respiratory viruses. However, similar data from Africa are limited. We explored the extent to which viruses such as influenza and rhinovirus co-circulated with SARS-CoV-2 in The Gambia during the COVID-19 pandemic.  Methods: Between April 2020 and March 2022, respiratory viruses were detected using RT-PCR in nasopharyngeal swabs from 1397 participants with influenza-like illness. An assay to detect SARS-CoV-2 and a viral multiplex RT-PCR assay was used as previously described  to detect influenza A and B, respiratory syncytial virus (RSV) A and B, parainfluenza viruses 1-4, human metapneumovirus (HMPV), adenovirus, seasonal coronaviruses (229E, OC43, NL63) and human rhinovirus. Results: Overall virus positivity was 44.2%, with prevalence higher in children <5 years (80%) compared to children aged 5-17 years (53.1%), adults aged 18-50 (39.5%) and >50 years (39.9%), p<0.0001. After SARS-CoV-2 (18.3%), rhinoviruses (10.5%) and influenza viruses (5.5%) were the most prevalent. SARS-CoV-2 positivity was lower in children <5 (4.3%) and 5-17 years (12.7%) than in adults aged 18-50 (19.3%) and >50 years (24.3%), p<0.0001. In contrast, rhinoviruses were most prevalent in children <5 years (28.7%), followed by children aged 5-17 (15.8%), adults aged 18-50 (8.3%) and >50 years (6.3%), p<0.0001. Four SARS-CoV-2 waves occurred, with 36.1%-52.4% SARS-CoV-2 positivity during peak months. Influenza infections were observed in both 2020 and 2021 during the rainy season as expected (peak positivity 16.4%-23.5%). Peaks of rhinovirus were asynchronous to the months when SARS-CoV-2 and influenza peaked. Conclusion: Our data show that many respiratory viruses continued to circulate during the COVID-19 pandemic in The Gambia, including human rhinoviruses, despite the presence of NPIs during the early stages of the pandemic, and influenza peaks during expected months.

Differential effects of frozen storage on the molecular detection of bacterial taxa that inhabit the nasopharynx.

BACKGROUND: Frozen storage often precedes metagenomic analysis of biological samples; however, the freezing process can have adverse effects on microbial composition. The effect of freezing on the detection of bacteria inhabiting the infant nasopharynx, a major reservoir of bacterial pathogens, was investigated. METHODS: 16S ribosomal RNA (rRNA) gene-based terminal restriction fragment length polymorphism (T-RFLP) analysis of nasopharyngeal (NP) swabs from twelve Gambian infants was employed. NP swabs were analysed within hours of collection and then after 30 days of storage at -70°C. RESULTS: There was substantial heterogeneity among subjects with respect to the effect of freezing on the number of operational taxonomic units (OTUs) detected. Nevertheless, the mean number of OTUs decreased after frozen storage and the relative abundance for 72% of the OTUs changed by less than 0.5% after deep frozen storage. There were differences in the odds of detection and relative abundance of OTUs matched with Moraxella sp., Haemophilus sp./Burkholderia sp., and Pseudomonas sp. A strong interaction between sex and the effect of freezing was found, whereby there was no significant change observed for males while the mean number of OTUs significantly declined among female infants following frozen storage. CONCLUSIONS: Although frozen storage of biological samples is often necessary for archiving and logistic purposes, the potential effects on the number of taxa (composition) detected in microbial community studies are significant and should not be overlooked. Moreover, genetic factors such as sex may influence the integrity of nucleic acids during the freezing process.

Deploying Machine Learning Models Using Progressive Web Applications: Implementation Using a Neural Network Prediction Model for Pneumonia Related Child Mortality in The Gambia.

BACKGROUND: Translating research outputs into practical tools for medical practitioners is a neglected area and could have a substantial impact. One of the barriers to implementing artificial intelligence (AI) and machine learning (ML) applications is their practical deployment in the field. Traditional web-based (i.e., server sided) applications are dependent on reliable internet connections, which may not be readily available in rural areas. Native mobile apps require device specific programming skills as well as contemporary hardware and software, with often rapid and unpredictable platform specific changes. This is a major challenge for using AI/ML tools in resource-limited settings. METHODS: An emerging technology, progressive web applications (PWAs), first introduced by Google in 2015, offers an opportunity to overcome the challenges of deploying bespoke AI/ML systems. The same PWA code can be implemented across all desktop platforms, iOS and Android phones and tablets. In addition to platform independence, a PWA can be designed to be primarily offline. RESULTS: We demonstrate how a neural network-based pneumonia mortality prediction triage tool was migrated from a typical academic framework (paper and web-based prototype) to a tool that can be used offline on any mobile phone-the most convenient deployment vehicle. After an initial online connection to download the software, the application runs entirely offline, reading data from cached memory, and running code via JavaScript. On mobile devices the application is installed as a native app, without the inconvenience of platform specific code through manufacturer code stores. DISCUSSION: We show that an ML application can be deployed as a platform independent offline PWA using a pneumonia-related child mortality prediction tool as an example. The aim of this tool was to assist clinical staff in triaging children for hospital admission, by predicting their risk of death. PWAs function seamlessly when their host devices lose internet connectivity, making them ideal for e-health apps that can help improve health and save lives in resource-limited settings in line with the UN Sustainable Development Goal 3 (SDG3).

The effect of live attenuated influenza vaccine on pneumococcal colonisation densities among children aged 24-59 months in The Gambia: a phase 4, open label, randomised, controlled trial.

BACKGROUND: Influenza and other respiratory viruses promote Streptococcus pneumoniae proliferation in the upper respiratory tract. We sought to investigate for what we believe is the first time, the effect of intranasal live attenuated influenza vaccine (LAIV) on nasopharyngeal S pneumoniae density in a low-income to middle-income country population with high pneumococcal carriage rates. METHODS: In an open-label, randomised, controlled trial in The Gambia, 330 healthy children aged 24-59 months were randomly assigned 2:1 to receive one trivalent LAIV dose at enrolment (day 0, intervention) or at the end of active follow-up (day 21, control). The investigator team were initially masked to block size and randomisation sequence to avoid allocation bias. Group allocation was later revealed to the investigator team. The primary outcome was PCR-quantified day 7 and 21 pneumococcal density. Asymptomatic respiratory viral infection at baseline and LAIV strain shedding were included as covariates in generalised mixed-effects models, to assess the effect of LAIV and other variables on pneumococcal densities. The study is registered at ClinicalTrials.gov, NCT02972957, and is closed to recruitment. FINDINGS: Between Feb 8 and April 12, 2017, and Jan 15 and March 28, 2018, of 343 children assessed for eligibility, 213 in the intervention group and 108 in the control group completed the study and were included in the final analysis. Although no significant differences were seen in pneumococcal carriage or density at each timepoint when comparing groups, changes from baseline were observed in the LAIV group. The baseline S pneumoniae carriage prevalence was high in both LAIV and control groups (75%) and increased by day 21 in the LAIV group (85%, p=0·0037), but not in the control group (79%, p=0·44). An increase in pneumococcal density from day 0 amounts was seen in the LAIV group at day 7 (+0·207 log10 copies per µL, SE 0·105, p=0·050) and day 21 (+0·280 log10 copies per µL, SE 0·105, p=0·0082), but not in the control group. Older age was associated with lower pneumococcal density (-0·015 log10 copies per µL, SE 0·005, p=0·0030), with the presence of asymptomatic respiratory viruses at baseline (+0·259 log10 copies per µL, SE 0·097, p=0·017), and greater LAIV shedding at day 7 (+0·380 log10 copies per µL, SE 0·167, p=0·024) associated with higher pneumococcal density. A significant increase in rhinorrhoea was reported in the LAIV group compared with the control group children during the first 7 days of the study (103 [48%] of 213, compared with 25 [23%] of 108, p<0·0001), and between day 7 and 21 (108 [51%] of 213, compared with 28 [26%] of 108, p<0·0001). INTERPRETATION: LAIV was associated with a modest increase in nasopharyngeal pneumococcal carriage and density in the 21 days following vaccination, with the increase in density lower in magnitude than previously described in the UK. This increase was accelerated when LAIV was administered in the presence of pre-existing asymptomatic respiratory viruses, suggesting that nasopharyngeal S pneumoniae proliferation is driven by cumulative mixed-viral co-infections. The effect of LAIV on pneumococcal density is probably similar to other respiratory viral infections in children. Our findings provide reassurance for the use of LAIV to expand influenza vaccine programmes in low-income to middle-income country populations with high pneumococcal carriage. FUNDING: Wellcome Trust.

Etiology of Pediatric Meningitis in West Africa Using Molecular Methods in the Era of Conjugate Vaccines against Pneumococcus, Meningococcus, and Haemophilus influenzae Type b.

Despite the implementation of effective conjugate vaccines against the three main bacterial pathogens that cause meningitis, Streptococcus pneumoniae, Haemophilus influenzae type b (Hib), and Neisseria meningitidis serogroup A, the burden of meningitis in West Africa remains high. The relative importance of other bacterial, viral, and parasitic pathogens in central nervous system infections is poorly characterized. Cerebrospinal fluid (CSF) specimens were collected from children younger than 5 years with suspected meningitis, presenting at pediatric teaching hospitals across West Africa in five countries including Senegal, Ghana, Togo, Nigeria, and Niger. Cerebrospinal fluid specimens were initially tested using bacteriologic culture and a triplex real-time polymerase chain reaction (PCR) assay for N. meningitidis, S. pneumoniae, and H. influenzae used in routine meningitis surveillance. A custom TaqMan Array Card (TAC) assay was later used to detect 35 pathogens including 15 bacteria, 17 viruses, one fungus, and two protozoans. Among 711 CSF specimens tested, the pathogen positivity rates were 2% and 20% by the triplex real-time PCR (three pathogens) and TAC (35 pathogens), respectively. TAC detected 10 bacterial pathogens, eight viral pathogens, and Plasmodium. Overall, Escherichia coli was the most prevalent (4.8%), followed by S. pneumoniae (3.5%) and Plasmodium (3.5%). Multiple pathogens were detected in 4.4% of the specimens. Children with human immunodeficiency virus (HIV) and Plasmodium detected in CSF had high mortality. Among 220 neonates, 17% had at least one pathogen detected, dominated by gram-negative bacteria. The meningitis TAC enhanced the detection of pathogens in children with meningitis and may be useful for case-based meningitis surveillance.

Effect of a Russian-backbone live-attenuated influenza vaccine with an updated pandemic H1N1 strain on shedding and immunogenicity among children in The Gambia: an open-label, observational, phase 4 study.

BACKGROUND: The efficacy and effectiveness of the pandemic H1N1 (pH1N1) component in live attenuated influenza vaccine (LAIV) is poor. The reasons for this paucity are unclear but could be due to impaired replicative fitness of pH1N1 A/California/07/2009-like (Cal09) strains. We assessed whether an updated pH1N1 strain in the Russian-backbone trivalent LAIV resulted in greater shedding and immunogenicity compared with LAIV with Cal09. METHODS: We did an open-label, prospective, observational, phase 4 study in Sukuta, a periurban area in The Gambia. We enrolled children aged 24-59 months who were clinically well. Children received one dose of the WHO prequalified Russian-backbone trivalent LAIV containing either A/17/California/2009/38 (Cal09) or A/17/New York/15/5364 (NY15) based on their year of enrolment. Primary outcomes were the percentage of children with LAIV strain shedding at day 2 and day 7, haemagglutinin inhibition seroconversion, and an increase in influenza haemagglutinin-specific IgA and T-cell responses at day 21 after LAIV. This study is nested within a randomised controlled trial investigating LAIV-microbiome interactions (NCT02972957). FINDINGS: Between Feb 8, 2017, and April 12, 2017, 118 children were enrolled and received one dose of the Cal09 LAIV from 2016-17. Between Jan 15, 2018, and March 28, 2018, a separate cohort of 135 children were enrolled and received one dose of the NY15 LAIV from 2017-18, of whom 126 children completed the study. Cal09 showed impaired pH1N1 nasopharyngeal shedding (16 of 118 children [14%, 95% CI 8·0-21·1] with shedding at day 2 after administration of LAIV) compared with H3N2 (54 of 118 [46%, 36·6-55·2]; p<0·0001) and influenza B (95 of 118 [81%, 72·2-87·2]; p<0·0001), along with suboptimal serum antibody (seroconversion in six of 118 [5%, 1·9-10·7]) and T-cell responses (CD4+ interferon γ-positive and/or CD4+ interleukin 2-positive responses in 45 of 111 [41%, 31·3-50·3]). After the switch to NY15, a significant increase in pH1N1 shedding was seen (80 of 126 children [63%, 95% CI 54·4-71·9]; p<0·0001 compared with Cal09), along with improvements in seroconversion (24 of 126 [19%, 13·2-26·8]; p=0·011) and influenza-specific CD4+ T-cell responses (73 of 111 [66%, 60·0-75·6; p=0·00028]). The improvement in pH1N1 seroconversion with NY15 was even greater in children who were seronegative at baseline (24 of 64 children [38%, 95% CI 26·7-49·8] vs six of 79 children with Cal09 [8%, 2·8-15·8]; p<0·0001). Persistent shedding to day 7 was independently associated with both seroconversion (odds ratio 12·69, 95% CI 4·1-43·6; p<0·0001) and CD4+ T-cell responses (odds ratio 7·83, 95% CI 2·99-23·5; p<0·0001) by multivariable logistic regression. INTERPRETATION: The pH1N1 component switch that took place between 2016 and 2018 might have overcome the poor efficacy and effectiveness reported with previous LAIV formulations. LAIV effectiveness against pH1N1 should, therefore, improve in upcoming influenza seasons. Our data highlight the importance of assessing replicative fitness, in addition to antigenicity, when selecting annual LAIV components. FUNDING: The Wellcome Trust.

Is ambient air pollution associated with onset of sudden infant death syndrome: a case-crossover study in the UK.

OBJECTIVES: Air pollution has been associated with increased mortality and morbidity in several studies with indications that its effect could be more severe in children. This study examined the relationship between short-term variations in criteria air pollutants and occurrence of sudden infant death syndrome (SIDS). DESIGN: We used a case-crossover study design which is widely applied in air pollution studies and particularly useful for estimating the risk of a rare acute outcome associated with short-term exposure. SETTING: The study used data from the West Midlands region in the UK. PARTICIPANTS: We obtained daily time series data on SIDS mortality (ICD-9: 798.0 or ICD-10: R95) for the period 1996-2006 with a total of 211 SIDS events. PRIMARY OUTCOME MEASURES: Daily counts of SIDS events. RESULTS: For an IQR increase in previous day pollutant concentration, the percentage increases (95% CI) in SIDS were 16 (6 to 27) for PM10, 1 (-7 to 10) for SO2, 5 (-4 to 14) for CO, -17 (-27 to -6) for O3, 16 (2 to 31) for NO2 and 2 (-3 to 8) for NO after controlling for average temperature and national holidays. PM10 and NO2 showed relatively consistent association which persisted across different lag structures and after adjusting for copollutants. CONCLUSIONS: The results indicated ambient air pollutants, particularly PM10 and NO2, may show an association with increased SIDS mortality. Thus, future studies are recommended to understand possible mechanistic explanations on the role of air pollution on SIDS incidence and the ways in which we might reduce pollution exposure among infants.

A novel nano-iron supplement to safely combat iron deficiency and anaemia in young children: The IHAT-GUT double-blind, randomised, placebo-controlled trial protocol.

Background: Iron deficiency and its associated anaemia (IDA) are the leading forms of micronutrient malnutrition worldwide. Here we describe the rationale and design of the first clinical trial evaluating the efficacy and safety of an innovative nano iron supplement, iron hydroxide adipate tartrate (IHAT), for the treatment of IDA in young children (IHAT-GUT trial). Oral iron is often ineffective due to poor absorption and/or gastrointestinal adverse effects. IHAT is novel since it is effectively absorbed whilst remaining nanoparticulate in the gut, therefore should enable supplementation with fewer symptoms. Methods: IHAT-GUT is a three-arm, double-blind, randomised, placebo-controlled phase II trial conducted in Gambian children 6-35 months of age. The intervention consists of a 12-week supplementation with either IHAT, ferrous sulphate (both at doses bioequivalent to 12.5 mg Fe/day) or placebo. The trial aims to include 705 children with IDA who will be randomly assigned (1:1:1) to each arm. The primary objectives are to test non-inferiority of IHAT in relation to ferrous sulphate at treating IDA, and to test superiority of IHAT in relation to ferrous sulphate and non-inferiority in relation to placebo in terms of diarrhoea incidence and prevalence. Secondary objectives are mechanistic assessments, to test whether IHAT reduces the burden of enteric pathogens, morbidity, and intestinal inflammation, and that it does not cause detrimental changes to the gut microbiome, particularly in relation to Lactobacillaceae, Bifidobacteriaceae and Enterobacteriaceae. Discussion: This trial will test the hypothesis that supplementation with IHAT eliminates iron deficiency and improves haemoglobin levels without inducing gastrointestinal adverse effects. If shown to be the case, this would open the possibility for further testing and use of IHAT as a novel iron source for micronutrient intervention strategies in resource-poor countries, with the ultimate aim to help reduce the IDA global burden. Registration: This trial is registered at clinicaltrials.gov ( NCT02941081).

Comparison of mucosal lining fluid sampling methods and influenza-specific IgA detection assays for use in human studies of influenza immunity.

We need greater understanding of the mechanisms underlying protection against influenza virus to develop more effective vaccines. To do this, we need better, more reproducible methods of sampling the nasal mucosa. The aim of the current study was to compare levels of influenza virus A subtype-specific IgA collected using three different methods of nasal sampling. Samples were collected from healthy adult volunteers before and after LAIV immunization by nasal wash, flocked swabs and Synthetic Absorptive Matrix (SAM) strips. Influenza A virus subtype-specific IgA levels were measured by haemagglutinin binding ELISA or haemagglutinin binding microarray and the functional response was assessed by microneutralization. Nasosorption using SAM strips lead to the recovery of a more concentrated sample of material, with a significantly higher level of total and influenza H1-specific IgA. However, an equivalent percentage of specific IgA was observed with all sampling methods when normalized to the total IgA. Responses measured using a recently developed antibody microarray platform, which allows evaluation of binding to multiple influenza strains simultaneously with small sample volumes, were compared to ELISA. There was a good correlation between ELISA and microarray values. Material recovered from SAM strips was weakly neutralizing when used in an in vitro assay, with a modest correlation between the level of IgA measured by ELISA and neutralization, but a greater correlation between microarray-measured IgA and neutralizing activity. In conclusion we have tested three different methods of nasal sampling and show that flocked swabs and novel SAM strips are appropriate alternatives to traditional nasal washes for assessment of mucosal influenza humoral immunity.

A Preliminary Assessment of the Role of Ambient Nitric Oxide Exposure in Hospitalization with Respiratory Syncytial Virus Bronchiolitis.

Some in vitro studies have indicated a possible link between respiratory syncytial virus (RSV) infection and exposure to Nitric Oxide (NO). However, these studies used much higher NO concentrations than normally found in the ambient environment. This preliminary study explored whether an association was present with short-term exposure to NO in the environment. RSV-related admission data between November 2011 and February 2012 were obtained from Sheffield Children's Hospital. The dates of admission were linked to contemporaneous ambient NO derived from sentinel air monitors. The case-crossover design was used to study the relationship between daily RSV admissions and NO, controlling for temperature and relative humidity. We found little evidence of association between daily RSV admission rates and exposure to ambient NO at different lags or average exposure across several lags. The findings should, however, be viewed with caution due to the low number of events observed during the time frame. It is possible that the apparent lack of association may be accounted for by the timing of the seasonal RSV epidemic in relation to peaks in NO concentrations. A larger study incorporating a wider range of RSV and NO peaks would determine whether said peaks enhanced the number of RSV hospitalizations in children.

Clonal differences between Non-Typhoidal Salmonella (NTS) recovered from children and animals living in close contact in the Gambia.

BACKGROUND: Non-Typhoidal Salmonella (NTS) is an important cause of invasive bacterial disease and associated with mortality in Africa. However, little is known about the environmental reservoirs and predominant modes of transmission. Our study aimed to study the role of domestic animals in the transmission of NTS to humans in rural area of The Gambia. METHODOLOGY: Human NTS isolates were obtained through an active population-based case-control surveillance study designated to determine the aetiology and epidemiology of enteric infections covering 27,567 Gambian children less than five years of age in the surveillance area. Fourteen children infected with NTS were traced back to their family compounds and anal swabs collected from 210 domestic animals present in their households. Identified NTSs were serotyped and genotyped by multi-locus sequencing typing. PRINCIPAL FINDINGS: NTS was identified from 21/210 animal sources in the households of the 14 infected children. Chickens carried NTS more frequently than sheep and goats; 66.6%, 28.6% and 4.8% respectively. The most common NTS serovars were S. Colindale in humans (21.42%) and S. Poona in animals (14.28%). MLST on the 35 NTS revealed four new alleles and 24 sequence types (ST) of which 18 (75%) STs were novel. There was no overlap in serovars or genotypes of NTS recovered from humans or animal sources in the same household. CONCLUSION: Our results do not support the hypothesis that humans and animals in close contact in the same household carry genotypically similar Salmonella serovars. These findings form an important baseline for future studies of transmission of NTS in humans and animals in Africa.