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Journal articleDerqui N, Blake IM, Gray EJ, et al., 2024,
Timeliness of 24 childhood immunisations and evolution of vaccination delay: analysis of data from 54 low- and middle-income countries
, PLOS Global Public Health, Vol: 4, ISSN: 2767-3375Vaccination timeliness is often not considered among standard performance indicators of routine vaccination programmes, such as vaccination coverage, yet quantifying vaccination delay could inform policies to promote in-time vaccination and help design vaccination schedules. Here, we analysed vaccination timeliness for 24 routine childhood immunisations for 54 countries. We extracted individual vaccination status and timing from Demographic and Health Surveys data from 54 countries with surveys from 2010 onwards. Individual data was used to estimate age at vaccination for <5 year-old children. Recommended age of vaccination for each country and vaccine was compared to the age at vaccination to determine vaccination delay. The evolution of vaccination delay over time was described using estimates from different birth cohorts. To identify socio-demographic indicators associated with delayed vaccination, we used multivariable Cox regression models with country as random effect and estimated the Hazard Ratio for vaccination with each vaccine-dose for each week post recommended vaccination age. Vaccine coverage at the recommended age was highest for birth and first doses (e.g. 50.5% BCG, 18.5% DTP-D1) and lowest for later doses (e.g. 5.5% DTP-D3, 16.3% MCV-D1, 8.2% MCV-D2). Median delay was lowest for birth doses, e.g. BCG (1 week (IQR: 0 to 4)), and it increased with later doses in vaccination courses: 1 (0, 4) week for DTP-D1 versus 4 (2, 9) weeks for DTP-D3. Although the median delay for each vaccine-dose remained largely constant over time, the range of delay estimates moderately decreased. Children living in rural areas, their countries’ poorer wealth quintiles and whose mothers had no formal education were more likely to received delayed vaccinations. Although we report most children are vaccinated within the recommended age window, we found little reduction on routine immunisation delays over the last decade and that children from deprived socioeconomic b
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Journal articleKamau E, Lambert B, Allen DJ, et al., 2024,
Enterovirus A71 and coxsackievirus A6 circulation in England, UK, 2006–2017: a mathematical modelling study using cross-sectional seroprevalence data
, PLoS Pathogens, Vol: 20, ISSN: 1553-7366Enterovirus A71 (EV-A71) and coxsackievirus A6 (CVA6) primarily cause hand, foot and mouth disease and have emerged to cause potential fatal neurological and systemic manifestations. However, limited surveillance data collected through passive surveillance systems hampers characterization of their epidemiological dynamics. We fit a series of catalytic models to age-stratified seroprevalence data for EV-A71 and CVA6 collected in England at three time points (2006, 2011 and 2017) to estimate the force of infection (FOI) over time and assess possible changes in transmission. For both serotypes, model comparison does not support the occurrence of important changes in transmission over the study period, and we find that a declining risk of infection with age and / or seroreversion are needed to explain the seroprevalence data. Furthermore, we provide evidence that the increased number of reports of CVA6 during 2006–2017 is unlikely to be explained by changes in surveillance. Therefore, we hypothesize that the increased number of CVA6 cases observed since 2011 must be explained by increased virus pathogenicity. Further studies of seroprevalence data from other countries would allow to confirm this. Our results underscore the value of seroprevalence data to unravel changes in the circulation dynamics of pathogens with weak surveillance systems and large number of asymptomatic infections.
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Journal articleCholette F, Lazarus L, Macharia P, et al., 2024,
HIV phylogenetic clusters point to unmet hiv prevention, testing and treatment needs among men who have sex with men in kenya
, BMC Infectious Diseases, Vol: 24, ISSN: 1471-2334BackgroundThe HIV epidemic in Kenya remains a significant public health concern, particularly among gay, bisexual, and other men who have sex with men (GBMSM), who continue to bear a disproportionate burden of the epidemic. This study’s objective is to describe HIV phylogenetic clusters among different subgroups of Kenyan GBMSM, including those who use physical hotspots, virtual spaces, or a combination of both to find male sexual partners.MethodsDried blood spots (DBS) were collected from GBMSM in Kisumu, Mombasa, and Kiambu counties, Kenya, in 2019 (baseline) and 2020 (endline). HIV pol sequencing was attempted on all seropositive DBS. HIV phylogenetic clusters were inferred using a patristic distance cutoff of ≤ 0.02 nucleotide substitutions per site. We used descriptive statistics to analyze sociodemographic characteristics and risk behaviors stratified by clustering status.ResultsOf the 2,450 participants (baseline and endline), 453 (18.5%) were living with HIV. Only a small proportion of seropositive DBS specimens were successfully sequenced (n = 36/453; 7.9%), likely due to most study participants being virally suppressed (87.4%). Among these sequences, 13 (36.1%) formed eight distinct clusters comprised of seven dyads and one triad. The clusters mainly consisted of GBMSM seeking partners online (n = 10/13; 76.9%) and who tested less frequently than recommended by Kenyan guidelines (n = 11/13; 84.6%).ConclusionsOur study identified HIV phylogenetic clusters among Kenyan GBMSM who predominantly seek sexual partners online and test infrequently. These findings highlight potential unmet HIV prevention, testing, and treatment needs within this population. Furthermore, these results underscore the importance of tailoring HIV programs to address the diverse needs of GBMSM in Kenya across different venues, including both physical hotspots and online platforms, to ensure comprehensive prevention and car
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Journal articleShaw SY, Biegun JCS, Leung S, et al., 2024,
Describing the effect of COVID-19 on sexual and healthcare-seeking behaviours of men who have sex with men in three counties in Kenya: a cross-sectional study
, Sexually Transmitted Infections, Vol: 100, Pages: 497-503, ISSN: 1368-4973Background While the COVID-19 pandemic disrupted HIV preventative services in sub-Saharan Africa, little is known about the specific impacts the pandemic has had on men who have sex with men (MSM) in Kenya.Methods Data were from an HIV self-testing intervention implemented in Kisumu, Mombasa and Kiambu counties in Kenya. Baseline data collection took place from May to July 2019, and endline in August–October 2020, coinciding with the lifting of some COVID-19 mitigation measures. Using endline data, this study characterised the impact the pandemic had on participants’ risk behaviours, experience of violence and behaviours related to HIV. Logistic regression was used to understand factors related to changes in risk behaviours and experiences of violence; adjusted AORs (AORs) and 95% CIs are reported.Results Median age was 24 years (IQR: 21–27). Most respondents (93.9%) reported no change or a decrease in the number of sexual partners (median number of male sexual partners: 2, IQR: 2–4). Some participants reported an increase in alcohol (10%) and drug (16%) consumption, while 40% and 28% reported decreases in alcohol and drug consumption, respectively. Approximately 3% and 10% reported an increase in violence from intimate partners and police/authorities, respectively. Compared with those with primary education, those with post-secondary education were 60% less likely to report an increase in the number of male sexual partners per week (AOR: 0.4, 95% CI: 0.2 to 0.9), while those who were HIV positive were at twofold the odds of reporting an increase or sustained levels of violence from intimate partners (AOR: 2.0, 95% CI: 1.1 to 4.0).Conclusion The results of this study demonstrate heterogeneity in participants’ access to preventative HIV and clinical care services in Kenya after the onset of the COVID-19 epidemic. These results indicate the importance of responding to specific needs of MSM and adapting programmes during time
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Journal articlevan Elsland S, O'Hare R, McCabe R, et al., 2024,
Policy impact of the Imperial College COVID-19 Response Team: global perspective and UK case study
, Health Research Policy and Systems, Vol: 22, ISSN: 1478-4505BackgroundMathematical models and advanced analytics play an important role in policy decision making and mobilizing action. The Imperial College Coronavirus Disease 2019 (COVID-19) Response Team (ICCRT) provided continuous, timely and robust epidemiological analyses to inform the policy responses of governments and public health agencies around the world. This study aims to quantify the policy impact of ICCRT outputs, and understand which evidence was considered policy-relevant during the COVID-19 pandemic.MethodsWe collated all outputs published by the ICCRT between 01-01-2020 and 24-02-2022 and conducted inductive thematic analysis. A systematic search of the Overton database identified policy document references, as an indicator of policy impact.ResultsWe identified 620 outputs including preprints (16%), reports (29%), journal articles (37%) and news items (18%). More than half (56%) of all reports and preprints were subsequently peer-reviewed and published as a journal article after 202 days on average. Reports and preprints were crucial during the COVID-19 pandemic to the timely distribution of important research findings. One-fifth of ICCRT outputs (21%) were available to or considered by United Kingdom government meetings. Policy documents from 41 countries in 26 different languages referenced 43% of ICCRT outputs, with a mean time between publication and reference in the policy document of 256 days. We analysed a total of 1746 policy document references. Two-thirds (61%) of journal articles, 39% of preprints, 31% of reports and 16% of news items were referenced in one or more policy documents (these 217 outputs had a mean of 8 policy document references per output). The most frequent themes of the evidence produced by the ICCRT reflected the evidence-need for policy decision making, and evolved accordingly from the pre-vaccination phase [severity, healthcare demand and capacity, and non-pharmaceutical interventions (NPIs)] to the vaccination phase of the ep
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Journal articleBose I, Dreibelbis R, Green R, et al., 2024,
Coping strategies for household water insecurity in rural Gambia, mediating factors in the relationship between weather, water and health.
, BMC Public Health, Vol: 24BACKGROUND: Rural communities in low- and middle-income countries, such as The Gambia, often experience water insecurity periodically due to climate drivers such as heavy rainfall and reduced rainfall, as well as non-climate drivers such as infrastructural issues and seasonal workloads. When facing these challenges households use a variety of coping mechanisms that could pose a risk to health. We aimed to understand the drivers of water insecurity (climate and non-climate), the behavioural responses to water insecurity and the risks these responses pose to the health of communities in rural Gambia and map these findings onto a conceptual framework. METHODS: We interviewed 46 participants using multiple qualitative methods. This included in-depth interviews and transect walks. A subset of 27 participants took part in three participatory pile-sorting activities. In these activities participants were asked to rank water-related activities, intrahousehold prioritisation of water, and the coping strategies utilised when facing water insecurity. RESULTS: Multiple strategies were identified that people used to cope with water shortages, including: reductions in hygiene, changes to food consumption, and storing water for long periods. Many of these could inadvertently introduce risks for health. For example, limiting handwashing increases the risk of water-washed diseases. Deprioritising cooking foods such as millet, which is a nutrient-dense staple food, due to the high water requirements during preparation, could impact nutritional status. Additionally, storing water for long periods could erode water quality. Social factors appeared to play an important role in the prioritisation of domestic water-use when faced with water shortages. For example, face-washing was often maintained for social reasons. Health and religion were also key influencing factors. People often tried to protect children from the effects of water insecurity, particularly school-aged children, but giv
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Journal articleMori AT, Mallange G, Kühl M-J, et al., 2024,
Cost of treating severe malaria in children in Africa: a systematic literature review.
, Malar J, Vol: 23BACKGROUND: Malaria is a major cause of ill health and death in children in Africa. The disease also imposes a severe social and economic burden on households and health systems and is strongly associated with poverty. This study summarizes the most up-to-date cost of treating severe malaria in children in Africa. METHODS: A systematic search was conducted in PubMed, Embase, Cinahl, and Web of Science databases. Google and Google Scholar were searched for grey literature followed by scanning of the reference lists of the previous systematic reviews. The search was limited to children < 12 years, malaria-endemic countries in Africa, and the English language. All costs were adjusted to the year 2023. RESULTS: 19 studies conducted in 12 countries were identified: 14 reported provider costs, and 11 household costs. Out of the 19 studies found, 11 were published before 2018 while 11 reported data that are currently more than ten years old. Studies varied methodologically and in the scope of resources included to estimate the cost. The provider costs ranged from USD 27 in Uganda to USD 165 per patient in Kenya (median value USD 90), while household costs ranged from USD 13 in Kenya to USD 245 per patient in Gabon (median value USD 50). All identified household malaria treatment costs except one represented catastrophic health expenditure, making out more than 10% of the monthly Gross National Income per capita in the respective countries. CONCLUSION: Evidence on the cost of treating severe malaria in children in Africa is scarce. However, the few existing studies show that severe malaria in children imposes a significant economic burden on the providers and households. More studies are needed, particularly in high-burden high-impact countries, to inform resource allocation decisions.
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Journal articleRomanello M, Walawender M, Hsu S-C, et al., 2024,
The 2024 report of the Lancet Countdown on health and climate change: facing record-breaking threats from delayed action.
, Lancet, Vol: 404, Pages: 1847-1896UNLABELLED: Despite the initial hope inspired by the 2015 Paris Agreement, the world is now dangerously close to breaching its target of limiting global multiyear mean heating to 1·5°C. Annual mean surface temperature reached a record high of 1·45°C above the pre-industrial baseline in 2023, and new temperature highs were recorded throughout 2024. The resulting climatic extremes are increasingly claiming lives and livelihoods worldwide. The Lancet Countdown: tracking progress on health and climate change was established the same year the Paris Agreement entered into force, to monitor the health impacts and opportunities of the world’s response to this landmark agreement. Supported through strategic core funding from Wellcome, the collaboration brings together over 300 multidisciplinary researchers and health professionals from around the world to take stock annually of the evolving links between health and climate change at global, regional, and national levels. The 2024 report of the Lancet Countdown, building on the expertise of 122 leading researchers from UN agencies and academic institutions worldwide, reveals the most concerning findings yet in the collaboration’s 8 years of monitoring. THE RECORD-BREAKING HUMAN COSTS OF CLIMATE CHANGE: Data in this year’s report show that people all around the world are facing record-breaking threats to their wellbeing, health, and survival from the rapidly changing climate. Of the 15 indicators monitoring climate change-related health hazards, exposures, and impacts, ten reached concerning new records in their most recent year of data. Heat-related mortality of people older than 65 years increased by a record-breaking 167%, compared with the 1990s, 102 percentage points higher than the 65% that would have been expected without temperature rise (indicator 1.1.5). Heat exposure is also increasingly affecting physical activity and sleep quality, in turn affecting physical and mental healt
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Journal articleCordeiro AA, Moorhouse L, Dadirai T, et al., 2024,
Intimate partner violence, behaviours associated with risk of HIV acquisition and condom use in married women in Manicaland, East Zimbabwe: an HIV prevention cascade analysis
, BMC Women's Health, Vol: 24, ISSN: 1472-6874BackgroundIntimate partner violence (IPV) is widespread in the WHO African region with generalised HIV epidemics and may contribute to ongoing HIV transmission through its associations with behaviours associated with HIV acquisition risk and low use of prevention methods particularly in marital relationships.MethodsWe conducted a male condom HIV prevention cascade analysis using data from a general-population survey in Manicaland, Zimbabwe (July 2018-December 2019) to develop an understanding of how interventions that reduce IPV might be built upon to also reduce HIV incidence. Multivariable logistic regression was used to measure associations between currently-married HIV-negative women’s experience of IPV and: (1) being in the priority population for HIV prevention methods (i.e. married women engaging in behaviours associated with HIV acquisition risk or with a spouse who engages in similar behaviours or is living with HIV), and (2) male condom use by women in this priority population. Male condom HIV prevention cascades, with explanatory barriers for gaps between successive cascade bars (motivation, access and effective use), were compared for women in the priority population reporting and not reporting IPV.ResultsWe found a positive association between IPV and being in the priority population for HIV prevention methods (72.3% versus 58.5%; AOR = 2.26, 95% CI:1.74–2.93). Condom use was low (< 15%) for women in the priority population and did not differ between those reporting and not reporting IPV. The HIV prevention cascades for women reporting and not reporting IPV were similar; both showing large gaps in motivation and capacity to use male condoms effectively. Women reporting motivation and access to male condoms were more likely to report their partner being a barrier to condom use if they experienced IPV (84.8% versus 75.5%; AOR = 2.25, 95% CI:1.17–4.31).ConclusionThe findings of this study support the
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Journal articleBarnsley G, Olivera Mesa D, Hogan A, et al., 2024,
Impact of the 100 days mission for vaccines on COVID-19: a mathematical modelling study
, The Lancet Global Health, Vol: 12, Pages: e1764-e1774, ISSN: 2214-109XBackgroundThe COVID-19 pandemic has underscored the beneficial impact of vaccines. It alsohighlighted the need for future investments to expedite an equitable vaccine distribution.The 100 Days Mission aims to develop and make available a new vaccine against a futurepathogen with pandemic potential within 100 days of that pathogen threat beingrecognised. We assessed the value of this mission by estimating the impact that it couldhave had on the COVID-19 pandemic.MethodsUsing a previously published model of SARS-CoV-2 transmission dynamics fit to excessmortality during the COVID-19 pandemic, we projected scenarios for three differentinvestment strategies: rapid development and manufacture of a vaccine, increasingmanufacturing capacity to eliminate supply constraints, and strengthening health systems toenable faster vaccine roll-outs and global equity. Each scenario was compared against theobserved COVID-19 pandemic to estimate the public health and health-economic impactsof each scenario.FindingsIf countries implemented non-pharmaceutical interventions (NPIs) as they did historically,the 100 Days Mission could have averted an estimated 8.33 million (95% credible interval7.70 – 8.68 million) deaths globally, mostly in low-middle income countries. Thiscorresponds to a monetary saving of $14.35 trillion (95% CrI $12.96 – $17.87) based on thevalue of statistical life years saved. Investment in manufacturing and health systems furtherincreases deaths averted to 11.01 million (95% CrI 10.60 – 11.49 million). Under analternative scenario whereby NPIs are lifted earlier based on vaccine coverage, the 100Days Mission alone could have reduced restrictions by 12,600 (95% CrI 12,300 – 13,100)days globally whilst still averting 5.76 million (95% CrI 4.91 – 6.81 million) deaths.InterpretationOur findings demonstrate the value of the 100 Days Mission and how these can beamplified through improvements in manufacturing and health systems equity. However,t
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