Model-based geostatistical design and analysis of prevalence for soil-transmitted helminths in Kenya: Results from ten-years of the Kenya national school-based deworming programme.

Background: Kenya is endemic for soil-transmitted helminths (STH) with over 6 million children in 27 counties currently at-risk. A national school-based deworming programme (NSBDP) was launched in 2012 with a goal to eliminate parasitic worms as a public health problem. This study used model-based geostatistical (MBG) approach to design and analyse the impact of the NSBDP and inform treatment strategy changes. Methods: A cross-sectional study was used to survey 200 schools across 27 counties in Kenya. The study design, school selection and analysis followed the MBG approach which incorporated historical data on treatment, morbidity and environmental covariates to efficiently predict the helminths prevalence in Kenya. Results: Overall, the NSBDP geographic area prevalence for any STH was estimated to sit between 2 % and <10 % with a high predictive probability of >0.999. Species-specific thresholds were between 2 % and <10 % for Ascaris lumbricoides, 0 % to <2 % for hookworm, and 0 % to <2 % for Trichuris trichiura, all with high predictive probability of >0.999. Conclusions: Based on the World Health Organization guidelines, STH treatment requirements can now be confidently refined. Ten counties may consider suspending treatment and implement appropriate surveillance system, while another 10 will require treatment once every two years, and the remaining seven will require treatment once every year.

Low Prevalence of Soil-Transmitted Helminth Infections among Children in the States of Chhattisgarh and Himachal Pradesh, India, 2018.

Large-scale impact assessments of soil-transmitted helminth (STH) programs are essential for determining the frequency of mass drug administration (MDA). In baseline surveys, the prevalence of STHs in the Indian States of Chhattisgarh and Himachal Pradesh was 80.2% in 2015 and 29.0% in 2016, respectively. In 2018, we estimated the prevalence and intensity of STHs after six rounds of biannual MDA in Chhattisgarh and annual MDA in Himachal Pradesh. We conducted multistage cluster sampling surveys in preschool-age children (PSAC), school-age children (SAC), and adolescent cohorts. Stool samples from 3,033 respondents (PSAC, n = 625; SAC, n = 1,363; adolescents, n = 1,045) in Chhattisgarh and 942 respondents (PSAC, n = 192; SAC, n = 388; adolescents, n = 362) in Himachal Pradesh were examined for presence of STH infection using the Kato-Katz method. The overall cluster-adjusted prevalence in Chhattisgarh was 11.6% among all age groups (95% CI, 5.6-22.4)-an 85.5% reduction in the prevalence since 2015. Prevalence was not significantly different across cohorts (PSAC, 11.0% [95% CI, 5.0-22.6]; SAC, 10.9% [95% CI, 5.2-21.6]; adolescents, 12.8% [95% CI, 6.2-24.5]). Ascaris lumbricoides was the most common helminth, with most infections of light intensity. In Himachal Pradesh, only three STH infections were detected in 2018, resulting in a cluster-adjusted prevalence of 0.3% (95% CI, 0.1-1.7)-a 99.0% reduction in prevalence since 2016. All infections were of light intensity. Both states showed substantial improvements in socioeconomic and water, sanitation, and hygiene (WASH) indicators since the baseline surveys. Extensive reductions in prevalence and intensity are linked to sustained, high deworming coverage, as well as socioeconomic WASH indicators.

Cost-effectiveness and impact of pre-exposure prophylaxis to prevent HIV among men who have sex with men in Asia: A modelling study.

INTRODUCTION: More than 70% of new HIV infections in Asia occurred in eight countries in 2020: Cambodia, China, India, Indonesia, Myanmar, Nepal, Thailand, and Vietnam-with a rising incidence among men who have sex with men (MSM). The World Health Organization (WHO) recommends pre-exposure prophylaxis (PrEP) for those at risk of acquiring HIV, yet wide-scale implementation of PrEP, on a daily or event-driven basis, has been limited in Asia. METHODS: The Optima HIV model was applied to examine the impact of scaling-up PrEP over five-years to cover an additional 15% of MSM compared with baseline coverage, a target deemed feasible by regional experts. Based on behavioral survey data, we assume that covering 15% of higher-risk MSM will cover 30% of all sexual acts in this group. Scenarios to compare the impact of generic-brand daily dosing of PrEP with generic event-driven dosing (15 days a month) were modelled from the start of 2022 to the end of 2026. Cost-effectiveness of generic versus branded PrEP was also assessed for China, the only country with an active patent for branded, higher cost PrEP. The impact on new HIV infections among the entire population and cost per HIV-related disability-adjusted life year (DALY) averted were estimated from the beginning of 2022 to the end of 2031 and from 2022 to 2051. RESULTS: If PrEP were scaled-up to cover an additional 15% of MSM engaging in higher-risk behavior from the beginning of 2022 to the end of 2026 in the eight Asian countries considered, an additional 100,000 (66,000-130,000) HIV infections (17%) and 300,000 (198,000-390,000) HIV-related DALYs (3%) could be averted over the 2022 to 2031 period. The estimated cost per HIV-related DALY averted from 2022 to 2031 ranged from US$600 for event-driven generic PrEP in Indonesia to US$34,400 for daily branded PrEP in Thailand. Over a longer timeframe from 2022 to 2051, the cost per HIV-related DALY averted could be reduced to US$100-US$12,700. CONCLUSION: PrEP is a critical tool to further reduce HIV incidence in highly concentrated epidemics. Implementing PrEP in Asia may be cost-effective in settings with increasing HIV prevalence among MSM and if PrEP drug costs can be reduced, PrEP could be more cost-effective over longer timeframes.

Prevalence and Correlation Analysis of Soil-Transmitted Helminths Infections and Treatment Coverage for Preschool and School Aged Children in Kenya: Secondary Analysis of the National School Based Deworming Program Data.

Background: Soil-transmitted helminths (STH) are among the most common parasitic infections globally, disproportionately affecting children. Treatment of STH in Kenya is often targeted at preschool (PSAC) and school aged (SAC) children delivered through annual mass drug administration (MDA) in primary schools. Understanding group-specific prevalence and dynamics between treatment and coverage is critical for continued treatment success. This study aims to provide detailed information on group-specific infection prevalence and relative reductions (RR), and their relationships with treatment coverage over time. Additionally, it aims to quantify the correlation between the observed school level infection prevalence and treatment coverage. Methods: Secondary analysis of existing data collected between 2012 and 2018 by the monitoring and evaluation (M&E) program of the National School-Based Deworming (NSBD) program was used. The M&E program conducted surveys utilizing cross-sectional study design, at four survey time points, in a nationally-representative sample of schoolchildren across counties in Kenya. In each participating school, the program randomly sampled 108 children per school, of both groups. Infection prevalence was estimated using binomial regression, RR in prevalence using multivariable mixed effects model, statistical correlations using structural equation modeling, and change-point-analysis using the binary segmentation algorithm. Results: Overall, STH prevalence for PSAC was 33.7, 20.2, 19.0, and 17.9% during Year 1 (Y1), Year 3 (Y3), Year 5 (Y5), and Year 6 (Y6) surveys, respectively with an overall RR of 46.9% (p = 0.001) from Y1 to Y6. Similarly, overall STH prevalence for SAC was 33.6, 18.4, 14.7, and 12.5% during Y1, Y3, Y5, and Y6 surveys, respectively with an overall RR of 62.6% (p < 0.001). An overall (all time points) significant but very weak negative correlation was found between treatment coverage and undifferentiated STH prevalence (r = -0.144, p = 0.002) among PSAC but not in SAC. Further, we observed inter-county heterogeneity variation in infection prevalence, RR, as well as correlations. Conclusion: The analysis showed that after six rounds of MDA, prevalence of STH has significantly declined among both groups of children, however not to a point where it is not a public health problem (below 1%). The analysis, additionally established an overall significant but weak negative correlation between treatment coverage and prevalence, indicating that the current treatment coverage might not be sufficient to drive the overall STH prevalence to below 1%. These findings will allow STH control programs in Kenya to make decisions that will accelerate the attainment of STH elimination as a public health problem.

Model-Based Geostatistical Methods Enable Efficient Design and Analysis of Prevalence Surveys for Soil-Transmitted Helminth Infection and Other Neglected Tropical Diseases.

Maps of the geographical variation in prevalence play an important role in large-scale programs for the control of neglected tropical diseases. Precontrol mapping is needed to establish the appropriate control intervention in each area of the country in question. Mapping is also needed postintervention to measure the success of control efforts. In the absence of comprehensive disease registries, mapping efforts can be informed by 2 kinds of data: empirical estimates of local prevalence obtained by testing individuals from a sample of communities within the geographical region of interest, and digital images of environmental factors that are predictive of local prevalence. In this article, we focus on the design and analysis of impact surveys, that is, prevalence surveys that are conducted postintervention with the aim of informing decisions on what further intervention, if any, is needed to achieve elimination of the disease as a public health problem. We show that geospatial statistical methods enable prevalence surveys to be designed and analyzed as efficiently as possible so as to make best use of hard-won field data. We use 3 case studies based on data from soil-transmitted helminth impact surveys in Kenya, Sierra Leone, and Zimbabwe to compare the predictive performance of model-based geostatistics with methods described in current World Health Organization (WHO) guidelines. In all 3 cases, we find that model-based geostatistics substantially outperforms the current WHO guidelines, delivering improved precision for reduced field-sampling effort. We argue from experience that similar improvements will hold for prevalence mapping of other neglected tropical diseases.

Opportunities for improved HIV prevention and treatment through budget optimization in Eswatini.

INTRODUCTION: Eswatini achieved a 44% decrease in new HIV infections from 2014 to 2019 through substantial scale-up of testing and treatment. However, it still has one of the highest rates of HIV incidence in the world, with 14 infections per 1,000 adults 15-49 years estimated for 2017. The Government of Eswatini has called for an 85% reduction in new infections by 2023 over 2017 levels. To make further progress towards this target and to achieve maximum health gains, this study aims to model optimized investments of available HIV resources. METHODS: The Optima HIV model was applied to estimate the impact of efficiency strategies to accelerate prevention of HIV infections and HIV-related deaths. We estimated the number of infections and deaths that could be prevented by optimizing HIV investments. We optimize across HIV programs, then across service delivery modalities for voluntary medical male circumcision (VMMC), HIV testing, and antiretroviral refill, as well as switching to a lower cost antiretroviral regimen. FINDINGS: Under an optimized budget, prioritising HIV testing for the general population followed by key preventative interventions may result in approximately 1,000 more new infections (2% more) being averted by 2023. More infections could be averted with further optimization between service delivery modalities across the HIV cascade. Scaling-up index and self-testing could lead to 100,000 more people getting tested for HIV (25% more tests) with the same budget. By prioritizing Fast-Track, community-based, and facility-based antiretroviral refill options, an estimated 30,000 more people could receive treatment, 17% more than baseline or US$5.5 million could be saved, 4% of the total budget. Finally, switching non-pregnant HIV-positive adults to a Dolutegravir-based antiretroviral therapy regimen and concentrating delivery of VMMC to existing fixed facilities over mobile clinics, US$4.5 million (7% of total budget) and US$6.6 million (10% of total budget) could be saved, respectively. SIGNIFICANCE: With a relatively short five-year timeframe, even under a substantially increased and optimized budget, Eswatini is unlikely to reach their ambitious national prevention target by 2023. However, by optimizing investment of the same budget towards highly cost-effective VMMC, testing, and treatment modalities, further reductions in HIV incidence and cost savings could be realized.

Neonatal Mortality and Inequalities in Bangladesh: Differential Progress and Sub-national Developments.

A rapid reduction in under-five mortality has put Bangladesh on-track to reach Millennium Development Goal 4. Little research, however, has been conducted into neonatal reductions and sub-national rates in the country, with considerable disparities potentially masked by national reductions. The aim of this paper is to estimate national and sub-national rates of neonatal mortality to compute relative and absolute inequalities between sub-national groups and draw comparisons with rates of under-five mortality. Mortality rates for under-five children and neonates were estimated directly for 1980-1981 to 2010-2011 using data from six waves of the Demographic and Health Survey. Rates were stratified by levels of rural/urban location, household wealth and maternal education. Absolute and relative inequalities within these groups were measured by rate differences and ratios, and where possible, slope and relative indices of inequality. National mortality was shown to have decreased dramatically although at differential rates for under-fives and neonates. Across all equity markers, a general pattern of declining absolute but constant relative inequalities was found. For mortality rates stratified by education and wealth mixed evidence suggests that relative inequalities may have also fallen. Although disparities remain, Bangladesh has achieved a rare combination of substantive reductions in mortality levels without increases in relative inequalities. A coalescence of substantial increases in coverage and equitable distribution of key child and neonatal interventions with widespread health sectoral and policy changes over the last 30 years may in part explain this exceptional pattern.

A cross sectional study of knowledge and attitudes towards tuberculosis amongst front-line tuberculosis personnel in high burden areas of Lima, Peru.

INTRODUCTION: Tuberculosis, reported as the second most common infectious cause of death worldwide, is a key mortality contributor in developing countries and globally. The disease is endemic in Peru and while relative success was achieved during the 1990s in its control, this slowed as new complications, such as multi drug resistant TB arose. Health centre workers participating in the national DOTS program, create the front-line TB work-force in Peru meaning their knowledge and attitudes about the disease are key in its control. METHODS: A Spanish language, multiple choice knowledge and attitudes survey was designed based on previous successful studies and the national Peruvian TB control guidelines. It was applied to two health networks in Lima, Peru amongst 301 health workers participating in the national TB control program from 66 different health centres. The study results were analysed to test mean knowledge scores amongst different groups, overall gaps in key areas of TB treatment and control knowledge, and attitudes towards the disease and the national TB control program. RESULTS: A mean knowledge score of 10.1 (+/- 1.7) out of 15 or 67.3% correct was shown. Demographics shown to have an effect on knowledge score were age and level of education. Major knowledge gaps were noted primarily in themes relating to treatment and diagnostics. Greater community involvement including better patient education about TB was seen as important in implementing the national TB control program. Participants were in disagreement about the current distribution of health resources throughout the study area. Discussion Serious knowledge gaps were identified from the survey; these reflect findings from a previous study in Lima and other studies from TB endemic areas throughout the world. Understanding these gaps and observations made by front-line TB workers in Lima may help to improve the national TB control program and other control efforts globally.

Disparities in child mortality trends in two new states of India.

BACKGROUND: India has the world's highest total number of under-five deaths of any nation. While progress towards Millennium Development Goal 4 has been documented at the state level, little information is available for greater disaggregation of child health markers within states. In 2000, new states were created within the country as a partial response to political pressures. State-level information on child health trends in the new states of Chhattisgarh and Jharkhand is scarce. To fill this gap, this article examines under-five and neonatal mortality across various equity markers within these two new states, pre-and post-split. METHODS: Both direct and indirect estimation using pooled data from five available sources were undertaken. Inter-population disparities were evaluated by mortality data stratification of rural-urban location, ethnicity, wealth and districts. RESULTS: Both states experienced an overall reduction in under-five and neonatal mortality, however, this has stagnated post-2001 and various disparities persist. In cases where disparities have declined, such as between urban-rural populations and low- and high-income groups, this has been driven by modest declines within the disadvantaged groups (i.e. low-income rural households) and stagnation or worsening of outcomes within the advantaged groups. Indeed, rising trends in mortality are most prevalent in urban middle-income households. CONCLUSIONS: The results suggest that rural health improvements may have come at the expense of urban areas, where poor performance may be attributed to factors such as lack of access to quality private health facilities. In addition, the disparities may in part be associated with geographical access, traditional practices and district-level health resource allocation.