Dataset Information

The potential impact of preventive therapy against tuberculosis in the WHO South-East Asian Region: a modelling approach.

ABSTRACT:

Background

The prevention of tuberculosis (TB) is key for accelerating current, slow declines in TB burden. The 2018 World Health Organization (WHO) guidelines on eligibility for preventive therapy to treat latent TB infection (LTBI) include people living with human immunodeficiency virus (PLHIV), household contacts of TB patients including children, and those with clinical conditions including silicosis, dialysis, transplantation, etc. and other country-specific groups. We aimed to estimate the potential impact of full implementation of these guidelines in the WHO South-East Asian (SEA) Region, which bears the largest burden of TB and LTBI amongst the WHO regions.

Methods

We developed mathematical models of TB transmission dynamics, calibrated individually to each of the 11 countries in the region. We modelled preventive therapy in the absence of other TB interventions. As an alternative comparator, reflecting ongoing developments in TB control in the region, we also simulated improvements in the treatment cascade for active TB, including private sector engagement and intensified case-finding. Relative to both scenarios, for each country in the region, we projected TB cases and deaths averted between 2020 and 2030, by full uptake of preventive therapy, defined as comprehensive coverage amongst eligible populations as per WHO guidelines, and assuming outcomes consistent with clinical trials. We also performed sensitivity analysis to illustrate impact under less-than-optimal conditions.

Results

At the regional level, full uptake of preventive therapy amongst identified risk groups would reduce annual incidence rates in 2030 by 8.30% (95% CrI 6.48-10.83) relative to 2015, in the absence of any additional interventions. If implemented against a backdrop of improved TB treatment cascades, preventive therapy would achieve an incremental 6.93 percentage points (95% CrI 5.81-8.51) of reduction in annual incidence rates, compared to 2015. At the regional level, the numbers of individuals with latent TB infection that need to be treated to avert 1 TB case is 64 (95% CrI 55-74). Sensitivity analysis illustrates that results for impact are roughly proportional to 'effective coverage' (the product of actual coverage and effectiveness of the regimen).

Conclusions

Full implementation of WHO guidelines is important for ending TB in the SEA Region. Although future strategies will need to be expanded to the population level, to achieve large declines in TB incidence, the uptake of current tools can offer a valuable step in this direction.

SUBMITTER: Mandal S

PROVIDER: S-EPMC7369473 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Background & objectivesTo support recent political commitments to end tuberculosis (TB) in the World Health Organization South-East Asian Region (SEAR), there is a need to understand by what measures, and with what investment, these goals could be reached. These questions were addressed by using mathematical models of TB transmission by doing the analysis on a country-by-country basis in SEAR.MethodsA dynamical model of TB transmission was developed, in consultation with each of the 11 countries in the SEAR. Three intervention scenarios were examined: (i) strengthening basic TB services (including private sector engagement), (ii) accelerating TB case-finding and notification, and (iii) deployment of a prognostic biomarker test by 2025, to guide mass preventive therapy of latent TB infection. Each scenario was built on the preceding ones, in successive combination.ResultsComprehensive improvements in basic TB services by 2020, in combination with accelerated case-finding to increase TB detection by at least two-fold by 2020, could lead to a reduction in TB incidence rates in SEAR by 67.3 per cent [95% credible intervals (CrI) 65.3-69.8] and TB deaths by 80.9 per cent (95% CrI 77.9-84.7) in 2035, relative to 2015. These interventions alone would require an additional investment of at least US$ 25 billion. However, their combined effect is insufficient to reach the end TB targets of 80 per cent by 2030 and 90 per cent by 2035. Model projections show how additionally, deployment of a biomarker test by 2025 could end TB in the region by 2035. Targeting specific risk groups, such as slum dwellers, could mitigate the coverage needed in the general population, to end TB in the Region.Interpretation & conclusionsWhile the scale-up of currently available strategies may play an important role in averting TB cases and deaths in the Region, there will ultimately be a need for novel, mass preventive measures, to meet the end TB goals. Achieving these impacts will require a substantial escalation in funding for TB control in the Region.

Project description:Improving sexual, reproductive, maternal, newborn, and adolescent health outcomes necessitates greater commitment to, and investments in, midwifery. To identify future research priorities to advance and strengthen midwifery, we conducted a scoping review to synthesise and report areas of midwifery that have been explored in the previous 10 years in the 11 countries of the World Health Organization's South-East Asia region. Electronic peer-reviewed databases were searched for primary peer-reviewed research published in any language, published between January 2012 and December 2022 inclusive. A total of 7086 citations were screened against the review inclusion criteria. After screening and full text review, 195 sources were included. There were 94 quantitative (48.2%), 67 qualitative (34.4%) and 31 mixed methods (15.9%) studies. The majority were from Indonesia (n = 93, 47.7%), India (n = 41, 21.0%) and Bangladesh (n = 26, 13.3%). There were no sources identified from the Democratic People's Republic of Korea or the Maldives. We mapped the findings against six priority areas adapted from the 2021 State of the World's Midwifery Report and Regional Strategic Directions for Strengthening Midwifery in the South-East Asia region (2020-2024): practice or service delivery (n = 73, 37.4%), pre-service education (n = 60, 30.8%), in-service education or continuing professional development (n = 51, 26.2%), workforce management (n = 46, 23.6%), governance and regulation (n = 21, 10.8%) and leadership (n = 12, 6.2%). Most were published by authors with affiliations from the country where the research was conducted. The volume of published midwifery research reflects country-specific investment in developing a midwifery workforce, and the transition to midwifery-led care. There was variation between countries in how midwife was defined, education pathways, professional regulation, education accreditation, governance models and scope of practice. Further evaluation of the return on investment in midwifery education, regulation, deployment and retention to support strategic decision-making is recommended. Key elements of leadership requiring further exploration included career pathways, education and development needs and regulatory frameworks to support and embed effective midwifery leadership at all levels of health service governance.

Project description:BackgroundTrials of intermittent preventive treatment against malaria in infants (IPTi) using sulphadoxine-pyrimethamine (SP) have shown a positive, albeit variable, protective efficacy against clinical malaria episodes. The impact of IPTi in different epidemiological settings and over time is unknown and predictions are hampered by the lack of knowledge about how IPTi works. We investigated mechanisms proposed for the action of IPTi and made predictions of the likely impact on morbidity and mortality.Methods/principal findingsWe used a comprehensive, individual-based, stochastic model of malaria epidemiology to simulate recently published trials of IPTi using SP with site-specific characteristics as inputs. This baseline model was then modified to represent hypotheses concerning the duration of action of SP, the temporal pattern of fevers caused by individual infections, potential benefits of avoiding fevers on immunity and the effect of sub-therapeutic levels of SP on parasite dynamics. The baseline model reproduced the pattern of results reasonably well. None of the models based on alternative hypotheses improved the fit between the model predictions and observed data. Predictions suggest that IPTi would have a beneficial effect across a range of transmission intensities. IPTi was predicted to avert a greater number of episodes where IPTi coverage was higher, the health system treatment coverage lower, and for drugs which were more efficacious and had longer prophylactic periods. The predicted cumulative benefits were proportionately slightly greater for severe malaria episodes and malaria-attributable mortality than for acute episodes in the settings modelled. Modest increased susceptibility was predicted between doses and following the last dose, but these were outweighed by the cumulative benefits. The impact on transmission intensity was negligible.ConclusionsThe pattern of trial results can be accounted for by differences between the trial sites together with known features of malaria epidemiology and the action of SP. Predictions suggest that IPTi would have a beneficial impact across a variety of epidemiological settings.

Project description:BackgroundThe flat-headed cat (Prionailurus planiceps) is one of the world's least known, highly threatened felids with a distribution restricted to tropical lowland rainforests in Peninsular Thailand/Malaysia, Borneo and Sumatra. Throughout its geographic range large-scale anthropogenic transformation processes, including the pollution of fresh-water river systems and landscape fragmentation, raise concerns regarding its conservation status. Despite an increasing number of camera-trapping field surveys for carnivores in South-East Asia during the past two decades, few of these studies recorded the flat-headed cat.Methodology/principal findingsIn this study, we designed a predictive species distribution model using the Maximum Entropy (MaxEnt) algorithm to reassess the potential current distribution and conservation status of the flat-headed cat. Eighty-eight independent species occurrence records were gathered from field surveys, literature records, and museum collections. These current and historical records were analysed in relation to bioclimatic variables (WorldClim), altitude (SRTM) and minimum distance to larger water resources (Digital Chart of the World). Distance to water was identified as the key predictor for the occurrence of flat-headed cats (>50% explanation). In addition, we used different land cover maps (GLC2000, GlobCover and SarVision LLC for Borneo), information on protected areas and regional human population density data to extract suitable habitats from the potential distribution predicted by the MaxEnt model. Between 54% and 68% of suitable habitat has already been converted to unsuitable land cover types (e.g. croplands, plantations), and only between 10% and 20% of suitable land cover is categorised as fully protected according to the IUCN criteria. The remaining habitats are highly fragmented and only a few larger forest patches remain.Conclusion/significanceBased on our findings, we recommend that future conservation efforts for the flat-headed cat should focus on the identified remaining key localities and be implemented through a continuous dialogue between local stakeholders, conservationists and scientists to ensure its long-term survival. The flat-headed cat can serve as a flagship species for the protection of several other endangered species associated with the threatened tropical lowland forests and surface fresh-water sources in this region.

Project description:BackgroundProgress towards achieving Universal Health Coverage and institutionalizing healthcare priority setting through health technology assessment (HTA) in the Association of South-East Asian Nations (ASEAN) region varies considerably across countries because of differences in healthcare expenditure, political support, access to health information and technology infrastructure. To explore the status and capacity of HTA in the region, the ASEAN Secretariat requested for member countries to be surveyed to identify existing gaps and to propose solutions to help countries develop and streamline their priority-setting processes for improved healthcare decision-making.MethodsA mixed survey questionnaire with open- and closed-ended questions relating to HTA governance, HTA infrastructure, supply and demand of HTA and global HTA networking opportunities in each country was administered electronically to representatives of HTA nodal agencies of all ASEAN members. In-person meetings or email correspondence were used to clarify or validate any unclear responses. Results were collated and presented quantitatively.ResultsResponses from eight out of ten member countries were analysed. The results illustrate that countries in the ASEAN region are at different stages of HTA institutionalization. While Malaysia, Singapore and Thailand have well-established processes and methods for priority setting through HTA, other countries, such as Cambodia, Indonesia, Lao PDR, Myanmar, the Philippines and Vietnam, have begun to develop HTA systems in their countries by establishing nodal agencies or conducting ad-hoc activities.Discussion and conclusionThe study provides a general overview of the HTA landscape in ASEAN countries. Systematic efforts to mitigate the gaps between the demand and supply of HTA in each country are required while ensuring adequate participation from stakeholders so that decisions for resource allocation are made in a fair, legitimate and transparent manner and are relevant to each local context.

Project description:MERS coronavirus cases notified in the Middle East region since the identification of the virus in 2012 have displayed variations in time and across geography. Through a combined modelling approach, we estimate the rates of generation of cases along the zoonotic and human-to-human transmission routes and assess their spatiotemporal heterogeneity. We consider all cases notified to WHO from March 2012 to mid-September 2014. We use a stochastic modelling of the time series of case incidence in the Middle East region to estimate time- and space-dependent zoonotic and human-to-human transmission parameters. The model also accounts for possible lack of identification of secondary transmissions among notified cases. This approach is combined with the analysis of imported cases out of the region to assess the rate of underreporting of cases. Out of a total of 32 possible models, based on different parameterisation and scenario considered, the best-fit model is characterised by a large heterogeneity in time and across space for both zoonotic and human-to-human transmission. The variation in time that occurred during Spring 2014 led to a 17-fold and 3-fold increase in the two transmissions, respectively, bringing the reproductive rate to values above 1 during that period for all regions under study. The model suggests that 75% of MERS-CoV cases are secondary cases (human-to-human transmission), which is substantially higher than the 34% of reported cases with an epidemiological link to another case. Overall, estimated reporting rate is 0.26. Our findings show a higher level of spatial heterogeneity in zoonotic transmission compared to human-to-human, highlighting the strong environmental component of the epidemic. Since sporadic introductions are predicted to be a small proportion of notified cases and are responsible for triggering secondary transmissions, a more comprehensive understanding of zoonotic source and path of transmission could be critical to limit the epidemic spread.

Project description:BACKGROUND:Caesarean section is considered a relatively preferable and safe method of delivery as compared to normal delivery. Since the last decade, its prevalence has increased in both developed and developing countries. In the context of developing countries viz., South Asia (the highest populated region) and South-East Asia (the third-highest populated region), where a significant proportion of home deliveries were reported,however, the preference for, caesarean delivery and its associated factors are not well understood. OBJECTIVE:To study the caesarean delivery in the South and South-East Asian countries and to determine the factors associated with the preference for caesarean delivery. METHODOLOGY:Demographic and Health Survey Data on from ever-married women of nine developing countries of South and South-East Asia viz., Vietnam, India, Maldives, Timor-Leste, Nepal, Indonesia, Pakistan, Bangladesh, and Cambodia have been considered. Both bivariate and binary logistic regression models were used to estimate the propensity of a woman undergoing for caesarean delivery and to assess the influence of maternal socioeconomic characteristics towards the preference for caesarean delivery. RESULTS:Obtained results have shown an inclination of caesarean delivery among urban than rural women and are quite conspicuous, but is found to be underestimated mostly among rural women. Caesarean delivery in general is mostly predisposed among women whose baby sizes are either very large or smaller than average, have a higher level of education and place of delivery is private medical institutions. The logistic regression also revealed the influence of maternal socioeconomic characteristics towards the preference for caesarean delivery. Based on nine South and South-East Asian countries an overall C-section prevalence of 13%, but based on institutional births its increase to 19%. The forest plot demonstrated that a significant inclination of C-section among urban than rural regions. In Meta-Analysis, very high and significant heterogeneity among countries is observed, but confirms that in terms of prevalence of C-section all of the countries follow independent pattern. CONCLUSION:Study of seven urban and four rural regions of nine South and South- East Asian countries showed, a significant inclination towards the caesarean delivery above the more recent outdated WHO recommended an optimal range of 10-15%and are associated maternal socioeconomic characteristics. In order to control unwanted caesarean delivery, the government needs to develop better healthcare infrastructure and along with more antenatal care related schemes to reduce the risks associated with increased caesarean delivery.