Prevalence of major non-communicable diseases and their associated risk factors in Afghanistan: a systematic review and meta-analysis

Background

Non-communicable diseases (NCDs) are the leading cause of mortality worldwide, and increasingly so in low- and middle-income countries. Afghanistan is dealing with a double burden of diseases, yet there has been no evidence synthesis on the prevalence of major NCDs and their risk factors.

Objective

This study aims to provide a comprehensive synthesis of the existing data on the prevalence of major NCDs and the common related risk factors in Afghanistan.

Method

We systematically reviewed scientific articles from 2000 to 2022 that reported the prevalence of diabetes, chronic respiratory diseases (CRDs), cardiovascular diseases (CVDs) or cancer, and their risk factors in Afghanistan. Four online databases (PubMed, Web of Science, Cochrane and Google Scholar) and two local journals in Afghanistan (not indexed online) were systematically searched and screened. Two reviewers independently screened and appraised the quality of the articles. Data extraction and synthesis were performed using tabulated sheets.

Results

Among 51 eligible articles, 10 (19.6%) focused on cancer, 10 (19.6%) on diabetes, 4 (7.8%) on CVDs, 4 (7.8%) on CRDs and 23 (45.1%) on risk factors as the primary outcome. Few articles addressed major NCD prevalence; no evidence of CVDs, cancer was 0.15%, asthma ranged between 0.3% and 17.3%, and diabetes was 12%. Pooled prevalence of hypertension and overweight were 31% and 35%, respectively. Central obesity was twice as prevalent in females (76% versus 40%). Similarly, gender differences were observed in smoking and snuff use with prevalence rates of 14% and 25% among males and 2% and 3% among females, respectively. A total of 14% of the population engaged in vigorous activity. Pooled prevalence for physical inactivity, general obesity, fruit and vegetable consumption, dyslipidaemia and alcohol consumption couldn't be calculated due to the heterogeneity of articles.

Conclusion

Only little evidence is available on the prevalence of major NCDs in Afghanistan; however, the NCD risk factors are prevalent across the country. The quality of the available data, especially those of the local resources, is poor; therefore, further research should generate reliable evidence in order to inform policymakers on prioritizing interventions for controlling and managing NCDs.

Secondary vectors of Zika Virus, a systematic review of laboratory vector competence studies

BACKGROUND

After the unprecedented Zika virus (ZIKV) outbreak in the western hemisphere from 2015-2018, Aedes aegypti and Ae. albopictus are now well established primary and secondary ZIKV vectors, respectively. Consensus about identification and importance of other secondary ZIKV vectors remain. This systematic review aims to provide a list of vector species capable of transmitting ZIKV by reviewing evidence from laboratory vector competence (VC) studies and to identify key knowledge gaps and issues within the ZIKV VC literature.

METHODS

A search was performed until 15th March 2022 on the Cochrane Library, Lilacs, PubMed, Web of Science, WHOLIS and Google Scholar. The search strings included three general categories: 1) "ZIKA"; 2) "vector"; 3) "competence", "transmission", "isolation", or "feeding behavior" and their combinations. Inclusion and exclusion criteria has been predefined and quality of included articles was assessed by STROBE and STROME-ID criteria.

FINDINGS

From 8,986 articles retrieved, 2,349 non-duplicates were screened by title and abstracts,103 evaluated using the full text, and 45 included in this analysis. Main findings are 1) secondary vectors of interest include Ae. japonicus, Ae. detritus, and Ae. vexans at higher temperature 2) Culex quinquefasciatus was not found to be a competent vector of ZIKV, 3) considerable heterogeneity in VC, depending on the local mosquito strain and virus used in testing was observed. Critical issues or gaps identified included 1) inconsistent definitions of VC parameters across the literature; 2) equivalency of using different mosquito body parts to evaluate VC parameters for infection (mosquito bodies versus midguts), dissemination (heads, legs or wings versus salivary glands), and transmission (detection or virus amplification in saliva, FTA cards, transmission to neonatal mice); 3) articles that fail to use infectious virus assays to confirm the presence of live virus; 4) need for more studies using murine models with immunocompromised mice to infect mosquitoes.

CONCLUSION

Recent, large collaborative multi-country projects to conduct large scale evaluations of specific mosquito species represent the most appropriate approach to establish VC of mosquito species.

Interventions against Aedes/dengue at the household level: a systematic review and meta-analysis

BACKGROUND

Because the evidence for the role of structural housing and combinations of interventions (domestic or peri-domestic) against Aedes mosquitoes or dengue is still lacking, this systematic review and meta-analysis aimed to analyse and synthesize research focusing on the household as the unit of allocation.

METHODS

We searched MEDLINE, LILACS, and Web of Science databases until February 2023 using three general keyword categories: (1) "Aedes" or "dengue"; (2) structural housing interventions including "house", "water", or "drainage"; and (3) vector control interventions of potential relevance and their combinations. We performed a qualitative content analysis and a meta-analysis for 13 entries on dengue seroconversion data.

FINDINGS

14,272 articles were screened by titles, 615 by abstracts, 79 by full-text. 61 were selected. Satisfactory data quality allowed for detailed content analysis. Interventions at the household level against the immature mosquito stages (21 studies, 34%) showed positive or mixed results in entomological and epidemiological outcomes (86% and 75% respectively). Combined interventions against immature and adult stages (11 studies, 18%) performed similarly (91% and 67%) while those against the adult mosquitoes (29 studies, 48%) performed less well (79%, 22%). A meta-analysis on seroconversion outcomes showed a not-statistically significant reduction for interventions (log odds-ratio: -0.18 [-0.51, 0.14 95% CI]).

INTERPRETATION

No basic research on housing structure or modification was eligible for this systematic review but many interventions with clear impact on vector indices and, to a lesser extent, on dengue were described. The small and not-statistically significant effect size of the meta-analysis highlights the difficulty of proving effectiveness against this highly-clustered disease and of overcoming practical implementation obstacles (e.g. efficacy loss, compliance). The long-term success of interventions depends on suitability, community commitment and official support and promotion. The choice of a specific vector control package needs to take all these context-specific aspects into consideration.

FUNDING

This work was funded by a grant from the World Health Organization (2021/1121668-0, PO 202678425, NTD/VVE).

The prevalence of emotional abuse in children living in Sub-Saharan Africa - A systematic review

OBJECTIVES

This study is meant to put a focus on the prevalence of emotional abuse in low-income states like the Sub-Saharan region.

METHODOLOGY

Searching PubMed, Google scholar, and web of science during February and April 2021 a total of 2264 articles were identified, 27 met the inclusion criteria. We added the results of 13 VAC (Violence Against Children and Youth) studies, conducted by UNICEF capturing information about experienced sexual, physical, or emotional violence in 13-24-year-olds, as well as 56 MIC (Multiple Indicator Cluster) studies, conducted by the CDC to research the disciplinary methods used with children aged 1-14 years in the past month by older household members. Finally, in a meta-analytic approach, we aimed to calculate a pooled estimate of the prevalence.

RESULTS

The included studies depicted a wide range in prevalence rates across countries. For example, while the VAC study in Lesotho in 2018 showed low incidence rates of emotional violence (6.9 % Females, 3.8 % Males), the average prevalence recorded by the MIC study was as high as 57.8 % for females and 59.2 % for males. On average, the MIC studies displayed a higher incidence and the discrepancy of prevalence of emotional abuse between females and males was small. Calculating a pooled estimate of the prevalence was not possible, due to the heterogeneity of the data.

CONCLUSIONS

In general countries displayed a high prevalence. A standardized use of a uniform definition of emotional abuse might help to display a more homogenous data set in the future, giving the opportunity for pooled estimates of prevalence.

Evaluation of the Ghana Heart Initiative - Design and Rationale of a Pragmatic Mixed-Methods Study from Diverse Perspectives: A Study Protocol

Background

Rigorous evaluations of health system interventions to strengthen hypertension and cardiovascular disease (CVD) care remain scarce in sub-Saharan Africa. This study aims to evaluate the reach, effectiveness, adoption / acceptability, implementation fidelity, cost, and sustainability of the Ghana Heart Initiative (GHI), a multicomponent supply-side intervention to improve cardiovascular health in Ghana.

Methods

This study adopts a mixed- and multi-methods design comparing the effects of the GHI in 42 intervention health facilities (i.e. primary, secondary and tertiary) in the Greater Accra Region versus 56 control health facilities in the Central and Western Regions. The evaluation design is guided by the RE-AIM framework underpinned by the WHO health systems building blocks framework, integrated by the Institute of Medicine's six dimensions of health care quality: safe, effective, patient-centered, timely, effi cient, equitable. The assessment tools include: (i) a health facility survey, (ii) a healthcare provider survey assessing the knowledge, attitudes, and practices on hypertension and CVD management, (iii) a patient exit survey, (iv) an outpatient and in-patient medical record review and (v) qualitative interviews with patients and various health system stakeholders to understand the barriers and facilitators around the implementation of the GHI. In addition to primary data collection, the study also relies on secondary routine health system data, i.e., the District Health Information Management System to conduct an interrupted time series analysis using monthly counts for relevant hypertension and CVD specific indicators as outcomes. The primary outcome measures are performance of health service delivery indicators, input, process and outcome of care indicators (including screening of hypertension, newly diagnosed hypertension, prescription of guideline directed medical therapy, and satisfaction with service received and acceptability) between the intervention and control facilities. Lastly, an economic evaluation and budget impact analysis is planned to inform the nationwide scale-up of the GHI.

Discussion

This study will generate policy-relevant data on the reach, effectiveness, implementation fidelity, adoption / acceptability, and sustainability of the GHI, and provide insights on the costs and budget-impacts to inform nation-wide scale-up to expand the GHI to other regions across Ghana and offer lessons to other low- and middle-income countries settings as well.

RIDIE Registration Number

RIDIE-STUDY-ID-6375e5614fd49 (https://ridie.3ieimpact.org/index.php).

Prevalence of anemia among Indigenous children in Latin America: a systematic review

OBJECTIVE

To describe the prevalence pattern of anemia among Indigenous children in Latin America.

METHODS

PRISMA guidelines were followed. Records were identified from the databases PubMed, Google Scholar, and Lilacs by two independent researchers between May and June 2021. Studies were included if the following criteria were met: a) studied Indigenous people b) was about children (from 0 to 12 years old); c) reported a prevalence estimate of anemia; d) had been conducted in any of the countries of Latin America; e) was published either in English, Portuguese, or Spanish; f) is a peer-reviewed article; and g) was published at any date.

RESULTS

Out of 2,401 unique records retrieved, 42 articles met the inclusion criteria. A total of 39 different Indigenous communities were analyzed in the articles, and in 21 of them (54.0%) child anemia was a severe public health problem (prevalence ≥ 40%). Those communities were the Aymara (Bolivia); Aruak, Guaraní, Kamaiurá, Karapotó, Karibe, Kaxinanuá, Ma-cro-Jê, Suruí, Terena, Xavante (Brazil); Cabécar (Costa Rica), Achuar, Aguaruna, Awajún, Urarina, Yomybato (Peru); Piaroa and Yucpa (Venezuela); and Quechua (Peru and Bolivia). Children below two years had the highest prevalence of anemia (between 16.2% and 86.1%). Among Indigenous people, risk factors for anemia include nutrition, poor living conditions, access to health services, racism, and discrimination. Bolivia and Guatemala are scarcely studied, despite having the highest proportion of Indigenous communities in Latin America.

CONCLUSIONS

Anemia constitutes a poorly documented public health problem among Indigenous children in 21 Indigenous communities in Bolivia, Brazil, Colombia, Costa Rica, Ecuador, Guatemala, Mexico, and Peru. In all Indigenous communities included in this study child anemia was an issue, especially in younger children.

Prevalence of unnecessary antibiotic use in European hospitals – a systematic review

Background

Antibiotics (AB) are essential to modern day medicine as prophylaxis and therapy. Yet, unnecessary use has various negative effects on individual and global health, such as antimicrobial resistance (AMR) and contribution to high greenhouse gas (GHG) emissions of the healthcare sector. This systematic review provides an overview of unnecessary AB use in European hospitals in order to present possible ways forward.

Methods

The systematic review followed PRISMA guidelines, included as databases were: Embase, ProQuest Environmental Science Collection, PubMed, ScienceDirect, Scopus and Web of Science. Studies conducted among adult in-patients in EU/EEA countries were included if they provided assessment methodology, included a clear standard of measurement and chart reviews were used as evaluation basis.

Results

Fifty-six included studies were categorised into the following three groups: (1) Studies using an established evaluation method; 20 studies belong to this group, 18 used the same, established approach. Eleven of these studies performed an observational audit, while the interventions in the remaining studies were of educational or advisory nature. Unnecessary AB use ranged from 1.5% to 51% of all observed prescriptions. Outcomes of interventions showed great variation of effects on unnecessary use (-34.7% - +11.6). (2) Studies using a newly developed, clearly stated evaluation method (4 studies); (3) Studies which conform with established evaluation methods but the processes were not specified (32 studies). Results are subject to further analysis.

Conclusions

The studies included reported a great range of unnecessary AB use in adult in-patients, for both prophylactic and therapeutic indications. Evaluation methods of unnecessary AB use vary greatly between studies. In future research, comprehensive application of established approaches is essential for better overview and identification of key areas for AMR and GHG emission reduction activities.

Key messages

• Unnecessary antibiotic use varies greatly among studies conducted in European adult in-patients.

• In future research, wider application of established evaluation methods will improve comparability and targeting of interventions.

The economic burden of treating uncomplicated hypertension in Sub-Saharan Africa: a systematic literature review

Background and Objectives

Hypertension is one of the leading cardiovascular risk factors with high numbers of undiagnosed and untreated patients in Sub Saharan Africa (SSA). The health systems and affected people are often overwhelmed by the social and economic burden that comes with the disease. However, the research on the economic burden and consequences of hypertension treatment remains scare in SSA. The objective of our review was to compare different hypertension treatment costs across the continent and identify major cost drivers.

Material and Methods

Systematic literature searches were conducted in multiple databases (e.g., PubMed, Web of Science, Google Scholar) for peer reviewed articles written in English language with a publication date from inception to Jan. 2022. We included studies assessing direct and indirect costs of hypertension therapy in SSA from a provider or user perspective. The search and a quality assessment were independently executed by two researchers. All results were converted to 2021 US Dollar.

Results

Of 3999 results identified in the initial search, 33 were selected for data extraction. Costs differed between countries, costing perspectives and cost categories. Only 25% of the SSA countries were mentioned in the studies, with Nigeria dominating the research with a share of 27% of the studies. We identified 15 results each from a user or provider perspective. Medication costs were accountable for the most part of the expenditures with a range from 1.70$ to 97.06$ from a patient perspective and 0.09$ to 193.55$ from a provider perspective per patient per month. Major cost drivers were multidrug treatment, inpatient or hospital care and having a comorbidity like diabetes.

Conclusion

Hypertension poses a significant economic burden for patients and governments in SSA. Interpreting and comparing the results from different countries and studies is difficult as there are different financing methods and cost items are defined in different ways. However, our results identify medication costs as one of the biggest cost contributors. When fighting the economic burden in SSA, reducing medication costs in form of subsidies or special interventions needs to be considered.

Trial registration

Registration: PROSPERO, ID CRD42020220957.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13877-4.

Real-life Evaluation of an Interactive Versus Noninteractive e-Learning Module on Chronic Obstructive Pulmonary Disease for Medical Licentiate Students in Zambia: Web-Based, Mixed Methods Randomized Controlled Trial

BACKGROUND

e-Learning for health professionals in many low- and middle-income countries (LMICs) is still in its infancy, but with the advent of COVID-19, a significant expansion of digital learning has occurred. Asynchronous e-learning can be grouped into interactive (user-influenceable content) and noninteractive (static material) e-learning. Studies conducted in high-income countries suggest that interactive e-learning is more effective than noninteractive e-learning in increasing learner satisfaction and knowledge; however, there is a gap in our understanding of whether this also holds true in LMICs.

OBJECTIVE

This study aims to validate the hypothesis above in a resource-constrained and real-life setting to understand e-learning quality and delivery by comparing interactive and noninteractive e-learning user satisfaction, usability, and knowledge gain in a new medical university in Zambia.

METHODS

We conducted a web-based, mixed methods randomized controlled trial at the Levy Mwanawasa Medical University (LMMU) in Lusaka, Zambia, between April and July 2021. We recruited medical licentiate students (second, third, and fourth study years) via email. Participants were randomized to undergo asynchronous e-learning with an interactive or noninteractive module for chronic obstructive pulmonary disease and informally blinded to their group allocation. The interactive module included interactive interfaces, quizzes, and a virtual patient, whereas the noninteractive module consisted of PowerPoint slides. Both modules covered the same content scope. The primary outcome was learner satisfaction. The secondary outcomes were usability, short- and long-term knowledge gain, and barriers to e-learning. The mixed methods study followed an explanatory sequential design in which rating conferences delivered further insights into quantitative findings, which were evaluated through web-based questionnaires.

RESULTS

Initially, 94 participants were enrolled in the study, of whom 41 (44%; 18 intervention participants and 23 control participants) remained in the study and were analyzed. There were no significant differences in satisfaction (intervention: median 33.5, first quartile 31.3, second quartile 35; control: median 33, first quartile 30, second quartile 37.5; P=.66), usability, or knowledge gain between the intervention and control groups. Challenges in accessing both e-learning modules led to many dropouts. Qualitative data suggested that the content of the interactive module was more challenging to access because of technical difficulties and individual factors (eg, limited experience with interactive e-learning).

CONCLUSIONS

We did not observe an increase in user satisfaction with interactive e-learning. However, this finding may not be generalizable to other low-resource settings because the post hoc power was low, and the e-learning system at LMMU has not yet reached its full potential. Consequently, technical and individual barriers to accessing e-learning may have affected the results, mainly because the interactive module was considered more difficult to access and use. Nevertheless, qualitative data showed high motivation and interest in e-learning. Future studies should minimize technical barriers to e-learning to further evaluate interactive e-learning in LMICs.

COVID-19-related knowledge, attitudes and practices: a mixed-mode cross-sectional survey in Liberia

OBJECTIVES

To examine the knowledge, attitudes and practices (KAP) of COVID-19 of rural and urban residents in Liberia to inform the development of local social and behaviour change communication strategies.

DESIGN

Cross-sectional, mixed-mode (online and telephone) survey using non-probability sampling.

SETTING

All 15 counties in Liberia with a focus on Maryland County.

PARTICIPANTS

From 28 May to 28 June 2020, data were collected from a total of 431 adults aged 18 years and older (telephone 288 (66.8%); online 143 (33.2%)) out of a total of 741 contacts.

MAIN OUTCOME MEASURES

KAP scores. Frequencies and proportions were calculated, followed by univariate and multivariable analyses to examine the association between KAP scores and the sociodemographic variables.

RESULTS

Around 69% of the online survey respondents were younger than 35 years of age, compared with 56% in the telephone interviews. The majority (87%) of online respondents had completed tertiary education, compared with 77% of the telephone respondents. Male participants, on average, achieved higher knowledge (52%) and attitude scores (72%), in contrast to females (49% and 67%, respectively). Radio (71%) was the most cited source for COVID-19 information, followed by social media (63%). After controlling for sociodemographic variables, adaptive regression modelling revealed that survey mode achieved 100% importance for predicting knowledge and practice levels with regard to COVID-19.

CONCLUSIONS

The survey population demonstrated moderate COVID-19 knowledge, with significant differences between survey mode and educational level. Correct knowledge of COVID-19 was associated with appropriate practices in Maryland County. Generalisation of survey findings must be drawn carefully owing to the limitations of the sampling methods. Yet, given the differences in knowledge gaps between survey modes, sex, education, occupation and place of residence, it is recommended that information is tailored to different audiences.

Is biological larviciding against malaria a starting point for integrated multi-disease control? Observations from a cluster randomized trial in rural Burkina Faso

Objectives

To evaluate the impact of anti-malaria biological larviciding with Bacillus thuringiensis israelensis on non-primary target mosquito species in a rural African setting.

Methods

A total of 127 villages were distributed in three study arms, each with different larviciding options in public spaces: i) no treatment, ii) full or iii) guided intervention. Geographically close villages were grouped in clusters to avoid contamination between treated and untreated villages. Adult mosquitoes were captured in light traps inside and outside houses during the rainy seasons of a baseline and an intervention year. After enumeration, a negative binomial regression was used to determine the reductions achieved in the different mosquito species through larviciding.

Results

Malaria larviciding interventions showed only limited or no impact against Culex mosquitoes; by contrast, reductions of up to 34% were achieved against Aedes when all detected breeding sites were treated. Culex mosquitoes were captured in high abundance in semi-urban settings while more Aedes were found in rural villages.

Conclusions

Future malaria larviciding programs should consider expanding onto the breeding habitats of other disease vectors, such as Aedes and Culex and evaluate their potential impact. Since the major cost components of such interventions are labor and transport, other disease vectors could be targeted at little additional cost.

Performance of alternative COPD case-finding tools: a systematic review and meta-analysis

RATIONALE

Guidelines recommend pre-/post-bronchodilator spirometry for diagnosing COPD, but resource constraints limit the availability of spirometry in primary care in low- and middle-income countries. Although spirometry is the diagnostic gold standard, we shall assess alternative tools for settings without spirometry.

METHODS

A systematic literature review and meta-analysis was conducted, utilising Cochrane, CINAHL, Google Scholar, PubMed and Web of Science (search cut-off was May 01, 2020). Published studies comparing the accuracy of diagnostic tools for COPD with post-bronchodilator spirometry were considered. Studies without sensitivity/specificity data, without a separate validation sample and outside of primary care were excluded. Sensitivity, specificity and area under the curve (AUC) were assessed.

RESULTS

Of 7578 studies, 24 were included (14 635 participants). Hand devices yielded a larger AUC than questionnaires. The meta-analysis included 17 studies and the overall AUC of micro-spirometers (0.84, 95% CI 0.80-0.89) was larger when compared to the COPD population screener (COPD-PS) questionnaire (0.77, 95% CI 0.63-0.85) and the COPD diagnostic questionnaire (CDQ) (0.72, 95% CI 0.64-0.78). However, only the difference between micro-spirometers and the CDQ was significant.

CONCLUSIONS

The CDQ and the COPD-PS questionnaire were approximately equally accurate tools. Questionnaires ensured testing of symptomatic patients, but micro-spirometers were more accurate. A combination could increase accuracy but was not evaluated in the meta-analysis.

Biological larviciding against malaria vector mosquitoes with Bacillus thuringiensis israelensis (Bti) - Long term observations and assessment of repeatability during an additional intervention year of a large-scale field trial in rural Burkina Faso

The first line of malaria vector control to date mainly relies on the use of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS). For integrated vector management, targeting the vector larvae with biological larvicides such as Bacillus thuringiensis israelensis (Bti) can be an effective additional mainstay. This study presents data from the second intervention year of a large-scale trial on biological larviciding with Bti that was carried out in 127 rural villages and a semi-urban town in Burkina Faso. Here we present the reductions in malaria mosquitoes that were achieved by continuing the initial interventions for an additional year, important to assess sustainability and repeatability of the results from the first intervention year. Larviciding was performed applying two different larviciding choices ((a) treatment of all environmental breeding sites, and (b) selective treatment of those that were most productive for Anopheles larvae indicated by remote sensing based risk maps). Adult Anopheles spp. mosquito abundance was reduced by 77.4% (full treatment) and 63.5% (guided treatment) compared to the baseline year. The results showed that malaria vector abundance can be dramatically reduced using biological larviciding and that this effect can be achieved and maintained over several consecutive transmission seasons.

Reduction of malaria vector mosquitoes in a large-scale intervention trial in rural Burkina Faso using Bti based larval source management

Background

Malaria remains one of the most important causes of morbidity and death in sub-Saharan Africa. Along with early diagnosis and treatment of malaria cases and intermittent preventive treatment in pregnancy (IPTp), vector control is an important tool in the reduction of new cases. Alongside the use of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS), targeting the vector larvae with biological larvicides, such as Bacillus thuringiensis israelensis (Bti) is gaining importance as a means of reducing the number of mosquito larvae before they emerge to their adult stage. This study presents data corroborating the entomological impact of such an intervention in a rural African environment.

Methods

The study extended over 2 years and researched the impact of biological larviciding with Bti on malaria mosquitoes that were caught indoors and outdoors of houses using light traps. The achieved reductions in female Anopheles mosquitoes were calculated for two different larviciding choices using a regression model.

Results

In villages that received selective treatment of the most productive breeding sites, the number of female Anopheles spp. dropped by 61% (95% CI 54–66%) compared to the pre-intervention period. In villages in which all breeding sites were treated, the number of female Anopheles spp. was reduced by 70% (95% CI 64–74%) compared to the pre-intervention period.

Conclusion

It was shown that malaria vector abundance can be dramatically reduced through larviciding of breeding habitats and that, in many geographical settings, they are a viable addition to current malaria control measures.

Lessons learned on teaching a global audience with massive open online courses (MOOCs) on health impacts of climate change: a commentary

BACKGROUND

The adverse health impacts of climate change are increasing on a global level. However, knowledge about climate change and health is still unavailable to many global citizens, in particular on adaptation measures and co-benefits of health mitigation. Educational technologies, such as massive open online courses (MOOCs), may have a high potential for providing access to information about climate change links to health for a global audience.

MAIN BODY

We developed three MOOCs addressing the link between climate change and health to take advantage of the methodology's broad reach and accelerate knowledge dissemination on the nexus of climate change and health. The primary objective was to translate an existing face-to-face short course that only reached a few participants on climate change and health into globally accessible learning opportunities. In the following, we share and comment on our lessons learned with the three MOOCs, with a focus on global teaching in the realm of climate change and health.

CONCLUSIONS

Overall, the three MOOCs attracted a global audience with diverse educational backgrounds, and a large number of participants from low-income countries. Our experience highlights that MOOCs may play a part in global capacity building, potentially for other health-related topics as well, as we have found that our MOOCs have attracted participants within low-resource contexts. MOOCs may be an effective method for teaching and training global students on health topics, in this case on the complex links and dynamics between climate change and health and may further act as an enabler for equitable access to quality education.

Investigating spatio-temporal distribution and diffusion patterns of the dengue outbreak in Swat, Pakistan

INTRODUCTION

Dengue has been endemic to Pakistan in the last two decades. There was a massive outbreak in the Swat valley in 2013. Here we demonstrate the spatio-temporal clustering and diffusion patterns of the dengue outbreak.

METHODS

Dengue case data were acquired from the hospital records in the Swat district of Pakistan. Ring maps visualize the distribution and diffusion of the number of cases and incidence of dengue at the level of the union council. We applied space-time scan statistics to identify spatio-temporal clusters. Ordinary least squares and geographically weighted regression models were used to evaluate the impact of elevation, population density, and distance to the river.

RESULTS

The results show that dengue distribution is not random, but clustered in space and time in the Swat district. Males constituted 68% of the cases while females accounted for about 32%. A majority of the cases (>55%) were younger than 40 years of age. The southern part was a major hotspot affected by the dengue outbreak in 2013. There are two space-time clusters in the spatio-temporal analysis. GWR and OLS show that population density is a significant explanatory variable for the dengue outbreak, while GWR exhibits better performance in terms of 'R²=0.49 and AICc=700'.

CONCLUSION

Dengue fever is clustered in the southern part of the Swat district. This region is relatively urban in character, with most of the population of the district residing here. There is a need to strengthen the surveillance system for reporting dengue cases in order to respond to future outbreaks in a robust way.

Novel tools for the surveillance and control of dengue: findings by the DengueTools research consortium

BACKGROUND

Dengue fever persists as a major global disease burden, and may increase as a consequence of climate change. Along with other measures, research actions to improve diagnosis, surveillance, prevention, and predictive models are highly relevant. The European Commission funded the DengueTools consortium to lead a major initiative in these areas, and this review synthesises the outputs and findings of this work conducted from 2011 to 2016. Research areas: DengueTools organised its work into three research areas, namely [1] Early warning and surveillance systems; [2] Strategies to prevent dengue in children; and [3] Predictive models for the global spread of dengue. Research area 1 focused on case-studies undertaken in Sri Lanka, including developing laboratory-based sentinel surveillance, evaluating economic impact, identifying drivers of transmission intensity, evaluating outbreak prediction capacity and developing diagnostic capacity. Research area 2 addressed preventing dengue transmission in school children, with case-studies undertaken in Thailand. Insecticide-treated school uniforms represented an intriguing potential approach, with some encouraging results, but which were overshadowed by a lack of persistence of insecticide on the uniforms with repeated washing. Research area 3 evaluated potential global spread of dengue, particularly into dengue-naïve areas such as Europe. The role of international travel, changing boundaries of vectors, developing models of vectorial capacity under different climate change scenarios and strategies for vector control in outbreaks was all evaluated.

CONCLUDING REMARKS

DengueTools was able to make significant advances in methods for understanding and controlling dengue transmission in a range of settings. These will have implications for public health agendas to counteract dengue, including vaccination programmes.

OUTLOOK

Towards the end of the DengueTools project, Zika virus emerged as an unexpected epidemic in the central and southern America. Given the similarities between the dengue and Zika viruses, with vectors in common, some of the DengueTools thinking translated readily into the Zika situation.

Household preferences for reducing greenhouse gas emissions in four European high-income countries: Does health information matter? A mixed-methods study protocol

BACKGROUND

It is now universally acknowledged that climate change constitutes a major threat to human health. At the same time, some of the measures to reduce greenhouse gas emissions, so-called climate change mitigation measures, have significant health co-benefits (e.g., walking or cycling more; eating less meat). The goal of limiting global warming to 1,5° Celsius set by the Conference of the Parties to the United Nations Framework Convention on Climate Change in Paris in 2015 can only be reached if all stakeholders, including households, take actions to mitigate climate change. Results on whether framing mitigation measures in terms of their health co-benefits increases the likelihood of their implementation are inconsistent. The present study protocol describes the transdisciplinary project HOPE (HOuseholds' Preferences for reducing greenhouse gas emissions in four European high-income countries) that investigates the role of health co-benefits in households' decision making on climate change mitigation measures in urban households in France, Germany, Norway and Sweden.

METHODS

HOPE employs a mixed-methods approach combining status-quo carbon footprint assessments, simulations of the reduction of households' carbon footprints, and qualitative in-depth interviews with a subgroup of households. Furthermore, a policy analysis of current household oriented climate policies is conducted. In the simulation of the reduction of households' carbon footprints, half of the households are provided with information on health co-benefits of climate change mitigation measures, the other half is not. Households' willingness to implement the measures is assessed and compared in between-group analyses of variance.

DISCUSSION

This is one of the first comprehensive mixed-methods approaches to investigate which mitigation measures households are most willing to implement in order to reach the 1,5° target set by the Paris Agreement, and whether health co-benefits can serve as a motivator for households to implement these measures. The comparison of the empirical data with current climate policies will provide knowledge for tailoring effective climate change mitigation and health policies.

Characteristics of and factors associated with dengue vector breeding sites in the City of Colombo, Sri Lanka

Introduction

Dengue has emerged as a major public health problem in Sri Lanka. Vector control at community level is a frequent and widespread strategy for dengue control. The aim of the study was to assess Aedes mosquito breeding sites and the prevention practices of community members in a heavily urbanized part of Colombo.

Methods

A cross-sectional entomological survey was conducted from April to June 2013 in 1469 premises located in a subdistrict of the City of Colombo. Types of breeding sites and, where found, their infestation with larvae or pupae were recorded. Furthermore, a questionnaire was administered to the occupants of these premises to record current practices of dengue vector control.

Results

The surveyed premises consisted of 1341 residential premises and 110 non-residential premises (11 schools, 99 work or public sites), 5 open lands, and 13 non-specified. In these 1469 premises, 15447 potential breeding sites suitable to host larvae of pupae were found; of these sites18.0% contained water. Among the 2775 potential breeding sites that contained water, 452 (16.3%) were positive for larvae and/or pupae. Schools were associated with the proportionally highest number of breeding sites; 85 out of 133 (63.9%) breeding sites were positive for larvae and/or pupae in schools compared with 338 out of 2288 (14.8%) in residential premises. The odds ratio (OR) for schools and work or public sites for being infested with larvae and/or pupae was 2.77 (95% CI 1.58, 4.86), when compared to residential premises. Occupants of 80.8% of the residential premises, 54.5% of the schools and 67.7% of the work or public sites reported using preventive measures. The main prevention practices were coverage of containers and elimination of mosquito breeding places. Occupants of residential premises were much more likely to practice preventive measures than were those of non-residential premises (OR 2.23; 1.49, 3.36).

Conclusion

Schools and working sites were associated with the highest numbers of breeding sites and lacked preventive measures for vector control. In addition to pursuing vector control measures at residential level, public health strategies should be expanded in schools and work places.

A Spatial Hierarchical Analysis of the Temporal Influences of the El Niño-Southern Oscillation and Weather on Dengue in Kalutara District, Sri Lanka

Dengue is the major public health burden in Sri Lanka. Kalutara is one of the highly affected districts. Understanding the drivers of dengue is vital in controlling and preventing the disease spread. This study focuses on quantifying the influence of weather variability on dengue incidence over 10 Medical Officer of Health (MOH) divisions of Kalutara district. Weekly weather variables and data on dengue notifications, measured at 10 MOH divisions in Kalutara from 2009 to 2013, were retrieved and analysed. Distributed lag non-linear model and hierarchical-analysis was used to estimate division specific and overall relationships between weather and dengue. We incorporated lag times up to 12 weeks and evaluated models based on the Akaike Information Criterion. Consistent exposure-response patterns between different geographical locations were observed for rainfall, showing increasing relative risk of dengue with increasing rainfall from 50 mm per week. The strongest association with dengue risk centred around 6 to 10 weeks following rainfalls of more than 300 mm per week. With increasing temperature, the overall relative risk of dengue increased steadily starting from a lag of 4 weeks. We found similarly a strong link between the Oceanic Niño Index to weather patterns in the district in Sri Lanka and to dengue at a longer latency time confirming these relationships. Part of the influences of rainfall and temperature can be seen as mediator in the causal pathway of the Ocean Niño Index, which may allow a longer lead time for early warning signals. Our findings describe a strong association between weather, El Niño-Southern Oscillation and dengue in Sri Lanka.

Spatial Variations in Dengue Transmission in Schools in Thailand

Background

Dengue is an important neglected tropical disease, with more than half of the world’s population living in dengue endemic areas. Good understanding of dengue transmission sites is a critical factor to implement effective vector control measures.

Methods

A cohort of 1,811 students from 10 schools in rural, semi-rural and semi-urban Thailand participated in this study. Seroconversion data and location of participants’ residences and schools were recorded to determine spatial patterns of dengue infections. Blood samples were taken to confirm dengue infections in participants at the beginning and the end of school term. Entomological factors included a survey of adult mosquito density using a portable vacuum aspirator during the school term and a follow up survey of breeding sites of Aedes vectors in schools after the school term. Clustering analyses were performed to detect spatial aggregation of dengue infections among participants.

Results

A total of 57 dengue seroconversions were detected among the 1,655 participants who provided paired blood samples. Of the 57 confirmed dengue infections, 23 (40.0%) occurred in students from 6 (6.8%) of the 88 classrooms in 10 schools. Dengue infections did not show significant clustering by residential location in the study area. During the school term, a total of 66 Aedes aegypti mosquitoes were identified from the 278 mosquitoes caught in 50 classrooms of the 10 schools. In a follow-up survey of breeding sites, 484 out of 2,399 water containers surveyed (20.2%) were identified as active mosquito breeding sites.

Discussion and Conclusion

Our findings suggest that dengue infections were clustered among schools and among classrooms within schools. The schools studied were found to contain a large number of different types of breeding sites. Aedes vector densities in schools were correlated with dengue infections and breeding sites in those schools. Given that only a small proportion of breeding sites in the schools were subjected to vector control measures (11%), this study emphasizes the urgent need to implement vector control strategies at schools, while maintaining efforts at the household level.

An insecticide-treated bed-net campaign and childhood malaria in Burkina Faso

OBJECTIVE

To investigate if the first national insecticide-treated bed-net campaign in Burkina Faso, done in 2010, was followed by a decrease in childhood malaria in a district with high baseline transmission of the disease.

METHODS

We obtained data on the prevalence of Plasmodium falciparum parasitaemia in children aged 2 weeks to 36 months from malaria surveys in 2009 and 2011. We assessed morbidity in children younger than 5 years by comparing data from the Nouna health district's health management information system before and after the campaign in 2010. We analysed mortality data from 2008 to 2012 from Nouna's health and demographic surveillance system.

FINDINGS

The bed-net campaign was associated with an increase in the reported use of insecticide-treated nets. In 2009, 73% (630/869) of children reportedly slept under nets. In 2011, 92% (449/487) did. The campaign had no effect on the proportion of young children with P. falciparum parasitaemia after the rainy season; 52% (442/858) in 2009 and 53% (263/499) in 2011. Cases of malaria increased markedly after the campaign, as did the number of children presenting with other diseases. The campaign was not associated with any changes in child mortality.

CONCLUSION

The 2010 insecticide-treated net campaign in Burkina Faso was not associated with a decrease in care-seeking for malaria or all-cause mortality in children younger than 5 years. The most likely explanation is the high coverage of nets in the study area before the campaign which could have had an effect on mosquito vectors, limiting the campaign's impact.

Modeling tools for dengue risk mapping - a systematic review

Introduction

The global spread and the increased frequency and magnitude of epidemic dengue in the last 50 years underscore the urgent need for effective tools for surveillance, prevention, and control. This review aims at providing a systematic overview of what predictors are critical and which spatial and spatio-temporal modeling approaches are useful in generating risk maps for dengue.

Methods

A systematic search was undertaken, using the PubMed, Web of Science, WHOLIS, Centers for Disease Control and Prevention (CDC) and OvidSP databases for published citations, without language or time restrictions. A manual search of the titles and abstracts was carried out using predefined criteria, notably the inclusion of dengue cases. Data were extracted for pre-identified variables, including the type of predictors and the type of modeling approach used for risk mapping.

Results

A wide variety of both predictors and modeling approaches was used to create dengue risk maps. No specific patterns could be identified in the combination of predictors or models across studies. The most important and commonly used predictors for the category of demographic and socio-economic variables were age, gender, education, housing conditions and level of income. Among environmental variables, precipitation and air temperature were often significant predictors. Remote sensing provided a source of varied land cover data that could act as a proxy for other predictor categories. Descriptive maps showing dengue case hotspots were useful for identifying high-risk areas. Predictive maps based on more complex methodology facilitated advanced data analysis and visualization, but their applicability in public health contexts remains to be established.

Conclusions

The majority of available dengue risk maps was descriptive and based on retrospective data. Availability of resources, feasibility of acquisition, quality of data, alongside available technical expertise, determines the accuracy of dengue risk maps and their applicability to the field of public health. A large number of unknowns, including effective entomological predictors, genetic diversity of circulating viruses, population serological profile, and human mobility, continue to pose challenges and to limit the ability to produce accurate and effective risk maps, and fail to support the development of early warning systems.

Electronic supplementary material

The online version of this article (doi:10.1186/1476-072X-13-50) contains supplementary material, which is available to authorized users.