Tropical Medicine & International Health最新文献

Background: Schistosomiasis is the leading cause of fatal upper gastrointestinal bleeding among adults in East Africa. The prevalence among school-aged children in villages along the Albert-Nile shoreline in North-Western Uganda is estimated at 85%. Efforts to control schistosomiasis in low- and-middle-income countries remain limited due to an incomplete understanding of the pathogenesis, disease manifestations, transmission mechanisms, preventive measures and interventions. In addition, there is insufficient capacity to analyse, model and predict relevant clinical case management systems, biological interventions and disease control efforts. We conducted a needs assessment for schistosomiasis research training at academic and research institutions in Uganda to inform the development of a structured training programme to build capacity to conduct locally relevant research to control the disease.

Methods: Using an online survey, we collected data on training needs, potential trainees, available resources including local and international collaborations, as well as priority areas for schistosomiasis research and training at academic and research institutions in Uganda. Data were analysed and presented in frequency tables and figures.

Results: Overall, schistosomiasis had the lowest number of studies conducted, based on the studies approved by research ethics committees at the two leading medical schools in Uganda: Makerere University College of Health Sciences (MakCHS) and Mbarara University of Science and Technology (MUST) between 2016 and 2022. The top ranked schistosomiasis focus areas of interest, by scientists at MakCHS, MUST, the Vector Borne and Neglected Tropical Diseases Division of the Ministry of Health and the Uganda Virus Research Institute (UVRI), were schistosomiasis prevention and transmission, vector biology, diagnostics, treatment and clinical trials, respectively. The top ranked training needs were schistosomiasis prevention and control, research ethics, data analysis, epidemiology and research methods (quantitative and qualitative), malacology, infectious diseases modelling, scientific writing and communication skills.

Conclusion: Priority areas for schistosomiasis research and training will be utilised to develop a robust, collaborative, multidisciplinary schistosomiasis research training programme, to increase the critical mass of scientists with the competencies required to design, execute and utilise schistosomiasis biology, clinical, laboratory and epidemiology research to advance disease control interventions and minimise/eliminate schistosomiasis-associated morbidity and mortality in sub-Saharan Africa.

Background: Bali, one of the world's most popular tourist destinations, is hyper-endemic to dengue, an acute febrile illness caused by infection with dengue virus (DENV). Outbreaks of dengue occur annually with worrisome rates of morbidity and mortality. Despite this, comprehensive and continuous virus surveillance is yet to be established. We conducted DENV serotype and genotype surveillance in Bali to monitor viral transmission dynamics.

Methods: We enrolled febrile patients with dengue clinical symptoms in hospitals in Denpasar, Bali. Clinical evaluations and laboratory assessments were conducted, and blood samples were collected. DENV serotypes were determined using RT-PCR, and genotyping was performed by sequencing the envelope protein gene and the complete genomes. Subsequently, phylogenetic analyses were conducted to analyse the recent data alongside retrospective sequence data.

Results: A total of 62 and 66 dengue patients were recruited during 2018-2020 and 2022, and from these, we obtained DENV serotype data for 49 and 48 individuals, respectively. Among the DENV analysed, the most prevalent serotype in 2018-2020 was DENV-1 (30%) and shifted to DENV-3 (57.6%) in 2022. When compared to data from the last 10 years, serotype shifting was clearly observed. We sequenced the genomes of 60 isolates and observed the presence of multiple virus lineages and the replacement of Genotype IV of DENV-1 with Genotype I. The Cosmopolitan, Genotype I and Genotype II remained the predominant genotypes for DENV-2, DENV-3 and DENV-4, respectively.

Conclusion: We reveal that DENV serotype predominance in Bali has been shifting in the past 10 years. While genotype replacement occurred, continuous circulation of local endemic viruses was responsible for the annual outbreak of dengue. These findings indicate the genetic diversity and dynamic nature of DENV circulating in Bali. Routine virus surveillance is important to understand the cyclical patterns of DENV serotypes that is useful to predict the future outbreaks.

Background: Drug-related adverse events cause poorer treatment outcomes amongst people with multi-drug-resistant tuberculosis, exacerbating a major global public health problem. The Harnessing new mHealth technologies to Strengthen the Management of Multi-Drug-Resistant Tuberculosis in Vietnam (V-SMART) trial tests whether a mobile health (mHealth) application (app) can optimise management of drug-related adverse events, within routine health services in Vietnam. Implementation of digital health within routine services is complex and driven by behaviour change as well as a range of health system factors. Understanding implementation is key to informing the evidence base for digital health prior to scale up, despite its potential appeal.

Methods: Through a process evaluation of the V-SMART trial, we aim to (i) understand the multi-drug-resistant tuberculosis service delivery context and how trial procedures are implemented within services; (ii) describe 'dose' and 'reach' of the app; and (iii) understand health worker and patient perspectives of app implementation and identify areas for improvement. To achieve this, we will (i) conduct process maps (patient flow maps) to describe implementation of the mHealth intervention within routine multi-drug-resistant tuberculosis health services including adverse event management pathways at different levels of the health system; (ii) measure app usage by all participating health workers and people with multi-drug-resistant tuberculosis over time; and (iii) conduct a total of up to 45 semi-structured interviews in seven provinces, with people with multi-drug-resistant tuberculosis, health workers, and policymakers, to identify determinants of app uptake and suggestions for future person-centred app design. Interview topic guides are informed by the Theoretical Framework for Acceptability, Normalisation Process Theory, and the Tailored Implementation of Chronic Diseases framework respectively.

Discussion: The process evaluation will strongly complement the parent trial impact evaluation, and the economic evaluation. Moreover, it will inform future tailored approaches to scaling up digital health as part of broader health system strengthening initiatives.

Aims: Our study aimed to derive and validate a diet risk score for clinical use in Nigeria to screen for hypertension risk and evaluate its association against a panel of cardiovascular biomarkers.

Methods: The Nigerian dietary screening tool was used to collect dietary intake data from 151 participants visiting the River State University Teaching Hospital, Port Harcourt, Nigeria, for routine medical care. Blood samples were collected from a subsample (n = 94) for biomarker assessment. Multiple logistic regression was used to derive the Nigerian diet risk score for hypertension. Internal validation of the Nigerian diet risk score for hypertension was performed using measures of discrimination and calibration. Mediation analysis was used to evaluate the biomarker-mediated effects of the diet risk score for hypertension on hypertension. All statistical analyses were performed in R.

Results: Each one-point increment in Nigerian diet risk score (on a scale of 0 to 30) was associated with a twofold increase in odds of hypertension (odds ratio: 2.04, 95% confidence interval [CI]: 1.16, 3.58, p = 0.01), with the highest score associated with >18-fold increased odds of hypertension, compared to lowest Nigerian diet risk score for hypertension. The score demonstrated good discrimination (area under the curve: 0.92, 95% CI: 0.80, 1.00) with a high sensitivity (0.85) and specificity (0.94). Additionally, mediation analysis suggested that the association between Nigerian diet risk score for hypertension and blood pressure is partly explained by shared biological pathways that mediate cholesterol, triglycerides, LDL-C, CRP and homocysteine levels.

Conclusion: The resulting Nigerian diet risk score for hypertension is a valuable tool for clinicians to identify individuals at risk of hypertension, and will advance community efforts in the prevention and management of hypertension in Nigeria.

Objectives: Infection with the fish-borne liver fluke Opisthorchis felineus, which is transmitted through the consumption of raw or undercooked fish, results in serious liver damage in humans. Currently, limited clinical and experimental data reveal kidney damage co-occurring with chronic opisthorchiasis. We conducted a retrospective analysis of kidney autopsy samples over a five-year period (n = 84). The aim of the study was to assess pathomorphological changes in the kidneys and evaluate whether there is an association between IgA nephropathy and liver fluke infection.

Methods: Histological analysis, immunohistochemistry, and statistical analysis were performed.

Results: In this study, we demonstrated for the first time that chronic O. felineus infection in humans was associated with tubular dystrophy, the accumulation of renal tubular casts, and glomerulosclerosis. The hypertension increases the pathomorphological changes associated with chronic opisthorchiasis. We also detected IgA and the O. felineus total antigen in glomeruli of infected people. Fisher's test showed a significant association between O. felineus infection and IgA nephropathy, as well as between O. felineus infection and glomerulosclerosis.

Conclusions: Therefore, the findings of this study highlight the importance of recognising O. felineus infection as a more than hepatobiliary disease and emphasise the need for careful, personalised monitoring of kidney function in infected individuals.

Introduction: Chikungunya fever is a debilitating arthritic disease that can lead to atypical severe complications and sometimes be fatal. The risk factors for fatal outcomes of chikungunya fever have not been thoroughly studied. This systematic review and meta-analysis aimed to identify mortality risk factors in patients with chikungunya. These findings will aid clinicians in targeting high-risk groups with severe chikungunya for timely interventions, ultimately improving patient outcomes.

Objective: The objective of this study is to identify mortality risk factors in patients with chikungunya.

Methods: We conducted a systematic review and meta-analysis by searching the MEDLINE, Embase, Cochrane, BVS, BDTD and OpenGrey databases to identify eligible observational studies on patients with chikungunya. These studies analysed mortality risk factors, providing adjusted risk measures along with their corresponding confidence intervals (CIs). We estimated the pooled weighted mean difference and 95% CIs using a random-effects model, and the methodological quality was assessed using the Newcastle-Ottawa Scale.

Results: Our search yielded a total of 334 records. After removing duplicates, we screened 275 records, reviewed 31 full articles and included seven studies in the systematic review and four in the meta-analysis, with a total of 220,215 patients and 908 fatal cases. Diabetes Mellitus (OR = 2.86, 95% CI 1.75-4.69), hypertension (OR = 3.10, 95% CI 2.02-4.77), age ≥ 60 years (OR = 19.49, 95% CI 1.98-191.88), chronic kidney disease (OR = 5.81, 95% CI 1.30-25.99), male sex (OR = 2.07, 95% CI 1.71-2.51) and vomiting (OR = 2.18, 95% CI 1.75-2.73) are significantly and positively associated with mortality in chikungunya.

Conclusion: Elderly men with chronic diseases have a higher risk of death from chikungunya; therefore, they deserve more careful evaluation.

Introduction: Classic vector control tools do not sustainably reduce Aedes populations or prevent the surge of arboviruses. The sterile insect technique (SIT) by irradiation relies on mass-rearing and release of male insects that will not produce viable offspring. It has been successfully integrated into controlling agricultural and livestock pests. Experiments are conducted to determine the effectiveness of the approach for suppressing Aedes aegypti and curbing dengue transmission. Detailed implementation cycle costs have not been reported yet.

Objective: To detail the costs of producing and releasing male A. aegypti mosquitoes sterilised by irradiation.

Method: We carried out a cost analysis during a SIT pilot trial in Havana. We took a provider perspective and used microcosting. From the cost function, we subsequently calculated costs for base case variations in production volume and mosquito release rate per hectare.

Results: The setup expenses to establish the capacity to produce and release 450,000 mosquitoes weekly amounted to 155,452.00 and 2456.40 USD in capital means and training, respectively. The average number of sterile mosquitoes released per hectare per week during the trial was 1500, utilising 17% of the installed capacity. Including capital depreciation, the average cost per 10,000 sterile male mosquitoes released was 110.12 USD. When producing at 85% capacity, this reduces nearly threefold, to 41.06 USD. At that production level, releasing 500 or 4500 sterile male mosquitoes per hectare costs on average 2.70 or 16.54 USD per hectare covered. In densely populated areas with 500 inhabitants per hectare, this corresponds to 0.28 or 1.72 USD per inhabitant per year.

Conclusion: Our cost estimates for SIT by irradiation are within the range of estimates reported for alternative mass-rearing and release methods to control Aedes populations, and the approach appears competitive with insecticide-based interventions. The cost-effectiveness in different contexts remains to be investigated.

Objectives: Preterm birth (<37 weeks), low birth weight (2500 g), small-for-gestational-age (birth weight <10th percentile of a given reference), and large-for-gestational-age (birth weight >90th percentile of a given reference) are indicators of vulnerable infants and risk factors for neonatal mortality. We estimated the prevalence and risk of neonatal mortality associated with these phenotypes and their mutually exclusive phenotypes in rural Bangladesh.

Methods: We conducted a prospective cohort study in five rural districts of Bangladesh using data collected from births in the Shonjibon Trial from 2013 to 2015. We estimated the prevalence of preterm birth, low birth weight, small-for-gestational-age, and large-for-gestational-age infants, individually and for mutually exclusive phenotypes, using a combination of these phenotypes. Neonatal mortality associated with preterm birth, low birth weight, small-for-gestational-age, large-for-gestational-age, and mutually exclusive phenotypes were calculated using Kaplan-Meier survival analysis and Poisson regression for adjusted relative risks (aRR) with 95% confidence intervals (CI).

Results: We included 24,314 live births in this study. The prevalence of preterm birth, low birth weight, small-for-gestational-age, and large-for-gestational-age was 26.2%, 22.9%, 41.7%, and 8.2%, respectively. The prevalence of babies born appropriate for gestational age, with term gestation (≥37 weeks) and normal birth weight (≥2500 g) was 33.3%. For individual phenotypes, the neonatal mortality risk was approximately 3-fold for preterm, low birth weight, and large-for-gestational-age newborns and 1.5-fold for small-for-gestational-age newborns compared with appropriate-for-gestational-age, term, and normal birth weight newborns. The risk of neonatal mortality for mutually exclusive phenotypes was highest in small-for-gestational-age, preterm, and low birth weight newborns (aRR = 6.3, 95% CI 4.1-9.6) relative to appropriate for gestational age, term, and normal birth weight newborns.

Conclusions: In rural Bangladesh, most infants are born with one or more vulnerable phenotypes associated with an increased risk of neonatal mortality. Our findings highlight the value of categorising newborns using mutually exclusive vulnerable phenotypes and their neonatal mortality risks, which can be used to tailor interventions to improve survival.

Background: Epidemiological modelling studies in snakebite envenoming research are evolving. Their techniques can be essential in filling the knowledge gap needed to attain the World Health Organization's (WHO) goal of halving the burden of snakebite envenoming by complementing the current data scarcity. Hence, there is a need for a systematic review to summarise epidemiological models used in estimating the burden of snakebite envenoming.

Methods: We conducted a systematic review by searching PubMed, EMBASE, and Scopus to identify articles reporting epidemiological models in snakebite envenoming from database inception to 31st December 2023. A narrative synthesis was performed to summarise types of models, methodologies, input parameters, model outputs, and associating factors.

Results: Thirty-nine modelling studies were included from 2426 retrieved articles, comprising statistical models (76.9%) and mathematical models (23.1%). Most of the studies were conducted in South Asia, (35.9%) and Latin America (35.9%), and only a few (5.1%) were a global burden estimation. The eligible studies constructed 42 epidemiological models, of which 33 were statistical models that included regression, (60.6%) geostatistical (21.2%), and time series, (18.2%) while 9 mathematical models comprised compartmental, (44.4%) agent-based, (22.2%) transmission dynamics, (11.1%) network, (11.1%) and a simple mathematical model (11.1%). The outputs of the models varied across the study objectives. Statistical models analysed the relationship between incidence, (83.3%) mortality, (33.3%) morbidity (16.7%) and prevalence (10.0%) and their associating factors (environmental, [80%] socio-demographic [33.3%] and therapeutic [10.0%]). Mathematical models estimated incidence, (100%) mortality (33.3%), and morbidity (22.2%). Five mathematical modelling studies considered associating factors, including environmental (60%) and socio-demographic factors (40%).

Conclusion: Mathematical and statistical models are crucial for estimating the burden of snakebite envenoming, offering insights into risk prediction and resource allocation. Current challenges include low-quality data and methodological heterogeneity. Modelling studies are needed, and their continued improvement is vital for meeting WHO goals. Future research should emphasise standardised methodologies, high-quality community data, and stakeholder engagement to create accurate, applicable models for prevention and resource optimization in high-burden regions, including Africa and Asia.