Measuring disease burden of dominant variants of COVID-19 in Taiwan.

Objectives: The disability-adjusted life years (DALYs) of COVID-19 have been applied as a time-based measurement to estimate years of life lost due to premature mortality or healthy life lost in different countries. Limited information was found for DALYs among different variants of concern (VOC). Methods: Disease severities based on categories of asymptomatic, mild, moderate, severe, and critical cases were explored among different VOC by analyzing the proportions in confirmed cases. DALY or years of healthy life lost due to disability (YLD)-based annual burdens of COVID-19 on different ages, genders as well as trend analysis were also evaluated for VOC in Taiwan. Results: Different trends were observed in years of life lost due to premature mortality (YLLs) or YLD for various age or gender categories. Disease severity at critical stage had the highest percentage for overall YLDs encompassed from 2020 to 2022. Also, critical-grade cases were found to be predominantly caused by Wild-type, Alpha, and Omicron variants in 2020, 2021, and 2022, respectively. Conclusion: Precautionary measures are also suggested for policy makers to take in specific seasons, age or gender groups based on YLL and YLD analyses.

Pharmacogenomic Landscape of Ivermectin and Selective Antioxidants: Exploring Gene Interplay in the Context of Long COVID.

COVID-19 pandemic has caused widespread panic and fear among the global population. As such, repurposing drugs are being used as viable therapeutic options due to the limited effective treatments for Long COVID symptoms. Ivermectin is one of the emerging repurposed drugs that has been shown effective to have antiviral effects in clinical trials. In addition, antioxidant compounds are also gaining attention due to their capabilities of reducing inflammation and severity of symptoms. Due to the absence of knowledge in pharmacogenomics and modes of actions in the human body for these compounds, this study aims to provide a pharmacogenomic profile for the combination of ivermectin and six selected antioxidants (epigallocatechin gallate (EGCG), curcumin, sesamin, anthocyanins, quercetin, and N-acetylcysteine (NAC)) as potentially effective regimens for long COVID symptoms. Results showed that there were 12 interacting genes found among the ivermectin, 6 antioxidants, and COVID-19. For network pharmacology, the 12 common interacting genes/proteins had the highest associations with Pertussis pathway, AGE-RAGE signaling pathway in diabetic complications, and colorectal cancer in the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Disease analyses also revealed that the top three relevant diseases with COVID-19 infections were diabetes mellitus, ischemia, reperfusion injury. We also identified 6 potential target microRNAs (miRNAs) of the 12 commonly curated genes used as molecular biomarkers for COVID-19 treatments. The established pharmacogenomic network, disease analyses, and identified miRNAs could facilitate developments of effective regimens for chronic sequelae of COVID-19 especially in this post-pandemic era. However, further studies and clinical trials are needed to substantiate the effectiveness and dosages for COVID-19 treatments.

Disease burden due to COVID-19 in Taiwan: Disability-adjusted life years (DALYs) with implication of Monte Carlo simulations.

BACKGROUND: The novel coronavirus disease 2019 (COVID-19) has affected a large number of countries. Informing the public and decision makers of the COVID-19's economic burdens is essential for understanding the real pandemic impact. METHODS: COVID-19 premature mortality and disability impact in Taiwan was analyzed using the Taiwan National Infectious Disease Statistics System (TNIDSS) by estimating the sex/age-specific years of life lost through death (YLLs), the number of years lived with disability (YLDs), and the disability-adjusted life years (DALYs) from January 2020 to November 2021. RESULTS: Taiwan recorded 1004.13 DALYs (95% CI: 1002.75-1005.61) per 100,000 population for COVID-19, with YLLs accounting for 99.5% (95% CI: 99.3%99.6%) of all DALYs, with males suffering more from the disease than females. For population aged ≥ 70 years, the disease burdens of YLDs and YLLs were 0.1% and 99.9%, respectively. Furthermore, we found that duration of disease in critical state contributed 63.9% of the variance in DALY estimations. CONCLUSIONS: The nationwide estimation of DALYs in Taiwan provides insights into the demographic distributions and key epidemiological parameter for DALYs. The essentiality of enforcing protective precautions when needed is also implicated. The higher YLLs percentage in DALYs also revealed the fact of high confirmed death rates in Taiwan. To reduce infection risks and disease, it is crucial to maintain moderate social distancing, border control, hygiene measures, and increase vaccine coverage levels.

Control measure implications of COVID-19 infection in healthcare facilities reconsidered from human physiological and engineering aspects.

The Wells-Riley model invokes human physiological and engineering parameters to successfully treat airborne transmission of infectious diseases. Applications of this model would have high potentiality on evaluating policy actions and interventions intended to improve public safety efforts on preventing the spread of COVID-19 in an enclosed space. Here, we constructed the interaction relationships among basic reproduction number (R0) - exposure time - indoor population number by using the Wells-Riley model to provide a robust means to assist in planning containment efforts. We quantified SARS-CoV-2 changes in a case study of two Wuhan (Fangcang and Renmin) hospitals. We conducted similar approach to develop control measures in various hospital functional units by taking all accountable factors. We showed that inhalation rates of individuals proved crucial for influencing the transmissibility of SARS-CoV-2, followed by air supply rate and exposure time. We suggest a minimum air change per hour (ACH) of 7 h-1 would be at least appropriate with current room volume requirements in healthcare buildings when indoor population number is < 10 and exposure time is < 1 h with one infector and low activity levels being considered. However, higher ACH (> 16 h-1) with optimal arranged-exposure time/people and high-efficiency air filters would be suggested if more infectors or higher activity levels are presented. Our models lay out a practical metric for evaluating the efficacy of control measures on COVID-19 infection in built environments. Our case studies further indicate that the Wells-Riley model provides a predictive and mechanistic basis for empirical COVID-19 impact reduction planning and gives a framework to treat highly transmissible but mechanically heterogeneous airborne SARS-CoV-2.

Pharmacological Mechanism of NRICM101 for COVID-19 Treatments by Combined Network Pharmacology and Pharmacodynamics.

Symptom treatments for Coronavirus disease 2019 (COVID-19) infection and Long COVID are one of the most critical issues of the pandemic era. In light of the lack of standardized medications for treating COVID-19 symptoms, traditional Chinese medicine (TCM) has emerged as a potentially viable strategy based on numerous studies and clinical manifestations. Taiwan Chingguan Yihau (NRICM101), a TCM designed based on a medicinal formula with a long history of almost 500 years, has demonstrated its antiviral properties through clinical studies, yet the pharmacogenomic knowledge for this formula remains unclear. The molecular mechanism of NRICM101 was systematically analyzed by using exploratory bioinformatics and pharmacodynamics (PD) approaches. Results showed that there were 434 common interactions found between NRICM101 and COVID-19 related genes/proteins. For the network pharmacology of the NRICM101, the 434 common interacting genes/proteins had the highest associations with the interleukin (IL)-17 signaling pathway in the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Moreover, the tumor necrosis factor (TNF) was found to have the highest association with the 30 most frequently curated NRICM101 chemicals. Disease analyses also revealed that the most relevant diseases with COVID-19 infections were pathology, followed by cancer, digestive system disease, and cardiovascular disease. The 30 most frequently curated human genes and 2 microRNAs identified in this study could also be used as molecular biomarkers or therapeutic options for COVID-19 treatments. In addition, dose-response profiles of NRICM101 doses and IL-6 or TNF-α expressions in cell cultures of murine alveolar macrophages were constructed to provide pharmacodynamic (PD) information of NRICM101. The prevalent use of NRICM101 for standardized treatments to attenuate common residual syndromes or chronic sequelae of COVID-19 were also revealed for post-pandemic future.

Demographic Control Measure Implications of Tuberculosis Infection for Migrant Workers across Taiwan Regions.

A sharp increase in migrant workers has raised concerns for TB epidemics, yet optimal TB control strategies remain unclear in Taiwan regions. This study assessed intervention efforts on reducing tuberculosis (TB) infection among migrant workers. We performed large-scale data analyses and used them to develop a control-based migrant worker-associated susceptible-latently infected-infectious-recovered (SLTR) model. We used the SLTR model to assess potential intervention strategies such as social distancing, early screening, and directly observed treatment, short-course (DOTS) for TB transmission among migrant workers and locals in three major hotspot cities from 2018 to 2023. We showed that social distancing was the best single strategy, while the best dual measure was social distancing coupled with early screening. However, the effectiveness of the triple strategy was marginally (1-3%) better than that of the dual measure. Our study provides a mechanistic framework to facilitate understanding of TB transmission dynamics between locals and migrant workers and to recommend better prevention strategies in anticipation of achieving WHO's milestones by the next decade. Our work has implications for migrant worker-associated TB infection prevention on a global scale and provides a knowledge base for exploring how outcomes can be best implemented by alternative control measure approaches.

Assessing the effect of probiotics on tilapia lake virus-infected tilapia: Transmission and immune response.

Probiotics have been used to alleviate disease transmission in aquaculture. However, there are limited studies on probiotic use in modulating tilapia lake virus (TiLV). We assessed commercially available probiotic supplements used in TiLV-infected tilapia and performed mortality and cohabitation assays. We developed a mechanistic approach to predict dose-response interactions of probiotic effects on mortality and immune gene response. We used a susceptible-infected-mortality disease model to assess key epidemiological parameters such as transmission rate and basic reproduction number (R0 ) based on our viral load dynamic data. We found that the most marked benefits of probiotics are significantly associated with immune system enhancements (~30%) and reductions in disease transmission (~80%) and R0 (~70%) in tilapia populations, resulting in a higher tolerance of farming densities (~400 fold) in aquaculture. These findings provide early insights as to how probiotic use-related factors may influence TiLV transmission and the immune responses in TiLV-infected tilapia. Our study facilitates understanding the mode of action of probiotics in disease containment and predicting better probiotic dosages in diet and supplements to achieve the optimal culturing conditions. Overall, our analysis assures that further study of rationally designed and targeted probiotics, or mechanistic modelling is warranted on the basis of promising early data of this approach.

Estimates of lung burden risk associated with long-term exposure to TiO2 nanoparticles as a UV-filter in sprays.

Titanium dioxide (TiO2) nanoparticles (NPs) are employed as an ultraviolet filter in sunscreen products because of their high ultraviolet absorptivity. However, sunscreen sprays may pose health risks due to the toxicity of inhaled TiO2 NPs. Therefore, we estimated the potential human health risk posed by inhaled TiO2 NPs emitted from sunscreen sprays. The physiology-based lung model was employed to predict the lung TiO2 NPs burden caused by long-term exposure. A Hill-based dose-response model described the relationship between lung inflammation and TiO2 NP accumulation. The Weibull threshold model was used to estimate the threshold amount of accumulation inducing 0.5% of the maximum increase in neutrophils. The potential health risk was assessed using a hazard quotient-based probabilistic risk model. All data obtained to date indicate that application of sunscreen sprays poses no significant health risk. However, using data simulations based on the threshold criterion, we discovered that in terms of practical strategies for preventing the risks posed by inhaled TiO2 NPs emitted from spray products, the suggested daily use amount and pressing number are 40 g (95% confidence interval: 11-146 g) and 66 (18-245), respectively. In this study, we successfully translated the potential health risk of long-term exposure to NP-containing sunscreen sprays and recommendations for daily application into mechanistic insights.

Toxicokinetic/toxicodynamic-based risk assessment of freshwater fish health posed by microplastics at environmentally relevant concentrations.

The pervasive contamination of microplastics (MPs) in freshwater ecosystems is of emerging concern. Mechanistic link between exposure and effect on assessing health risk of freshwater fish posed by environmental MPs, however, is more limited. Our study filled this gap by developing a toxicokinetic/toxicodynamic (TK/TD)-based risk assessment framework to examine health effects of zebrafish and red tilapia responses to environmental concentrations of MPs appraised with a variety of valuable published data on a global scale. We assessed organ-specific TK parameters and mean residence times for polystyrene (PS)-MPs-exposed freshwater fish in size- and concentration-dependent manners. We estimated the relatively sensitive benchmark concentrations (BMCs) of PS-MPs for oxidative stress in zebrafish and detoxification in red tilapia to be ~1.0 and ~119 µg g-1, respectively. Based on continental scale MPs trends, the high MPs concentrations were over Asia, with a mean value of 36 mg L-1. Given metabolic disturbances in zebrafish and red tilapia as bioindicators, we found that MPs pollution was highly likely to enhance fish health risks and that this factor must therefore be considered in evaluations of MPs susceptibility of freshwater fish. Our TK/TD-based risk scheme could help inform intensified efforts to mitigate environmental MPs pollution in order to benefit freshwater fish species and people who depend on healthy stocks of different fish.

Modelling the effect of vaccination on transmission dynamics of nervous necrosis virus in grouper larvae Epinephelus coioides.

Nervous necrosis virus (NNV) infection in susceptible grouper larvae has been reported to cause high mortalities, leading to great economic losses in aquaculture industry. Although the effects of NNV vaccines on grouper have been broadly investigated, vaccination strategies have not been fully established. To this end, we introduced the parsimonious epidemiological models that explored the assessment of key epidemiological parameters and how they changed when vaccinations showed the effects. We showed that the models capture the published cumulative mortality data accurately. We estimated a basic reproduction number R0  = 2.44 for NNV transmission in grouper larvae without vaccination. To effectively control NNV transmission by vaccination, a model for disease control was also generalized to attain the goals of controlled reproduction number less than 1. Our results indicated that at least 60% of grouper population needed to be immunized for ~75 min. Our data-driven modelling approach that links the transmission dynamics of NNV and vaccination strategies for grouper has the potential to support evidence-based planning and adaptation of integrated control measures. We encourage that the epidemiology-based framework introduced here can be further implemented for establishing effective vaccination and mitigation actions aimed at controlling diseases in fish farming practices.

Shorter antibiotic regimens impact the control efforts in high tuberculosis burden regions of Taiwan.

OBJECTIVES: To assess the potential epidemiological impact and cost-effectiveness of shorter antibiotic regimens in high tuberculosis (TB) burden regions of Taiwan. METHODS: This study combined the TB population dynamic model and cost-effectiveness analysis with local data to simulate the disease burdens, effectiveness and costs of hypothetical 4-month, 2-month and 7-day regimens compared with the standard regimen. RESULTS: The main outcomes were the potential of shorter regimens for averted incidence, mortality and disability-adjusted life years, incremental cost-effectiveness ratio and net monetary benefit. Shorter regimens would lower incidence rates and mortality cases in a high TB burden region by an average of 19-33% and 27-41%, respectively, with the potential for cost-effectiveness or cost-saving. The 2-month and 7-day regimens would be more cost-effective than the 4-month regimen. The threshold daily drug prices for achieving cost-effectiveness and cost-saving for 4-month, 2-month and 7-day regimens were $US1, $US2 and $US70, respectively. Such cost-effectiveness would remain, even if the willingness-to-pay threshold was less than one gross domestic product per capita. CONCLUSIONS: The findings support the inclusion of shorter regimens in global guidelines and regional-scale TB control strategies, which would improve disease control, particularly in settings with high rates of incidence and poor treatment outcomes.

Assessing dietary exposure risk to neonicotinoid residues among preschool children in regions of Taiwan.

Neonicotinoids (NEOs) are a class of pesticides widely used worldwide. This study analyzed post-cooking residues of NEO pesticides and assessed their potential health risks for preschool children (0-6 years old) by conducting a total diet study (TDS). It involved food sampling, preparation, analysis of pesticide residues, estimation of food consumption data, and assessment of food safety risks. Food sampling was conducted between March and June 2015. A total of 128 food samples were obtained from 4 parts of Taiwan. After the food had been prepared, the 128 samples were aggregated into 32 composite food items and the NEO residues analyzed. Acetamiprid had the highest detection rate of the NEO residues (59.4%), and the concentrations ranged from not detected to 80.5 µg/kg. The estimated daily intake (EDI) of NEO residues among preschool children was found to be lower than the adjusted acceptable daily intake (ADI) even for highly exposed groups. The results showed that NEO pesticides were primarily detected in preserved fruits, cherry tomato, rape, bell fruit, and baby bok choy. The main health risk posed by detected NEO residues at high consumption rates for preschool children was attributed to acetamiprid (34.20 %ADI) and imidacloprid (23.69 %ADI), respectively. Therefore, this research implicates that the present level of NEO residues in the diets for preschool children in Taiwan does not exceed 100 %ADI.

Quantifying the impact of temperature variation on birnavirus transmission dynamics in hard clams Meretrix lusoria.

Susceptibility of hard clams Meretrix lusoria to birnavirus (BV) infections caused by temperature variations, from a mechanistic perspective, has rarely been explored. We used a deterministic susceptible-infectious-mortality (SIM) model to derive temperature-dependent key epidemiologic parameters based on data sets of viral infections in hard clams subjected to acute temperature changes. To parameterize seasonal pattern dependence, we estimated monthly based cumulative mortality and basic reproduction numbers (R0 ) between 1997 and 2017 by way of statistical analysis. Two alternative disease control models were also proposed to assess status of controlled temperature-mediated BV infection by using, respectively, control reproduction number (RC )-control line criterion and removal strategy-based control measure. We showed that based on RC -control strategy, when temperatures ranged from 15 to 26.8°C, proportion of susceptible hard clams removed should be at least 0.22%. Based on removal-control strategy, we found that by limiting pond water temperature to 25-30°C, together with increased removal rates and periods to remove hard clams, it is better to remove hard clams from June and August to reduce both mortality rate and spread of BV. Our results can be used to monitor BV transmission potential in hard clams that will contribute to government control strategy to eradicate future BV epidemics.

Impact of consumer-resource dynamics on C. elegans-E. coli system exposed to nano zero-valent iron (nZVI).

Nano zero-valent iron (nZVI) is one of the most paramount nanoparticles (NPs) applied in environmental remediation, leading to great concerns for the potential impacts on soil ecosystem health. The objective of this study was to link toxicokinetics and consumer-resource dynamics in the Caenorhabditis elegans-Escherichia coli (worm-bacteria) ecosystem. The biokinetic parameters of bacteria and worms were obtained from toxicokinetic experiments and related published literature. Biomass dynamics of bacteria and worms were estimated by employing the modified Lotka-Volterra model. Dynamics of bacteria and worm biomass, internal concentrations of nZVI, bioconcentration factors (BCFs), and biomagnification factors (BMFs) were simulated based on the consumer-resource dynamics. Results showed that the biomass of worms steadily increased from 22.25 to 291.49 g L-1, whereas the biomass of bacteria decreased from 17.17 to 4.70 × 10-8 g L-1 after 96-h exposures of nZVI. We also observed ratios of nZVI concentrations in worms and bacteria increased from 0.06 to 26.60 after 96 h. Moreover, decrements of the bioconcentration factor of E. coli (BCFE) values from 0.82 to 0.03 after 96 h were observed, whereas values of BMFs increased from 0.06 to 57.62 after 96 h. Internal concentrations of nZVI in worms were found to be mainly influenced by the ingestion rate of bacteria by worms, and the biomass conversion of bacteria had the lowest effect. Implementation of the integrated bioaccumulation-consumer-resource model supports the hypothesis that the C. elegans-E. coli dynamics of internal nZVI concentrations could be effectively associated with the predator-prey behavior and was dominated by the same physiological parameter in the two biological systems.

Association Between Ambient Air Pollution and Elevated Risk of Tuberculosis Development.

BACKGROUND: Broad-scale evidence has shown the significant association between ambient air pollutants and the development of tuberculosis (TB). However, the impact of air quality on the risk of TB in Taiwan is still poorly understood. OBJECTIVE: To develop a probabilistic integrated population-level risk assessment approach for evaluating the contribution of ambient air pollution exposure to the risk of TB development among different regions of Taiwan. MATERIALS AND METHODS: A Bayesian-based probabilistic risk assessment model was implemented to link exposure concentrations of various air pollutants quantified in a probabilistic manner with the population-based exposure-response models developed by using an epidemiological investigation. RESULTS: The increment of the risk of TB occurred in a region with a higher level of air pollution, indicating a strong relationship between ambient air pollution exposures and TB incidences. Carbon monoxide (CO) exposure showed the highest population attributable fraction (PAF), followed by nitrogen oxides (NOX) and nitrogen dioxide (NO2) exposures. In a region with higher ambient air pollution, it is most likely (80% risk probability) that the contributions of CO exposure to development of TB were 1.6-12.2% (range of median PAFs), whereas NOX and NO2 exposures contributed 1.2-9.8% to developing TB. CONCLUSION: Our findings provide strong empirical support for the hypothesis and observations from the literature that poor air quality is highly likely to link aetiologically to the risk of TB. Therefore, substantial reductions in CO, NOX, and NO2 exposures are predicted to have health benefits to susceptible and latently infected individuals that provide complementary mitigation efforts in reducing the burden of TB. Considering that people continue to be exposed to both TB bacilli and ambient air pollutants, our approach can be applied for different countries/regions to identify which air pollutants contribute to a higher risk of TB in order to develop potential mitigation programs.

Assessing human exposure risk and lung disease burden posed by airborne silver nanoparticles emitted by consumer spray products.

BACKGROUND: No systematic investigations have been conducted to assess the lung burden imposed by the chronic inhalation of silver nanoparticles (AgNPs) emitted by spray products. OBJECTIVE: The objective of this study was to formulate a study framework that integrates a probabilistic risk assessment scheme with a mechanistic lung burden model for the estimation of health risks associated with the long-term inhalation of AgNP-containing spray products. MATERIALS AND METHODS: A compartmentalized physiologically based alveolar deposition (PBAD) model was used to estimate AgNP lung burden. Dose-response relationships were established using nanotoxicity data sets obtained from rats (as a model organism). Weibull model-based thresholds of AgNP lung burden based on neutrophil-elevated inflammation bio-markers were estimated from Hill-based exposure-response relationships. Finally, the risks of lung disease posed by various AgNP-containing spray products were assessed. RESULTS: Conservative thresholds for the prevention of pulmonary disease were estimated as follows (mean ± SE): 34 nm AgNPs (0.32±0.22 mg) and 60 nm AgNPs (1.08±0.64 mg). Our results indicate that the risk probability was ~0.5 that the hazard quotient (HQ) estimates of deodorant with a count median diameter (CMD) ≈30 nm exceeded 1. The primary risk posed by AgNPs is transferred from the interstitial region to lymph nodes. Under the condition of 50% risk probability, the 97.5 percentile of HQ for the spray products were as follows: CMD ≈30 nm (~3.4) and CMD ≈60 nm (~1.1). CONCLUSION: Our application of the proposed risk assessment scheme to the results obtained in an in vivo animal model proved highly effective in elucidating the relationship between the characteristics of metallic NP-containing spray products and their corresponding toxicity. The integration of the proposed PBAD model with a risk assessment framework enables the rapid assessment of risk posed by spray products containing metallic NPs over various time scales.

Toxicity-based toxicokinetic/toxicodynamic assessment for bioaccumulation of polystyrene microplastics in mice.

While a large body of literature has shown that microplastics (MPs) are highly likely to be accumulated in marine organisms and terrestrial animals, information about toxicity of MPs in mammal from a mechanistic point of view is more limited. Our paper fills this knowledge gap by assessing polystyrene (PS)-MPs-mice system based on toxicity-based toxicokinetic/toxicodynamic (TBTK/TD) modeling to quantify organ-bioaccumulation and biomarker responses appraised with published dataset. The key TBTK-parameters for mice liver, kidney, and gut posed by 5 or 20 µm PS-MPs could be obtained. We found that gut had the highest bioaccumulation factor (BCF) of ∼8 exposed to 5 µm PS-MPs with a mean residence time of ∼17 days. We showed that threshold concentrations of 5 and 20 µm PS-MPs among the most sensitive biomarkers were 8 ± 5 (mean ± SE) and 0.71 ± 0.14 µg g-1 bw, respectively, implicating that particle size was likely to affect TK/TD behavior in mice. The mice-based TK parameters and threshold criteria greatly assist in designing robust researches to evaluate MP consumption by humans. We establish a TBTK/TD framework for mechanistically assessing potential from mice size-specific MPs exposure that would offer a tool-kit for extrapolating to humans from health risk assessment perspective.

Assessing health burden risk and control effect on dengue fever infection in the southern region of Taiwan.

BACKGROUND: The high prevalence of dengue in Taiwan and the consecutive large dengue outbreaks in the period 2014-2015 suggest that current control interventions are suboptimal. Understanding the effect of control effort is crucial to inform future control strategies. OBJECTIVES: We developed a framework to measure season-based health burden risk from 2001 to 2014. We reconstructed various intervention coverage to assess the attributable effect of dengue infection control efforts. MATERIALS AND METHODS: A dengue-mosquito-human transmission dynamic was used to quantify the vector-host interactions and to estimate the disease epidemics. We used disability-adjusted life years (DALYs) to assess health burden risk. A temperature-basic reproduction number (R0)-DALYs relationship was constructed to examine the potential impacts of temperature on health burden. Finally, a health burden risk model linked a control measure model to evaluate the effect of dengue control interventions. RESULTS: We showed that R0 and DALYs peaked at 25°C with estimates of 2.37 and 1387, respectively. Results indicated that most dengue cases occurred in fall with estimated DALYs of 323 (267-379, 95% CI) at 50% risk probability. We found that repellent spray had by far the largest control effect with an effectiveness of ~71% in all seasons. Pesticide spray and container clean-up have both made important contributions to reducing prevalence/incidence. Repellent, pesticide spray, container clean-up together with Wolbachia infection suppress dengue outbreak by ~90%. CONCLUSION: Our presented modeling framework provides a useful tool to measure dengue health burden risk and to quantify the effect of dengue control on dengue infection prevalence and disease incidence in the southern region of Taiwan.

Assessing the population transmission dynamics of tilapia lake virus in farmed tilapia.

A novel virus, tilapia lake virus (TiLV), has been identified as a key pathogen responsible for disease outbreak and mass mortality of farmed tilapia. We used a deterministic susceptible-infectious-mortality (SIM) model to derive key disease information appraised with published TiLV-induced cumulative mortality data. The relationship between tilapia mortality and TiLV exposure dosages was described by the Hill model. Furthermore, a disease control model was proposed to determine the status of controlled TiLV infection using a parsimonious control reproduction number (RC )-control line criterion. Results showed that the key disease determinants of transmission rate and basic reproduction number (R0 ) could be derived. The median R0 estimate was 2.59 in a cohabitation setting with 2.6 × 105  TCID50 fish-1 TiLV. The present RC -control model can be employed to determine whether TiLV containment is feasible in an outbreak farm by quantifying the current level of transmission. The SIM model can then be applied to predict what additional control is required to manage RC  < 1. We offer valuable tools for aquaculture engineers and public health scientists the mechanistic-based assessment that allows a more rigorous evaluation of different control strategies to reduce waterborne diseases in aquaculture farming systems.