Infectious Diseases of Poverty

RationaleSeveral studies have estimated basic production number of novel coronavirus pneumonia (NCP). However, the time-varying transmission dynamics of NCP during the outbreak remain unclear. ObjectivesWe aimed to estimate the basic and time-varying transmission dynamics of NCP across China, and compared them with SARS. MethodsData on NCP cases by February 7, 2020 were collected from epidemiological investigations or official websites. Data on severe acute respiratory syndrome (SARS) cases in Guangdong Province, Beijing and Hong Kong during 2002-2003 were also obtained. We estimated the doubling time, basic reproduction number (R0) and time-varying reproduction number (Rt) of NCP and SARS. Measurements and main resultsAs of February 7, 2020, 34,598 NCP cases were identified in China, and daily confirmed cases decreased after February 4. The doubling time of NCP nationwide was 2.4 days which was shorter than that of SARS in Guangdong (14.3 days), Hong Kong (5.7 days) and Beijing (12.4 days). The R0 of NCP cases nationwide and in Wuhan were 4.5 and 4.4 respectively, which were higher than R0 of SARS in Guangdong (R0=2.3), Hongkong (R0=2.3), and Beijing (R0=2.6). The Rt for NCP continuously decreased especially after January 16 nationwide and in Wuhan. The R0 for secondary NCP cases in Guangdong was 0.6, and the Rt values were less than 1 during the epidemic. ConclusionsNCP may have a higher transmissibility than SARS, and the efforts of containing the outbreak are effective. However, the efforts are needed to persist in for reducing time-varying reproduction number below one. At a Glance CommentaryO_ST_ABSScientific Knowledge on the SubjectC_ST_ABSSince December 29, 2019, pneumonia infection with 2019-nCoV, now named as Novel Coronavirus Pneumonia (NCP), occurred in Wuhan, Hubei Province, China. The disease has rapidly spread from Wuhan to other areas. As a novel virus, the time-varying transmission dynamics of NCP remain unclear, and it is also important to compare it with SARS. What This Study Adds to the FieldWe compared the transmission dynamics of NCP with SARS, and found that NCP has a higher transmissibility than SARS. Time-varying production number indicates that rigorous control measures taken by governments are effective across China, and persistent efforts are needed to be taken for reducing instantaneous reproduction number below one.

Backgroud and ObjectiveTo predict the epidemic of COVID-19 based on quarantined surveillance from real world in China by modified SEIR model different from the previous simply mathematical model. Design and MethodsWe forecasted the epidemic of COVID-19 based on current clinical and epidemiological data and built a modified SEIR model to consider both the infectivity during incubation period and the influence on the epidemic from strict quarantined measures. ResultsThe peak time of the curve for the infected newly diagnosed as COVID-19 should substantially present on Feb. 5, 2020 (in non-Hubei areas) and Feb. 19, 2020 (in Hubei). It is estimated that the peak of the curve of the cumulative confirmed cases will appear in non-Hubei areas on Mar. 3, 2020 and in Hubei province on Mar. 10, 2020, and the total number of the patients diagnosed as COVID-19 is 18,000 in non-Hubei areas and 78,000-96,000 in Hubei. The Chinese COVID-19 epidemic can be completetly controlled in May, 2020. ConclusionsCOVID-19 is only a local outbreak in Hubei Province, China. It can be probably avoided the pandemic of global SARS-CoV-2 cases rise with the great efforts by Chinese government and its people.

Huanglongbing (HLB, ex-greening) is the most devastating citrus disease around the world. We modelled HLB spread in scenarios with different populational levels of the main alternative host (Murraya paniculata) and Diaphorina citri Kuwayama, vector of HLB associated bacteria; and removal of HLB-symptomatic plants. A compartmental deterministic mathematical model was built for representing the HLB dynamics in the Reconcavo Baiano, Bahia State, Brazil. The model encompasses delays on latency and incubation disease periods and on the D. citri nymphal stages. The simulations indicated that the presence of alternative hosts at low proportion would not play a crucial role in HLB dynamics in situations of poor D. citri management, regardless of HLB-symptomatic plants eradication. Symptomatic citrus plants contribute more to increase the HLB-incidence than the alternative host in scenarios without a suitable D. citri management.

Eastern equine encephalitis virus (EEEV) is a deadly arboviral pathogen with 30% severe case fatality. EEEV exhibits pronounced 2-3 year cyclical outbreak patterns in the northeastern United States, linked to shifts in mosquito feeding preferences between hatch-year and adult avians. We developed an age-structured vector-host model incorporating differential feeding patterns of Culiseta melanura mosquitoes on European Starlings and American Robins. Global sensitivity analysis revealed mosquito biting rate (a) as the dominant driver in transmission, with avian infectivity ({delta}) and exposure () playing secondary roles. Pairing tree-based machine learning algorithms with SHAP analysis on 100,000 parameter sets identified parameter hierarchies that govern cyclic transmission. Adult avian mortality ({micro}a) was identified as the key parameter underlying cyclic and stable transmission patterns. SHAP further revealed these patterns to be grounded on opposite sides of the same epidemiological mechanism. Stable endemics emerge from demographic stability paired with transmission optimization, while cyclic endemics emerge from demographic instability paired with minimal transmission optimization. Numerical simulations illustrated critical threshold dynamics at 0.2 [≤] [≤] 0.4, where heightened hatch-year exposure triggers demographic instability responsible for observed 2-3 year cycles, while balanced exposure ( {approx} 0.5) leads to stable endemics. These mechanisms provide a foundation for targeted surveillance and control interventions.

The role of modelling in predicting the spread of an epidemic is important for health planning and policies. This study aimed to apply a compartmental model for predicting the variations of epidemiological parameters in Sri Lanka. We used a dynamic Susceptible-Exposed-Infected-Recovered-Vaccinated (SEIRV) model and simulated potential vaccine strategies under a range of epidemic conditions. The predictions were based on different vaccination coverages (5% to 90%), vaccination-rates (1%, 2%, 5%) and vaccine-efficacies (40%, 60%, 80%) under different R0 (2,4,6). We estimated the duration, exposed, and infected populations. When the R0 was increased, the days of reduction of susceptibility and the days to reach the peak of the infection were reduced gradually. At least 45% vaccine coverage is required for reducing the infected population to mitigate a disastrous situation in Sri Lanka. The results revealed that when R0 is increased in the SEIRV model along with the increase of vaccination efficacy and vaccination rate, the population to be vaccinated is reducing. Thus, the vaccination offers greater benefits to the local population by reducing the time to reach the peak, exposed and infected population through flattening the curves.

BackgroundWhile the COVID-19 pandemic seemed far from the end, the booster vaccine project was proposed to further reduce the transmission risk and infections. However, handful studies have focused on questions that with limited vaccine capacity ether boosting high-risk workers first or prioritizing susceptible normal individuals is optimal, and vaccinating how many people can lead us to the goal of herd immunity. In this study we aimed to explore the conclusions of such two problems with consideration of non-pharmacological interventions including mandatory quarantine for international entrants, keeping social distance and wearing masks. MethodsBy implementing the corresponding proportion of individuals who remain infectious after four lengths of quarantine strategies to the novel population-stratified model, we quantified the impact of such measures on optimizing vaccine prioritization between high-risk workers and normal populations. Furthermore, by setting the hypothetical COVID-19 transmission severity (reproduction number, R0) to the level of the most contagious COVID-19 variant (B.1.617.2, delta variant, R0 = 5.0), we separately estimated the threshold vaccine coverage of five countries (China, United States, India, South Africa and Brazil) to reach herd immunity, with and without the consideration of interventions including wearings masks and keeping social distance. At last, the sensitive analysis of essential parameter settings was performed to examine the robustness of conclusions. ResultsFor Chinese scenarios considered with moderate hypothetical transmission rate (R0 = 1.15-1.8), prioritizing high-risk workers the booster dose reached lower cumulative infections and deaths if at least 7-days of quarantine for international travelers is maintained, and the required screening time to remain such vaccinating strategy as optimal increased from 7-days to 21-days with the transmission severity. Although simply maintaining at least 7-days quarantine can lead to over 69.12% reduction in total infections, the improvement of longer quarantine strategies was becoming minimum and the least one was 2.28% between the 21 and the 28-days of quarantine. Besides, without the vaccination program, the impact of such measures on transmission control dropped significantly when R0 exceeded 1.5 and reached its minimal level when R0 equal to 2.5. On the other hand, when we combat the delta variant, the threshold vaccine coverage of total population to reach herd immunity lay within 74%-89% (corresponding to the vaccine efficiency from 70% to 50%), and such range decreased to 71%-84% if interventions including wearing mask and keeping social distance were implemented. Furthermore, Results of other countries with 85% vaccine efficiency were estimated at 79%, 91%, 94% and 96% for South Africa, Brazil, India and United States respectively. ConclusionsNon-pharmacological interventions can substantially affect booster vaccination prioritization and the threshold condition to reach herd immunity. To combat the delta variant, restrictions need to be integrated with mass vaccination so that can reduce the transmission to the minimum level, and the 21-days might be the suggested maximum quarantine duration according to the cost-effectiveness. Besides, by implementing interventions, the requirement to reach herd immunity can be lower in all countries. Lastly, the following surveillance after vaccination can help ensure the real-time proportion of vaccinated individuals with sufficient protection.

BackgroundIncidence in children was much less than in adults during the COVID-19 outbreak. Sports and entertainment events were canceled (VEC) in Japan for two weeks during 26 February - 13 March. Most schools were closed (SC). ObjectWe construct a susceptible-infected-recovered model using three age classes and estimate the basic reproduction number (R0) and protection level among children simultaneously. Then we simulate SC and VEC effects. MethodWe used data of patients with symptoms in Japan during 14 January to assess SC and VEC introduction. Effects of SC and VEC were incorporated into the model through change in the contact pattern or frequencies among age classes. ResultsResults suggest R0 as 2.86 [95%CI of 2.73, 2.97]. The protection level was estimated as 0.4 [0.2, 0.7]. SC and VEC can reduce the total number of patients significantly, by 6-7%. Discussion and ConclusionThe estimated R0 was similar to that found from other studies in China and Japan. We found a significant protection level among children, and by effects of SC and VEC. Introduction

Bovine cysticercosis is an infection of cattle caused by the larval stage of Cysticercus Bovis, the human intestinal cestodes and it has economic important and public health importance. Across-sectional study was conducted from March 2022 to August 2022 to determine the prevalence of Bovine Cysticercosis, Human Taeniasis and associated risk factors in selected towns of Silte zone. The study was conducted in Silte zone municipal abbatoir, Southern Ethiopia in cattle slaughtered randomly selected towns,namely, at Kilto,Kutery,Kirate and Werabe Tawon municipal abattoirs. Systematic random sampling technique was used to collect all the necessary data from abattoir survey of the study animals and questionnaire survey collected data stored by using in Epi data software and analyzed using (SPSS-22) software program. The sample size required for this study was determined to be based on the expected prevalence (50%) of C. bovis and the 5% desired absolute precision and 95% CI. Out of 422 carcasses examined during the study period in 4 municipality abattoirs, 36 % were infected with C.bovis. A prevalence of 35.7%, 35.92%, 37.96% and 34.11% were Kilto,Kutery,Kirate and Werabe Tawon were observed, respectively. Among considered risk factors, sex, body condition and breed showed statistically significant difference in prevalence of C. bovis in study area. Regarding the anatomical distribution of the cysts, shoulder muscle showed highest prevalence 28.44%, was followed by tongue 20.79% tricepsbrachi muscle 18.35%, masseter muscle 17.74%, heart 12.84%, and Liver 1.8%. Out of 110 respondents, 64.5% had contracted T.saginata. Among considered risk factors, sex, age, occupation, education status, raw meat consumption and knowledge about the disease showed statistically significant difference in prevalence of T.saginata in study area. The findings of this study indicated that importance of Bovine Cysticercosis and Taeniasis in the study area. Therefore, attention should be given to the public awareness, detailed meat inspection to be safe to public health, consumption of well-cooked cattle meat should be implemented for breaking the cycle of the diseases and promote meat industry in the country.

Large-scale outbreaks of scrub typhus combined with the emergence of this vector-borne rickettsiosis in new areas indicate that this disease remains seriously neglected. This study aimed to explore the long-term changes and regional leading factors of scrub typhus in China, so as to provide fresh insights for the prevention and control of this disease. In this study, a Bayesian space-time hierarchical model (BSTHM) was used to identify the long-term spatiotemporal heterogeneity of scrub typhus and quantify the association between meteorological factors and scrub typhus in southern and northern China from 2012 to 2018. GeoDetector model was used to quantify the dominant forces of environmental and socioeconomic factors in the Northern and the Southern China. Scrub typhus often appeared in summer and autumn (June to November), and epidemically peaked in October, with obvious temporal seasonality. Spatially, the hot spots (high-risk regions) were concentrated in the south, on the contrary the cold spots (low-risk regions) in the north. In addition, the main meteorological factor, average temperature, gave a significant impact in both areas. The average temperature increased by 1 {degrees}C, resulting in a decrease of 1.10% in southern China and an increase of 0.96% in northern China in the risk of scrub typhus. The determinant environmental and socio-economic factors of scrub typhus in the two areas were altitude and per capita GDP, with q-values of 0.91 and 0.87, respectively. Meteorological, environmental and socio-economic factors had a significant impact on the distribution of scrub typhus, with obvious seasonality and spatial heterogeneity. This study provides helpful suggestions and basis for reasonably allocating resources and controlling the occurrence of scrub typhus. Author summaryScrub typhus is a natural-focus disease caused by the bite of chigger mite larval. In this study, we use BSTHM to capture the overall temporal trend and spatial hot spots of scrub typhus, and quantify the relationship between the disease and major meteorological factors. Meanwhile, Geodetector model was used to quantify the influence of other potential risk factors and estimate the spatio-temporal heterogeneity of scrub typhus. The results showed that scrub typhus had significant seasonality, with a q value of 0.52, and spatial heterogeneity, with a q-value of 0.64. Scrub typhus mainly occurred in summer and autumn, and high-risk areas were mainly distributed in southern China (Yunnan, Hainan and Guangdong). These heterogeneity were closely related to the vector and host. Whether in the South or the north, scrub typhus was closely related to risk factors such as temperature, per capita GDP, NDVI, altitude and the percentage of children aged 0-14. These results suggest that the relevant departments should strengthen the monitoring of the ecological environment, the host and vector of Orientia tsutsugamushi, and strengthen the risk awareness, so as to prevent and control the possible increased risk of scrub typhus under these meteorological, environmental and socio-economic conditions. Considering the differences in different regions, resources should be allocated reasonably.

The current outbreak of novel coronavirus disease 2019 (COVID-19) is already causing a serious disease burden worldwide, this paper analyzed data of a delta variant Covid-19 outbreak in Hunan, China, and proposed an optimal dose-wise dynamical vaccinating process based on local contact pattern and vaccine coverage that minimize the accumulative cases in a certain future time interval. The optimized result requires an immediate vaccination to that none vaccinated at age group 30 to 39, which is coherent to the prevailing strategies. The dose-wise optimal vaccinating process can be directive for countries or regions where vaccines are not abundant. We recommend that vaccination should be further intensified to increase the coverage of booster shots, thus effectively reducing the spread of COVID-19.

West Nile virus (WNV; Flaviviridae) and Eastern Equine Encephalitis virus (EEEV; Togaviridae) represent the two most significant mosquito-borne zoonoses in the southeastern United States. While both viruses utilize avian amplifying hosts and mosquito vectors, it is unclear if they occur within distinct ecological niches. This study assessed the cumulative effects of both landscape composition and weather variables on the spatial-temporal distribution of WNV and EEEV outbreaks in Georgia over a twenty-four-year period (2001-2025). We used a modeling framework that directly accounts for both spatial and temporal effects but additionally integrates key EO variables (Earth observation). These environmental effects were investigated using Bernoulli generalized linear mixed-effects models (GLMMs) and executed with an integrated nested Laplace approximation (INLA). Our findings revealed disproportional distribution ranges of Culex quinquefasciatus, Aedes albopictus and Culiseta melanura in highly urbanized Georgian counties such as Chatham, Dekalb, and Fulton. Results showed that WNV transmission was heavily influenced by urban land cover (Posterior Mean: +0.78, 95% CrI: [0.61,0.95]) but negatively associated with lagged precipitation (Posterior Mean: -0.18, 95% CrI: [-0.29, -0.07]), confirming drought-driven amplification. Conversely, EEEV transmission was strongly influenced by wetland cover (Posterior Mean: +1.12, 95% CrI: [0.94,1.30]) and precipitation (Posterior Mean: +0.51, 95% CrI: [0.39,0.63]). These results underscore the need for improved mosquito surveillance across all Georgian counties in the face of growing vector-borne disease risks.

BackgroundThe number of patients of COVID-19 in Tokyo has been increasing gradually through the end of March, 2020. ObjectSupport for policymaking requires forecasting of the entire course and outcome of the outbreak if a self-restraint in going out is not initiated. Moreover, the effects of a self-restraint in going out must be considered when choosing to initiate one. Method: Data of Tokyo patients with symptoms during January 14 - March 28, 2020 were used to formulate a susceptible-infected-recovered (SIR) model using three age classes and to estimate the basic reproduction number (R0). Based on the estimated R0, We inferred outbreak outcomes and medical burden if a self-restraint in going out were not enacted. Then we estimate the self-restraint in going out effects. ResultsResults suggest R0 as 2.86, with a 95% confidence interval of [2.73, 2.97]. Exhaustion of medical resources can be expected to occur on April 26 if no self-restraint in going out occurs. If a self-restraint in going out were enacted from April 6, and if more than 60% of trips outside the home were restricted voluntarily, then medical care service could be maintained. Discussion and ConclusionThe estimated R0 was similar to that found from other studies conducted in China and Japan. Results demonstrate that a self-restraint in going out with reasonable cooperation of residents is required to maintain medical care.

Coronavirus disease 2019 (COVID-19), a novel infectious disease first identified in December 2019 in the city of Wuhan of Chinas Hubei province, is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The disease has become a pandemic in just a few months and spread globally with more than 2.89 million cases and 203,000 deaths across 185 countries, as of April 26th, 2020. Ecuador has reported one of the highest rates of COVID-19 in Latin America, with more than 10K cases and 500 deaths in a country of approximately 17 million people. The dynamics of the outbreak is being observed quite different in different provinces of Ecuador with high reported prevalence in some low population density provinces. In this study, we aim to understand variations in outbreaks between provinces and provide assistance in essential preparedness planning in order to respond effectively to ongoing COVID-19 outbreak. The study estimated the critical level of quarantine rate along with corresponding leakage in order to avoid overwhelming the local health care system. The results suggest that provinces with high population density can avoid a large disease burden provided they initiate early and stricter quarantine measures even under low isolation rate. To best of our knowledge, this study is first from the region to determine which provinces will need much preparation for current outbreak in fall and which might need more help.

At present, the factors influencing Tuberculosis (TB) treatment effectiveness in HIV/TB co-infected patients need to be supported by more substantial real-world evidence. A retrospective study is conducted to fill the vacancy. 461 TB patients with HIV are defined as 742 samples according to each TB detection period. 7788 valid treatment records corresponding to 17 drug compositions for TB and 150 clinical indicators with more than 100 records are used to conduct data mining with consensus clustering, Fishers exact test, stratified analysis, and three modeling approaches, including logistic regression, support vector machine, and random forest. We find that A CD4+ T cell count of 42 cells per L may serve as a sensitive classification standard for the immune level to assist in evaluating or predicting the efficacy of TB (P=0.007); Rifabutin and levofloxacin alone or in combination may be more effective than other first- and second-line anti-TB agents in combination (P=0.037); Samples with low immune levels (CD4[less double equals]42) may be more resistant to first-line TB drugs (P=0.049); Age (P=0.015), bicarbonate radical (P=0.007), high-density lipoprotein cholesterol (P=0.026), pre-treatment CD8+ T cell count (P=0.015, age<60, male), neutrophil percentage (P=0.033, age<60), rifabutin (P=0.010, age<60), and cycloserine (P=0.027, age<60) may influence the TB treatment effectiveness; More evidence is needed to support the relationship between pre-treatment clinical indicators or drug regimens and TB treatment effectiveness (The best AUC is 0.560[~]0.763); The percentage of lymphocytes (P=0.028) can be used as an effective TB therapeutic target. These perspectives supplement knowledge in relevant clinical aspects.

The co-existence of coronavirus disease 2019 (COVID-19) and seasonal influenza epidemics has become a potential threat to human health, particularly in China in the oncoming season. However, with the relaxation of nonpharmaceutical interventions (NPIs) during the COVID-19 pandemic, the rebound extent of the influenza activities is still poorly understood. In this study, we constructed a susceptible-vaccinated-infectious-recovered-susceptible (SVIRS) model to simulate influenza transmission and calibrated it using influenza surveillance data from 2018 to 2022. We projected the influenza transmission over the next 3 years using the SVIRS model. We observed that, in epidemiological year 2021-2022, the reproduction numbers of influenza in southern and northern China were reduced by 64.0% and 34.5%, respectively, compared with those before the pandemic. The percentage of people susceptible to influenza virus increased by 138.6% and 57.3% in southern and northern China by October 1, 2022, respectively. After relaxing NPIs, the potential accumulation of susceptibility to influenza infection may lead to a large-scale influenza outbreak in the year 2022-2023, the scale of which may be affected by the intensity of the NPIs. And later relaxation of NPIs in the year 2023 would not lead to much larger rebound of influenza activities in the year 2023-2024. To control the influenza epidemic to the pre-pandemic level after relaxing NPIs, the influenza vaccination rates in southern and northern China should increase to 53.8% and 33.8%, respectively. Vaccination for influenza should be advocated to reduce the potential reemergence of the influenza epidemic in the next few years.

Realized vaccine efficacy in population is highly different from the individual vaccine efficacy measured in clinical trial. The realized vaccine efficacy in population is substantially affected by the vaccine age-stratified prioritization strategy, population age-structure, non-pharmaceutical intervention (NPI). We proposed a population vaccine efficacy which integrated individual vaccine efficacy, vaccine prioritization strategy and NPI to measure and monitor the control of the spread of COVID-19. We found that 11 states in the US had low population vaccine efficacy and 20 states had high population efficacy. We demonstrated that although the proportion of the population who received at least one dose of COVID-19 vaccine across 11 low population vaccine efficacy states, in general, was greater than that in 20 high population vaccine efficacy states, the 11 low population vaccine efficacy states experienced the recent COVID-19 surge, while the number of new cases in the 20 high population vaccine efficacy states exponentially decreased. We demonstrated that the proportions of adults in the population across 50 states were significantly associated with the forecasted ending date of the COVID-19. We show that it was recent low proportion of adults vaccinated in Michigan that caused its COVID-19 surge. Using population vaccination efficacy, we forecasted that the earliest COVID-19 ending states were Hawaii, Arizona, Arkansas, and California (in the end of June, 2021) and the last COVID-19 ending states were Colorado, New York and Michigan (in the Spring, 2022).

COVID-19 has become a global pandemic. However, the impact of the public health interventions in China needs to be evaluated. We established a SEIRD model to simulate the transmission trend of China. In addition, the reduction of the reproductive number was estimated under the current forty public health interventions policies. Furthermore, the infection curve, daily transmission replication curve, and the trend of cumulative confirmed cases were used to evaluate the effects of the public health interventions. Our results showed that the SEIRD curve model we established had a good fit and the basic reproductive number is 3.38 (95% CI, 3.25-3.48). The SEIRD curve show a small difference between the simulated number of cases and the actual number; the correlation index (H2) is 0.934, and the reproductive number (R) has been reduced from 3.38 to 0.5 under the current forty public health interventions policies of China. The actual growth curve of new cases, the virus infection curve, and the daily transmission replication curve were significantly going down under the current public health interventions. Our results suggest that the current public health interventions of China are effective and should be maintained until COVID-19 is no longer considered a global threat.

COVID-19 was declared as pandemic on 11th March 2020 by WHO. There are apparent dissimilarities in incidence and mortality of COVID-19 cases in different parts of world. Developing countries in Asia and Africa with fragile health system have shown lower incidence and mortality compared to developed countries with superior health system in Europe and America. Most countries in Asia and Africa have national BCG vaccination program while Europe and America do not have such program, or have ceased it. At present, there is no known therapy to treat COVID-19 disease. There is no vaccine available currently to prevent COVID-19 disease. As mathematical modelling is ideal for predicting the rate of disease transmission as well as evaluating efficacy of possible public health prevention measures, we have created a mathematical model with seven compartments to understand nationwide BCG vaccine recommendation on COVID-19 transmission, severity and mortality. We have computed two basic reproduction number, one at vaccine free equilibrium point and other at non-vaccine free equilibrium point and carried out local stability, sensitivity and numerical analysis. Our result showed that individuals with BCG vaccinations have lower risk of getting COVID-19 infection, shorter hospital stays, and increased rate of recovery. Furthermore, countries with long-standing universal BCG vaccination policies have reduced incidence, mortality, and severity of COVID-19. Further research will focus on exploring the immediate benefits of vaccination to healthcare workers and patients as well as benefits of BCG re-vaccination.

Dengue virus, with all four serotypes in cocirculation, has created significant epidemiological and economic burdens in Singapore. Despite integrated vector control programs, the magnitude and frequency of dengue outbreaks has increased over the last few decades, which highlights the limits of existing strategies. In this context, vaccination has emerged as a promising approach to enhance population immunity and complement ongoing efforts. Qdenga (TAK-003), a commercially available dengue vaccine, has been recommended by the the World Health Organization Strategic Advisory Group of Experts (WHO-SAGE) for use in high-transmission settings. Although classified as a low transmission setting, Singapore faces a recurring public health burden from dengue, with high costs associated with both healthcare and sustained vector control. The age distribution of dengue in Singapore differs from high transmission settings, with more cases in young adults and hospitalizations concentrated among older individuals. These factors, combined with the complex efficacy profile of Qdenga, varying by baseline serostatus, infecting serotype, make it challenging to directly apply global vaccination recommendations to Singapore. Therefore, the population-level impact of introducing dengue vaccination remains uncertain, underscoring the need for context-specific evaluation. To estimate the potential public health impact of introducing routine dengue vaccination in Singapore, we develop an age-stratified, multi-serotype, compartmental transmission model informed by age-specific dengue seroprevalence and routine surveillance data. Our model predicts that vaccination can avert up to on average 9%, 12%, 7%, and 5% cases in DENV-1-4 dominant serotype scenarios respectively, over a 10-year routine vaccination program with 80% vaccine coverage. Moreover, dengue hospitalizations can be reduced by 12%-15% across all dominant serotype scenarios. Our results suggest that, in Singapore, targeting older age groups will be more beneficial than the 6-16-year window recommended by the WHO-SAGE for high-transmission settings. Vaccinating individuals aged 17-30 years achieves the greatest reduction in cases, whereas targeting those aged 51-70 years leads to the highest reduction in hospitalizations. Our model-based analysis provides useful insights to support policymakers and public health authorities in designing evidence-based, dengue vaccination strategies in Singapore. The findings also underscore the importance of tailoring dengue vaccination programs to local epidemiological conditions for effective disease control. Authors summarySingapore is experiencing more frequent dengue outbreaks, which impose a substantial burden through treatment costs and sustained vector control programs. Vaccination is a key public health measure that can help ease this burden by complementing existing control efforts. In clinical trials, Qdenga (TAK-003) demonstrated consistent protections against DENV-1 and DENV-2 among vaccine recipients irrespective of their baseline serostatus, but uncertainty remains for DENV-3 and DENV-4. Although WHO-SAGE recommended its use among children aged 6-16 years in high dengue transmission setting, uncertainty arises when extrapolating these recommendations to low transmission settings like Singapore. Moreover, unlike high transmission settings, Singapore currently shows a different age pattern of dengue burden, with higher incidence in young adults and more severe outcomes among older individuals, highlighting the need to contextualize these global recommendations using country-specific data and modelling approaches. To address this, we developed a detailed modelling framework that integrates local epidemiological characteristics and operational aspects of vaccine implementation and evaluated the potential impact of introducing a routine vaccination program in Singapore. We show that, with 80% coverage, vaccination can avert up to 12% of reported cases and 15% of hospitalizations over a 10-year period, with impact varying mainly by circulating serotype and target age group. Our findings suggest that in low-transmission settings like Singapore, vaccinating adults will achieve a greater public health impact than targeting children, as currently recommended for high-transmission settings by WHO-SAGE. These findings provide timely evidence to support national policy discussions on dengue vaccination in Singapore and other low-transmission settings, where adult disease burden is substantial.

Clonorchiasis is one of the major parasitic diseases in South Korea. Spatially explicit estimates of the infection risk are important for control and intervention. We did a systematic review of collected prevalence data on Clonorchis sinensis infection in South Korea. Data of potential influencing factors (e.g., environmental and social-economic factors) was obtained from open-access databases. Bivariate Bayesian geostatistical joint modeling approaches were applied to analyze disease data, within a logit regression in combination of potential influencing factors and spatial-temporal random effects. We identified surveys of C. sinensis infection done at 1362 unique locations, and presented the first spatial-temporal risk maps at high spatial resolution (5x5km) in South Korea. High infection risk areas shrunk significantly from 1970 to 2017. The overall risk decreased since the start of the national deworming program in 1969, and then slightly increased since the year 1995 when the program suspended, and maintained stable since 2005 when the Clonorchiasis Eradication Program begun. The population-weighted prevalence was estimated as 3.87% (95% BCI: 3.04-4.82%) in 2017, accounting to 1.92 (95% BCI: 1.51-2.40) million infected people. Although the prevalence over the country has been low, C. sinensis infection was still endemic in areas of eastern and southern regions, particularly the five major river basins. We also defined factors significantly correlated, such as, distance to the nearest open water bodies, annual precipitation, and land surface temperature at night. All findings above provide important information on spatial-targeting control and preventive strategies of C. sinensis infection in South Korea.