Abstract: Objective To analyze the influence of meteorological factors on Aedes larvae density in Haikou City, Hainan Province, and to study its lagged effect, providing a basis for monitoring and controlling dengue vectors. Methods The Aedes larvae monitoring data and meteorological factor data were collected from 2017 to 2022. The X11 model was employed to decompose and examine the basic characteristics of seasonality and trend in the Aedes aegypti larval density time series. The correlation between Aedes aegypti larval density and meteorological factors was assessed using the Spearman correlation coefficient test. A distributed lag non-linear model was employed to examine the lag non-linear impact of meteorological factors on Aedes larval density. The significance test of relative risk at the longest lag time and the principle of minimizing Akaike's information criterion were utilized to ascertain the optimal parameters of the model. Results The time-series analysis of Aedes larval density revealed distinct seasonality and a decreasing trend. The distribution lag non-linear modeling results indicated that, compared to the median precipitation of 120 mm, with the increase in monthly average precipitation, the relative risk of Aedes larvae density first increased and then decreased, showing an inverted "U" shaped non-linear relationship. The longest lag time of the average precipitation was 1 month, with a lag effect on Aedes larvae density when the precipitation ranged from 119.89 mm to 562.14 mm (P<0.05), peaking at 397.98 mm (RR=1.57, 95%CI: 1.11-2.20). Compared to a median temperature of 25.35 ℃, the relative risk to Aedes larvae density increased with the increase of monthly average temperature in a “J” shape. The longest lag time of average temperature was 1 month, with a lag effect on Aedes larvae density between 25.35 ℃ and 30.10 ℃ (P<0.05), peaking at 30.10 ℃ (RR=2.24, 95%CI: 1.24-4.05). Conclusions High precipitation and high temperature both have a risk effect on Aedes larvae density, with a 1-month lag effect. Timely knowledge of the effects of meteorological factors on Aedes larvae density can provide a basis for vector prevention and control and early warning of dengue fever.

INTRODUCTION: Normal stress myocardial perfusion imaging (MPI) carries a favourable prognosis. Conversely, elevated coronary artery calcium (CAC) is associated with increased major adverse cardiovascular events (MACE). There is limited information on the prognosis and management of patients with elevated CAC and normal MPI. We aimed to assess the outcomes of patients with elevated CAC and normal MPI in relation to post-MPI statin use. METHODS: A retrospective review of normal MPI with CAC score >300 was performed between 1 March 2016 and 31 January 2017 in a Singapore tertiary hospital. Patients with known atherosclerotic cardiovascular disease or left ventricular ejection fraction <50% on MPI were excluded. Patient demographics, prescriptions and MACE (cardiac death, nonfatal myocardial infarction and/or ischaemic stroke) at 24 months after MPI were traced using electronic records. Binary logistic regression was used to evaluate for independent predictors of MACE. RESULTS: We included 311 patients (median age 71 years, 56.3% male), of whom 65.0% were on moderate to high-intensity statins (MHIS) after MPI. MACE was significantly lower in the post-MPI MHIS group (3.5% vs. 9.2%, P = 0.035). On univariate binary logistic regression, post-MPI MHIS use was the only significant predictor for MACE (odds ratio [OR] 0.355 [95% confidence interval (CI) 0.131-0.962], P = 0.042), even after multivariate adjustment (adjusted OR 0.363, 95% confidence interval 0.134-0.984, P = 0.046). CONCLUSION Post-MPI MHIS use is associated with lower MACE and is an independent negative predictor for 24-month MACE among patients with normal MPI and CAC >300.
Humans ; Male ; Aged ; Female ; Coronary Artery Disease ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; Myocardial Perfusion Imaging/methods* ; Calcium ; Stroke Volume ; Brain Ischemia ; Risk Factors ; Ventricular Function, Left ; Stroke ; Prognosis

INTRODUCTION: The cost-effectiveness of screening asymptomatic non-alcoholic fatty liver disease (NAFLD) patients remains debatable, with current studies assuming lifelong benefits of NAFLD screening while neglecting cardiovascular outcomes. This study aims to assess the cost-effectiveness of NAFLD screening among type 2 diabetes mellitus (T2DM) patients, and to establish a price threshold for NAFLD treatment, when it becomes available. METHOD: A Markov model was constructed comparing 4 screening strategies (versus no screening) to identify NAFLD with advanced fibrosis among T2DM patients: fibrosis-4 (FIB-4), vibration-controlled transient elastography (VCTE), FIB-4 and VCTE (simultaneous), and FIB-4 and VCTE (sequential). Sensitivity analyses and price threshold analyses were performed to assess parameter uncertainties in the results. RESULTS: VCTE was the most cost-effective NAFLD screening strategy (USD24,727/quality-adjusted life year [QALY]), followed by FIB-4 (USD36,800/QALY), when compared to no screening. Probabilistic sensitivity analysis revealed a higher degree of certainty for VCTE as a cost-effective strategy compared to FIB-4 (90.7% versus 73.2%). The duration of expected screening benefit is the most influential variable based on incremental cost-effectiveness ratio tornado analysis. The minimum duration of screening benefit for NAFLD screening to be cost-effective was at least 2.6 years. The annual cost of NAFLD treatment should be less than USD751 for NAFLD screening to be cost-effective. CONCLUSION Both VCTE and FIB-4 are cost-effective NAFLD screening strategies among T2DM patients in Singapore. However, given the lack of access to VCTE at primacy care and potential budget constraints, FIB-4 can also be considered for NAFLD screening among T2DM patients in Singapore.
Humans ; Non-alcoholic Fatty Liver Disease/diagnosis* ; Cost-Benefit Analysis ; Diabetes Mellitus, Type 2/diagnosis* ; Research ; Fibrosis

Objective: To assess the public health risk to Singapore posed by the emergence of artemisinin-resistant (ART-R) malaria in the Greater Mekong Subregion (GMS). Methods: We assessed the likelihood of importation of drug-resistant malaria into Singapore and the impact on public health of its subsequent secondary spread in Singapore. Literature on the epidemiology and contextual factors associated with ART-R malaria was reviewed. The epidemiology of malaria cases in Singapore was analysed. The vulnerability and receptivity of Singapore were examined, including the connectivity with countries reporting ART-R malaria, as well as the preparedness of Singaporean health authorities. Sources of information include international journals, World Health Organization guidelines, data from the Singapore Ministry of Health and National Public Health Laboratory of the National Centre for Infectious Diseases, and the International Air Transport Association. Results: The importation of ART-R malaria into Singapore is possible given the close proximity and significant travel volume between Singapore and the GMS countries reporting artemisinin resistance. Singapore’s vulnerability is further enhanced by the presence of foreign workers from neighbouring endemic countries. Nonetheless, the overall likelihood of such an event is low based on the rarity and decreasing trend of imported malaria incidence. With the presence of Anopheles vectors in Singapore, imported cases of drug-resistant malaria could cause secondary transmission. Nevertheless, the risk of sustained spread is likely to be mitigated by the comprehensive surveillance and control system in place for both infected vectors and human cases. Discussion This risk assessment highlights the need for a continued high degree of vigilance of ART-R malaria locally and globally to minimize the risk and public health impact of drug-resistant malaria in Singapore.

BACKGROUNDCollagen VI-related myopathies are autosomal dominant and recessive hereditary myopathies, mainly including Ullrich congenital muscular dystrophy (UCMD) and Bethlem myopathy (BM). Muscle magnetic resonance imaging (MRI) has been widely used to diagnosis muscular disorders. The purpose of this study was to evaluate the diagnostic value of thigh muscles MRI for collagen VI-related myopathies.

METHODSEleven patients with collagen VI gene mutation-related myopathies were enrolled in this study. MRI of the thigh muscles was performed in all patients with collagen VI gene mutation-related myopathies and in 361 patients with other neuromuscular disorders (disease controls). T1-weighted images were used to assess fatty infiltration of the muscles using a modified Mercuri's scale. We assessed the sensitivity and specificity of the MRI features of collagen VI-related myopathies. The relationship between fatty infiltration of muscles and specific collagen VI gene mutations was also investigated.

RESULTSEleven patients with collagen VI gene mutation-related myopathies included six UCMD patients and five BM patients. There was no significant difference between UCMD and BM patients in the fatty infiltration of each thigh muscle except sartorius (P = 0.033); therefore, we combined the UCMD and BM data. Mean fatty infiltration scores were 3.1 and 3.0 in adductor magnus and gluteus maximus, while the scores were 1.3, 1.3, and 1.5 in gracilis, adductor longus, and sartorius, respectively. A "target" sign in rectus femoris (RF) was present in seven cases, and a "sandwich" sign in vastus lateralis (VL) was present in ten cases. The "target" and "sandwich" signs had sensitivities of 63.6% and 90.9% and specificities of 97.3% and 96.9% for the diagnosis of collagen VI-related myopathies, respectively. Fatty infiltration scores were 2.0-3.0 in seven patients with mutations in the triple-helical domain, and 1.0-1.5 in three of four patients with mutations in the N- or C-domain of the collagen VI genes.

CONCLUSIONSThe "target" sign in RF and "sandwich" sign in VL are common MRI features and are useful for the diagnosis of collagen VI-related myopathies. The severity of fatty infiltration of muscles may have a relationship with the mutation location of collagen VI gene.

Adolescent ; Adult ; Child ; Child, Preschool ; Collagen Type VI ; genetics ; metabolism ; Female ; Humans ; Infant ; Infant, Newborn ; Magnetic Resonance Imaging ; Male ; Muscle, Skeletal ; pathology ; Muscular Diseases ; genetics ; metabolism ; pathology ; Mutation ; genetics ; Sensitivity and Specificity ; Thigh ; pathology ; Young Adult