Interventions targeting non-symptomatic cases can be important to prevent local outbreaks: SARS-CoV-2 as a case study

During infectious disease epidemics, an important question is whether cases travelling to new locations will trigger local outbreaks. The risk of this occurring depends on the transmissibility of the pathogen, the susceptibility of the host population and, crucially, the effectiveness of surveillance in detecting cases and preventing onward spread. For many pathogens, transmission from pre-symptomatic and/or asymptomatic (together referred to as non-symptomatic) infectious hosts can occur, making effective surveillance challenging. Here, by using SARS-CoV-2 as a case study, we show how the risk of local outbreaks can be assessed when non-symptomatic transmission can occur. We construct a branching process model that includes non-symptomatic transmission and explore the effects of interventions targeting non-symptomatic or symptomatic hosts when surveillance resources are limited. We consider whether the greatest reductions in local outbreak risks are achieved by increasing surveillance and control targeting non-symptomatic or symptomatic cases, or a combination of both. We find that seeking to increase surveillance of symptomatic hosts alone is typically not the optimal strategy for reducing outbreak risks. Adopting a strategy that combines an enhancement of surveillance of symptomatic cases with efforts to find and isolate non-symptomatic infected hosts leads to the largest reduction in the probability that imported cases will initiate a local outbreak.     

Performance gaps in energy consumption: household groups and building characteristics

ABSTRACT

The difference between actual and calculated energy is called the ‘energy-performance gap’. Possible explanations for this gap are construction mistakes, improper adjusting of equipment, excessive simplification in simulation models and occupant behaviour. Many researchers and governmental institutions think the occupant is the main cause of this gap. However, only limited evidence exists for this. Therefore, an analysis is presented of actual and theoretical energy consumption based on specific household types and building characteristics. Using a large dataset (1.4 million social housing households), the average actual and theoretical energy consumptions (gas and electricity) of different household types and characteristics (income level, type of income, number of occupants and their age) were compared for each energy label. Additionally, the 10% highest and lowest energy-consuming groups were analysed. The use of combinations of occupant characteristics instead of individual occupant characteristics provides new insights into the influence of the occupant on energy demand. For example, in contrast to previous studies, low-income households consume more gas per m² (space heating and hot water) than households with a high income for all types of housing. Furthermore, the performance gap is caused not only by the occupant but also by the assumed building characteristics.     

2011—2020年全国河鲀毒素中毒事件分析

目的 分析2011—2020年全国河鲀毒素中毒事件的流行病学特征,为制定河鲀毒素中毒的精准防控措施提供科学依据。方法 对2011—2020年通过“国家食源性疾病暴发监测系统”上报的河鲀毒素中毒事件进行描述性流行病学分析。结果 我国2011—2020年共报告河鲀毒素中毒事件92起,中毒339人,死亡15人,病死率为4.4%。河鲀毒素中毒主要发生在我国沿海地区,原因食品包括鲜河鲀鱼（71.7%,66/92）、河鲀鱼干（13.0%,12/92）、织纹螺（7.6%,7/92）、鲎（5.4%,5/92）和云斑裸颊虾虎鱼（2.2%,2/92）,每年3~4月是中毒高发期。结论 做好河鲀毒素中毒的防控,建立生物标本中河鲀毒素检测方法,提高河鲀毒素中毒病原学鉴定能力;加强流通环节监管和科普宣传,改变民众捕食野生河鲀的饮食习惯。     

Uptake of energy efficiency interventions in English dwellings

Little detailed evidence has previously been available regarding the uptake rate or prevalence of energy efficiency interventions among specific household groups. This study uses the Home Energy Efficiency Database (HEED) to investigate both the combination of measures that have been installed, and in which dwellings, according to key neighbourhood socio-demographic variables, including income and tenure. Analysis of 2000–07 data indicates that approximately 40% (9.3 million) dwellings in England had approximately 23.7 million efficiency measures installed, with an average of 2.5 measures per dwelling. Building fabric-related measures were the most frequent (e.g. cavity wall insulation, loft insulation and glazing) with an average of 2.1 million installed each year. Dwellings with the highest number of fabric interventions (the top 20%) were more likely to be found in areas with low income, with more owner-occupied dwellings, experiencing lower winter temperatures, having a lower proportion of flats, and having a slightly higher proportion of older adults and children. Energy efficiency installations have tended to occur among specific types of households or parts of the building stock. These findings have implications for the design of future government programmes for targeting energy efficiency measures to specific household groups or dwelling types.     

Simultaneous reconstruction of evolutionary history and epidemiological dynamics from viral sequences with the birth–death SIR model

The evolution of RNA viruses, such as human immunodeficiency virus (HIV), hepatitis C virus and influenza virus, occurs so rapidly that the viruses'' genomes contain information on past ecological dynamics. Hence, we develop a phylodynamic method that enables the joint estimation of epidemiological parameters and phylogenetic history. Based on a compartmental susceptible–infected–removed (SIR) model, this method provides separate information on incidence and prevalence of infections. Detailed information on the interaction of host population dynamics and evolutionary history can inform decisions on how to contain or entirely avoid disease outbreaks. We apply our birth–death SIR method to two viral datasets. First, five HIV type 1 clusters sampled in the UK between 1999 and 2003 are analysed. The estimated basic reproduction ratios range from 1.9 to 3.2 among the clusters. All clusters show a decline in the growth rate of the local epidemic in the middle or end of the 1990s. The analysis of a hepatitis C virus genotype 2c dataset shows that the local epidemic in the Córdoban city Cruz del Eje originated around 1906 (median), coinciding with an immigration wave from Europe to central Argentina that dates from 1880 to 1920. The estimated time of epidemic peak is around 1970.     

毒品滥用流行病模型的稳定性分析

现有毒品滥用流行病模型假设吸毒者康复后对毒品拥有永久"免疫"力，而忽视了其再次成为毒品易感者的可能性。针对这一问题，通过考虑社区治疗和隔离治疗两种措施，分析了毒品滥用人群的演化过程，提出了基于暂时"免疫"力的毒品滥用流行病模型，并计算了模型的基本再生数，讨论了模型平衡点的存在性和稳定性。当基本再生数小于1时，模型存在一个局部渐进稳定的无毒平衡点；当基本再生数大于1时，模型存在唯一的地方病平衡点，并利用几何方法证明了地方病平衡点的全局稳定性；当基本再生数等于1时，如果满足一定条件，模型出现后向分支现象。数值模拟验证了上述所有结果。研究结果表明提高隔离治疗率、改善社区治疗效果和降低接触传染率可以有效抑制毒品滥用的流行。     

Relation between Breast Cancer and High Glycemic Index or Glycemic Load: A Meta-analysis of Prospective Cohort Studies

Breast cancer is the commonest form of cancer in women worldwide. It has been suggested that chronic hyperinsulinemia associated with insulin resistance plays a role in breast cancer etiology. To test the hyperinsulinemia hypothesis, a dietary pattern associated with a high glycemic index and glycemic load, both proxies for chronic hyperinsulinemia, should be associated with an increased risk of breast cancer. A meta-analysis restricted to prospective cohort studies was undertaken using a random effects model with tests for statistical significance, publication bias and heterogeneity. The metric for analysis was the risk of breast cancer in the highest relative to the lowest glycemic index and glycemic load dietary pattern. A dietary pattern with a high glycemic index was associated with a summary relative risk (SRR) of 1.05 (95% CI: 1.00, 1.11), and a high glycemic load with a SRR of 1.06 (95% CI: 1.00, 1.13). Adjustments for body mass index [BMI], physical activity and other lifestyle factors did not influence the SRR, nor did menopausal status and estrogen receptor status of the tumor. In conclusion, the current evidence supports a modest association between a dietary pattern with high glycemic index or glycemic load and the risk of breast cancer.     

2012—2017年云南省有毒动植物中毒事件分析

目的 探讨2012—2017年云南省有毒动植物中毒事件的发生规律和特点,为制定预防和控制措施提供依据。方法 对2012—2017年云南省报告的有毒动植物中毒事件资料建立数据库,并按时间、地区、场所、中毒因素等进行统计分析。结果 共报告有毒动植物中毒事件530起,发病4 147人,死亡64人。第四季度为发病高峰,报告起数、发病人数和死亡人数分别占全年总数的30.8%(163/530)、37.4%(1 553/4 147)和50.0%(32/64);有毒植物中毒事件报告起数较多的州(市)为楚雄州、大理州、玉溪市,占总数的44.2%(212/480);有毒动物中毒报告起数较多的州(市)为迪庆州、怒江州、保山市,占总数的80.0%(40/50)。家庭中毒报告起数、发病人数和死亡人数最多,分别占总数的63.6%(337/530)、40.3%(1 672/4 147)和89.1%(57/64)。引起有毒动物中毒事件的食物主要是蜂蛹(7.9%,42/530),引起有毒植物中毒事件的食物前5位依次为乌头(30.2%,160/530)、四季豆(29.2%,155/530)、蓖麻子(5.3%,28/530)、蜂蜜(3.8%,20/530)和油桐(3.6%,19/530)。结论 云南省有毒动植物中毒问题突出,应完善食物中毒的应急处理体系,广泛宣传有毒动植物中毒的预防知识,以有效地减少云南省中毒事件的发生。     

Herd- and cow-level prevalence of digital dermatitis in the Netherlands and associated risk factors

The objective of this cross-sectional study was to reevaluate the prevalence of digital dermatitis (DD) and associated risk factors in The Netherlands. Between May 2002 and December 2003, information about the presence or absence of DD lesions and other claw disorders on the hind claws of dairy cows in The Netherlands was collected by 20 hoof trimmers during trimming of all dairy cows in 383 herds. A questionnaire was used to acquire information regarding management and housing. Additional information, such as parity, breed, and stage of lactation of the cows, was provided by the Dutch Herd Book Organization. Digital dermatitis was present in 21.2% (SE = 0.3) of the study population (n = 22,454 cows). The herd prevalence varied from 0% (9.1% of the herds) to 83.0%. Most common was herd prevalence between 5 and 10%. The Holstein-Friesian breed was at higher risk for DD [odds ratio (OR) = 1.7] than was the Meuse Rhine IJssel breed (dual purpose breed). The risk for DD decreased with increasing parity. Cows at the peak of their lactation (30 to 60 d in milk) and in the third parity had higher odds for DD in comparison with cows that were later than 60 DIM. The presence of other claw disorders, such as interdigital dermatitis/heel horn erosion (IDHE), interdigital hyperplasia (HYP), and interdigital phlegmon, appeared to be predisposing for DD. Based on estimation of the population-attributable fraction, it was concluded that if IDHE, HYP, and interdigital phlegmon were not present among the study population, respectively, 32.2, 9.0, and 1.1% of the DD cases could have been prevented. The risk for DD slightly decreased when cows affected by IDHE had access to pasture. Because of the interrelation between infectious claw disorders, an effective intervention strategy against DD should focus on an integrated approach to the control of all infectious claw diseases. Cows trimmed >12 mo before the study (during regular trimming of the entire herd) were at lower risk for DD than were cows that were trimmed at shorter intervals. Animals that had >8 h of access to pasture were at higher risk for DD (OR = 1.6) compared with no access to pasture. Finally, cows in small-sized herds (<45 cows) affected with HYP were at lower risk (OR = 0.6) for DD than were cows affected with HYP in medium- and large-sized herds (60 to 85 cows per herd).     

Examination of general health following Typhoon Xangsane: A pre–postanalysis.

An individual's health status immediately following a disaster may predict long-term morbidity and mortality. However, relative to the growing literature on postdisaster mental health, less is known about physical health outcomes, particularly in developing countries. Unlike most studies, the current investigation obtained physical health data both before and after Typhoon Xangsane, which struck the Da Nang province of Vietnam in 2006, and related these predisaster data to postdisaster health functioning, among other factors. Specifically, a sample of 795 randomly selected adults was interviewed both prior to, and after the typhoon. Results indicated that participants with symptoms of major depressive disorder and panic disorder, older participants, and participants who reported high distress during the actual typhoon were most at-risk for lower self-rated health postdisaster compared to those without these risk factors. Given that Vietnam is still designated a developing country, the present study enhances the literature on postdisaster physical health correlates in developing nations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)