Daryl Stevens , Aravind Surapaneni , Dan Deere , Nick O'Connor , Nick Crosbie , Alex Keegan , Leon Stackpole , Martin Robards
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引用次数: 1
Abstract
The probability of cysticercus bovis (CB) infection of cattle (cysticerci from Taenia saginata) in a country where T. saginata is not endemic (i.e. Australia) was assessed using a Quantitative Microbial Risk Assessment (QMRA) approach. Two important features of the QMRA were (i) a dose-response curve to describe ingestion of eggs of the helminth T. saginata (HE) by cattle and the development of cysticerci due to the infection, and (ii) characterisation of HE concentrations. Data limitations relating to HE quantification are described, and several other key variables provided the basis for a probabilistic QMRA model.
Data from over 554 sewage samples from 11 wastewater treatment plants (WWTPs) in Southern Australia indicated the background concentration of T. saginata eggs was low (<0.1 HE L-1 measured, 0.003 HE L-1 as an estimated baseline modelled on a ratio of Taenia:Ascaris determined from the literature). Such a low sewage concentration was estimated to require only a 2.2 log10 reduction value (LRV) via sewage treatment to maintain the baseline risk of CB equivalent to background levels in Australia. However, to protect against potential future detectable outbreaks of Taeniasis in the human population and all potential exposure scenarios considered, a 3.5 LRV for WWTP was considered appropriate with confirmation by appropriate sewage monitoring. In addition, analysis of several specific exposure scenarios using the QMRA indicated that LRV credits (0.5 to 2.0 LRV) could decrease the required LRV for wastewater treatment based on the size of the WWTP and on-site management strategies (e.g. restriction of recycled water use for livestock drinking water, the years of exposure for cattle to sites irrigated with recycled water, and the use of fodder off-site). Without such measures, a HE LRV of 4.0 is recommend for WWTPs to ensure adequate protection of systems with no on-site controls.
采用定量微生物风险评估(QMRA)方法评估了牛囊尾蚴(来自牛带绦虫的囊虫)在一个牛带绦虫不流行的国家(即澳大利亚)感染牛囊尾蚴的可能性。QMRA的两个重要特征是:(i)描述牛摄入saginata (T. saginata, HE)虫卵和因感染而产生囊虫的剂量-反应曲线,以及(ii) HE浓度特征。描述了与HE量化相关的数据限制,以及其他几个关键变量为概率QMRA模型提供了基础。来自南澳大利亚11个污水处理厂(WWTPs)的超过554个污水样本的数据表明,saginata卵的背景浓度很低(测量到的<0.1 HE L-1,根据文献确定的带绦虫:蛔虫比例建模的估计基线为0.003 HE L-1)。据估计,如此低的污水浓度只需要通过污水处理降低2.2 log10 (LRV),就能使澳大利亚的CB基线风险保持在与背景水平相当的水平。然而,为了防止未来可能在人群中发现的带绦虫病暴发,并考虑到所有可能的暴露情况,经适当的污水监测确认,认为污水处理厂的最小限值为3.5是合适的。此外,利用QMRA对几种特定暴露情景进行分析表明,LRV积分(0.5 ~ 2.0 LRV)可以根据污水处理厂的规模和现场管理策略(如限制牲畜饮用水使用循环水、牛在循环水灌溉场地的暴露年限以及场地外饲料的使用)降低废水处理所需的LRV。如果没有这些措施,建议污水处理厂的HE LRV为4.0,以确保没有现场控制的系统得到充分保护。
期刊介绍:
The journal Microbial Risk Analysis accepts articles dealing with the study of risk analysis applied to microbial hazards. Manuscripts should at least cover any of the components of risk assessment (risk characterization, exposure assessment, etc.), risk management and/or risk communication in any microbiology field (clinical, environmental, food, veterinary, etc.). This journal also accepts article dealing with predictive microbiology, quantitative microbial ecology, mathematical modeling, risk studies applied to microbial ecology, quantitative microbiology for epidemiological studies, statistical methods applied to microbiology, and laws and regulatory policies aimed at lessening the risk of microbial hazards. Work focusing on risk studies of viruses, parasites, microbial toxins, antimicrobial resistant organisms, genetically modified organisms (GMOs), and recombinant DNA products are also acceptable.