一項(xiàng)研究提出,，給奶牛接種疫苗防范大腸埃希氏菌O157可能減少將近85%的人類大腸埃希氏菌感染病例,，這種感染導(dǎo)致了嚴(yán)重的胃腸疾病和死亡。Louise Matthews及其同事使用獸醫(yī)數(shù)據(jù),、人類監(jiān)測(cè)數(shù)據(jù)和分子數(shù)據(jù)研究了大腸埃希氏菌O157從奶牛傳給人的風(fēng)險(xiǎn),，并且估計(jì)了為牛這種大腸埃希氏菌感染的主要儲(chǔ)存宿主接種疫苗的效率。有兩種針對(duì)這種細(xì)菌的疫苗,，能減少牛在其糞中排出這種細(xì)菌的頻率,、時(shí)間和數(shù)量。然而,，成本和管理問(wèn)題妨礙了這些疫苗的廣泛使用,。這組作者證明了只有在奶牛在糞便中排出大量的這種細(xì)菌的罕見環(huán)境下，人感染大腸埃希氏菌O157的風(fēng)險(xiǎn)才是重大的,。由于目前可用的疫苗針對(duì)細(xì)菌排出率,，這組作者預(yù)測(cè)說(shuō)，為牛接種疫苗可能減少人感染大腸埃希氏菌的病例將近85%,，這遠(yuǎn)遠(yuǎn)高于關(guān)于這些疫苗對(duì)牛的效率的研究預(yù)測(cè)的50%的數(shù)字,。這組作者說(shuō)，這些發(fā)現(xiàn)強(qiáng)有力地支持了畜牧業(yè)采用這些疫苗,。（生物谷 Bioon.com）
生物谷推薦的英文摘要
PNAS doi: 10.1073/pnas.1304978110
Predicting the public health benefit of vaccinating cattle against Escherichia coli O157
Louise Matthewsa,1, Richard Reevea,b, David L. Gallyc, J. Chris Lowd, Mark E. J. Woolhousee, Sean P. McAteerc, Mary E. Lockingf, Margo E. Chase-Toppinge, Daniel T. Haydona, Lesley J. Allisong, Mary F. Hansong, George J. Gunnh, and Stuart W. J. Reidi
Identifying the major sources of risk in disease transmission is key to designing effective controls. However, understanding of transmission dynamics across species boundaries is typically poor, making the design and evaluation of controls particularly challenging for zoonotic pathogens. One such global pathogen is Escherichia coli O157, which causes a serious and sometimes fatal gastrointestinal illness. Cattle are the main reservoir for E. coli O157, and vaccines for cattle now exist. However, adoption of vaccines is being delayed by conflicting responsibilities of veterinary and public health agencies, economic drivers, and because clinical trials cannot easily test interventions across species boundaries, lack of information on the public health benefits. Here, we examine transmission risk across the cattle–human species boundary and show three key results. First, supershedding of the pathogen by cattle is associated with the genetic marker stx2. Second, by quantifying the link between shedding density in cattle and human risk, we show that only the relatively rare supershedding events contribute significantly to human risk. Third, we show that this finding has profound consequences for the public health benefits of the cattle vaccine. A naïve evaluation based on efficacy in cattle would suggest a 50% reduction in risk; however, because the vaccine targets the major source of human risk, we predict a reduction in human cases of nearly 85%. By accounting for nonlinearities in transmission across the human–animal interface, we show that adoption of these vaccines by the livestock industry could prevent substantial numbers of human E. coli O157 cases.
