A study published in the online edition of the Journal of the Royal Society Interface reports that researchers have been exploring the likelihood that vCJD might be spread via the reuse of surgical instruments, and calls for more data in order to allay fears over the possible transmission of vCJD.
The number of vCJD cases continues to decline, and it is believed that most cases to date are the result of consumption of BSE-infected beef. There were 161 recorded cases by the end of 2005, and the annual incidence has been steadily decreasing since 2000, with estimates for the total scale of the epidemic through this route now lie in the low hundreds.
However, concern has been raised that transmission could, in theory, occur directly from one person to another via routes such as blood transfusions and surgical operations, despite instruments being decontaminated routinely before being used. Scientists based at both the
The results show that key factors determining the scale of any epidemic are the number of times a single instrument is re-used, combined with how infectious contaminated instruments are and how effective the cleaning is.
The authors begin by presenting data on the surgical procedures undertaken on vCJD patients prior to the onset of clinical symptoms which support the hypothesis that cases via this route are possible. They then apply a mathematical framework to assess the potential for self-sustaining epidemics via surgical procedures.
They conclude that further research is needed into how surgical instruments are used so as to reduce uncertainty and assess the potential risk of this transmission route.
They comment, "Given the frequency of high- and medium-risk surgical procedures undertaken in the
Reference: Garske T, Ward H, Clarke P, Will R, and Ghani A. Factors determining the potential for onward transmission of vCJD via surgical instruments. Journal of the Royal Society Interface.