Bluetongue in Eurasian Lynx

1496 Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 14, No. 9, September 2008 The precision of subtyping assays is a matter of importance and debate for epidemiologic and, recently, forensic investigations. Strain identity is commonly used to infer a common source even when spatial and temporal data are not congruent. Moreover, the defi nition of a strain is somewhat unclear and relies on analytical methods that vary widely. Therefore, isolates may be erroneously excluded or included into a strain defi nition and disease outbreak as illustrated with the Ames strain and 2 contrasting approaches to identifi cation. MLVA15 ties naturally occurring isolates to bioterrorism-associated attacks, while specifi c SNP assays can distinguish among them. MLVA is an unbiased approach and can be used on any set of B. anthracis strains, although, as in the 2006 and 2007 Texas outbreaks, it can be limited in resolving power. In contrast, our SNP assays have great resolving power but are useful only for differentiating the Ames strain, thus limiting their value to categorical inclusion or exclusion in outbreaks. Future rational use of a battery of different molecular signatures will yield far greater insights into strain identity than the application of 1 specifi c signature.