On 2017 Feb 25, Marcia Herman-giddens commented:

It is already known that C6 is not a test for acute LB. This study found "All (34/34) seropositive blood donors followed over time remained seropositive at follow-up after 22-29 months." Perhaps seropositivity remains much longer than this. (Doesn't this question beg for a longer study unless the whole test is thrown out as useless?) This could explain why the older people get the more likely they are to be positive since they would have a longer exposure period ("seroprevalence was significantly higher in males and increased with age"). Males are usually more exposed to the outdoors over a lifetime than women. Thus, it would seem that the conclusion of the study should be that a lot of people have had LB infections in Kalmar County, and that a positive C6 could well indicate ongoing infection or a past infection, rather than the study's implication of false positivity. One wonders who would want blood from a C6 positive donor? The bottom line from this study seems to be that C6 is a useless test for blood screening for LB and should not be used.

On 2017 Feb 25, Marcia Herman-giddens commented:

It is already known that C6 is not a test for acute LB. This study found "All (34/34) seropositive blood donors followed over time remained seropositive at follow-up after 22-29 months." Perhaps seropositivity remains much longer than this. (Doesn't this question beg for a longer study unless the whole test is thrown out as useless?) This could explain why the older people get the more likely they are to be positive since they would have a longer exposure period ("seroprevalence was significantly higher in males and increased with age"). Males are usually more exposed to the outdoors over a lifetime than women. Thus, it would seem that the conclusion of the study should be that a lot of people have had LB infections in Kalmar County, and that a positive C6 could well indicate ongoing infection or a past infection, rather than the study's implication of false positivity. One wonders who would want blood from a C6 positive donor? The bottom line from this study seems to be that C6 is a useless test for blood screening for LB and should not be used.