a blood test will check for antibodies but it is not 100% accurate in testing for HSV2, i have been adv a swab of the fluid from the blisters is the only way. I am sure I have HSV2 i have monthly outbreaks, however my blood test only shows HSV1 which i know i have anyway because of coldsores on nose. I have not read any literature that suggests HSV2 will cause alzheimers