Hi welcome to Healthcaremagic
Hi.., on exposure to Infection, the first antibodies
will appear in the blood, which will be dtetected by Tridot card test, it is a screening test,.. if it is negative, then no need to do again, or else you can go for ELISA
also.... But any test you do, you must repeat it after 6 months to completely rule out the infection... PCR is bit costly.. but test is very specific and sensitive also, hence can detect even very small dose of infection,..
Hope I have answered your question..