However, one of the drawbacks of antibodies screening test is the probability of a false-positive result due to: 1- IgG remains in the serum for approximately eighteen months after infection, 2- levels of IgM decline after two or three weeks after infection because IgM is regarded as a useful detector in acute infection (Heyworth, 2014) and 3- Cross-reactivity against other protozoan antigens (Pacheco et al. 2020). Here, CD40LG is linked to infection.