This study was focused on comprehensively investigating (the first time) the effect of HLA-DRB1-DQB1 alleles on Ct infection outcome, given that it has been shown that HLA molecules could be related to Ct-induced diseases, such as trachoma17, PID6,18 and infertility19,20, or be associated with infection prevalence and bacterial reinfection8,21,22. Here, HLA-DRB1 is linked to infection.