HSPD1 and Trichiasis: While it is possible that the immunoreactivity to recombinant Chlamydiaceae Hsp60 of the different species represents cross-reactivity due to the high degree of homology between species (C. trachomatis Hsp60 is 93% homologous to the Hsp60 of C. psittaci [78] and 85% to that of C. pneumoniae [79]), the associations with scarring and/or trichiasis were significant when assaying tears and sera from individuals infected with one species for responses to the specific recombinant Hsp60 for that species (Table 5).