Our data also hints at the co-evolutionary arms race between parasite and host: MHC alleles DRB*001 and DRB*005 were negatively affected, while allele DRB*003 was positively associated with nematode N13 infections; and allele DRB*005 was positively associated with Hepacivirus infection, though negatively associated with nematode N13. Here, HLA-C is linked to infection.