Serum CMV PCR, EBV PCR, herpes simplex (HSV) virus type 1 and 2, cryptococcus blood antigen, human Immunodeficiency virus (HIV) 1 and 2 antibody and antigen, influenza A/B, adenovirus, parainfluenza 1–4, chlamydia pneumoniae, bocavirus, coronavirus, respiratory syncytial virus (RSV) A/B, rhinovirus/enterovirus, metapneumovirus, Lyme disease serologies, Brucella IgM/IgG, and West Nile IgM/IgG were all negative/unremarkable. Here, CD40LG is linked to Lyme disease.