Six (55%) of the 11 outpatients had a laboratory-confirmed co-infection with another pathogen, such as HSV (antigen positive), acute Puumala virus infection (i.e., the same serum sample was positive for Puumala virus IgM), an Escherichia coli urosepsis, and impetigo contagiosa. The gene discussed is CD40LG; the disease is coinfection.