The present invention discloses compositions and methods for treating, preventing and/or monitoring viral, bacterial, eukaryotic protist and/or fungal infections. In some embodiments, these compositions and methods involve human polyclonal antibodies affinity purified from human blood using certain viral, bacterial, eukaryotic protist and/or fungal antigens as described herein. Methods of making the antigenic preparations and the affinity-purified human polyclonal antibodies for passive immunization are also provided.