focus on recurrent febrile illnesses and the presence of any diseases or drug regimens that would compromise normal host defenses, such as sickle cell anemia, asplenia (functional, congenital, or surgical), malignancy (noting particularly chemotherapeutic or radiation treatments), human immunodeficiency virus (HIV), renal disease, prolonged steroid or other immunosuppressive agent use, or indwelling catheters or ventriculoperitoneal shunts Personal immunization status as well as known exposure to unimmunized or incompletely immunized individuals should also be determined An understanding of prior evaluation and treatments during this illness may be helpful