Listerial meningitis in a patient with undiagnosed acquired immunodeficiency syndrome: ampicillin should be added to the empirical antibiotic coverage.

Meningitis is an important differential diagnosis in patients with fever, headache, and/or altered consciousness in the emergency department (ED). With human immunodeficiency virus (HIV) infection becoming increasingly common, patients with acquired immunodeficiency syndrome (AIDS) need to be recognised promptly to facilitate the choice of appropriate antibiotic therapy for potential opportunistic infections. Physicians should be able to recognise a patient with undiagnosed AIDS who presents to the ED and perform further confirmational tests without violating the rights of the patient. Additional tests focusing on discovering potential opportunistic pathogens should be performed. Ampicillin should be added to the empirical regimen for the coverage of Listeria meningocerebritis, which should be considered in all potentially immunocompromised hosts with suggestive clinical presentations. Failure to recognise patients with AIDS and provide antibiotics active against L monocytogenes in such hosts may lead to a catastrophic outcome.