A 60-year-old male, with a history of intravenous drug use, presented with fever and abdominal pain, diagnosed with Haemophilus influenzae bacteremia. He was treated with a 6-week course of ceftriaxone. Months later, he developed a mycotic aneurysm of the abdominal aorta, confirmed by imaging and surgical pathology to be associated with nontypeable Haemophilus influenzae (NTHi). This case highlights that NTHi bacteremia can lead to delayed and severe vascular complications like mycotic aneurysms, even after appropriate initial antibiotic therapy. Clinical suspicion for vascular complications should remain high in patients with NTHi bacteremia.
Key note: Nontypeable Haemophilus influenzae bacteremia can cause delayed mycotic aneurysms despite initial treatment.