INFECTIOUS AORTITIS DUE TO STAPHYLOCOCCUS AUREUS AFTER DENGUE INFECTION

Male patient, 81 years old, with a history of coronary artery disease status post revascularization, hypertension, and hypothyroidism. One month prior to the current hospitalization, he was admitted for dengue and hyponatremia and developed right upper limb phlebitis with fever, treated with daptomycin for three days. One week after discharge, he presented purulent drainage at the phlebitis site and received amoxicillin-clavulanate for seven days. After completing antibiotics, he developed fever and intense interscapular pain. During investigation, spine MRI suggested spondylodiscitis, and urine culture confirmed methicillin-susceptible Staphylococcus aureus (MSSA). On admission, blood cultures positive for MSSA confirmed bacteremia, and cefazolin 2 g every 8 hours was started. CT angiography of the chest revealed a descending thoracic aortic pseudoaneurysm with hematoma, 26 mm from the left subclavian artery. Transesophageal echocardiography identified an 8.2 × 1.7 mm vegetation on the aortic valve, confirming endocarditis, aortitis, and pseudoaneurysm. The following day, a thoracic endograft was implanted. After negative follow-up blood cultures, rifampin was added. Ten days later, repeat CT angiography showed a 20 mm abdominal pseudoaneurysm between the renal arteries and the superior mesenteric artery. Despite clinical improvement, he was discharged on cefazolin and rifampin with planned radiological follow-up. In the fifth week, he developed lower gastrointestinal bleeding and died. Discussion: Infectious aortitis due to S. aureus is rare, with 30–50% mortality. Pathophysiology involves septic embolization or direct invasion of the aortic wall, producing pseudoaneurysms with high rupture risk. Multiple pseudoaneurysms triple the chance of complications. Diagnosis should be suspected in unexplained chest or abdominal pain in bacteremic patients and confirmed by CT angiography showing wall thickening or hematoma. Treatment requires prolonged antibiotic therapy (≥6 weeks) and urgent vascular intervention. Open surgery is the gold standard, but TEVAR is an alternative in high-risk patients, with infectious recurrence in 20–30%. Hemorrhagic complications occur in 15–20% and carry high mortality, especially in patients >80 years and in abdominal locations. Periodic radiologic surveillance is essential, as up to 30% develop new aneurysms within 3 months.