Staphylococcal endocarditis in a quadricuspid aortic valve following uncomplicated dengue infection: a case report

BACKGROUND: Dengue fever is endemic and a leading health problem in Sri Lanka. Increased incidence of concurrent bacteremia in patients with dengue infection is a recognized complication. However, Staphylococcal endocarditis following dengue fever is uncommon. Quadricuspid aortic valve (QAV) is a rare congenital anomaly and few cases of infective endocarditis have been reported in QAV. CASE PRESENTATION: A 32-year-old Sri Lankan male presented to the National Hospital of Sri Lanka with recurrence of fever and acute left hemiplegia following an uncomplicated recovery of dengue fever. He was diagnosed to have Staphylococcal infective endocarditis of quadricuspid aortic valve, with septic emboli to brain and spleen. He was managed with intravenous vancomycin initially, however, due to inadequate response, intravenous linezolid was added. He developed rhabdomyolysis with very high creatine phosphokinase leading to acute kidney injury, which settled with the cessation of linezolid. The patient succumbed to his illness despite aggressive antimicrobial therapy and maximum supportive care while being assessed for aortic valve replacement. CONCLUSIONS: This case illustrates three clinical issues that a clinician should be aware of. Firstly, the possibility of a serious secondary bacterial infection as a cause for recurrence of fever following dengue infection. Secondly, this case highlights the importance of identifying QAV as a cause for complicated infective endocarditis of increased severity. The report also denotes the value of being vigilant of linezolid induced rhabdomyolysis which had a causal relationship with the commencement of the drug and its cessation.