Sudden Death From Influenza in a Child Due to Superimposed Bacterial Infection and Secondary Herpetic Changes

Abstract

Background: We report the second documented case of pneumonia caused by influenza virus with superimposed MRSA and herpes virus. Case Report: A 13-year-old female with no past medical history presented to the hospital with acute cough, fever, and lethargy. Her oxygen saturation and blood pressure declined rapidly. She was given normal saline with dopamine infusion for hypotension related to septic shock along with empiric antibiotics. Chest x-ray revealed diffuse bilateral parenchymal infiltrates and edema. Patient had not received flu vaccine. Labs revealed low WBC, low platelets, and elevated coagulation parameters concerning for DIC. Patient cannulated for extracorporeal membrane oxygenation (ECMO). Vitamin K, packed RBCs, platelets, FFP, and cryoprecipitate administered for worsening DIC. Despite ECMO, patient continued to have poor perfusion, became pulseless, and subsequently died. Results: Postmortem findings confirmed influenza B virus Yamagata lineage. Blood cultures grew MRSA. Large gram-positive coccal bacteria noted on gram stain. Microscopic sections of lungs showed diffuse alveolar damage with hemorrhage and patchy zones of necrosis reminiscent of herpes-type necrosis although no distinct viral cytopathic effect. Herpes-type 1 and 2 immunostains showed positive staining of granular debris with areas of necrosis. Findings consistent with fatal influenza B infection complicated by severe necrotizing bacterial pneumonia with diffuse alveolar damage and secondary herpetic changes. Discussion: Herpetic pneumonia is usually limited to immunocompromised patients. In this previously healthy teenager, viral pneumonia with superimposed bacterial infection resulted in diffuse alveolar damage and depressed immunity, making her susceptible to herpetic infection likely leading to her rapid decline and death within 19 hours. When patients present with influenza unresponsive to treatment, it is important to rule out superimposed infections.