Severe Sepsis With Septic Shock as a Consequence of a Severe Hospital-Acquired Pneumonia Resulting From Legionella Pneumophila in Children: A Case Series and Literature Review

BackgroundLegionella pneumophila is responsible for hospital or community-acquired pneumonia in adults. Immunocompromised patients with Legionella pneumophila infection are associated with rapidly severe clinical course and high mortality rates. Legionella pneumophila infection is rare in children, especially combined with extrapulmonary manifestations. In this report, we describe 2 children of severe hospital-acquired pneumonia and septic shock resulting from Legionella pneumophila. Standardized metagenomics next-generation sequencing allowed early diagnosis. Appropriate antibiotic therapy and timely extracorporeal life support were effective in achieving complete recovery. This is the first report of children with septic shock related to Legionella pneumophila infections diagnosed by metagenomics next-generation sequencing and recovered successfully.Case presentationThere were 2 cases about septic shock resulting from Legionella pneumophila. One was a six-month girl with congenital biliary atresia who underwent liver transplantation. She was suspected for rejecting the liver and admitted to hospital. The other one was a five-year-old boy with Burkitt lymphoma who was in the end of early chemotherapy. They both presented with fever, cough or shortness of breath during hospitalization. And they were transferred to PICU because of worsening dyspnea and decreased blood pressure. Patients were diagnosed by severe sepsis with septic shock likely resulting from hospital-acquired pneumonia. Metagenomics next-generation sequencing indicated L. pneumophila in blood and sputum. Aggressive intravenous fluids resuscitation and vasopressors were initiated on arrival to PICU, and they were placed on mechanical ventilation and continuous renal replacement therapy. Intravenous antibiotic therapy followed by azithromycin. Finally, the patients recovered without any long-term sequelae.ConclusionsThough sepsis or sepsis shock caused by Legionella pneumophila is rare in children, it can occur at high-risk population. Metagenomics next-generation sequencing is useful for conforming hard-to-culture pathogens and severely ill patients. The report remind pediatric physicians that we should be aware that Legionella pneumophila can cause severe sepsis or sepsis shock, especially in immunocompromised children. It is significant to select appropriate samples and pathogen detection methods in the early stage of disease.