Listeria Monocytogenes Meningoencephalitis in the Elderly Caused by Needle Injection: A Case Report

Abstract Background: Listeria is widely distributed in nature, and Listeria monocytogenes is the main strain that causes human infections. Listeriosis is usually a food-borne disease with low incidence and high mortality, and elderly individuals with low immunity are at a high risk of infection. However, we report a very rare case of injection-induced Listeria monocytogenesmeningoencephalitis in an elderly individual. The clinical characteristics of this case are different from those of healthy adults or food-borne infections with Listeria monocytogenes. Case presentation: This case report describes an 80-year-old woman with diabetes who developed progressive coma, respiratory failure and shock due to repeated use of the same needle for injectinginsulin. Multiple examinations of cerebrospinal fluid pathogen culture werenegative, CT examination showed no specific changes, and the empirical use of antibiotics was ineffective. Listeria monocytogenes genes were found by next-generation sequencing of cerebrospinal fluid, and her infection was definitivelydiagnosed as Listeria monocytogenesmeningoencephalitis. After the appropriate antibiotic therapy, the patient's condition was well alleviated andreturned to normal life after six months of follow-up. Conclusions: We learned from the cases that Listeria monocytogenes meningoencephalitis in elderly individuals infected by nonfood-borne routes is characterized by occult onset, rapid progression, easily confused clinical manifestations and a low positive rate of cerebrospinal fluid culture. Due to easy misdiagnosis early on, a thorough examination should be started as soon as possible, and doctors should be aware of the symptoms of this disease. Early diagnosis and early treatment will helpreduce the mortality and debilitation caused by this disease.