Clinical manifestations of respiratory syncytial virus-associated encephalopathy in Fukushima, Japan

Background We investigated the epidemiology and clinical course of children with respiratory syncytial virus (RSV)-associated encephalopathy. Methods We retrospectively collected data for 280 patients from a questionnaire survey of acute encephalitis/encephalopathy (AE/E) in Fukushima Prefecture. We enrolled six patients diagnosed with RSV-associated encephalopathy from these 280 patients, and retrospectively investigated the clinical features and prognosis. Results Six (2.1%) of the 280 patients with AE/E were found to have RSV-associated encephalopathy. The age at onset and male-to-female ratio were 1.3 +/- 0.5 years and 2:4, respectively. The mean duration of fever and the duration of loss of consciousness were 3.7 +/- 1.5 days (range, 2-6 days), and 3.3 +/- 2.3 days (range, 2-8 days), respectively. Four patients had leukocytosis and two patients had high serum C-reactive protein. On admission, one child presented with normal renal and hepatic function, but, high serum ferritin, renal and hepatic dysfunction, and disseminated intravascular coagulation were observed along with progressive multiple organ failure, with the patient dying on the second day of hospitalization. On computed tomography of the brain, five patients had brain edema and one patient had a low-density area. Two of the six children had sequelae while three children had no sequelae. Conclusions The incidence of RSV-associated encephalopathy in all AE/E patients was 2.1% Given that half of the children with RSV-associated encephalopathy had sequelae or death, the prognosis for RSV-associated encephalopathy is not particularly good and it is necessary to pay careful attention to patients with RSV-associated encephalopathy.