Another case of respiratory syncytial virus-related limbic encephalitis

Occurrence of Central Nervous System Complications of Respiratory Syncytial Virus Infections: A Systematic Review with Meta-Analysis

An increasing base of evidence suggests that respiratory syncytial virus (RSV) infections may be associated with neurological complications. In accord with the PRISMA statement, we performed a systematic review and meta-analysis on the occurrence of encephalitis and encephalopathy associated with documented RSV infections. PubMed, Embase, and Scopus databases were searched for eligible observational studies published up to 10 April 2024. Raw data included the occurrence of RSV infections among cases of encephalitis and/or encephalopathy and cases of encephalitis and/or encephalopathy among series of RSV infections. Data were pooled in a random effects model. Case reports were also collected, and their data pooled as a cumulative series. Heterogeneity was assessed using the I2 measure, while reporting bias was assessed by means of funnel plots and regression analysis. A total of 15 studies for a total of 7719 RSV infections and 1631 cases of encephalitis were analyzed. Moreover, 27 case reports and case series were retrieved, for a total of 84 individual cases of encephalitis/encephalopathy occurring during a documented RSV infection. A pooled prevalence of 2.20 cases of encephalitis/encephalopathy per 100 RSV cases (I2 = 99%) was calculated, while a prevalence of RSV infections among cases of encephalitis/encephalopathy was estimated to 3.53 per 100 cases for studies on respiratory specimens (I2 = 48%) and 0.37 per cases on central nervous system (CNS) specimens (I2 = 0%). Detection of RSV within the CNS was relatively rare (17.86% of pooled case reports), being associated with male gender (adjusted odds ratio [aOR] 5.021, 95% confidence interval [95%CI] 1.104 to 22.831) and recovery with long-term sequelae (aOR 5.699, 95%CI 1.152; 28.183). Case fatality ratio was estimated to be 0.43 per 100 cases on observational studies and 10.71% in case reports, a difference likely due to publication bias. In summary, RSV represented a not frequent but notable cause of encephalitis/encephalopathy in adults and children. The paucity of available studies not only recommends a cautious appraisal of our results but stresses the clinical significance of future studies on incident cases of encephalitis and/or encephalopathy.

The presence of human respiratory syncytial virus in the cerebrospinal fluid of a child with Anti-N-methyl-D-aspartate receptor encephalitis of unknown trigger

BACKGROUND

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an important type of brain inflammation caused by autoantibody. As one of the primary agents responsible for respiratory tract infection, the human respiratory syncytial virus (hRSV) has also been reported to be capable of causing extrapulmonary diseases. Here, we first describe a case of anti-NMDAR encephalitis when hRSV was shown to be present in the cerebrospinal fluid.

CASE PRESENTATION

The child was noted to have ataxia and positive anti-NMDA receptors in the cerebrospinal fluid, diagnosed as anti-NMDA receptor encephalitis in combination with cranial MRI images. After high-dose hormone pulse therapy and medication, the disease improved, and he was discharged. However, a relapse occurred almost a year later, and the cranial MRI imaging showed progressive cerebellar atrophy. An hRSV strain from group B was detected in his cerebrospinal fluid, and the whole genome sequence was recovered using transcriptome sequencing.

CONCLUSIONS

To our knowledge, this is the first report of hRSV being found in the cerebrospinal fluid of a patient with anti-NMDAR encephalitis. Even though more clinical records and experimental evidence are needed for validation, this work expands the types of diseases linked to hRSV and the likely cause of anti-NMDAR encephalitis.

Potential Neurocognitive Symptoms Due to Respiratory Syncytial Virus Infection

Respiratory infections are among the major public health burdens, especially during winter. Along these lines, the human respiratory syncytial virus (hRSV) is the principal viral agent causing acute lower respiratory tract infections leading to hospitalization. The pulmonary manifestations due to hRSV infection are bronchiolitis and pneumonia, where the population most affected are infants and the elderly. However, recent evidence suggests that hRSV infection can impact the mother and fetus during pregnancy. Studies have indicated that hRSV can infect different cell types from the placenta and even cross the placenta barrier and infect the fetus. In addition, it is known that infections during the gestational period can lead to severe consequences for the development of the fetus due not only to a direct viral infection but also because of maternal immune activation (MIA). Furthermore, it has been described that the development of the central nervous system (CNS) of the fetus can be affected by the inflammatory environment of the uterus caused by viral infections. Increasing evidence supports the notion that hRSV could invade the CNS and infect nervous cells, such as microglia, neurons, and astrocytes, promoting neuroinflammation. Moreover, it has been described that the hRSV infection can provoke neurological manifestations, including cognitive impairment and behavioral alterations. Here, we will review the potential effect of hRSV in brain development and the potential long-term neurological sequelae.

Respiratory Syncytial Virus-Associated Neurologic Complications in Children: A Systematic Review and Aggregated Case Series

OBJECTIVES

To describe the features and frequency of respiratory syncytial virus (RSV)-associated severe acute neurologic disease in children.

STUDY DESIGN

We performed a systematic review of the literature to identify reports of severe acute neurologic complications associated with acute RSV infection in children aged <15 years (PROSPERO Registration CRD42019125722). Main outcomes included neurologic, clinical, and demographic features of cases and the frequency of disease. We aggregated available case data from the published literature and from the Australian Acute Childhood Encephalitis (ACE) study.

RESULTS

We identified 87 unique studies from 26 countries describing a spectrum of RSV-associated severe acute neurologic syndromes including proven encephalitis, acute encephalopathy, complex seizures, hyponatremic seizures, and immune-mediated disorders. The frequency of RSV infection in acute childhood encephalitis/encephalopathy was 1.2%-6.5%. We aggregated data from 155 individual cases with RSV-associated severe acute neurologic complications; median age was 11.0 months (IQR 2.0-21.5), most were previously healthy (71/104, 68%). Seizure was the most frequently reported neurologic feature (127/150, 85%). RSV was detected in the central nervous system of 12 cases. Most children recovered (81/122, 66%); however, some reports described partial recovery (33/122, 27%) and death (8/122, 7%).

CONCLUSIONS

RSV-associated neurologic complications have been widely reported, but there is substantial heterogeneity in the design and quality of existing studies. The findings from our study have implications for the investigation, management, and prevention of RSV-associated neurologic complications. Further, this systematic review can inform the design of future studies aiming to quantify the burden of childhood RSV-associated neurologic disease.

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.

New insights on the viral and host factors contributing to the airway pathogenesis caused by the respiratory syncytial virus

The respiratory syncytial virus (RSV) is the most prevalent etiological agent of lower respiratory tract infections and the first cause of hospitalization in infants due to respiratory disease worldwide. However, efforts to develop safe and effective vaccines and antivirals have been challenged by an incomplete understanding of the RSV pathogenesis and the host immune response to RSV infection in the airways. Here, we discuss recent advances in understanding the interaction between RSV and the epithelium to induce pathogenesis in the airways, such as the role of the RSV NS2 protein in the airway epithelium, as well as the events involved in the RSV entry process. In addition, we summarize the cellular factors produced by airway epithelial cells (AECs) in response to RSV infection that lead to the activation of innate and adaptive immune responses, inducing lung inflammation and disease. Further, we discuss the possible contribution of a recently identified cytokine, thymic stromal lymphopoitein (TSLP), in the lung immunopathology caused by RSV.