Nationwide survey of rotavirus-associated encephalopathy and sudden unexpected death in Japan

Neurologic Complications of Rotavirus Infections in Children

BACKGROUND

Rotavirus is the leading cause of complicated gastroenteritis in children younger than 5 years in countries where rotavirus vaccination is not implemented as a routine vaccination. Besides the intestinal symptoms that are associated with ordinary gastroenteritis, rotavirus can cause neurological complications. The aim of this study is to describe the clinical characteristics of complicated rotavirus infections.

METHODS

From January 1, 2016 to January 31, 2022, all children (below the age of 18 years) with a positive rotavirus test in feces that were either hospitalized or presented at the outpatient clinic or emergency department of a large pediatric hospital in the Netherlands were included. Rotavirus was only tested in case of a severe or abnormal disease course. We described the clinical characteristics and outcomes with a particular focus on neurological manifestations.

RESULTS

In total, 59 patients with rotavirus were included of whom 50 (84.7%) were hospitalized and 18 (30.5%) needed intravenous rehydration. Ten patients (16.9%) had neurologic complications, of whom 6 patients (60.0%) presented encephalopathy. Two patients (20.0%) with neurological symptoms showed abnormalities on diagnostic imaging.

CONCLUSIONS

Rotavirus can cause gastroenteritis with severe, but apparently self-limiting, neurological manifestations. Considering rotavirus in pediatric patients with neurological symptoms such as encephalopathy and encephalitis is therefore important. Early detection of rotavirus infection may predict a favorable course of the disease and may thereby prevent unnecessary treatment and should be further investigated.

Analysis of forensic autopsy cases associated with epilepsy: Comparison between sudden unexpected death in epilepsy (SUDEP) and not-SUDEP groups

Background and aims

Epilepsy is a common and chronic neurological disorder characterized by seizures that increase the risk of mortality. SUDEP is the most common seizure-related category of death. The study aimed to evaluate the key characteristics between SUDEP and not-SUDEP death cases.

Methods

A retrospective study of forensic autopsy cases from 2002 to 2021, performed by the Academy of Forensic Science (Ministry of Justice, China), identified a total of 31 deaths associated with epilepsy. We compared the different characteristics between individuals who died of SUDEP (SUDEP group) and individuals with epilepsy died suddenly due to unrelated causes (not-SUDEP group).

Results and conclusions

13 cases met the general accepted definition of SUDEP; and 18 cases were classified as not-SUDEP. The mean age of the not-SUDEP group was significantly higher than that of the SUDEP groups (p < 0.05) and there were more cases without a clear cause of epilepsy in the SUDEP group than in the not-SUDEP group (p < 0.05). Death position differed significantly between the two groups, with more cases dying in the prone position in the SUDEP group (p < 0.05). Complete autopsies were performed in 24 of the 31 cases. There were no significant differences in heart, lungs and brain weights, or in ventricular thickness (p > 0.05) between the SUDEP and not-SUDEP groups. In addition, compared to the not-SUDEP group, the SUDEP group featured a significantly more cases with coronary lesions (grades 1-3, p < 0.05). Neuropathological lesions were identified in 12 of the 13 SUDEP cases (92.3%), cardiac lesions were present in 10 cases (76.9%) and pulmonary edema and pulmonary congestion were present in all cases. The primary cause of death in 13 of the 31 cases was seizure disorder or epilepsy. The primary mechanism of death in SUDEP group was mainly asphyxia while that in the not-SUDEP group was cardiopulmonary failure (p < 0.05). Patients in the prone position had a significantly higher risk of asphyxia than those who were not. Here, we investigated the key characteristics between SUDEP and not-SUDEP death cases, which may help to facilitate forensic diagnosis in presumed SUDEP cases.

Rotavirus infection-associated central nervous system complications: clinicoradiological features and potential mechanisms

Despite the introduction of vaccines in 2006, rotavirus remains one of the most common causes of pediatric gastroenteritis worldwide. While many studies have conclusively shown that rotavirus infection causes gastroenteritis and is associated with various extraintestinal manifestations including central nervous system (CNS) complications, extraintestinal manifestations due to rotavirus infection have been relatively overlooked. Rotavirus infection-associated CNS complications are common in children and present with diverse clinicoradiological features. Rotavirus infection-associated CNS complications can be classified based on clinical features and brain magnetic resonance imaging findings, particularly lesion location on diffusion-weighted imaging. Common clinicoradiological features of rotavirus infection-associated CNS complications include: (1) benign convulsions with mild gastroenteritis; (2) acute encephalopathies/encephalitis, such as mild encephalopathy with a reversible splenial lesion, acute encephalopathy with biphasic seizures and late reduced diffusion, and acute necrotizing encephalopathy; (3) acute cerebellitis; and (4) neonatal rotavirus-associated leukoencephalopathy. The precise mechanism underlying the development of these complications remains unknown despite a number of clinical and laboratory studies. Here we review the diverse clinicoradiological features of rotavirus infection-associated CNS complications and propose a hypothesis of their pathophysiology.

Increased Platelet-Derived Growth Factor and Cytokine Levels in the Cerebrospinal Fluid of Patients of Sudden Unexpected Death with or without Viral Infection

OBJECTIVE

To clarify the pathogenesis of sudden unexpected natural death (SUD) as well as biomarkers to differentiate the underlying diseases, by performing cytokine analysis in the acute phase of pediatric patients in whom viral infection led to SUD.

METHODS

An acute phase cytokine analysis of pediatric patients in whom viral infection led to SUD was performed, and the data obtained were compared with those from SUD patients not associated with viral infections. Subjects included 4 boys aged 1-16 mo who died of cardiopulmonary arrest associated with viral infections. The causative viruses were identified as enterovirus, parainfluenza virus, respiratory syncytial virus, and rotavirus. The 4 other infants/children (aged 2-12 mo) died of non-infectious episodes, i.e., 1, 2, and 1 died of drowning, falling, and a traffic accident, respectively. Cerebrospinal fluid samples (CSF) of the subjects were collected during cardiopulmonary resuscitation or within 24 h of the events.

RESULTS

The infection-induced sudden death group showed elevated CSF levels of inflammatory cytokines and chemokines. No increase was observed in interleukin-10 levels. Furthermore, in the infection-induced sudden death group, platelet-derived growth factor levels correlated with inflammatory cytokine levels.

CONCLUSIONS

Infection-associated SUD may be differentiated from noninfectious SUD by measuring the levels of acute phase-inflammatory cytokines and chemokines at the onset of SUD.

Implementing vaccination policies based upon scientific evidence in Japan

The theme of the 24th Annual Meeting of the Japanese Society for Vaccinology was “Sustainable Future Medical Care Created by Vaccines.” This theme includes topics such as the proposal to reduce the medical costs incurred by societies with aging populations through prophylactic vaccination. The coronavirus disease 2019 (COVID-19) pandemic alerted us to the important roles that preventive measures, such as vaccines, play in fighting infectious diseases. In order to inform the public of the benefits of vaccines, it is important to provide society with information regarding new vaccine developments, adjuvants, the cost–benefit ratio of vaccine introduction, and vaccine effectiveness and safety. Clinical research is essential for obtaining evidence of vaccine effectiveness and safety. The United States Centers for Disease Control and Prevention (CDC) conducts active surveillance in defined areas before and after the introduction of vaccines and documents the reduction in infection rates as a measure of vaccine effectiveness. However, vaccine efficacy and side effects may vary by country and ethnicity. Therefore, it is necessary for individual countries to develop their own evidence-based surveillance programs. We have studied vaccine efficacy and documented side-effects observed in patients for the varicella and rotavirus vaccines in Japan. This review outlines the importance of providing scientific evidence for vaccine effectiveness and safety.

Enteric viruses circulating in undiagnosed central nervous system infections at tertiary hospital in São José do Rio Preto, São Paulo, Brazil

Enterovirus (EV) is commonly associated with central nervous system (CNS) syndromes. Recently, gastroenteric viruses, including rotavirus (RVA), human astrovirus (HAstV), and norovirus (NoV), have also been associated with CNS neurological disorders. The aim of the present study was to investigate the presence of EV, RVA, HAst, and NoV associated to CNS infections with undiagnosed etiology in Northwest region of São Paulo State, Brazil, and to conduct the molecular characterization of the positive samples detected. A total of 288 cerebrospinal fluid samples collected from July to December 2017 were tested for EV and NoV by quantitative real-time polymerase chain reaction (RT-qPCR), HAstV by conventional RT-PCR, and RVA by enzyme-linked immunosorbent assay. Positive-EV samples were inoculated in cells lines, amplified by RT-PCR and sequenced. RVA, NoV, and HAstV were not detected. EV infection was detected in 5.5% (16/288), and five samples successful genotyped: echovirus 3 (E3) (1/5), coxsackie virus A6 (CVA6) (1/5), and coxsackie virus B4 (CVB4) (3/5). Meningitis was the main syndrome observed (12/16; 75%). CVA6, CVB4, and E3 were identified associated with aseptic meningitis. Reports of CVA6 associated with aseptic meningitis are rare, E3 had not been previously reported in Brazil, and epidemiological data on CVB4 in the country is virtually unknown. The present investigation illustrates the circulation of diverse EV types in a small regional sample set and in a short period of time, highlighting the importance of an active EV surveillance system in CNS infections. Enhanced understanding of undiagnosed CNS infections will assist in public health and health care planning.

Molecular characterization of rotaviruses obtained from patients with rotavirus-associated encephalitis/encephalopathy

Group A rotavirus (RVA) rarely causes severe complications such as encephalitis/encephalopathy. However, the pathophysiology of this specific complication remains unclear. Next-generation sequence analysis was used to compare the entire genome sequences of RVAs detected in patients with encephalitis/encephalopathy and gastroenteritis. This study enrolled eight patients with RVA encephalitis/encephalopathy and 10 with RVA gastroenteritis who were treated between February 2013 and July 2014. Viral RNAs were extracted from patients' stool, and whole-genome sequencing analysis was carried out to identify the specific gene mutations in RVA obtained from patients with severe neurological complications. Among the eight encephalitis/encephalopathy cases, six strains were DS-1-like G1P[8] and the remaining two were Wa-like G1P[8] (G1-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1). Meanwhile, eight of the 10 viruses detected in rotavirus gastroenteritis patients were DS-1-like G1P[8], and the remaining two were Wa-like G1P[8]. These strains were further characterized by conducting phylogenetic analysis. No specific clustering was demonstrated in RVAs detected from encephalitis/encephalopathy patients. Although the DS-1-like G1P[8] strain was predominant in both groups, no specific molecular characteristics were detected in RVAs from patients with severe central nervous system complications.

Clinical and Imaging Findings of Neonatal Seizures Presenting as Diffuse Cerebral White Matter Abnormality on Diffusion-Weighted Imaging without any Structural or Metabolic Etiology

Purpose

Some patients with neonatal seizures show diffuse, symmetric diffusion-restricted lesions in the cerebral white matter. The aim of this study was to describe clinical and imaging findings of patients with neonatal seizures who had diffuse, symmetric diffusion-restricted lesions without any structural or metabolic etiology.

Materials and Methods

A total of 56 neonates aged less than 1 week underwent brain magnetic resonance imaging (MRI) for evaluation of seizures from November 2008 to February 2017. After excluding 43 patients, 13 patients showed diffuse white matter abnormality on diffusion-weighted imaging. Initial and follow-up clinical and MRI findings were analyzed retrospectively.

Results

All 13 patients were born at full term. Among the ten patients who underwent a stool test for viruses, six were positive for rotavirus and one for astrovirus. MRI revealed diffuse, symmetric diffusion-restricted lesions distributed along the cerebral white matter, thalami, and midbrain variably.

Conclusion

Diffuse, symmetric diffusion-restricted lesions involving the cerebral white matter can be seen in patients with neonatal seizures without any structural or metabolic etiology. Rotavirus is commonly but not exclusively detected in these patients. Nevertheless, viral infection-associated encephalopathy should be considered for patients with characteristic clinical and MRI findings.

Acetazolamide-Triggered Acute Flaccid Paralysis and Toxic-Metabolic Encephalopathy in a Toddler with Gastroenteritis: A Case Report

Acetazolamide is an infrequently prescribed medication in the outpatient pediatric setting, as one of its major indications is for the treatment of glaucoma, which is a largely adult disease. Though incredibly rare, serious neurologic side effects such as stroke, flaccid paralysis, and coma can occur after its administration. This case presentation of acute flaccid paralysis with metabolic derangement underscores the unusual, yet possible, toxic-metabolic and neurologic sequelae that can occur in an already acidotic host (in this case, caused by gastroenteritis) with acetazolamide ingestion. Life-threatening conditions must always be ruled out in patients who present with encephalopathy, but a medication history was crucial in clinching this case's unifying diagnosis. While there are case reports highlighting the rare central nervous system toxicities associated with acetazolamide ingestion, to our knowledge, none exist in the pediatric literature.

A nationwide survey of norovirus-associated encephalitis/encephalopathy in Japan

BACKGROUND

Norovirus is a major pathogen of gastroenteritis and is known to cause encephalitis/encephalopathy. The aim of this national survey was to clarify the clinical features of norovirus-associated encephalitis/encephalopathy (NoVE) among children in Japan.

METHODS

A nationwide survey of children with NoVE was conducted using a structured research form. The initial survey asked pediatricians about children with NoVE treated between January 2011 and March 2016. The second survey obtained patient information from two sources: hospitals that responded to the initial survey and those identified as having treated cases from a literature search.

RESULTS

Clinical information was available for 29 children. Their median age was 2 y 8 m. The outcome was good in 13 patients and poor in 15. The interval between the onset of gastrointestinal symptoms and that of encephalitis/encephalopathy was significantly shorter in those with a poor outcome. At the onset of an elevated serum creatinine level and an abnormal blood glucose level were correlated with a poor outcome. Regarding the subtypes of encephalitis/encephalopathy, acute encephalopathy with biphasic seizures and late reduced diffusion and hemorrhagic shock and encephalopathy syndrome were frequent.

CONCLUSION

The outcome of children with NoVE was poor. Early onset of neurological symptoms, an elevated serum creatinine level, and an abnormal blood glucose level were associated with a poor outcome. No effective treatment was identified and this should be the subject of future studies.

Review: The past, present and future challenges in epilepsy-related and sudden deaths and biobanking

Awareness and research on epilepsy-related deaths (ERD), in particular Sudden Unexpected Death in Epilepsy (SUDEP), have exponentially increased over the last two decades. Most publications have focused on guidelines that inform clinicians dealing with these deaths, educating patients, potential risk factors and mechanisms. There is a relative paucity of information available for pathologists who conduct these autopsies regarding appropriate post mortem practice and investigations. As we move from recognizing SUDEP as the most common form of ERD toward in-depth investigations into its causes and prevention, health professionals involved with these autopsies and post mortem procedure must remain fully informed. Systematizing a more comprehensive and consistent practice of examining these cases will facilitate (i) more precise determination of cause of death, (ii) identification of SUDEP for improved epidemiological surveillance (the first step for an intervention study), and (iii) biobanking and cell-based research. This article reviews how pathologists and healthcare professionals have approached ERD, current practices, logistical problems and areas to improve and harmonize. The main neuropathology, cardiac and genetic findings in SUDEP are outlined, providing a framework for best practices, integration of clinical, pathological and molecular genetic investigations in SUDEP, and ultimately prevention.

Survey of rotavirus-associated severe complications in Aichi Prefecture

BACKGROUND

Rotavirus can, rarely, cause severe complications such as encephalopathy/encephalitis, myocarditis, sudden death, urinary stone, and gastrointestinal (GI) bleeding; and the incidence of these severe complications remains unclear. Additionally, it has not been determined whether rotavirus (RV) vaccine could reduce cases of severe complications or not.

METHODS

A two-part questionnaire was designed to determine the number and clinical features of severe complications between 1 September 2008 and 31 August 2015, including the observation periods before and after RV vaccine introduction in Aichi Prefecture.

RESULTS

Twenty-four cases of encephalitis/encephalopathy, eight cases of sudden death, three cases of urinary tract stone, and three cases of GI bleeding were reported during the 2008/2009 season and the 2012/2013 seasons. Although five cases of encephalitis/encephalopathy were reported, no other cases of severe complications were reported during the 2013/2014 and 2014/2015 seasons. No age difference was noted according to type of complication. Although onset of encephalitis/encephalopathy and of sudden death was around day 2 of illness, that of urinary tract stone and GI bleeding was slightly later (day 6 and day 4). In addition to the eight sudden deaths, fatal outcome was also noted in four cases (13.8%) of encephalitis/encephalopathy, and in one case of GI bleeding.

CONCLUSION

According to the questionnaire survey in Aichi Prefecture, the incidence of the four severe RV-associated complications appears to have declined as the vaccination rate has increased.

Prognostic factors in the early phase of acute encephalopathy

BACKGROUND

Neurological sequelae occur in 40% of patients with acute encephalopathy (AE). The early prediction of poor outcomes is critical to the initiation of appropriate treatment. The aim of the present study was therefore to elucidate prognostic factors that can be quickly and feasibly evaluated on hospital admission in patients with AE.

METHODS

We analyzed data from 51 AE patients admitted to Hirakata City Hospital between January 2005 and December 2014. Age at onset, sex, underlying disease, status epilepticus (SE), presence of benzodiazepine-resistant SE (BZD-resistant SE), and basic blood serum parameters on admission were evaluated in relation to each patient's outcome.

RESULTS

On univariate analysis age at onset, BZD-resistant SE, and serum aspartate aminotransferase (AST), alanine aminotransferase, lactate dehydrogenase, and platelet count varied significantly according to outcome. On multivariate analysis age at onset (≤21 months), presence of BZD-resistant SE, and AST (≥46 IU/L) were identified as independent variables associated with poor outcome.

CONCLUSION

Age at onset, presence of BZD-resistant SE, and AST are associated with a poor prognosis in AE.

Impact of rotavirus vaccination on the burden of acute gastroenteritis in Nagoya city, Japan

BACKGROUND

In Nagoya city, Japan, rotavirus (RV) vaccination has been available since 2011 with estimated coverage reaching 92% by 2015 after the introduction of a public subsidy in 2012. This study assessed the impact of vaccination on the RV gastroenteritis (RVGE) burden in children aged <5 years old (y) by comparing RVGE hospitalizations and outpatient visits during pre-vaccination (2007-2011), transition (2011-2012) and subsidization (2012-2016) periods.

METHODS

All hospitalizations and outpatient visits in children aged <5 y from 2 administrative districts of Nagoya city were identified from the hospital-based electronic databases of 4 hospitals. RVGE cases were identified by diagnostic code and/or positive results of diagnostic kits.

RESULTS

Compared to the pre-vaccination period, there was a decrease in RVGE hospitalizations for children <5 y from 5.59 per 1000 person-year (kPY) to 3.65/kPY in the subsidization period (i.e. 34.69%). In children <1 y, the incidence of RVGE hospitalizations decreased continuously from 6.62/kPY in the pre-vaccination period to 1.84/kPY in the subsidization period (i.e. 72.19%). The highest decrease was observed in the subsidization season i.e. when high coverage was reached: 69% and 75.57% in the 2013/2014 season for 2-3 y and 3-4 y, and 74.03% in the 2014/2015 season for 4-5 y, respectively. Proportion of RVGE outpatient visits decreased by 87.44% for children <1 y and 57.05% for <5 y from the pre-vaccination to the subsidization period. This decrease started the first year of subsidization for children <1 y, 1-2 y and 2-3 y (78.89%, 18.86% and 5.80%) and the second year (2013/2014 season) for children 3-4 y and 4-5 y (87.73% and 51.78%).

CONCLUSIONS

Although yearly fluctuations have been observed, the introduction of vaccination significantly decreased pediatric RVGE hospitalizations and outpatient visits, especially in the age group eligible for vaccination. During the second and third year of subsidization, we observed a herd protection effect on other age groups <5 y who were not eligible for vaccination. Clinicaltrial.gov.registered#:NCT01733862.

Economic evaluation of routine infant rotavirus immunisation program in Japan

Two rotavirus vaccines are currently available in Japan. We estimated the incremental cost-effectiveness ratio (ICER) of routine infant rotavirus immunisation program without defining which vaccine to be evaluated, which reflects the current deliberation at the Health Science Council in charge of Immunisation and Vaccine established by the Ministry of Health, Labor and Welfare of Japan. Three ICERs were estimated, one from payers' perspective and 2 from societal perspective depending on the scenarios to uptake vaccines. The health statuses following the birth cohort were as follows: not infected by rotavirus, asymptomatic infection, outpatients after infection, hospitalised after infection, developing encephalitis/encephalopathy followed by recovery, sequelae, and death. Costs of per course of vaccination was ¥30,000 (US$283; US$1 = ¥106). The model runs for 60 months with one month cycle. From payers' perspective, estimated ICERs were ¥6,877,000 (US$64,877) per QALY. From societal perspective, immunisation program turns out to be cost-saving for 75% simultaneous vaccination scenario, while it is at ¥337,000 (US$3,179) per QALY gained with vaccine alone scenario. The probability of rotavirus immunisation program to be under ¥5,000,000 (US$47,170) per QALY was at 19.8%, 40.7%, and 75.6% when costs per course of vaccination were set at ¥30,000 (US$283), ¥25,000 (US$236), and ¥20,000 (US$189), respectively. Rotavirus immunisation program has a potential to be cost-effective from payers' perspective and even cost-saving from societal perspective in Japan, however, caution should be taken with regard to the interpretation of the results as cost-effectiveness is critically dependent on vaccination costs.

Benign convulsions in children with mild gastroenteritis

BACKGROUND

Benign convulsions with mild gastroenteritis (CwG) is a clinical condition characterized by convulsions occurring in otherwise healthy children, usually in the absence of fever and in the presence of mild acute gastroenteritis. Until now, CwG had not been fully recognized as an epileptic syndrome, and several aspects of this condition are not clearly defined, especially its pathogenesis.

METHODS

The main aim of this paper is to discuss after the review of the literature what is known about CwG to facilitate its recognition and treatment.

RESULTS

CwG is a benign condition that has several clinical and prognostic similarities with febrile seizures. The disease occurs in infants and in children who are 1 month to 3 years old, during the winter and early spring when rotavirus and norovirus are circulating. In most cases, seizures follow gastrointestinal symptoms. In a minority of patients, the seizures and gastrointestinal symptoms occur before or simultaneously with the development of diarrhoea. Even if convulsions are mostly described as generalized tonic-clonic, the ictal recordings have always demonstrated a focal origin. Electroencephalography, lumbar punctures, and radiological examinations are not useful because they are normal in these patients; and when alterations are present, they disappear in a relatively short time. Only prolonged seizures, which are usually not common, require antiepileptic treatments in the acute phase.

CONCLUSION

Knowledge of CwG characteristics is essential for paediatricians to avoid useless hospitalization, examinations and, above all, drug administration, as the drugs have potential side effects.

Estimating rotavirus vaccine effectiveness in Japan using a screening method

Rotavirus gastroenteritis is a highly contagious, acute viral disease that imposes a significant health burden worldwide. In Japan, rotavirus vaccines have been commercially available since 2011 for voluntary vaccination, but vaccine coverage and effectiveness have not been evaluated. In the absence of a vaccination registry in Japan, vaccination coverage in the general population was estimated according to the number of vaccines supplied by the manufacturer, the number of children who received financial support for vaccination, and the size of the target population. Patients with rotavirus gastroenteritis were identified by reviewing the medical records of all children who consulted 6 major hospitals in Saga Prefecture with gastroenteritis symptoms. Vaccination status among these patients was investigated by reviewing their medical records or interviewing their guardians by telephone. Vaccine effectiveness was determined using a screening method. Vaccination coverage increased with time, and it was 2-times higher in municipalities where the vaccination fee was supported. In the 2012/13 season, vaccination coverage in Saga Prefecture was 14.9% whereas the proportion of patients vaccinated was 5.1% among those with clinically diagnosed rotavirus gastroenteritis and 1.9% among those hospitalized for rotavirus gastroenteritis. Thus, vaccine effectiveness was estimated as 69.5% and 88.8%, respectively. This is the first study to evaluate rotavirus vaccination coverage and effectiveness in Japan since vaccination began.