Enterovirus D68 respiratory infection in a children's hospital in Japan in 2015.

BACKGROUND: Outbreaks of enterovirus D68 (EV-D68) respiratory infections in children were reported globally in 2014. In Japan, there was an EV-D68 outbreak in the autumn of 2015 (September-October). The aim of this study was to compare EV-D68-specific polymerase chain reaction (PCR)-positive and EV-D68-specific PCR-negative patients. METHODS: Pediatric patients admitted for any respiratory symptoms between September and October 2015 were enrolled. Nasopharyngeal swabs were tested for multiplex respiratory virus PCR and EV-D68-specific reverse transcription-PCR. EV-D68-specific PCR-positive and -negative patients were compared regarding demographic data and clinical information. RESULTS: A nasopharyngeal swab was obtained from 76 of 165 patients admitted with respiratory symptoms during the study period. EV-D68 was detected in 40 samples (52.6%). Median age in the EV-D68-specific PCR-positive and -negative groups was 3.0 years (IQR, 5.5 years) and 3.0 years (IQR, 4.0 years), respectively. The rates of coinfection in the two groups were 32.5% and 47.2%, respectively. There was no significant difference in the history of asthma or recurrent wheezing, length of hospitalization, or pediatric intensive care unit admission rate between the groups. The median days between symptom onset and admission was significantly lower for the EV-D68-positive group (3.0 days vs 5.0 days, P = 0.001). EV-D68 was identified as clade B on phylogenetic analysis. No cases of acute flaccid myelitis were encountered. CONCLUSIONS: More than half of the samples from the children admitted with respiratory symptoms were positive for EV-D68-specific PCR during the outbreak. Asthma history was not associated with the risk of developing severe respiratory infection.

Whole genomic analysis of human G8P[14] group A rotavirus detected from community gastroenteritis outbreak.

Several suspected cases of zoonotic transmission of group A rotavirus (RVA)-related gastroenteritis were reported previously. In August 2012, G8P[14] RVA was detected in fecal specimens from a community gastroenteritis outbreak occurring during a school trip. In this study, additional analyses were performed and it was found that this strain had the G8-P[14]-I2-R2-C2-M2-A3-N2-T6-E2-H3 sequence, similar to bovine-like RVA strains. Some contamination by emesis and diarrheic feces was observed near a rest room in the lodging area. Contact history with animals was unknown in members of this school trip, and this case implied that the strain may have acquired the ability for person-to-person transmission.

Detection of Norovirus in Swab Specimens of Restrooms and Kitchens Collected for Investigation of Suspected Food Poisoning Outbreaks in Tokyo.

During 2015-2016, we examined norovirus (NoV) RNA in swab specimens collected for investigation of suspected food poisoning outbreaks in Tokyo by real-time RT-PCR. Of 1,726 swab samples, 65 (3.8%) were NoV-positive and all positive swab samples were derived from NoV-positive outbreaks. Swab specimens were positive in 41 of 181 (22.7%) NoV outbreaks, while no positive swabs were detected in NoV-negative outbreaks. PCR fragments amplified from 32 swabs were sequenced, and all of them displayed complete homology with sequences from clinical and food samples. Though the results of swabs may be useful for determining the causative agent and infection route in some outbreaks, there was no case in which the results of swabs alone could elucidate the cause of food poisoning. Swabs may be useful in food poisoning investigations, if the results are interpreted in conjunction with epidemiological findings and clinical data. Swab samples are often collected several days after an outbreak, and the influence of disinfection should be taken into consideration. In NoV outbreaks, 55 out of 640 (8.6%) restroom swab specimens were NoV-positive whereas six of 618 (1.0%) were positive among kitchen swab specimens. In the restroom, the toilet bowl (43.6%) showed the highest positive rate and next was the toilet seat (14.5%). Additionally, NoV was detected at various sites in the restroom, including doorknob and floor. Since NoV-positive swab specimens may suggest that sanitation management is not performed properly in the facility, swab results may be utilized as a basis for hygiene guidance.

Comparison of genetic characteristics in the evolution of Norovirus GII.4 and GII.17.

The genetic characteristics of Norovirus GII.17 were evaluated. Phylogenetic analysis and comparisons of amino acid (Aa) substitutions and nonsynonymous (NS) substitutions/site/year were performed. The complete VP1 sequence of Tokyo/27-3/1976 clustered independently with GII.P17_GII.17 strains. Aa substitutions were mainly accumulated in the P2 domain. NS substitutions/site/year for Tokyo/27-3/1976 compared to Kawasaki323/2014 and Kawasaki308/2015 were 0.57 × 10-3 and 0.78 × 10-3 , respectively; for GII.4 Sydney/NSW0514/2012 compared to CHDC2094/1974 and CHDC5191/1974 were 0.93 × 10-3 and 1.06 × 10-3 , respectively. These findings imply that evolutionary diversity in the VP1 of GII.17 might be strictly constrained in contrast to that of GII.4.

Genomic analysis of the evolutionary lineage of Norovirus GII.4 from archival specimens during 1975-1987 in Tokyo.

This study aimed to analyze NoV GII.4 sequences from archival specimens obtained during 1975-1987 by comparing them with reference sequences. The first NoV GII.P4_GII.4 sequence was identified in 1980. NoV GII.4 collected in 1970 had a GII.P1_GII.4 sequence. These results indicate that the GII.P4_GII.4 sequence may be the result of a recombination that might have occurred around 1980. Amino acid substitutions based on this replacement were mainly accumulated in the NTPase, p22, and RdRp regions. The emergence of GII.P4_GII.4 sequence is considered to have ended the major prevalence of NoV GII.4. J. Med. Virol. 89:363-367, 2017. © 2016 Wiley Periodicals, Inc.

Detection of Enteric Viruses in Fecal Specimens from Nonbacterial Foodborne Gastroenteritis Outbreaks in Tokyo, Japan between 1966 and 1983.

We investigated the prevalence of 5 enteric viruses (norovirus [NoV], sapovirus, rotavirus, astrovirus, and adenovirus) in archived stool specimens collected from 70 foodborne gastroenteritis outbreaks in Tokyo, Japan, which occurred from 1966 to 1983, and genetically characterized these viruses. NoV was detected in 48 (68.6%) outbreaks, while SaV, group C rotavirus (RVC), and astrovirus were detected in 1 (1.4%) outbreak each. Based on the partial capsid sequences, the detected NoVs were classified into the following genotypes: 9 in genogroup I (GI; GI.1-6, GI.8, GI.9, and GI.NA), 13 GII (GII.1-9, GII.13, GII.16, GII.17, and GII.22), and one in GIV. The oldest NoV outbreaks occurred in 1966. No predominant genotype was found. One strain, classified as GI. NA based on the N/S region sequence, was subsequently classified as GI.8 based on the complete VP1 sequence. Nine types of recombinant NoV sequences, including 7 unreported combinations, were identified. Further genetic characterization of NoV GII.17 and GII.4 demonstrated that the NoV GII.17 strains detected from 1970 to 1982 clustered independently from previously reported NoV GII.17 strains. Phylogenetic analysis, using the complete VP1 region and the P2 domain, demonstrated that NoV GII.4 strains collected between 1975 and 1980 clustered with archival strains collected in the USA in the mid-1970s. In contrast, a NoV GII.4 strain collected in 1983 formed an independent branch from reference strains collected in the mid-1970s to 2012.

[Serial Food Poisoning Outbreaks Caused by Norovirus-Contaminated Shredded Dried Laver Seaweed Provided at School Lunch, Tokyo, 2017].

In February 2017, four food poisoning outbreaks occurred in Tokyo, involving ten schools. Shredded dried laver seaweed processed by a single food manufacturer in December 2016 was provided in common for the school meals that caused all four outbreaks. Of 4,209 persons exposed, 1,193 (28.3%) had symptoms of gastroenteritis. Norovirus (NoV) GII was detected in 207 (78.1%) of 265 cases by real-time RT-PCR. Thirty-one shredded dried laver seaweed samples were examined and seven (22.6%) of them were positive for NoV GII. PCR fragments of NoV ORF1/2 junction region (302 bp) from seven shredded dried laver seaweed samples and 20 clinical samples derived from the four outbreaks were sequenced. All of them displayed complete homology, and the genotype was classified as GII.17. A nearly full-length sequence (7,420 bp) of NoV RNA derived from a case was obtained by next-generation sequencer analysis and phylogenetic analysis indicated that this strain belongs to the same cluster as Hu/GII/JP/2015/GII.P17_GII.17/Kawasaki308. Thus, our investigation elucidated that the causative agent of these four serial food poisoning outbreaks was NoV GII.17 and the infectious source was a single batch of shredded dried laver seaweed. The water activity of the shredded dried laver seaweed was found to be 0.119 to 0.129. It was epidemiologically clarified that NoV does not lose infectivity for about two months even in the dry state. We conclude that a large diffuse outbreak of food poisoning caused by NoV GII.17 contamination of shredded dried laver seaweed had occurred in Tokyo. Our elucidation of the causative agent indicated that the food poisoning outbreaks in multiple areas of Japan, including Tokyo, during January to February 2017 were caused by the same contaminated food.

Feasibility of viral dust infection via air movement and dispersion of dried viral particles from the floor.

The contributions of splash from vomiting and the dispersion of dried-up virus from a contaminated floor surface to community gastroenteritis outbreaks caused by Norovirus (NoV) were evaluated, using Feline calicivirus (FCV) as an NoV surrogate. There was no difference in the size distribution of FCV-containing particles around 0.75 µm) collected from a virus-sprayed chamber 1 and 12 hr after nebulization. FCV clearly dispersed after hitting a floor surface contaminated with dried virus. These results suggest that NoV can likely form airborne droplet nuclei, and dust may be the main route of infection transmission. J. Med. Virol. 89:931-935, 2017. © 2016 Wiley Periodicals, Inc.

Shedding of Rubella Virus among Infants with Congenital Rubella Syndrome Born in Tokyo, Japan, 2013-2014.

Rubella is usually a mild illness, with febrile rash being its main symptom. However, serious consequences of rubella infection can result when the infection occurs during the early stages of pregnancy. After the occurrence of a rubella outbreak in Japan that was observed from 2012 to 2013, 45 infants were reportedly born with congenital rubella syndrome (CRS). We prospectively followed the 15 CRS cases reported in Tokyo to determine the virus shedding periods by using nested reverse transcriptase-polymerase chain reaction to detect rubella virus genes. Throast swabs were used for virus detection. The virus shedding period was measured from birth until the time when the sample last tested positive followed by 2 consecutive negative samples. Kaplan-Meier method was used to estimate the proportion of cases remaining positive for rubella virus genes over time. The proportion of CRS cases shedding virus dropped steadily after birth, dropping to 33.8% at 6 months and 16.9% at 12 months. Our findings also suggested that the earlier the mother's onset of rubella during pregnancy, the longer the infant remained positive. Based on our findings, we believe that infants with CRS should be monitored for rubella virus shedding until 1 year of age.

Multiplex real-time PCR assays for the detection of group C rotavirus, astrovirus, and Subgenus F adenovirus in stool specimens.

Group C rotavirus (GCRV), astrovirus (AstV), and adenovirus (subgenus F AdenoV) are etiologic agents of acute nonbacterial gastroenteritis, which often represents community outbreaks. For the efficient detection of GCRV, AstV, and subgenus F AdenoV in stool specimens, a multiplex real-time PCR assay was developed to detect these three viruses simultaneously, with high sensitivity and specificity. In total, 8404 clinical specimens were collected between April 2008 and March 2011 and tested for GCRV, AstV, and subgenus F AdenoV by the multiplex real-time PCR, as well as for norovirus (NoV), sapovirus (SaV), and group A rotavirus (GARV) by non-multiplex real-time PCR. Forty-one specimens were positive for GCRV, AstV, or subgenus F AdenoV, including 15 specimens that were also positive for NoV, SaV, or GARV. Multiple viruses were detected simultaneously in 29 out of 4596 (0.63%) specimens infected with at least one virus. The association rates of AstV and subgenus F AdenoV with other viruses were significantly higher than those of NoV, SaV, GARV, or GCRV.

[Detection of norovirus RNA in bivalve molluscs by using bacteria-culture-employed method (A3T method)].

Norovirus (NV) RNA has rarely been detected in foods despite the use of highly sensitive methods such as RT-PCR and real-time RT-PCR. In the modified method (A3T method) reported previously, a bacterial culture process was introduced into the standard protocol for NV detection to remove some inhibitor(s) present in food ingredients. To confirm the efficiency of the A3T method and to examine NV contamination in bivalve molluscs, we tried to detect NV RNA in bivalve molluscs on the market and in oyster samples associated with foodborne outbreaks by using the standard method and the A3T method. NV RNAs were detected in 20 samples (18.0%) of 111 bivalve molluscs, including oysters, on the market by use of the A3T method, while only one sample (0.9%) was positive according to the standard method. NV RNA was also detected in 10 of 35 oyster samples related to foodborne outbreaks by the A3T method. Those results show that the A3T method is suitable for the detection of NV in bivalve molluscs in general laboratories.

High general self-efficacy is associated with less weight loss under a supervised dietary modification program.

SUMMARY: Self-efficacy is an important prospective predictor for behavior modification. As for weight loss intervention, many studies have shown significant associations between situation-specific self-efficacy and weight loss. In this study, we investigated the association between general self-efficacy and body weight change during a 14-week supervised dietary modification program. In total, 154 obese, middle-aged, Japanese women were selected as the subjects. The intervention program mainly comprised diet counseling. The diet counseling consisted of weekly lectures on weight loss practices and individual counseling by skilled dieticians. All subjects were instructed to choose and consume a well-balanced, 1200 kcal diet per day while also keeping a daily food diary in which they recorded in detail every food they ate during the intervention period. Body weight, waist circumference, and coronary heart disease risk factors were measured before and after the intervention. Energy intake and activity energy expenditure were assessed before and during the intervention. General self-efficacy was assessed with the General Self-Efficacy Scale (GSES) before the intervention. Body weight decreased significantly (-7.8 ± 2.7 kg; -11.4 ± 3.7%) following the intervention. The weight reduction was significantly greater for the low GSES group than for the other GSES groups. Self-efficacy regarding "degree of confidence in one's ability relative to others" especially influenced the association between the weight loss and the GSES score. Subjects' fat intake influenced the weight loss differences among GSES groups. In conclusion, inconsistent with previous studies, high general self-efficacy was associated with less weight loss under a supervised dietary modification program among middle-aged, Japanese women.:

[Enhancement of norovirus detection rates in oysters and other food samples by using bacterial treatment].

Factors such as low recovery rate and food contaminants may be responsible for the difficulty of detecting Norovirus (NV) by PCR in foodborne outbreaks. To detect NV more efficiently, we introduced a bacterial treatment, in which concentrated samples were incubated overnight with Klebsiella oxytoca at 35 degrees C before RNA extraction using the standard protocol. Recovery rates of NVs (G I/8 or G II/13) added to food suspensions in the modified method were compared with those in the standard method by quantification of NV RNAs using real-time PCR. Recovery rates in the modified method were 8.6% for G I/8 and 11.6% for G II/13 in 18 oyster samples and 13.9% for G I/8 and 19.6% for G II/13 in 15 other food samples, while those in the standard method were 0.3% for G I/8 and 0.5% for G II/13 in the oyster samples and 1.9% for G I/8 and 7.9% for G II/13 in the other food samples. These results indicate that the bacterial treatment increase the recovery of NV from foods such as oysters, suggesting that the modified method will be useful for NV detection in food samples.

[Effects of hand hygiene on feline calicivirus inactivation and removal as norovirus surrogate treated with antiseptic hand rubbing, wet wipes, and functional water].

As a preventive action plan against gastroenteritis caused by the Norovirus (NV), we studied hand hygiene effects using with three hand rubbing products, four wet wipe products, and two functional water types using Feline Calicivirus as a Norovirus surrogate. After treatment using antiseptic hand rubbing products containing chlorhexidine, quaternary ammonium, and povidone-iodine, high inactivation detected by TCID50 was observed compared to products containing povidone-iodine, although no difference was seen in viral removal measured by the amount of viral genome copies in real-time-PCR. Among wet wipes soaked in chlorhexidine, quaternary ammonium, benzoic acid and PHMB, two groups showed viral inactivation and removal. Two products were more effective for functional water, viral decrease was seen in rinsing in running electrolyzed acid water and handwashing by soap. Results underscore the importance of selection in hand washing metheds (alternative soap and also) in preventing viral gastroenteritis.