Web survey-based selection of controls for epidemiological analyses of a multi-prefectural outbreak of enterohaemorrhagic Escherichia coli O157 in Japan associated with consumption of self-grilled beef hanging tender.

An outbreak of enterohaemorrhagic Escherichia coli O157 occurred in multiple prefectures of Japan in November 2009. We conducted two case-control studies with trace-back and trace-forward investigations to determine the source. The case definition was met by 21 individuals; 14 (66.7%) were hospitalised, but no haemolytic uraemic syndrome, acute encephalopathy or deaths occurred. Median age was 23 (range 12-48) years and 14 cases were male (66.7%). No significant associations with food were found in a case-control study by local public health centres, but our matched case-control study using Internet surveys found that beef hanging tender (or hanger steak), derived from the diaphragm of the cattle, was significantly associated with illness (odds ratio = 15.77; 95% confidence interval, 2.00-124.11). Pulsed-field gel electrophoresis analysis of isolates from patients and the suspected food showed five different patterns: two in faecal and food samples, and another three in patient faecal samples only, although there were epidemiological links to the meat consumed at the restaurants. Trace-back investigation implicated a common food processing company from outside Japan. Examination of the logistics of the meat processing company suggested that contamination did not occur in Japan. We concluded that the source of the outbreak was imported hanging tender. This investigation revealed that Internet surveys could be useful for outbreak investigations.

Risk of haemolytic uraemic syndrome caused by shiga-toxin-producing Escherichia coli infection in adult women in Japan.

Shiga-toxin-producing Escherichia coli (STEC) infections usually cause haemolytic uraemic syndrome (HUS) equally in male and female children. This study investigated the localization of globotriaosylceramide (Gb3) in human brain and kidney tissues removed from forensic autopsy cases in Japan. A fatal case was used as a positive control in an outbreak of diarrhoeal disease caused by STEC O157:H7 in a kindergarten in Urawa in 1990. Positive immunodetection of Gb3 was significantly more frequent in female than in male distal and collecting renal tubules. To correlate this finding with a clinical outcome, a retrospective analysis of the predictors of renal failure in the 162 patients of two outbreaks in Japan was performed: one in Tochigi in 2002 and the other in Kagawa Prefecture in 2005. This study concludes renal failure, including HUS, was significantly associated with female sex, and the odds ratio was 4·06 compared to male patients in the two outbreaks. From 2006 to 2009 in Japan, the risk factor of HUS associated with STEC infection was analysed. The number of males and females and the proportion of females who developed HUS were calculated by age and year from 2006 to 2009. In 2006, 2007 and 2009 in adults aged >20 years, adult women were significantly more at risk of developing HUS in Japan.

Genetic analyses of GII.17 norovirus strains in diarrheal disease outbreaks from December 2014 to March 2015 in Japan reveal a novel polymerase sequence and amino acid substitutions in the capsid region.

A novel GII.P17-GII.17 variant norovirus emerged as a major cause of norovirus outbreaks from December 2014 to March 2015 in Japan. Named Hu/GII/JP/2014/GII.P17-GII.17, this variant has a newly identified GII.P17 type RNA-dependent RNA polymerase, while the capsid sequence displays amino acid substitutions around histo-blood group antigen (HBGA) binding sites. Several variants caused by mutations in the capsid region have previously been observed in the GII.4 genotype. Monitoring the GII.17 variant's geographical spread and evolution is important.

Increased prevalence of group A streptococcus isolates in streptococcal toxic shock syndrome cases in Japan from 2010 to 2012.

Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock, multi-organ failure, and high mortality. In Japan, appropriate notification measures based on the Infectious Disease Control law are mandatory for cases of STSS caused by ß-haemolytic streptococcus. STSS is mainly caused by group A streptococcus (GAS). Although an average of 60-70 cases of GAS-induced STSS are reported annually, 143 cases were recorded in 2011. To determine the reason behind this marked increase, we characterized the emm genotype of 249 GAS isolates from STSS patients in Japan from 2010 to 2012 and performed antimicrobial susceptibility testing. The predominant genotype was found to be emm1, followed by emm89, emm12, emm28, emm3, and emm90. These six genotypes constituted more than 90% of the STSS isolates. The number of emm1, emm89, emm12, and emm28 isolates increased concomitantly with the increase in the total number of STSS cases. In particular, the number of mefA-positive emm1 isolates has escalated since 2011. Thus, the increase in the incidence of STSS can be attributed to an increase in the number of cases associated with specific genotypes.

Epidemiological analysis of a large enterohaemorrhagic Escherichia coli O111 outbreak in Japan associated with haemolytic uraemic syndrome and acute encephalopathy.

A large outbreak of enterohaemorrhagic Escherichia coli (EHEC) O111 and O157 occurred in Japan in April 2011. We conducted an unmatched case-control study and trace-back investigation to determine the source of EHEC O111 infection and risk factors for severe complications. Pulsed-field gel electrophoresis was performed to help define cases. A total of 86 individuals met the case definition. Of these, 40% experienced haemolytic uraemic syndrome (HUS), 24% acute encephalopathy, and 6% died. Illness was significantly associated with eating the raw beef dish yukhoe (odds ratio 19·64, 95% confidence interval 7·03-54·83), the likely food vehicle. EHEC O111 and its closely related stx-negative variants were found in the beef. HUS occurred most frequently in individuals aged 5-9 years, and this age group was significantly associated with acute encephalopathy. The prevalence of HUS and acute encephalopathy was higher than in previous non-O157-related outbreaks, indicating a high risk of severe complications.

Aberrant forms of Yersinia pseudotuberculosis as spheroplasts and filaments in yersiniosis in squirrel monkeys.

This report describes atypical cases of yersiniosis in squirrel monkeys in which aberrant forms of Yersinia pseudotuberculosis were seen. There were 2 outbreaks due to yersiniosis in squirrel monkeys in Japan. The monkeys had systemic necrotizing and hemorrhagic lesions with Gram-negative rod-shaped bacilli and microthromboembolism in the kidneys. Some lesions contained filaments, globular bodies, and other pleomorphic forms of bacteria. All forms were usually seen in the same lesions, and those with pleomorphic morphology appeared to be an intermediate form between the rod-shaped bacteria and the filaments or globular bodies. In addition, they had strong immunolabeling for Y. pseudotuberculosis, as did the rod-shaped bacteria. Therefore, the globular bodies, filaments, and others are strongly suspected to be shape-changed bacilli of Y. pseudotuberculosis. These morphologically altered bacteria could cause errors in diagnosis since they resemble fungi or protozoa, and special staining techniques, including immunohistochemistry, can be helpful in establishing the correct diagnosis.

A Shiga toxin-producing Escherichia coli O157 outbreak associated with consumption of rice cakes in 2011 in Japan.

In May 2011, an outbreak of Shiga toxin-producing Escherichia coli (STEC) O157 was reported from Yamagata Prefecture, Japan. Investigations, including a case-control study, revealed that the outbreak was linked to two varieties of rice cakes produced by a local manufacturer between 2 and 7 May. Active and passive surveillance identified 136 suspected cases, 142 confirmed cases, 26 asymptomatic cases, and 25 secondary cases. While no environmental samples taken from the manufacturing premises tested positive for STEC, other than a stool sample taken from one employee, on-site and epidemiological investigations indicated that STEC was introduced during the manufacturing process of rice cakes rather than through contamination of raw materials. This was the first reported outbreak of STEC associated with cakes and confectionery in Japan, which indicates that contamination and outbreaks of STEC can occur in any food unless proper precautions are taken.

Cerebral CT angiography using a small volume of concentrated contrast material with a test injection method: optimal scan delay for quantitative and qualitative performance.

OBJECTIVES: The objective of this study was to determine the optimal scan delay quantitatively and qualitatively in cerebral CT angiography (CTA) with a test injection method at the circle of Willis (cW). METHODS: 66 consecutive patients suspected of having unruptured intracranial aneurysms underwent CTA using 40 ml of 370 mg iodine ml(-1) contrast material (CM). After the time until CM arrival at the cW (T(cW)) was calculated, scan delay was divided into three groups according to T(cW) and scan duration (SD) between the second cervical vertebra and cW as follows: [(T(cW)+6)-SD] in 21 patients (Group A); [(T(cW)+8)-SD] in 23 patients (Group B); and [(T(cW)+10)-SD] in 22 patients (Group C). Arterial and venous attenuation in the intracranial vessels was measured. Mean attenuation values were compared quantitatively. The arterial enhancement and venous overlap at the cW and above the cW were qualitatively compared among the three groups. RESULTS: Mean arterial attenuation in Groups B and C was significantly higher than that in Group A. Mean venous attenuation in Group C was significantly higher than those in Groups A and B. Arterial enhancement above the cW showed a significant difference between Groups A and C, and at the cW between Groups A and B, and Groups A and C. There was a significant difference in venous overlap among the three groups, except for that at the cW between Groups B and C. CONCLUSIONS: Setting scan delay as [(T(cW)+8)-SD] s can produce the best performance both quantitatively and qualitatively.

A norovirus outbreak associated with environmental contamination at a hotel.

SUMMARYIn December 2006, an outbreak of gastroenteritis occurred involving 372 guests and 72 employees at a hotel after a guest vomited in corridors on the third (F3) and 25th (F25) floors. Norovirus with identical genotype was confirmed by real-time reverse transcription-polymerase chain reaction in faecal samples from guest cases and employees. Spread of the outbreak on F25 was compared with that on F3. The attack rate in the guests who visited F25 alone (15·0%, 106/708 guests) was significantly higher than in those who visited F3 alone (3·5%, 163/4710 guests) (relative risk 4·3, 95% confidence interval 3·4-5·5, P < 0·001). The outbreak on F3 ended within 2 days, while that on F25 extended over 7 days. The environmental ratios of F3 to F25 were 7·4 for volume, 6·9 for floor area and 7·6 for ventilation rate. This outbreak suggests that environmental differences can affect the propagation and persistence of a norovirus outbreak following environmental contamination.

Household transmission of pandemic 2009 influenza A (H1N1) virus in Osaka, Japan in May 2009.

OBJECTIVE: To assess household transmission of pandemic influenza A (H1N1) and effectiveness of postexposure prophylaxis (PEP) of antiviral drugs among household contacts of patients during the first pandemic influenza A (H1N1) outbreak in Osaka, Japan in May 2009. METHODS: Active surveillance of patients and their families was conducted. Public Health Center staff visited each home with an infected patient and advised every household member with regard to precautionary measures, and PEP was provided to household contacts to prevent secondary infection. We analyzed the effectiveness of PEP and characteristics of secondary infection. RESULTS: The secondary attack rate (SAR) among household contacts was 3.7%. The SAR among household contacts without PEP was 26.1%. However, the SAR among those with PEP was 0.6%. Only two of 331 household contacts with PEP became infected. One of the two was infected with an oseltamivir-resistant strain. Analysis of SAR by age group showed that those under 20 years of age were at higher risk than those over 20 (relative risk [RR] = 7.9; 95% confidence interval [CI] = 2.24-27.8). Significant differences with respect to sex, number of household contacts, and use of antiviral medications in the index cases were not observed. CONCLUSIONS: Our present results indicate that PEP is effective for preventing secondary H1N1 infection among household contacts.

Construction of syndromic surveillance using a web-based daily questionnaire for health and its application at the G8 Hokkaido Toyako Summit meeting.

We constructed a syndromic surveillance system to collect directly information on daily health conditions directly from local residents via the internet [web-based daily questionnaire for health surveillance system (WDQH SS)]. This paper considers the feasibility of the WDQH SS and its ability to detect epidemics. A verification study revealed that our system was an effective surveillance system. We then applied an improved WDQH SS as a measure against public health concerns at the G8 Hokkaido Toyako Summit meeting in 2008. While in operation at the Summit, our system reported a fever alert that was consistent with a herpangina epidemic. The highly mobile WDQH SS described in this study has three main advantages: the earlier detection of epidemics, compared to other surveillance systems; the ability to collect data even on weekends and holidays; and a rapid system set-up that can be completed within 3 days.

Assessment of secondary attack rate and effectiveness of antiviral prophylaxis among household contacts in an influenza A(H1N1)v outbreak in Kobe, Japan, May-June 2009.

This report describes the assessment of the secondary attack rate (SAR) and the effectiveness of post-exposure antiviral prophylaxis among household contacts in the first domestic outbreak of a novel influenza A(H1N1)v between mid-May and early June 2009 in Kobe city, Japan. Of the 293 subjects, 14 (4.8%) household contacts met the case definition and most secondary cases were probably infected around the time of symptom onset date of the respective index case. The SAR among household contacts who did not receive prophylaxis was 7.6%, similar to the rate of seasonal influenza, and the attack rate in siblings was significantly higher than that in parents. We conclude that it is important to establish routine infection control measures for households in order to prevent the spread of the virus among household contacts and, possibly, to the community. We could not conclude whether antiviral prophylaxis was effective or not. However, among close contacts with underlying disease who received prophylaxis, nobody developed a severe form of the disease.

Clinical features of cases of influenza A (H1N1)v in Osaka prefecture, Japan, May 2009.

This report describes the clinical characteristics of influenza A(H1N1)v virus infection in Osaka. By the end of May, 171 cases had been reported in Osaka. Most patients were from one school. No patient had a serious underlying medical condition.Clinical symptoms were mild and resembled those of seasonal influenza. The sensitivity of the rapid antigen test was 77%. Antivirals were given to the majority of the cases. Early antiviral treatment may have shortened the duration of fever.

Epidemiology of influenza A(H1N1)v virus infection in Japan, May-June 2009.

Between 9 May and 4 June 2009, a total of 401 laboratory-confirmed cases of influenza A(H1N1)v virus were reported in Japan, from 16 of the 47 Japanese prefectures. The two areas most affected were Osaka prefecture and Kobe city where outbreaks in high schools occurred leading to school closures. To date all cases have had symptoms consistent with seasonal influenza and no severe or fatal cases have been reported.

Radial glia marker expression following experimental intracerebral hemorrhage.

In this study, we examine 3CB2 expression, a marker of radial glia, after intracerebral hemorrhage (ICH). Adult male Sprague-Dawley rats received an intracaudate injection of 100 microL autologous whole blood. Animals were sacrificed, and 3CB2 expression was quantified on Western blot. Single and double labeled immunohistochemistry was used to identify which cells express 3CB2. Neurobehavioral examinations (forelimb placing test) were perfomed as an evaluation of function. By Western blot, 3CB2 was strongly expressed at day 3 and expression persisted for at least 1 month. By immunohistochemistry, 3CB2 immunoreactivity was present in large numbers of astrocytes surrounding the hematoma at day 3 after ICH. At 1 month later, 3CB2 immunoreactivity was co-localized with a neuronal marker (TUC-4). Neurobehavioral function in the 1 month after ICH group was significantly improved compared with that of 3 days after ICH. The ICH-induced 3CB2 expression in astrocytes may reflect an early response of these cells to injury, while the delayed expression in neurons might be a part of the adaptative response to injury, perhaps leading to recovery of neurobehavioral function.

An outbreak of psittacosis in a bird park in Japan.

An outbreak of psittacosis related to a bird park occurred in Matsue City, Shimane Prefecture, Japan, during winter 2001. Seventeen cases of psittacosis (12 visitors, three staff, and two student interns) were confirmed. A cohort study was conducted among the park staff and students to determine the risk factors for the development of acute serologically confirmed psittacosis (SCP) infection. Being 'bird staff' had an increased risk of SCP infection (RR 3.96, 95% CI 1.48-10.58). Entering the staff building, where ill birds were maintained without proper isolation, was also associated with an increased risk of SCP infection (RR 3.61, 95% CI 1.03-12.6). Isolation of ill birds and quarantine measures were found to be insufficient. Dehumidifiers and a high-pressure water spray under a closed ventilation environment may have raised the concentration of Chlamydophila psittaci in the hothouses. Bird park staff and visitors should be educated about psittacosis.

Distribution of emm genotypes among group A streptococcus isolates from patients with severe invasive streptococcal infections in Japan, 2001-2005.

We surveyed emm genotypes of group A streptococcus (GAS) isolates from patients with severe invasive streptococcal infections during 2001-2005 and compared their prevalence with that of the preceding 5 years. Genotype emm1 remained dominant throughout 2001 to 2005, but the frequency rate of this type decreased compared with the earlier period. Various other emm types have appeared in recent years indicating alterations in the prevalent strains causing severe invasive streptococcal infections. The cover of the new 26-valent GAS vaccine fell from 93.5% for genotypes of isolates from 1996-2000 to 81.8% in 2001-2005.

Development of reformative surgery method using partial freezing for the liver.

To minimize surgical stresses including blood loss and operation time to the patients during hepatic resection, we studied the feasibility of a combination of a partial liver freezing technique and shape-memory alloy, which also enables a free-designed resection curve. In this surgical procedure, the region surrounding a tumor in the liver is frozen to excise and prevent hemorrhage. The liver was frozen by a Peltier module. The effects of cooling rate and freezing temperature on the excision force that arise between a scalpel and the liver are carried out experimentally as a basic research for partial freezing surgical procedures. A porcine liver was used as a liver sample. The physical properties were estimated by using the finite element method based on the heat transfer characteristics of the liver. Isolation of the liver was conducted using a scalpel attached to the end-effector of a 3 degrees of freedom robot. In the experiments, the minimum excision force was obtained at a temperature between 272 K and 275 K; therefore, it is preferable that the liver be excised within this temperature range. Lowering of the cooling rate decreases the excision force even if the temperature of the liver remains unchanged. The lower the temperature of the liver is, the larger the increment rate of excision force is with regard to the cooling rate.

Nonsteroidal anti-inflammatory drugs induce hypermotilinemia and disturbance of interdigestive migrating contractions in instrumented dogs.

Nonsteroidal anti-inflammatory drugs (NSAIDs) induce gastric ulcers due to inhibition of prostaglandin production. Prostaglandins have an influence on physiological gastrointestinal motility, but the relationships between NSAID-induced gastric ulcer, gastrointestinal motility and motilin are unknown. Fifteen dogs were allocated randomly to three groups in which either gelatin, meloxicam or indomethacin was administered. Fecal occult blood and gastrointestinal motility were monitored continuously for 6 days. In addition, analyses of the plasma motilin concentration, gastrointestinal endoscopy and gastric emptying, and detection of motilin cells were performed. Gastrointestinal motility was disturbed in the indomethacin group, presenting as disappearance of interdigestive migrating contractions (IMCs) 3 days before gastric ulcers were detected. Delayed gastric emptying and hypermotilinemia were observed significantly more often in the indomethacin group compared with the other groups. Motilin cell-crypt/villi ratio in the indomethacin group significantly decreased in the duodenum and jejunum, compared with the other groups. No significant changes in any tests were observed in the meloxicam group, when compared with the gelatin group. These findings suggest that the disturbance of IMCs caused by hypermotilinemia, with changes in motilin cell distribution, and delayed gastric emptying induced by indomethacin may contribute to the development of gastric ulcers.

Experimental surveillance using data on sales of over-the-counter medications--Japan, November 2003-April 2004.

OBJECTIVES: This report describes a study to explore the possibility of using data on sales of over-the- counter (OTC) medications as part of a routine syndromic surveillance system aimed at early detection of infections of public health concern. A retrospective evaluation was conducted of sales of OTC medications used to treat the common cold. This report discusses the correlation of these data to influenza activity in Japan during the 2003-04 influenza season and evaluates the potential of using such data to predict influenza epidemics. METHODS: Data from approximately 1,100 pharmacies throughout Japan collected during November 2003-April 2004 were analyzed. OTC sales data were compared with influenza incidence data (one weekly and two daily data sets) to determine correlations and predictability. Adjusted R-square was used as an index of goodness of-fit in the estimation. Data reflecting daily influenza activity were obtained from the National Surveillance of Daily Influenza Outpatients and the Mailing List-Based Influenza Epidemic Database. National sentinel surveillance data for influenza from approximately 5,000 sites nationwide also were analyzed. RESULTS: Although a correlation was demonstrated between sales of OTC medications used to treat the common cold and concurrent influenza activity, analysis of sales data alone was not sufficient to determine influenza activity in advance even when sales promotion effects were excluded from the analysis. CONCLUSION: Because visiting a health-care provider costs more than purchasing OTC medications, the hypothesis was formed that an ill person will purchase OTC medications first and visit a physician only if the condition does not resolve or worsens. The results of this study do not provide any clear evidence to support this hypothesis. For this reason, OTC sales do not appear to be a good candidate for a national real-time detection system for influenza epidemics in Japan.