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Enteroaggregative Escherichia coli (EAEC), an enteric pathogen, causes persistent diarrhea in children, HIV-infected individuals, and travelers in economically developing countries. However, the pathogenesis of EAEC infection is not well understood. This study aimed to characterize EAEC in Japan. Between 2012 and 2014, we identified 40 EAEC strains carrying the aggR gene at the Kawasaki City Institute for Public Health, Japan. We characterized these strains using O:H-antigen typing, polymerase chain reaction (for pCVD432, astA, extended-spectrum beta-lactamase, and 4 aggregative adherence fimbriae genes), HEp-2 cell adherence, clump formation, and antimicrobial susceptibility testing. We were able to classify the 40 EAEC strains into 20 O:H types. Although specific O:H types were not correlated with HEp-2 cell aggregative adherence, all the O99:H10, O131:H27, and O176:H34 EAEC strains that were the most frequent O:H types detected in this study showed co-resistance to ampicillin, sulfamethoxazole-trimethoprim, and tetracycline. Based on results of the adhesion assay and detection of virulence-related genes, no significant difference was found between asymptomatic and symptomatic cases. Irrespective of the origin, their potential for virulence was retained. Further characterization is vital to determine whether EAEC is virulent in Japan.

This study reports the epidemiological characteristics of hospitalized cases of influenza A(H1N1)pdm09 infection analyzed on the basis of surveillance data collected from July 24, 2009, the date on which the hospital-based surveillance of influenza cases was implemented in Japan, to September 5, 2010. During the study period, 13,581 confirmed cases were reported. Among those cases with information regarding the reason for hospitalization, 39% were admitted to hospitals for non-therapeutic purposes such as medical observation and laboratory testing. The overall hospitalization rate was 5.8 cases per 100,000 population when cases hospitalized for non-therapeutic purposes were excluded. While those aged under 20 years accounted for over 85% of hospitalized cases, the largest proportion of fatal cases was observed in those aged over 65 years. The overall case fatality rate for all hospitalized cases was 1.5%. The year-round surveillance for hospitalized influenza-like illness cases was launched in 2011, and it was expected that this surveillance system could add value by monitoring changes in the epidemiological characteristics of hospitalized cases of seasonal influenza.

Raw fish consumption is increasing worldwide. Since around the year 2000, western regions of Japan have reported a foodborne disease of unknown cause that occurred after the consumption of flounder. In October 2010, a particularly large outbreak was reported in these regions among individuals who consumed flounder fish that had been raised in aquaculture systems. The median incubation period was 5 h (range, 4-19 h), and the most frequently reported symptom was diarrhea (80%). The risk estimate of the consumption of flounder was significantly higher than that of the development of symptoms (odds ratio=9.50; 95% confidence interval, 1.59-∞). According to a trace-back investigation, all of the flounder responsible for the outbreak were raised in aquaculture systems. Microscopic examination revealed that the median amount of Kudoa septempunctata present in the muscle of flounder fish from the aquaculture farm was 4.5×10(3) spores/g (range, 1.0×10(3)-9.6×10(6) spores/g). The number of K. septempunctata spores required for the development of illness, as estimated using the Monte Carlo simulation, was 7.2×10(7) spores/g; therefore, thus this might be the minimum ingestion threshold for the development of gastrointestinal symptoms. As a public health measure, the current study results should be referred to for the prevention of the gastrointestinal symptoms related to the consumption of flounder; the national public health authority has disseminated these results. We concluded that K. septempunctata-contaminated flounder fish were associated with the gastrointestinal symptoms of this recent outbreak.

Enteroaggregative Escherichia coli (EAEC), an enteric pathogen, causes persistent diarrhea in children, HIV-infected individuals, and travelers in economically developing countries. However, the pathogenesis of EAEC infection is not well understood. This study aimed to characterize EAEC in Japan. Between 2012 and 2014, we identified 40 EAEC strains carrying the aggR gene at the Kawasaki City Institute for Public Health, Japan. We characterized these strains using O:H-antigen typing, polymerase chain reaction (for pCVD432, astA, extended-spectrum beta-lactamase, and 4 aggregative adherence fimbriae genes), HEp-2 cell adherence, clump formation, and antimicrobial susceptibility testing. We were able to classify the 40 EAEC strains into 20 O:H types. Although specific O:H types were not correlated with HEp-2 cell aggregative adherence, all the O99:H10, O131:H27, and O176:H34 EAEC strains that were the most frequent O:H types detected in this study showed co-resistance to ampicillin, sulfamethoxazole-trimethoprim, and tetracycline. Based on results of the adhesion assay and detection of virulence-related genes, no significant difference was found between asymptomatic and symptomatic cases. Irrespective of the origin, their potential for virulence was retained. Further characterization is vital to determine whether EAEC is virulent in Japan.

A number of novel recombinant human adenoviruses (HAdVs) have recently been identified through sequencing of the complete genomes. The recombinant HAdV sequences share similarity with other types in the major capsid genes, namely the hexon, penton base, and fiber genes, implying recombination events, which may result in escape from the immune response and the acquisition of different organotropisms. Therefore, a surveillance system of HAdVs that considers the effect of frequent recombination on genetic evolution in these genes must be constructed. In this study, we designed new primer sets that can amplify the partial penton base and fiber genes from species HAdV-A to HAdV-F and proteotype HAdVs on the basis of sequence analyses, including previously reported primers that amplify loop 1 of the hexon. Phylogenetic analysis through sequencing with these primers correctly classified clinical HAdV isolates in loop 1 of the hexon gene, the Arg-Gly-Asp (RGD) loop of the penton base gene, and the knob of the fiber gene, which contain neutralizing, hemagglutination, and receptor binding epitopes associated with immunogenicity and tissue tropisms of HAdVs. This study contributes to the accumulation of correct information regarding genetic diversity and evolution in the worldwide HAdV surveillance.

The identification of geographic trends of an influenza pandemic is important for analyzing its social epidemic factors. We performed spatiotemporal analyses focusing on the metropolitan areas in Japan by using the influenza-like illness (ILI) sentinel surveillance data for the pandemic (H1N1) 2009 and seasonal influenza. The epidemic curves and spread features expressed by the kriging method of geographic information system (GIS) and correlations between reported cases and demographic data were analyzed. The incidence of pandemic (H1N1) 2009 increased gradually at the beginning and showed more sporadic epidemic features compared to seasonal influenza. However, there were coincidental locations of patient clusters affected by the seasonal influenza, with a significant coefficient for the total sentinel reported cases (r = 0.71, P0.01). This suggested similar patterns of the epidemic over seasons. Patient clusters tended to be located in suburban areas, and there seemed to be stronger relationships between epidemics and higher ratio of larger families (with r = 0.26-0.35, P0.01, between ratio of families having more than 3 members and total reported cases in Tokyo and Nagoya areas). Whether populous areas had a greater probability of maintaining the epidemic patterns needs to be determined. Nonetheless, the patterns found in this study can be useful for further analyses for epidemic modeling and designing relevant controls.

A seventh round behavioral and serological surveillance found that the HIV epidemic had remarkably increased to 7% among intravenous drug users (IDU) in Central Bangladesh, indicating the urgent need to increase prevention. The main purposes of this study were to find out, by collecting data and the necessary information from sero-surveillances, published reports, and articles, what the prevalence of HIV/AIDS is, and what the acquisition and transmission routes are. In addition, trends in HIV-related risk behaviors among recognized high risk groups were observed, and estimations and projections of HIV transmission up to the year 2020 presented. The Estimation and Projection Package was used to estimate and project HIV transmission. The study results reveal that Bangladesh is a low prevalence country which is turning into one with a concentrated epidemic due to the high HIV prevalence rate of IDU (7%) among the most-at-risk groups. Within this at-risk population, IDU have the highest prevalence rate of HIV transmission, followed by female sex workers, clients of sex workers, and men who have sex with men. If the transmission rate continues to increase, the situation will be uncontrolled. Therefore, there is an urgent need for a comprehensive prevention program to control the spread of HIV.

Raw fish consumption is increasing worldwide. Since around the year 2000, western regions of Japan have reported a foodborne disease of unknown cause that occurred after the consumption of flounder. In October 2010, a particularly large outbreak was reported in these regions among individuals who consumed flounder fish that had been raised in aquaculture systems. The median incubation period was 5 h (range, 4-19 h), and the most frequently reported symptom was diarrhea (80%). The risk estimate of the consumption of flounder was significantly higher than that of the development of symptoms (odds ratio=9.50; 95% confidence interval, 1.59-∞). According to a trace-back investigation, all of the flounder responsible for the outbreak were raised in aquaculture systems. Microscopic examination revealed that the median amount of Kudoa septempunctata present in the muscle of flounder fish from the aquaculture farm was 4.5×10(3) spores/g (range, 1.0×10(3)-9.6×10(6) spores/g). The number of K. septempunctata spores required for the development of illness, as estimated using the Monte Carlo simulation, was 7.2×10(7) spores/g; therefore, thus this might be the minimum ingestion threshold for the development of gastrointestinal symptoms. As a public health measure, the current study results should be referred to for the prevention of the gastrointestinal symptoms related to the consumption of flounder; the national public health authority has disseminated these results. We concluded that K. septempunctata-contaminated flounder fish were associated with the gastrointestinal symptoms of this recent outbreak.

Enterovirus 71 (EV71) is one of the causative agents of hand, foot, and mouth disease (HFMD) and is known to cause encephalitis, but several reports have identified EV71 in cerebrospinal fluid (CSF). We detected EV71 in CSF from a 20-month-old infant. The patient was diagnosed with brainstem encephalitis associated with HFMD. The clinical features of the patient were high fever (39.1C) and myoclonic jerks, and magnetic resonance imaging of the brain showed a bright signal area around the 4th ventricle. From a nasopharyngeal swab and rectal swab, EV71 was detected using reverse transcription (RT)-nested polymerase chain reaction (PCR). From CSF, the EV71 genome was identified using pan-enterovirus RT-nested PCR and sequencing. By real-time PCR, the nasopharyngeal swab, rectal swab, and CSF contained 1.8 x 10(4), 9.8 x 10(4), and 1.8 x 10 copies of the EV71 genome/microL, respectively. The enterovirus could only be isolated by cell culture from the rectal swab, and it was identified by a neutralization test using EV71-specific antiserum. RT-nested PCR and real-time PCR are considered to be sensitive tools for EV71 diagnosis in CSF.

A local outbreak of epidemic keratoconjunctivitis (EKC) caused by human adenovirus type 8 (HAdV-D8) occurred in Kawasaki city, Japan in July-August 2011. Since the cases were sporadic in nature, the source of the infection could not be identified. The results of PCR analysis and the appearance of cytopathic effects in the samples indicated that 22 patients were positive for HAdV. The mean age of the patients (10 men and 12 women) was 64.3 ± 17.3 years (median, 68 years; range, 11-86 years). The sequences of hexon, which included hypervariable loop 1; the penton, which included RGD loops; and the fiber, which included the knob-coding regions, were identical in all the HAdV-positive cases. Phylogenetic analysis of the major capsid protein-encoding regions of HAdV confirmed that the isolates were HAdV-D8. Although the incidence of HAdV-D8 outbreaks has decreased in Japan since 1997, the results of our study imply that HAdV-D8 is still a causative agent for EKC outbreaks in Japan.

We performed the genotyping and phylogenetic analysis of respiratory syncytial virus (RSV) isolated from 17 infants with bronchiolitis in Kanagawa Prefecture, Japan in 2005 and 2006. The major genes in these samples (attachment [G] glycoprotein gene, fusion [F] protein gene, and nucleoprotein [N] gene) were sequenced and analyzed genetically. Phylogenetic analysis of these genes revealed that 7 and 10 strains could be classified into subgroups A and B, respectively. Phylogenetic analysis of the G gene revealed that the subgroup A and B strains were unique genotypes GA2 and BA, respectively. Moreover, the amino acid sequences for these genotypes suggested a relatively high frequency of amino acid substitutions in the G and F proteins in these strains, whereas the N protein was highly homologous. These results suggest that RSV genotypes GA2 and BA may be associated with bronchiolitis in the cases studied here.

Group G Streptococcus strains isolated from patients with severe invasive infections in the period 2002-2008 were surveyed and their prevalence compared with that observed in the period 1995-2001 in Japan. Strains with genotypes stg485, stg6792, stc36, stg6, and stg652 were isolated in both periods, whereas various new genotypes appeared in 2002-2008 and some genotypes found in 1995-2001 were not found subsequently, thus indicating a change in the prevalent genotyped strains causing severe invasive streptococcal infections.

The first confirmed case of 2009 influenza A (H1N1) in Fukuoka, Japan was reported in early-June 2009. The disease rapidly spread through this area, mainly in schools, until there were no new cases detected 3 weeks later. We describe herein the clinical characteristics of this novel infection that came to light through the investigation of this outbreak. The patient records at hospitals and local public health centers were reviewed, and we defined laboratory-confirmed cases as those of a person who had influenza-like symptoms, such as a fever of 37C or more, cough, sore throat, rhinorrhea, or headache. From May 19 to June 31, 2009, a total of 71 cases were identified. The median age was 11 years, and all the patient took neuraminidase inhibitors and fully recovered. The fevers lasted for 1 to 5 days (median, 2). Cough lasted for 2 to 11 days (median, 7), and in 10 cases (34.5%) cough started before the fever. The incubation period was 2 to 3 days. Infectors transmitted the disease to another person on the day of or the day before fever onset. The findings regarding the onset and duration of symptoms and the timing of disease transmission of 2009 influenza A (H1N1) may be useful for future response.

Quantitative real-time reverse transcription-polymerase chain reaction (q-RT-PCR) was used to diagnose echovirus infection and the results were compared to those obtained with the viral culture rate. Cerebrospinal fluid (CSF) from a total of 40 aseptic meningitis patients was used. Positive CSF samples, determined by viral culture (n=29), contained significantly higher echovirus genome copy numbers (mean, 329 copies/microL) than did culture-negative CSF samples (n=11) (mean, 34.2 copies/microL; P0.05). Echoviruses were identified as echovirus serotype 9 (E-9) (n=21); E-30 (n=16); and E-5, E-7, and E-18 (n=1 each) by neutralization and/or conventional PCR-sequencing techniques. Viral culture-positive samples were collected at 1.41-/+1.27 days after the onset of illness, and culture-negative samples were collected at 4.91-/+3.34 days. Samples from which virus could be isolated were collected significantly earlier than were samples from which virus could not be isolated. These results strongly suggest the importance of early collection of CSF for echovirus isolation, and demonstrate the high sensitivity of q-RT-PCR for the detection of echoviruses in CSF.

Surveillance is critical for both early detection and a timely public health response to infectious diseases. Electronic information systems have been widely adopted by pharmacies in Japan. The aim of this study is to evaluate the feasibility of using prescription data for influenza surveillance in Japan to facilitate the development of a daily reporting system. This is a retrospective study using questionnaires mailed to pharmacies in Sakai City, Osaka, Japan in October 2007. The total number of prescriptions for oseltamivir and zanamivir and the number of influenza cases reported by sentinel surveillance in Sakai during the investigation period showed excellent correlation, with a correlation coefficient of 0.954. Further analysis showed that the data from as few as eight pharmacies result in a correlation coefficient of 0.9. These results demonstrate the feasibility of such a system and that pharmacy prescription data are a very useful indicator of sentinel surveillance for influenza.

Japanese encephalitis (JE) surveillance has been conducted since 1965 as a part of the National Epidemiological Surveillance of Vaccine Preventable Diseases in Japan. Over 1,000 JE cases were reported annually in the late 1960s. The number of JE cases has since markedly decreased, with less than 10 cases reported annually from 1992 to 2004. A total of 361 JE cases were reported between 1982 and 2004. Prognosis was available for 320 cases; 58 (18%) died, 160 (50%) recovered with neuropsychiatric sequelae, and 102 (32%) completely recovered. Seventy-eight percent of these cases were 40 years old or over with a peak age group of 60-69 years old. JE predominantly occurred in unvaccinated populations. A high seroconversion rate among sentinel pigs was recorded every year. This suggests the presence of JE virus-infected mosquitoes during the summer in most areas of Japan, including the northern districts where no JE cases were reported from 1982 to 2004. Although JE cases have been reported in single figures since 1992, the risk of JE virus infection is still present. Thus, high immunization rates of JE vaccine should be maintained in Japan.

In 2007, relatively large outbreaks of measles occurred in the Kanto region of Japan, including Gunma Prefecture. We performed sequence and phylogenetic analysis of the nucleoprotein gene (N gene) of measles viruses from 3 measles patients in this area in May 2007. The N gene sequences of the present strains were identical to each other, and phylogenetic analysis showed these viruses were classified into genotype D5. The results suggest that highly homologous measles viruses may be associated with outbreaks of measles in Gunma, Japan.

Kawasaki City Institute for Public Health, Kanagawa 210-0821, JapanCommunicated by Takaji Wakita(Accepted April 24, 2013)A serious outbreak of hand, foot, and mouth disease(HFMD) occurred in Japan in the summer of 2011 (1,2).A major cause of this epidemic was coxsackievirus A6(CA6), and the clinical manifestations of the diseasediffered from those of typical HFMD. The InfectiousDiseases Control Law mandates medical doctors inJapan to officially report cases exhibiting the followingsymptoms immediately after diagnosis: fever with sorethroat and appetite loss, followed by the appearance ofreddish vesicles on the hands and feet approximately 2days after the onset of fever. The vesicles usually disap-pear within 7 to 10 days without specific treatment.Reported cases should satisfy both of the following clin-ical criteria: (i) vesicles measuring 2–5 mm with blisterson the palm of the hand and sole or dorsum of the footand oral mucosa and (ii) vesicles that heal without crustformation.During the 2011 outbreak, it was challenging forpediatricians to judge whether the majority of HFMDcases should be diagnosed as a subtype of conventionalHFMD or a new type caused by CA6 infection. Werecommend that pediatricians should be alert whilemaking diagnosis because the rashes caused by CA6 aresimilar to those caused by chickenpox. Establishingdifferential diagnoses is necessary in order to preventmisdiagnosis and inappropriate treatment. The criticalpoint in differentiating CA6 from other infections is thespecific clinical course and spread of eruptions withscabbing. For this purpose, in 2011, we summarized thedetailed clinical features of HFMD caused by CA6infection (CA6-associated HFMD).On the basis of laboratory confirmation (1), we re-viewed28 cases of CA6-associated HFMD thatoccurredin Japan between June 2011 and July 2011. CA6 strainswere detected in samples of feces and/or pharyngealswabs and tested using reverse transcription (RT)-PCRand sequencing of the VP1 region (AB649286–AB649291).Clinical samples were collected during the course ofmedical care in hospitals and laboratory tests were per-formed for the purpose of diagnosis and treatment.Informed consent for this study was obtained from allthe patients' guardians, and the clinical samples werediagnosed for national surveillance.Patient age ranged from 9 months to 9 years (mean,29.1 months), and 75z of patients were aged under 3years. There was no statistically significant genderdifference. All HFMD cases were associated with afever (38.0–40.29C; mean, 39.09C) that lasted for 1.5days on an average. The appearance of rashes on theoral mucosa was noted from the second day of onset offever, similar to that observed in cases of herpanginawith less oral pain and reluctance to eat. The appear-ance of reddish vesicles on the extremities and buttockswas noted on the third day of onset; these vesicles weremostly found on the upper arms, thighs, lips, neck, andbuttocks, while they were found less frequently on thehands and soles of the feet. The vesicles were flat andumbilicated. Some lesions grew to be more than 10 mmin diameter, and scabbing was observed within severaldays (Fig. 1).As described above, the criteria for notification inJapan require that the vesicles associated with HFMDheal without crust formation. However, in this study,crust formation was observed within several days of dis-ease onset in all 28 cases. The notification criteria forHFMD include vesicles that heal without crust forma-tion. Our results showed that CA6-associated HFMDdid not fulfill the notification criteria for HFMD.However, it was impossible to find crust formation inthe early stage of the illness. In some cases, a carefuldifferential diagnosis from chickenpox, impetigo con-tagiosa, herpes simplex disease, and varicella-zosterdisease was required. The critical features of CA6-asso-ciated HFMD were the successive appearance of her-pangina-like oral mucosal lesions, widely spread rashes,and crust formation during the healing process.We followed 16 recovered cases for 2–8 weeks andfound that 6 (37.5z) experienced onychomadesis,whichwasa significant finding. All cases healed withoutsevere sequelae, except for the 6 cases that developedonychomadesis. The incidence of CA6-associatedHFMD with crust formation is thought to be high(almost 100z), with the rate of onychomadesis esti-matedtobeover30z. Further studies are therefore

In January 2002, 12 patients with Serratia marcescens bloodstream infection (BSI) were identified in a hospital in Tokyo, Japan. We conducted an epidemiological investigation of this outbreak. We undertook a medical-records review and employee interviews, and performed a case-control study to determine risk factors for S. marcescens BSI. An observational study of the hospital's procedures and an environmental microbiologic sampling were performed. We identified 12 suspected and 12 confirmed patients with S. marcescens BSI, including 7 who died. A case-control study showed that vascular access devices (odds ratio [OR] = 30.46; 95% confidence interval [CI] = 3.5-685.6) and the use of heparin-locks, between December 26 and January 15 (OR = 25.7; 95% CI = 2.3-680.4) were significant risk factors for S. marcescens BSI. The observational study revealed multiple lapses in infection control, including use of multi-dose vials of heparin. The outbreak strain was isolated from a hand-towel in the nurse station. The use of multi-dose vials of heparinized-saline during a particularly busy period was associated with BSI risk. The results underscore the risks inherent in infection-control lapses and the use of multi-dose vials.

To assess the causal association of autism with measles, mumps, and rubella (MMR) vaccine versus that with monovalent measles, mumps, and rubella immunization, a 1:2 sex-adjusted logistic regression analysis was conducted using data on subjects who were growing up in the Tokyo area between 1988 and 1992. When MMR immunization was used as a reference, monovalent measles immunization (odds ratio [OR] = 5.33, 99% confidence interval [CI]: 1.03-27.74), non-mumps immunization (OR = 8, 99%CI: 1.33-48.2), and non-rubella immunization (OR = 8.57, 99%CI: 1.30-56.4) with development of autistic spectrum disorders (ASD) were significantly increased. These results suggest a decreased risk of developing ASD with MMR compared to monovalent antigens. However, our findings may reflect potential selection bias due to requiring written consent, possible delayed vaccination in suspected autism cases, and small sample size (case = 21). For the case group and the control group, immunization completeness rate of each antigen, regardless of the timing of immunization, was 90.5% versus 100% in measles, 42.9% versus 78.6% in mumps (P0.01), 52.3% versus 83.3% in rubella (P0.01), 14.3% versus 45.2% in varicella (P0.01), 100% versus 90.5% in polio2, 100% versus 97.6% in Diphtheria (D), pertussis, and tetanus (T)3, 85.7% versus 66.7% in DT, 95.2% versus 92.9% in BCG, and 52.4% versus 81.0% in Japanese encephalitis3 (P0.01). Only two case subjects and four control subjects received their measles, mumps, and rubella immunizations separately, suggesting that few Japanese parents might have had concerns about the safety of MMR vaccine. A nation-wide study would be a practical measure to scientifically judge the safety of MMR and other routine childhood immunizations.

The purpose of our study was to establish a seasonal model to simulate the oscillation of the number of influenza cases with weather conditions and calendar months in Tokyo, Japan, during the winter season. Surveillance data for influenza in Tokyo was retrieved from the Infectious Agents Surveillance Report, published by the National Institute of Infectious Diseases in Japan. We obtained data for 86 parameters of weather conditions from the Meteorological Agency. The best-fit model was built by multiple regression with stepwise analysis. The reported number of patients with influenza per week was significantly increased with fewer days of maximum temperature 10 per week (T10) and more days of relative humidity60% per week (S60), adjusted by calendar month, average temperature, and vapor pressure. Annual oscillation of the number of reported influenza cases at the start, peak, and end weeks almost exactly matched the model, although peak levels for each oscillation did not always match. However, this model showed that 81% of the variation among the observed number of influenza cases was explained by a linear relationship with the seasonal parameters utilized. The validity of this model applied to data from 1999 to 2002, showing a 75% correlation. Using this model, if the number of days with both T10 and S60 increased by one per week, the number of influenza cases was simulated to decrease by approximately half. These results suggest that most of the oscillation in the number of influenza cases may be explained using a seasonal model that can simulate the impact of global warming.

In order to investigate the effects of global warming, we attempted to establish seasonal models to predict fluctuations in rates of herpangina (HA) and hand-foot-mouth disease (HFMD) associated with weather conditions and calendar months in Tokyo, Japan. Surveillance data tracking HA/HFMD incidences in Tokyo was retrieved from the Infectious Agents Surveillance Report, published by the National Institute of Infectious Diseases in Japan. From the Meteorological Agency, we obtained data for 54 weather condition parameters. The annual fluctuations in reported HA cases comprising start, peak, and end weeks almost exactly matched the model, although peak levels for each fluctuation did not always match in HFMD. Furthermore, for the HA model, 88% of the variations among observed HA cases were explained by the linear relationship with the seasonal parameters investigated, which was higher than the 64% observed for the HFMD model. The HA and HFMD models were applied to data from the years 1999 to 2002, and demonstrated correlations of 86% and 64%, respectively. These models predicted that warmer climate conditions would lead to an increased number of HA and HFMD cases. These results suggest that our seasonal models may quantify the dependency of infectious diseases on seasonal parameters and simulate the impact of global warming.

In Japan, Tsutsugamushi disease, which is caused by Orientia tsutsugamushi, is re-emerging with newly recognized strains and is now endemic in all prefectures except Hokkaido and Okinawa. We analyzed recent surveillance data to describe the epidemiology of Tsutsugamushi disease and to evaluate the newly implemented national surveillance system according to the CDC guidelines for evaluating surveillance systems. In 2000, 756 cases of Tsutsugamushi disease were reported from 37 of 47 prefectures; two of these cases were fatal. The median age of case-patients was 64 years (range: 2 - 94 years); 414 (54.8%) were male. In northern Japan, most cases were diagnosed in the months of May through July and in the months of October through December, and in southern Japan, cases were diagnosed almost year-round with a peak from October through December and in January. Reporting and transfer of surveillance information from the prefecture to the national level was effective and timely, but the completeness and quality of case reporting could still be improved. The current system for Tsutsugamushi disease surveillance is useful for describing epidemiologic patterns by time, prefecture, and demographic characteristics. However, collection of additional information on suspected place of transmission, activity performed at the place of transmission, or the case-patient's profession would likely make the system more valuable for outbreak detection and for better defining populations at risk.

We compared a municipal sentinel surveillance system for influenza with the Microbial Isolation Surveillance System (MISS) in Kyoto City, Japan. Sensitivity, specificity, and predictive value positive (PVP) of the Influenza Sentinel Surveillance System (ISSS) compared to the MISS were calculated by influenza season and by month. Sensitivity ranged from 80 to 97%, specificity ranged from 55 to 77%, and PVP ranged from 29 to 52% by season (P0.001). On the other hand, sensitivity ranged from 86 to 100%, specificity ranged from 38 to 66%, and PVP ranged from 31 to 50% by month (P0.001). Specificity was calculated as 93% in November. The sensitivity of ISSS was found to be sufficient regardless of the magnitude of influenza activity. Specificity varied by season, indicating the difficulty of clinically diagnosing other respiratory illnesses. The PVP remained at less than 50% before and after the influenza seasons and it varied year by year. In general, the ISSS is a good surveillance system for monitoring influenza activity.

To assess the degree to which face masks reduce the strength of cough-wind, we measured the wind pressure in front of the mouth with and without the wearing of masks. We found that any conventional masks made from paper, cotton gauze, or non-woven fabrics reduced the wind pressure to less than one-tenth that recorded when no mask was worn.

Enterovirus 71 (EV71), one of the major causative agents for hand, foot and mouth disease (HFMD), is sometimes associated with severe central nervous system diseases. In 1997, in Malaysia and Japan, and in 1998 in Taiwan, there were HFMD epidemics involving sudden deaths among young children, and EV71 was isolated from the HFMD patients, including the fatal cases. The nucleotide sequences of each EV71 isolate were determined and compared by phylogenetical analysis. EV71 strains from previously reported epidemics belonged to genotype A-1, while those from recent epidemics could be divided into two genotypes, A-2 and B. In Malaysia, genotype A-2 was more prevalent, while in Japan and Taiwan, B genotype was more prevalent. Two isolates from fatal cases in Malaysia and one isolate from a fatal case in Japan were genotype A-2. However, all isolates from three fatal cases in Taiwan belonged to genotype B. The severity of the HFMD did not link directly to certain genotypes of EV71.