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Objective: Coxsackievirus B (CVB) is associated with the development of human diseases including type 1 diabetes. Previous studies identified cyclical variations in type 1 diabetes incidence—peak incidences occurring in 4- to 6-year periods in two regions in England, a 5-year period in Western Australia, and 5.33-year period in Poland. However, it is not clear whether CVB infection rates demonstrate similar cyclical variation characteristics. The purpose of this study was to characterize the periodicity in CVB surveillance data. Results: Maximum entropy spectral analysis was performed on monthly CVB surveillance data in Japan. In addition to demonstrate a 1-year cycle for all the serotypes, spectral peaks were demonstrated for dominant cycles—6.9-, 3.8-, 4.3-, 9.5-, and 7.8- year periods for CVB1, CVB2, CVB3, CVB4, and CVB5, respectively. Pearson correlation was used to compare the least-squares fit curves based on periods estimated from the analysis with the original data. The results for all five serotypes—CVB1, CVB2, CVB3, CVB4, and CVB5—demonstrated good correlation— ρ = 0.96, ρ = 0.60, ρ = 0.90, ρ = 0.88, and ρ = 0.67, respectively. This method could be a useful tool for the efficient investigation of CVB as a pathogen of type 1 diabetes.

The present study investigated associations between epidemiological mumps patterns and meteorological factors in Japan. We used mumps surveillance data and meteorological data from all 47 prefectures of Japan from 1999 to 2020. A time-series analysis incorporating spectral analysis and the least-squares method was adopted. In all power spectral densities for the 47 prefectures, spectral lines were observed at frequency positions corresponding to 1-year and 6-month cycles. Optimum least-squares fitting (LSF) curves calculated with the 1-year and 6-month cycles explained the underlying variation in the mumps data. The LSF curves reproduced bimodal and unimodal cycles that are clearly observed in northern and southern Japan, respectively. In investigating factors associated with the seasonality of mumps epidemics, we defined the contribution ratios of a 1-year cycle (Q1) and 6-month cycle (Q2) as the contributions of amplitudes of 1-year and 6-month cycles, respectively, to the entire amplitude of the time series data. Q1 and Q2 were significantly correlated with annual mean temperature. The vaccine coverage rate of a measles–mumps–rubella vaccine might not have affected the 1-year and 6-month modes of the time series data. The results of the study suggest an association between mean temperature and mumps epidemics in Japan.

ObjectiveStudies have identified serotypes of Coxsackievirus B (CVB) enterovirus as a cause of type 1 diabetes. Studies have also identified cyclical variations in type 1 diabetes incidence—peak incidences occurring in 4- to 6-years periods in two regions in England, a 5-year period in Western Australia, and 5.33-year period in Poland. To date, no studies have investigated whether CVB infection rates demonstrate similar cyclical variation characteristics. The purpose of this study was to characterize periodicity in CVB surveillance data.ResultsMaximum entropy spectral analysis was performed on monthly CVB surveillance data. In addition to demonstrating a 1-year cycle for all serotypes, spectral peaks demonstrated dominant cycles—6.9-, 3.8-, 4.3-, 9.5-, and 7.8- year periods for CVB1, CVB2, CVB3, CVB4, and CVB5, respectively. Pearson correlation was used to compare the least-squares fit curves based on periods estimated from the analysis with the original data. The results for all five serotypes—CVB1, CVB2, CVB3, CVB4, and CVB5—demonstrated good correlation—ρ = 0.96, ρ = 0.60, ρ = 0.90, ρ = 0.88, and ρ = 0.67, respectively. This method could be a useful tool for the efficient investigation of CVB as a pathogen of type 1 diabetes.

SUMMARYThe purpose of this study was to clarify the association between hand, foot, and mouth disease (HFMD) epidemics and meteorological conditions. We used HFMD surveillance data of all 47 prefectures in Japan from January 2000 to December 2015. Spectral analysis was performed using the maximum entropy method (MEM) for temperature-, relative humidity-, and total rainfall-dependent incidence data. Using MEM-estimated periods, long-term oscillatory trends were calculated using the least squares fitting (LSF) method. The temperature and relative humidity thresholds of HFMD data were estimated from the LSF curves. The average temperature data indicated a lower threshold at 12 °C and a higher threshold at 30 °C for risk of HFMD infection. Maximum and minimum temperature data indicated a lower threshold at 6 °C and a higher threshold at 35 °C, suggesting a need for HFMD control measures at temperatures between 6 and 35 °C. Based on our findings, we recommend the use of maximum and minimum temperatures rather than the average temperature, to estimate the temperature threshold of HFMD infections. The results obtained might aid in the prediction of epidemics and preparation for the effect of climatic changes on HFMD epidemiology.

女子大生とその母親・祖母の三世代の食生活の伝承と家族機能との関連性を明らかにし、家族が健康的な食習慣を形成するための支援の示唆を得ることを目的に、自記式質問紙を用いて調査を行った。個人特性と食生活15項目について、祖母・母親には子育て時、学生には現在の生活について把握し、家族機能は凝集性・適応性から分析した。三世代間における家族機能の回答の違いはχ2検定、食生活の違いはKruskal Wallis 検定、Wilcoxonの順位和検定、食べ物に関する設問から得られた第一主成分を「食べ物に気を遣う」指標とし平均値を一元配置分散分析、第一主成分を従属変数に、世代、凝集性、適応性を独立変数として重回帰分析を行った。家族機能による回答の違いはKruskal Wallis 検定を行った。有効回答数は学生138人、母親148人、祖母113人で、 「食べ物に気を遣う」ことは祖母と母親間には差がなく、子どもと母親、子どもと祖母間に差があった。祖母・母親世代が食生活に関して大切にしてきたことは子どもに伝承していなかった。また、「食べ物に気を遣う」ことは家族機能と相関していた。家族が健康的な食生活を形成するためには、家族機能を促す支援が有効であることが示唆された。, The purpose of the present study was to clarify the relationship between intergenerational tradition and familial eating habits among female college students, and their mothers and grandmothers. Based on the results obtained, we tried to derive a method of support for families with women of 3 generations in order to foster healthy eating habits. We administered a questionnaire to female college students, and their mothers and grandmothers. The questionnaire contained questions on demographic-data and 15 items concerning eating habits. For college students, the questions were based on life priorities, and for mothers and grandmothers, they were based on priorities concerning child raising. "Family feature." index of the health of the family, is characterized in terms of the cohesion and adaptability and is used as a unit of measurement. We used the χ2,Kruskal-Wallis test, and Wilcoxon's rank sum tests for estimating the presence of significant differences among the answers of the 3 generations. To assess eating habits among the 3 generations, we conducted principal component analysis, one-way analysis of variance, and multiple regression analysis. The female college students, mothers, and grandmothers, gave 138, 148 and 113 valid answers, respectively. Based on the results obtained, we suggest the following 2 points: (i) the students did not follow the eating habits of their mothers or grandmothers, and (ii) greater emphasis must be given to family support in order to form healthy eating habits in the family.

Twenty-two of 1,103 methicillin-resistant Staphylococcus aureus (MRSA) isolates containing the type II staphylococcal cassette chromosome mec element (SCC mec ) (collected in Hokkaido, Japan, from 2008 to 2011) harbored the arginine catabolic mobile element (ACME). Five genetic variations were identified in the ACME-staphylococcal cassette chromosome mec composite islands, 66 to 79 kb in size. The percentage of ACME carriage temporally increased from 0.85% to 4.5% in parallel with the emergence of shorter variants (66 to 72 kb). Shorter variants may have a selective advantage and accelerate the dissemination of ACME in Japanese MRSA.

The genetically diverse sapoviruses (SaVs) are a significant cause of acute human gastroenteritis. Human SaV surveillance is becoming more critical, and a better understanding of the diversity and distribution of the viral genotypes is needed. In this study, we analyzed 106 complete human SaV capsid nucleotide sequences to provide a better understanding of their diversity. Based on those results, we propose a novel standardized classification scheme that meets the requirements of the International Calicivirus Scientific Committee. We believe the classification scheme and strains described here will be of value for the molecular characterization and classification of newly detected SaV genotypes and for comparing data worldwide.

Prevalence and molecular characteristics of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) were studied in Hokkaido, the main northern island of Japan. Among the 1,015 S. aureus isolates derived from clinical specimens of outpatients collected in 2009, methicillin resistance gene mecA was detected in 189 isolates (18.6%). The most frequent staphylococcal cassette chromosome mec (SCCmec) type in MRSA was II (83.1%), followed by IV (6.9%) and V (3.2%). MRSA with type II-SCCmec showed multiple drug resistance and harbored various toxin and virulence factor genes except for Panton-Valentine leucocidin (PVL) gene. These isolates were mostly classified into sequence type 5 (ST5) (or other STs in CC5) and coagulase genotype II and were thus genetically similar to hospital-acquired MRSA, which have been predominating in Japan (New York/Japan clone). PVL gene was detected in three MRSA strains belonging to ST6 (two strains) and ST59 (one strain), having type IVa- and Vt-SCCmec, respectively, and also in two methicillin-susceptible S. aureus ST121 and ST188. The arcA gene within the arginine catabolic mobile element (ACME) was detected in the two PVL-negative ST5 MRSA strains, which had type IIa- or V-SCCmec. The PVL gene-positive ST6 and ST59 CA-MRSA strains were susceptible to more antimicrobials and had less virulence factor genes than the PVL-negative ST5 MRSA, including the ACME-arcA-positive strains. In the present study, ST6 was identified as a lineage of PVL-positive CA-MRSA, the ACME-arcA was first detected in ST5 MRSA with type V-SCCmec, and ST59 Taiwanese CA-MRSA strain was isolated in Hokkaido for the first time. These findings suggest a potential spread of these emerging CA-MRSA clones in Japan.

Background Much effort has been expended on interpreting the mechanism of influenza epidemics, so as to better predict them. In addition to the obvious annual cycle of influenza epidemics, longer-term incidence patterns are present. These so-called interepidemic periods have long been a focus of epidemiology. However, there has been less investigation of the interepidemic period of influenza epidemics. In the present study, we used spectral analysis of influenza morbidity records to indentify the interepidemic period of influenza epidemics in Japan. Methods We used time series data of the monthly incidence of influenza in Japan from January 1948 through December 1998. To evaluate the incidence data, we conducted maximum entropy method (MEM) spectral analysis, which is useful in investigating the periodicities of shorter time series, such as that of the incidence data used in the present study. We also conducted a segment time series analysis and obtained a 3-dimensional spectral array. Results Based on the results of power spectral density (PSD) obtained from MEM spectral analysis, we identified 3 periodic modes as the interepidemic periods of the incidence data. Segment time series analysis revealed that the amount of amplitude of the interepidemic periods increased during the occurrence of influenza pandemics and decreased when vaccine programs were introduced. Conclusions The findings suggest that the temporal behavior of the interepidemic periods of influenza epidemics is correlated with the magnitude of cross-reactive immune responses.

SUMMARYMeasles is regarded as a disease that can be eliminated by vaccination; however, disease epidemics still occur in Wuhan, China. This study explored the effect of measles control programmes on the periodic structure of disease epidemics in Wuhan. The monthly reported measles incidence from 1953 to 2008 was divided into pre-vaccine range (1953–1965) and post-vaccine range (1966–2008). For the incidence in each range, spectral analysis was conducted and power spectral density (PSD) was obtained. In PSD for the pre-vaccine range, the most dominant spectral line was observed at a 2·0-year period, as in the case of Japan. It was confirmed that spectral lines of periodic modes longer than a 1-year cycle of the incidence rates behave in response to the introduction of measles control programmes. The investigation of periodic structures of measles epidemics will contribute to effective measles control programmes in Wuhan.

SUMMARYAnnual periodicities of reported chickenpox cases have been observed in several countries. Of these, Japan has reported a two-peaked, bimodal annual cycle of reported chickenpox cases. This study investigated the possible underlying association of the bimodal cycle observed in the surveillance data of reported chickenpox cases with the meteorological factors of temperature, relative humidity and rainfall. A time-series analysis consisting of the maximum entropy method spectral analysis and the least squares method was applied to the chickenpox data and meteorological data of 47 prefectures in Japan. In all of the power spectral densities for the 47 prefectures, the spectral lines were observed at the frequency positions corresponding to the 1-year and 6-month cycles. The optimum least squares fitting (LSF) curves calculated with the 1-year and 6-month cycles explained the underlying variation of the chickenpox data. The LSF curves reproduced the bimodal and unimodal cycles that were clearly observed in northern and southern Japan, respectively. The data suggest that the second peaks in the bimodal cycles in the reported chickenpox cases in Japan occurred at a temperature of approximately 8·5 °C.

Group B rotaviruses detected in Bangladesh in 2000 and 2001 were analyzed genetically to clarify relatedness to human group B rotaviruses reported previously in China and India, and to animal group B rotaviruses. VP7 gene sequences of the Bangladeshi group B rotaviruses (Bang373, Bang544, Bang334, and Bang402) were almost identical to each other and also showed high sequence identity to the Indian strain CAL-1 (98%) and Chinese strain adult diarrhea rotavirus (ADRV) (92%), while identities to bovine and murine viruses were considerably low (60-63%). Other genes of Bang373 and Bang544 encoding VP2, VP4, VP6, and NSP1 through NSP5 also showed much higher sequence identities to those of CAL-1 (97.7-99.4%) than to those of ADRV (89.9-93.9%). Characterization of nucleotide substitutions among Bang373, CAL-1, and ADRV suggested that all the gene segments might have evolved neutrally at similar mutation rates, while some of the gene segments (e.g., VP2 gene) were suggested to be more conserved than others. In conclusion, group B rotaviruses detected in Bangladesh represented by Bang373 and the Indian virus CAL-1 were considered as virtually identical viruses which are distinct genetically from ADRV, and it was suggested that Bang373 (CAL-1)-like group B rotavirus (Bengali strains) might be distributed primarily in an area around the Bay of Bengal.

SUMMARYWe investigated the seasonality of tuberculosis (TB) in Wuhan, China, to evaluate the increased risk of disease transmission during each season and to develop an effective TB control strategy. We applied spectral analysis to the weekly prevalence data of sputum smear positive (SSP) and sputum smear negative (SSN) pulmonary TB reported from 2006 to 2010. Cases of both SSP and SSN feature 1·0- and 0·5-year periodic modes. The least squares method was used to fit curves to the two periodic modes for SSP and SSN data. The curves demonstrated dominant peaks in spring similar to cases reported previously for other locations. Notably for SSP, dominant peaks were also observed in summer. The spring peaks of SSP and SSN were explained in terms of poorly ventilated and humid rooms and vitamin D deficiency. For the summer peaks of SSP, summer influenza epidemics in Wuhan may contribute to the increase in TB prevalence.

The VP7 and VP4 genome segments of human rotavirus strain Mc35 (Urasawa et al., J. Infect. Dis. , 166, 227-234, 1992) were investigated. Analysis of its VP7 nucleotide and amino acid sequences confirmed that it belongs to G (or VP7) serotype 10; however, the nucleotide sequence homologies between Mc35 and the four G10 bovine strains examined were lower than those among the four G 10 bovine strains. The VP4 nucleotide and amino acid sequences of Mc35 were distinct (66.1-68.8% nucleotide and 64.9-70.0% amino acid homologies) from those of previously reported human and animal rotavirus strains representing different P (or VP4) types except for the strain K8 VP4, which was designated as type 3 of human rotavirus VP4 by Gorziglia et al. (Proc. Natl. Acad. Sci. USA., 87, 7155-7159, 1990). The VP4s of the K8 and Mc35 strains showed a relatively high degree of homology (77.6% nucleotide and 86.0% amino acid sequence homologies) and were presumed to represent subtypes of type 3 human rotavirus VP4 (type 3A (K8 VP4) and type 39 (Mc35 VP4)).

Human campylobacteriosis is a common bacterial cause of gastrointestinal infections. In this study, we tested whether spectral analysis based on the maximum entropy method (MEM) is useful in predicting the incidence of campylobacteriosis in five provinces in Finland, which has been accumulating good quality incidence data under the surveillance program for water- and food-borne infections. On the basis of the spectral analysis, we identified the periodic modes explaining the underlying variations of the incidence data in the years 2000-2005. The optimum least squares fitting (LSF) curve calculated by using the periodic modes reproduced the underlying variation of the incidence data. We extrapolated the LSF curve to the years 2006 and 2007 and predicted the incidence of campylobacteriosis. Our study suggests that MEM spectral analysis allows us to model temporal variations of the disease incidence with multiple periodic modes much more effectively than using the Fourier model, which has been previously used for modeling seasonally varying incidence data.

Staphylocoagulase (SC) is a major phenotypic determinant of Staphylococcus aureus. Serotype of SC (coagulase type) is used as an epidemiological marker and 10 types (I-X) have been discriminated so far. To clarify genetic diversity of SC within a single and among different serotype(s), we determined approximately 1500 bp-nucleotide sequences of SC gene encoding D1, D2, and central regions (N-terminal half and central regions of SC; SC(NC)) for a total of 33 S. aureus strains comprising two to three strains from individual coagulase types (I-VIII, X) and 10 strains which were not determined as previously known SC serotypes (ND-strains). Amino acid sequence identities of SC(NC) among strains with a single coagulase type of II, III, IV, V, VI and X were extremely high (more than 99%), whereas lower identity (56-87%) was observed among different types. In contrast, within a single coagulase type of I, VII, or VIII, sequence divergence was found (lowest identity; 82%). SC(NC) sequences from the ND-strains were discriminated into two genetic groups with an identity of 71% to each other (tentatively assigned to genotypes [XI] and [XII]), and exhibited less than 86% sequence identities to those of most known coagulase types. All the types [XI] and [XII] strains were methicillin susceptible and belonged to different sequence types from those of coagulase types I-X strains reported so far by multilocus sequence typing. These findings indicated genetic heterogeneity of SC in coagulase types I, VII, and VIII strains, and the presence of two novel SC genotypes related to antigenicity of SC serotypes.

The VP7 and VP4 genes of two human group A rotavirus strains Mc323 and Mc345 with unique serologic and genomic properties, and isolated in Chiang Mai, Thailand, in 1989 [Urasawa et al. (1992) Journal of Infectious Diseases 166:227-234] were further characterized. The nucleotide and deduced amino acid sequences of the VP7 genes allowed the classification of both strains as serotype G9. The VP4 genes of both strains are 2,359 nucleotides in length and encode a protein of 775 amino acids like in most human rotaviruses. A comparison of the VP4 amino acid sequence of strain Mc323 with those of strain Mc345 and 24 human and animal rotaviruses representing 20 distinct VP4 genotypes reported to date showed that VP4 of Mc323 and Mc345 belong to genotype 19 previously reported for porcine rotavirus [Burke et al. (1994) Journal of General Virology 75:2205-2212]. To investigate the serological type (P serotype) of these VP4s, six reassortant viruses each containing a distinct VP4 gene characteristic of human rotaviruses and the VP7 gene of porcine rotavirus strain Gottfried (G4) were prepared, and antisera to these reassortants produced in rabbits. In neutralization tests, the P serotype of Mc323 was clearly differentiated from the five major P serotypes reported previously for human rotaviruses, suggesting that Mc323 and Mc345 represent a new human rotavirus P serotype tentatively called P11.

We examined the usefulness of spectral analysis for investigating quantitatively the spatial pattern of pathologic tissue. To interpret the results obtained from real tissue, we constructed a two-dimensional spatial model of the tissue. Spectral analysis was applied to the spatial series data, which were obtained from the real tissue and model. From the results of spectral analysis, spatial patterns of the tissue and model were characterized quantitatively in reference to the frequencies and powers of the spectral peaks in power spectral densities (PSDs). The results for the model were essentially consistent with those for the tissue. It was concluded that the model was capable of adequately explaining the spatial pattern of the tissue. It is anticipated that spectral analysis will become a useful tool for characterizing the spatial pattern of the tissue quantitatively, resulting in an automated first screening of pathological specimens.

A reciprocal translocation involving the short arms of chromosomes #7 and #11, t(7;11)(p15;p15), was found in two patients with myeloid leukemia, one with acute myelogenous leukemia (AML-M2) and the other with Philadelphia chromosome-positive chronic myelocytic leukemia (CML) in blastic phase. In both cases, a minor fraction of leukemic blasts in the bone marrow had Auer rods in the cytoplasm. In situ chromosome hybridization showed that the c-Ha-ras-1 oncogene localized to the breakpoint (p15) of chromosome #11 is translocated to the rearranged chromosome #7 in the AML case, whereas, it remained on the conserved region of the rearranged chromosome #11 in the CML case. The significance of the t(7;11) abnormality in myeloid leukemia is discussed.

Background Hand, foot, and mouth disease (HFMD) is an infectious disease caused by a group of enteroviruses, including Coxsackievirus A16 (CVA16) and Enterovirus A71 (EV-A71). In recent decades, Asian countries have experienced frequent and widespread HFMD outbreaks, with deaths predominantly among children. In several Asian countries, epidemics usually peak in the late spring/early summer, with a second small peak in late autumn/early winter. We investigated the possible underlying association between the seasonality of HFMD epidemics and meteorological variables, which could improve our ability to predict HFMD epidemics. Methods We used a time series analysis composed of a spectral analysis based on the maximum entropy method (MEM) in the frequency domain and the nonlinear least squares method in the time domain. The time series analysis was applied to three kinds of monthly time series data collected in Wuhan, China, where high-quality surveillance data for HFMD have been collected: (i) reported cases of HFMD, (ii) reported cases of EV-A71 and CVA16 detected in HFMD patients, and (iii) meteorological variables. Results In the power spectral densities for HFMD and EV-A71, the dominant spectral lines were observed at frequency positions corresponding to 1-year and 6-month cycles. The optimum least squares fitting (LSF) curves calculated for the 1-year and 6-month cycles reproduced the bimodal cycles that were clearly observed in the HFMD and EV-A71 data. The peak months on the LSF curves for the HFMD data were consistent with those for the EV-A71 data. The risk of infection was relatively high at 10 °C ≤ t