Time series analysis of daily reported number of new positive cases of COVID-19 in Japan from January 2020 to February 2023.

This study investigated temporal variations of the COVID-19 pandemic in Japan using a time series analysis incorporating maximum entropy method (MEM) spectral analysis, which produces power spectral densities (PSDs). This method was applied to daily data of COVID-19 cases in Japan from January 2020 to February 2023. The analyses confirmed that the PSDs for data in both the pre- and post-Tokyo Olympics periods show exponential characteristics, which are universally observed in PSDs for time series generated from nonlinear dynamical systems, including the so-called susceptible/exposed/infectious/recovered (SEIR) model, well-established as a mathematical model of temporal variations of infectious disease outbreaks.

Associations between Meteorological Factors and Reported Mumps Cases from 1999 to 2020 in Japan.

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.

Clonal lineages and antimicrobial resistance of nonencapsulated Streptococcus pneumoniae in the post-pneumococcal conjugate vaccine era in Japan.

Objectives: The emergence and spread of nonencapsulated Streptococcus pneumoniae (NESp) is a public health concern in the post-pneumococcal conjugate vaccine era. We analyzed the prevalence, molecular characteristics, and antimicrobial resistance of NESp responsible for noninvasive infections in northern Japan.

Methods: NESp isolates were identified using molecular and phenotypical methods among 4463 S.

Drug Resistance Determinants in Clinical Isolates of in Bangladesh: Identification of Oxazolidinone Resistance Gene in ST59 and ST902 Lineages.

is one of the major causes of urinary tract infection, showing acquired resistance to various classes of antimicrobials. The objective of this study was to determine the prevalence of drug resistance and its genetic determinants for clinical isolates in north-central Bangladesh. Among a total of 210 isolates, isolated from urine, the resistance rates to erythromycin, levofloxacin, and gentamicin (high level) were 85.

Latitudes mediate the association between influenza activity and meteorological factors: A nationwide modelling analysis in 45 Japanese prefectures from 2000 to 2018.

Background: Cold and dry conditions were well-documented as a major determinant of influenza seasonality in temperate countries but the association may not be consistent when the climate in temperate areas is closer to that in sub-tropical areas. We hypothesized latitudes may mediate the association between influenza activity and meteorological factors in 45 Japanese prefectures.

Methods: We used the weekly incidence of influenza-like illness of 45 prefectures from 2000 to 2018 as a proxy for influenza activity in Japan, a temperate country lying off the east coast of Asia.

Molecular Epidemiological Characterization of a Clinical Isolates in Japan: Identification of Three Clones (ST1223, ST2198, and ST2550) and a Novel Staphylocoagulase Genotype XV.

a novel emerging species within complex (SAC), has been increasingly reported worldwide. In this study, prevalence of among human clinical isolates, and their clonal diversity and genetic characteristics of virulence factors were investigated in Hokkaido, the northern main island of Japan. During a four-month period starting from March 2019, twenty-four and 4330 isolates were recovered from clinical specimens (the ratio of to :0.

Prevalence and Genetic Diversity of Toxin Genes in Clinical Isolates of : Coexistence of Alpha-Toxin Variant and Binary Enterotoxin Genes (/).

() is responsible for food-borne gastroenteritis and other infectious diseases, and toxins produced by this bacterium play a key role in pathogenesis. Although various toxins have been described for isolates from humans and animals, prevalence of individual toxins among clinical isolates has not yet been well explored. In the present study, a total of 798 clinical isolates were investigated for prevalence of eight toxin genes and their genetic diversity by PCR, nucleotide sequencing, and phylogenetic analysis.

Clonal Diversity and Genetic Characteristics of Methicillin-Resistant Isolates from a Tertiary Care Hospital in Japan.

Molecular epidemiological characteristics were investigated for 1,041 isolates of methicillin-resistant (MRSA) collected in a tertiary care hospital in northern Japan for a 4-year period (2011-2014). Genotypes (staphylococcal cassette chromosome [SCC], sequence type, , , etc.) and the presence of drug resistance/virulence factor genes in the isolates were analyzed by multiplex/uniplex PCR, and PCR-direct sequencing as needed.

Time-series analysis of geographically specific monthly number of newly registered cases of active tuberculosis in Japan.

Background: Understanding seasonality of tuberculosis (TB) epidemics may lead to identify potentially modifiable risk factors. Studies conducted outside Japan have found seasonal variation among reported TB cases, with peaks in spring and summer and low prevalence in fall and winter. One hypothesis regarding spring or summer peaks in TB epidemics is that TB transmission likely increases in winter because of indoor crowding and poor ventilation, with development of primary TB among socially vulnerable people in spring and summer.

Molecular characterization of Staphylococcus argenteus in Myanmar: identification of novel genotypes/clusters in staphylocoagulase, protein A, alpha-haemolysin and other virulence factors.

Purpose: Staphylococcus argenteus is a novel emerging species of coagulase-positive staphylococcus that is genetically closely related to Staphylococcus aureus. To elucidate the molecular differences in the virulence factors (staphylocoagulase, protein A, alpha-haemolysin, enterotoxin-like toxin and staphylokinase) between these staphylococcal species, S. argenteus that had recently been isolated in Myanmar (five nasal isolates and four clinical isolates) were analysed.

Molecular Epidemiological Characterization of Methicillin-Susceptible and -Resistant Staphylococcus aureus Isolated from Skin and Soft Tissue Infections in Bangladesh.

Genetic background and molecular characteristics of Staphylococcus aureus collected from patients with skin and soft tissue infections were studied in the North-Central region of Bangladesh from 2015 to 2016. Among 430 clinical isolates, methicillin-resistant S. aureus (MRSA) accounted for 31% having SCCmec type IV (73%) and V (14%), and belonged mostly to coagulase (coa) genotypes IIa, IIIa, IVb, and XIa, while dominant coa type in methicillin-susceptible S.

Prevalence and Molecular Epidemiology of Clinical Isolates of and Harboring Extended-Spectrum Beta-Lactamase and Carbapenemase Genes in Bangladesh.

Spread of Gram-negative bacteria producing extended-spectrum beta-lactamases (ESBLs) and carbapenemases constitutes a growing challenge in control of bacterial infections. In this study, prevalence and genetic characteristics of and harboring ESBL and/or carbapenemase genes, with other beta-lactamase/resistance genes, were investigated for a total of 375 clinical isolates in Mymensingh located in north-central Bangladesh. The major ESBL gene was group, which was detected in 33.

Role of temperature in reported chickenpox cases in northern European countries: Denmark and Finland.

Objective: In this study, we sought to explore the temperature-dependent transition of patterns of reported chickenpox cases in the northern European countries of Denmark and Finland to help determine the potential relationship with epidemiological factors of the disease. We performed time-series analysis consisting of a spectral analysis based on the maximum entropy method in the frequency domain and the nonlinear least squares method in the time domain, using the following time-series data: monthly data of reported chickenpox cases and mean temperatures in the pre-vaccination era for Denmark and Finland. The results were compared with those reported for China and Japan in our previous studies.

Prevalence of Extended-Spectrum Beta-Lactamase and Carbapenemase Genes in Clinical Isolates of Escherichia coli in Myanmar: Dominance of bla and Emergence of bla.

The increasing trend of Escherichia coli producing extended-spectrum beta-lactamases (ESBLs) and carbapenemases is a global public health concern. In this study, prevalence and molecular characteristics of E. coli harboring ESBL and carbapenemase genes were investigated for 426 isolates derived from various clinical specimens in a teaching hospital in Yangon, Myanmar, for the 1-year period beginning January 2016.

Role of meteorological conditions in reported chickenpox cases in Wuhan and Hong Kong, China.

Background: Chickenpox is a common contagious disease that remains an important public health issue worldwide. Over 90% of unvaccinated individuals become infected, but infection occurs at different ages in different parts of the world. Many people have been infected by 20 to 30 years of age in China, and adults and pregnant women who become infected often develop severe infection.

[Collaborative Research with Chinese, Indian, Filipino and North European Research Organizations on Infectious Disease Epidemics].

In this report, we present a short review of applications of time series analysis, which consists of spectral analysis based on the maximum entropy method in the frequency domain and the least squares method in the time domain, to the incidence data of infectious diseases. This report consists of three parts. First, we present our results obtained by collaborative research on infectious disease epidemics with Chinese, Indian, Filipino and North European research organizations.

[Collaborative Research on Puerperal Infections in Bangladesh].

Bangladesh is considered as a high-risk country for emerging infectious diseases because of its high population density, poverty, and unhygienic conditions. Although control efforts have primarily been focused on major infectious diseases such as diarrheal diseases, tuberculosis, malaria, and HIV infection, the prevalence and impact of many local or minor infectious diseases are still unclarified in this country. In this review, we present our recent experience and outcomes of collaborative research on puerperal infection (PI), which is a poorly defined infectious disease in Bangladesh.

Molecular Characterization of Methicillin-Resistant Staphylococcus aureus from Outpatients in Northern Japan: Increasing Tendency of ST5/ST764 MRSA-IIa with Arginine Catabolic Mobile Element.

Arginine catabolic mobile element (ACME) is a genomic island of staphylococcus and is considered to confer enhanced ability to survive and growth on host bacterial cells. ACME has been typically identified in Panton-Valentine Leukocidin (PVL)-positive ST8 methicillin-resistant Staphylococcus aureus (MRSA) with SCCmec type IVa (USA300 clone), and it is also found in other lineages at low frequency. Prevalence and molecular characteristics of PVLand/or ACME MRSA were investigated for 624 clinical isolates collected from outpatients in northern Japan from 2013 to 2014.

Distribution of two distinct rotavirus B (RVB) strains in the north-central Bangladesh and evidence for reassortment event among human RVB revealed by whole genomic analysis.

Human rotavirus B (RVB), a rare cause of diarrhea in several Asian countries, has been reported to be genetically highly conserved. However, 14 RVB strains with two distinct RNA electropherotypes E1 and E2 (11 and 3 strains, respectively) were detected in adult patients with diarrhea, in Mymensingh in the north-central Bangladesh in 2014. In this study, VP7 gene sequences of all the 14 strains and nearly full-length sequences of all the 11 RNA segments of four RVB (two strains each representing E1 and E2 types) were determined and analyzed phylogenetically.

Whole genomic analysis of G2P[4] human Rotaviruses in Mymensingh, north-central Bangladesh.

Rotavirus A (RVA) is a dominant causative agent of acute gastroenteritis in children worldwide. G2P[4] is one of the most common genotypes among human rotavirus (HRV) strains, and has been persistently prevalent in South Asia including Bangladesh. In the present study, whole genome sequences of a total of 16 G2P[4] HRV strains (8 strains each in 2010 and 2013) detected in Mymensingh, north-central Bangladesh were determined.

Time series analysis of reported cases of hand, foot, and mouth disease from 2010 to 2013 in Wuhan, China.

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.

Function of homo- and hetero-oligomers of human nucleoplasmin/nucleophosmin family proteins NPM1, NPM2 and NPM3 during sperm chromatin remodeling.

Sperm chromatin remodeling after oocyte entry is the essential step that initiates embryogenesis. This reaction involves the removal of sperm-specific basic proteins and chromatin assembly with histones. In mammals, three nucleoplasmin/nucleophosmin (NPM) family proteins-NPM1, NPM2 and NPM3-expressed in oocytes are presumed to cooperatively regulate sperm chromatin remodeling.

MEM spectral analysis for predicting influenza epidemics in Japan.

Objectives: The prediction of influenza epidemics has long been the focus of attention in epidemiology and mathematical biology. In this study, we tested whether time series analysis was useful for predicting the incidence of influenza in Japan.

Methods: The method of time series analysis we used consists of spectral analysis based on the maximum entropy method (MEM) in the frequency domain and the nonlinear least squares method in the time domain.

Time series analysis of incidence data of influenza 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.

Predicting the incidence of human campylobacteriosis in Finland with time series analysis.

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.