Persistent inflammation during chronic human immunodeficiency virus (HIV) infection may affect the immune response against severe acute respiratory syndrome-coronavirus 2 (SARS- CoV-2) infection. Plasma levels of multiple proinflammatory cytokines during acute SARS-CoV-2 infection were measured in people with HIV (PWH) with effective combination antiretroviral therapy. There were no significant differences in any of the measured cytokines between severity levels of coronavirus disease 2019 (COVID-19) in PWH, while most were significantly higher in HIV-uninfected individuals with severe COVID-19, suggesting that excess cytokines release by hyperinflammatory responses do not occur in individuals with severe COVID-19 with HIV infection. The strong associations between the cytokines observed in HIV-uninfected individuals, particularly between IFN-α/TNF-α and other cytokines, were lost in PWH. The steady-state plasma levels of IP-10, ICAM-1, and CD62E were significantly higher in PWH, indicating that they were in an enhanced inflammatory state. The absence of several inter-cytokine correlations was observed in in vitro lipopolysaccharide stimulus-driven cytokine production in PWH. These data suggest that inflammatory responses during SARS-CoV-2 infection in PWH are distinct from those in HIV-uninfected individuals, partially because of the underlying inflammatory state and/or impairment of innate immune cells.

Hand, foot, and mouth disease (HFMD) has become one of the most common infectious diseases in the past few decades. Since 2013, coxsackievirus A6 (CVA6) has replaced enterovirus A71 (EV-A71) and coxsackievirus A16 (CVA16), becoming the predominant pathogen responsible for HFMD in many areas of China. This study aimed to investigate the genetic characteristics and molecular epidemiology of CVA6 in Linyi between the years 2022 and 2023. In total, 965 patients with HFMD were enrolled in this study, and analyses based on VP1 nucleotide sequences were performed to determine the evolutionary trajectory of CVA6. In 2022, 281/386 (72.8%) patients were positive for enteroviruses (EVs) and 217/281 (77.2%) were CVA6 positive. In 2023, 398/579 (68.7%) samples were positive for EVs and 243/398 (61.1%) were CVA6 positive. Six sequences were selected each year for homology analysis. The results showed that the 12 strains isolated from Linyi were distant from the prototype strain (AY421764) and the first CVA6 strain reported in China (JQ364886). Phylogenetic analysis showed that the CVA6 strains isolated from Linyi belonged to the D3 sub-genotype. CVA6 is emerging as a common pathogen causing HFMD in Linyi and continuous surveillance of HFMD etiologies agents is necessary.

An active epidemiological investigation of COVID-19 cases in the Setagaya Ward of Tokyo revealed that household transmission was the main route of spread. This study aimed to identify factors associated with household transmission in patients diagnosed with COVID-19 and cohabitants, during the wild-type (WT) (December 2020) and Alpha-variant (AV) (May 2021) epidemics. Factors in index cases significantly associated with household transmission of both WT and AV virus, included more than 3 days from onset to diagnosis (WT: risk ratio [RR] 1.44, 95% confidence interval [CI] 1.16–1.79; AV: RR 1.66, 95% CI 1.32–2.08), and a household size of three or more (WT: RR 1.37, 95% CI 1.10–1.72; AV: RR 1.29, 95% CI 1.05–1.59). Household transmission of WT was also significantly associated with the index case being aged ≥65 years (RR 2.39, 95% CI 1.26–4.54) and symptomatic at diagnosis (RR 3.05, 95% CI 1.22–7.63). Among cohabitants, factors associated with household transmission included being the spouse/partner of the index case (WT: RR 1.68, 95% CI 1.34–2.10; AV: RR 1.97, 95% CI 1.59–2.43) and at least 3 days from onset to diagnosis of the index case (WT: RR 1.48, 95% CI 1.21–1.82; AV: RR 1.86, 95% CI 1.52–2.28). Early diagnosis and isolation are effective for preventing household transmission.

This study aimed to investigate the combination of the four regions of Helicobacter pylori vacA with cagA, cagE, dupA genes and cagA-EPIYA motifs to identify the most likely combination that could be used as a disease determinant marker in the Moroccan population. A total of 838 H. pylori-positive samples were obtained from consenting patients, that were previously analyzed by PCR to characterize vacA-s, -m, and -i regions; cagE status; and cagA 3' region polymorphism, were used to characterize vacA-d region and to determine dupA gene status. The analysis showed the predominance of the less virulent combination {vacA(s2m2i2d2)dupA(-)cagE(-)cagA(-)}, and showed that the risk of gastric cancer is 13.33 fold higher (95% confidence interval [CI] = 1.06–166.37) in patients infected with strains harboring vacA(s1m1i1d1)dupA(-)cagE(+)cagA(2EPIYA-C) compared to patients with gastritis without lesions and infected by H. pylori strains harboring vacA(s2m2i2d2)dupA(-) cagE(-)cagA(-). Infection with strains harboring the vacA(s1m1i1d1)dupA(+)cagE(+)cagA(1EPIYA-C) genotype combination represented a risk factor for both gastric ulcer and duodenal ulcer than gastritis without lesions; odds ratio (OR) =16 (95% CI = 1.09–234.24) and OR = 12.39 (95% CI = 1.09–140.81), respectively. These results suggest that the combination of the active form of vacA genotypes, dupA gene status, and the number of EPIYA-C motifs may be helpful markers for discriminating between several gastric diseases.

The widespread prevalence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli limits treatment options and is a worldwide problem. This study aimed to investigate the antimicrobial susceptibility and ESBL types of 204 strains of CTX-M-type ESBLsproducing E. coli isolated from 2011 to 2017 in the Chubu region of Japan and to identify factors correlated with susceptibility. Minimal inhibitory concentrations were determined in accordance with the guidelines of the Clinical and Laboratory Standards Institute. Genes encoding β-lactamases were detected by PCR amplification. The CTX-M subtypes were determined using sequence analyses. CTX- M-15-producing strains showed significantly lower susceptibility rates to tazobactam/piperacillin (TAZ/ PIPC) than CTX-M-14 and -27-producing strains. Additional analyses of secondary β-lactamases revealed that most of the OXA-1-positive strains were CTX-M-15-producing strains (94.7%). The OXA-1-positive strains displayed significantly lower susceptibility to TAZ/PIPC (47.4%), sulbactam/ ampicillin (0.0%), and amikacin (73.7%) than the OXA-1-negative strains, suggesting that the high non-susceptibility rate of the CTX-M-15-producing strain was due to the co-carriage of OXA-1. Statistical analyses showed that OXA-1-positive strains were present in significant amounts in patients aged ≥65 years, suggesting that older patients have a higher risk of being refractory to treatment.

The persistence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among wildlife populations poses a potential risk for the emergence of novel variants. Therefore, monitoring SARS-CoV-2 infections in animals is crucial. As urban rodents live in close proximity to human habitats, there is a concern that they may be a potential source of zoonoses. To examine the prevalence of SARS-CoV-2 in rodent populations, we analyzed 128 serum samples and 129 oral swabs collected from 128 brown rats (Rattus norvegicus) and two black rats (Rattus rattus) captured for pest control purposes in Tokyo, Japan, between May and December 2023. A virus-neutralizing test using the omicron variant revealed no evidence of SARS-CoV-2 infection. Real-time reverse transcription- PCR of oral swabs did not detect any SARS-CoV-2 RNA-positive rats. These results indicate a low probability of SARS-CoV-2 circulation among rat populations in Tokyo.

The spread of antimicrobial resistant organisms (AROs) poses a major threat to animal and human health. In Japan, the estimated disability-adjusted life years (DALYs) due to ARO infections is 137.9 per 100,000 persons, with methicillin-resistant Staphylococcus aureus (MRSA) being the main contributor. Factors that can contribute to DALYs in Japan include younger age and a higher number of deaths in patients with MRSA bacteremia. Moreover, longer hospital stays may contribute to the higher rates of MRSA bacteremia in Japan than in western countries. We reviewed the diagnostic procedure combination data collected from January 1, 2016 to December 31, 2020, in an acute care hospital in Tokyo, Japan. We found that the median time from admission to MRSA bacteremia onset was 26 days, which is longer than that observed in western countries however similar to that in South Korea. Furthermore, our cohort was older than those in the United States and South Korea, potentially contributing to the higher number of years of life lost in Japan. These results underscore the need to develop strategies to reduce hospitalization rates in Japan. Larger multicenter studies are needed to comprehensively evaluate the economic and health burdens of MRSA bacteremia in Japan.

A previously healthy 22-year-old woman was admitted to our hospital after an out-of-hospital cardiac arrest. Spontaneous circulation was restored prior to arrival at the hospital. However, the patient’s vital signs remained unstable. Vasopressors and hyperhydration therapy were administered. Computed tomography did not reveal a cause of the cardiac arrest. Antibiotics were initiated after obtaining blood culture samples. The patient was admitted to the intensive care unit (ICU). High-dose vasopressors and hyperhydration therapy were continued and fresh frozen plasma was transfused. Two hours after ICU admission, gram staining of a blood smear revealed the presence of Streptococcus, and the antibiotics were switched to penicillin G potassium and clindamycin, and immunoglobulins were administered. Extracorporeal membrane oxygenation was initiated 10 h after ICU admission owing to respiratory failure caused by fluid overload; however, the patient’s condition did not improve and she died 40 h after admission. Blood culture results confirmed the presence of Streptococcus pyogenes; the T and M serotypes were unclassifiable. The emm genotype was emm22. Sequencing revealed the presence of streptococcal pyrogenic toxin genes, speA and speB, whereas speC was absent. CsrS, CsrR, and Rgg amino acid sequencing revealed the presence of a CsrS mutation.

Campylobacter jejuni is one of the major bacterial strains that cause diarrhea in humans. It has been associated with many cases of food poisoning in Japan caused by eating raw, undercooked, and/or improperly prepared chicken meat, liver, and grilled chicken (Yakitori). Campylobacter jejuni is also known to be a preceding infectious pathogen of Guillain–Barré syndrome (GBS), which has a considerably negative health impact on humans. In a case of C. jejuni food poisoning that occurred at a restaurant in Tokyo (Japan) in January 2022, 1 of 4 patients with diarrhea developed GBS, which was presumed to have been caused by undercooked chicken, which has emerged as one of the most common causes of food poisoning in Japan. Moreover, C. jejuni isolates from 3 patients, including those with GBS, had the same genotypes (ST22, HS19, and LOS A). This genotype was frequently detected in patients with GBS in the authors’ previous study. Findings confirmed that the patient developed GBS due to food poisoning after consuming undercooked chicken.