Resurgence of human metapneumovirus infection and influenza after three seasons of inactivity in the post-COVID-19 era in Hokkaido, Japan, 2022-2023.

Following the coronavirus disease 2019 (COVID-19) outbreak in February 2020, incidences of various infectious diseases decreased notably in Hokkaido Prefecture, Japan. However, Japan began gradually easing COVID-19 infection control measures in 2022. Here, we conducted a survey of children hospitalized with human metapneumovirus (hMPV), influenza A and B, and respiratory syncytial virus infections in 18 hospitals across Hokkaido Prefecture, Japan, spanning from July 2019 to June 2023. From March 2020 to June 2022 (28 months), only 13 patients were hospitalized with hMPV, and two patients had influenza A. However, in October to November 2022, there was a re-emergence of hMPV infections, with a maximum of 27 hospitalizations per week. From July 2022 to June 2023 (12 months), the number of hMPV-related hospitalizations dramatically increased to 317 patients, with the majority aged 3-6 years (38.2%, [121/317]). Influenza A also showed an increase from December 2022, with a peak of 13 hospitalizations per week in March 2023, considerably fewer than the pre-COVID-19 outbreak in December 2019, when rates reached 45 hospitalizations per week. These findings suggest the possibility of observing more resurgences in infectious diseases in Japan after 2023 if infection control measures continue to be relaxed. Caution is needed in managing potential outbreaks.

Molecular and clinical characterization of the equine-like G3 rotavirus that caused the first outbreak in Japan, 2016.

Since 2013, equine-like G3 rotavirus (eG3) strains have been detected throughout the world, including in Japan, and the strains were found to be dominant in some countries. In 2016, the first eG3 outbreak in Japan occurred in Tomakomai, Hokkaido prefecture, and the strains became dominant in other Hokkaido areas the following year. There were no significant differences in the clinical characteristics of eG3 and non-eG3 rotavirus infections. The eG3 strains detected in Hokkaido across 2 years from 2016 to 2017 had DS-1-like constellations (i.e. G3-P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2), and the genes were highly conserved (97.5-100 %). One strain, designated as To16-12 was selected as the representative strain for these strains, and all 11 genes of this strain (To16-12) exhibited the closest identity to one foreign eG3 strain (STM050) seen in Indonesia in 2015 and two eG3 strains (IS1090 and MI1125) in another Japanese prefecture in 2016, suggesting that this strain might be introduced into Japan from Indonesia. Sequence analyses of VP7 genes from animal and human G3 strains found worldwide did not identify any with close identity (>92 %) to eG3 strains, including equine RV Erv105. Analysis of another ten genes indicated that the eG3 strain had low similarity to G2P[4] strains, which are considered traditional DS-1-like strains, but high similarity to DS-1-like G1P[8] strains, which first appeared in Asia in 2012. These data suggest that eG3 strains were recently generated in Asia as mono-reassortant strain between DS-1-like G1P[8] strains and unspecified animal G3 strains. Our results indicate that rotavirus surveillance in the postvaccine era requires whole-genome analyses.

Surveillance in hospitalized children with infectious diseases in Japan: Pre- and post-coronavirus disease 2019.

INTRODUCTION: The epidemic of coronavirus disease 2019 (COVID-19) rapidly spread worldwide, and the various infection control measures have a significant influence on the spread of many infectious diseases. However, there have been no multicenter studies on how the number of hospitalized children with various infectious diseases changed before and after the outbreak of COVID-19 in Japan. METHODS: We conducted a multicenter, prospective survey for hospitalized pediatric patients in 18 hospitals in Hokkaido Prefecture, Japan, from July 2019 to February 2021. We defined July 2019 to February 2020 as pre-COVID-19, and July 2020 to February 2021 as post-COVID-19. We surveyed various infectious diseases by sex and age. RESULTS: In total, 5300 patients were hospitalized during the study period. The number of patients decreased from 4266 in the pre-COVID-19 period to 701 (16.4%) post-COVID-19. Patients with influenza and RSV decreased from 308 to 795 pre-COVID-19 to zero and three (0.4%) post-COVID-19. However, patients with adenovirus (respiratory infection) only decreased to 60.9% (46-28) of pre-COVID levels. Patients with rotavirus, norovirus, and adenovirus gastroenteritis decreased markedly post-COVID-19 to 2.6% (38-1), 27.8% (97-27) and 13.5% (37-5). The number of patients with UTIs was similar across the two periods (109 and 90). KD patients decreased to 31.7% (161-51) post-COVID-19. CONCLUSIONS: We suggest that current infection control measures for COVID-19 such as wearing masks, washing hands, and disinfecting hands with alcohol are effective against various infectious diseases. However, these effects vary by disease.

A case report of cutaneous polyarteritis nodosa in siblings.

Cutaneous polyarteritis nodosa (CPAN) is characterized by a necrotizing vasculitis of small and medium-sized arteries in the skin, which can be associated with fever, arthralgia, myalgia, and neuropathy, but, unlike polyarteritis nodosa (PAN), there is no visceral involvement. CPAN is rare in childhood. We report two siblings who developed CPAN during childhood. Interestingly, both had Mediterranean fever gene (MEFV) mutation, i.e. heterozygous E148Q. They also shared HLA-A24, -DR15 alleles. Simultaneous occurrence of MEFV mutation and HLA alleles with CPAN has never been reported in Japan. These cases could provide some hereditary clue for the development of CPAN.

Characteristics and outcome of intractable vasculitis syndrome in children: Nation-wide survey in Japan.

OBJECTIVE: Primary systemic vasculitis (PSV) is a rare disorder in children and difficult to distinguish from other diseases. However, appropriate diagnosis and prompt treatment will affect on the morbidity and mortality of intractable PSV. In this study, we conducted a nationwide survey in Japan, to clarify epidemiology and clinical outcome of PSV. METHODS: We had sent survey questionnaires to most of the Japanese institutions that employed pediatricians, requesting the number of patients with refractory PSV who were diagnosed and treated between 2007 and 2011. Respondents were asked to provide detailed information on the clinical and laboratory features of each case they had managed. Those with Kawasaki disease or Henoch-Shönlein purpura vasculitis (IgA vasculitis) were excluded. RESULTS: Of all the institutions surveyed, 1123 (37.3%) patients responded, finally, total of 49 patients with intractable PSV, defined by those with resistant to treatment and steroid-dependent, or with any complication associated with prognosis, were selected. The diagnosis was Takayasu arteritis in 31, polyarteritis nodosa in 11, granulomatosis with polyangitis in 2, microscopic polyangitis in 1, and ANCA negative microscopic polyangitis in 1. In those with Takayasu arteritis, 67% were treated with an immunosuppressive agent, 22% with biological modifiers, and 16% with surgical procedures. In other types of disease, 88% of the patients were treated with an immunosuppressive agent, and 12% with biological modifiers. Two with Takayasu arteritis died being terminally ill. CONCLUSION: This nationwide survey establishes the heterogeneous characteristics of PSV in children. Although questionnaire-based, the results of our analysis should be useful in planning prospective studies to identify the most effective therapy for each subtype of multifaceted disease.

Clinical and laboratory features of fatal rapidly progressive interstitial lung disease associated with juvenile dermatomyositis.

OBJECTIVE: Rapidly progressive interstitial lung disease (RP-ILD) is a rare but potentially fatal complication of JDM. The aim of this study was to establish markers for the prediction and early diagnosis of RP-ILD associated with JDM. METHODS: The clinical records of 54 patients with JDM were retrospectively reviewed: 10 had RP-ILD (7 died, 3 survived), 19 had chronic ILD and 24 were without ILD. Routine tests included a high-resolution CT (HRCT) scan of the chest and measurement of serum levels of creatine phosphokinase, ferritin and Krebs von den Lungen-6 (KL-6). Anti-melanoma differentiation-associated gene 5 (MDA5) antibodies and IL-18 levels were measured by ELISA. RESULTS: No differences were found in the ratio of juvenile clinically amyopathic DM between the three groups. Initial chest HRCT scan findings were variable and could not distinguish between RP-ILD and chronic ILD. Anti-MDA5 antibodies were positive in all 8 patients with RP-ILD and 10 of 14 with chronic ILD, but none of the patients without ILD. Serum levels of anti-MDA5 antibody, ferritin, KL-6 and IL-18 were significantly higher in the RP-ILD group than in the chronic ILD and non-ILD groups. Serum levels of IL-18 positively correlated with serum KL-6 (R = 0.66, P < 0.001). CONCLUSION: High serum levels of IL-18, KL-6, ferritin and anti-MDA5 antibodies (e.g. >200 units by ELISA) are associated with RP-ILD. These can be used as an indication for early intensive treatment. Both alveolar macrophages and autoimmunity to MDA5 are possibly involved in the development of RP-ILD associated with JDM.

Changing Patterns of Infectious Diseases Among Hospitalized Children in Hokkaido, Japan, in the Post-COVID-19 Era, July 2019 to June 2022.

BACKGROUND: Many reports have reported a reduction in respiratory infectious diseases and infectious gastroenteritis immediately after the coronavirus disease 2019 (COVID-19) pandemic, but data continuing into 2022 are very limited. We sought to understand the current situation of various infectious diseases among children in Japan as of July 2022 to improve public health in the post-COVID-19 era. METHODS: We collected data on children hospitalized with infectious diseases in 18 hospitals in Japan from July 2019 to June 2022. RESULTS: In total, 3417 patients were hospitalized during the study period. Respiratory syncytial virus decreased drastically after COVID-19 spread in early 2020, and few patients were hospitalized for it from April 2020 to March 2021. However, an unexpected out-of-season re-emergence of respiratory syncytial virus was observed in August 2021 (50 patients per week), particularly prominent among older children 3-6 years old. A large epidemic of delayed norovirus gastroenteritis was observed in April 2021, suggesting that the nonpharmaceutical interventions for COVID-19 are less effective against norovirus. However, influenza, human metapneumovirus, Mycoplasma pneumoniae , and rotavirus gastroenteritis were rarely seen for more than 2 years. CONCLUSIONS: The incidence patterns of various infectious diseases in Japan have changed markedly since the beginning of the COVID-19 pandemic to the present. The epidemic pattern in the post-COVID-19 era is unpredictable and will require continued careful surveillance.

Regional Variation of CH4 and N2 Production Processes in the Deep Aquifers of an Accretionary Prism.

Accretionary prisms are mainly composed of ancient marine sediment scraped from the subducting oceanic plate at a convergent plate boundary. Large amounts of anaerobic groundwater and natural gas, mainly methane (CH4) and nitrogen gas (N2), are present in the deep aquifers associated with an accretionary prism; however, the origins of these gases are poorly understood. We herein revealed regional variations in CH4 and N2 production processes in deep aquifers in the accretionary prism in Southwest Japan, known as the Shimanto Belt. Stable carbon isotopic and microbiological analyses suggested that CH4 is produced through the non-biological thermal decomposition of organic matter in the deep aquifers in the coastal area near the convergent plate boundary, whereas a syntrophic consortium of hydrogen (H2)-producing fermentative bacteria and H2-utilizing methanogens contributes to the significant production of CH4 observed in deep aquifers in midland and mountainous areas associated with the accretionary prism. Our results also demonstrated that N2 production through the anaerobic oxidation of organic matter by denitrifying bacteria is particularly prevalent in deep aquifers in mountainous areas in which groundwater is affected by rainfall.

Reactivation of varicella-zoster virus in facial palsy associated with infectious mononucleosis.

Facial palsy with infectious mononucleosis, although well-recognized, is rare in children, and its pathogenesis is uncertain. To our knowledge there has been no previous report describing varicella-zoster virus reactivation as a cause of facial palsy associated with infectious mononucleosis. We report such a patient in whom serology showed reactivation of varicella-zoster virus.

[A case of acute lymphotic leukemia which was difficult to make a diagnosis of CRMO for moving arthralgia and periarticular swelling].

A girl, 7 years of age, was reported who had been suffered from migratory arthralgia, bone pain and erythematous rash. She had increased inflammatory markers such as C-reactive protein, erythrocyte sedimentation rate, and mild anemia for more than 6 months. In the beginning, she was suspected of having either juvenile idiopathic arthritis or chronic recurrent multifocal osteomyelitis. However, after about 6 months, there were abrupt increases of LDH in serum titers and blast cells were also revealed by bone marrow examination. Upon these findings, she was diagnosed with acute lymphocytic leukemia. Since bone pain and arthralgia bone pain and arthralgia are both indicative of numerous inflammatory disorders such as infectious myelitis, juvenile chronic arthritis, childhood leukemia and malignancies, and auto-inflammatory bone diseases, especially chronic recurrent multifocal osteomyelitis, it is difficult to accurately diagnose right away. For now, these aforementioned inflammatory responses are the sole key findings for clinical investigations. Other than that, there are not enough reports yet to help diagnose incases similar to this. Therefore, it is difficult to differentiate between the disorders above even after blood tests, Ga-scincigraphy, and imaging examinations. Moreover, in the case of childhood leukemia, it was difficult to differentiate these diseases by routine X-ray surveys in the general pediatric fields. The reasons are because there are only a few descriptions on X-ray bone examinations on findings of X-ray bone investigations, and both are usually non-specific. However, according to the pediatric radiology specialists, of which there are only a few in Japan, the imaging results show somewhat abnormal findings could be spotted from the early stage. Through this present case, it is suggested to us that it is important to consult the pediatric radiology specialists in order to speed up the diagnostic process. Furthermore, the accumulation of radiological findings of leukemia in children with bone pain and arthralgia will attribute to an early diagnosis and lead to the resolution of pathogenesis of leukemia.

A phylogenetic study of human respiratory syncytial viruses group A and B strains isolated in two cities in Japan from 1980-2002.

The circulation pattern and genetic evolution of respiratory syncytial virus (RSV) in Japan were examined based on 109 RSV field strains isolated over 20 seasons (1980-2002) in two cities, Sapporo and Tokyo. The second hypervariable region of the large glycoprotein (G) gene was amplified by RT-PCR and the products sequenced directly. The nucleotide sequences were compared to those representatives of RSV genotypes identified previously. Japanese group A and B isolates clustered into five and four genotypes defined previously, respectively. Another one group A and one group B genotypes, which could not be assigned to previous genotypes, were also identified. Although different genotypes usually co-circulated in each season, the isolates in proximate seasons from two communities were usually located in the same branches. Moreover, the strains with genotypes defined previously were usually isolated at the same time as each reference strain of Western countries. Several mutant group B strains with 1-20 longer amino acid G proteins were newly identified in Sapporo. These findings suggest that Japanese RSV strains underwent geographical and also temporal clustering while participating in RSV genetic evolution in a global setting. In addition, Japanese strains, especially group B, might have evolved individually in each community, sometimes changing the length of the G protein.

Lactoferrin and surfactant protein A exhibit distinct binding specificity to F protein and differently modulate respiratory syncytial virus infection.

Surfactant protein A (SP-A) and lactoferrin (LF) play important roles in innate immune systems in the respiratory mucous membranes. We investigated how SP-A and LF act against respiratory syncytial virus (RSV) infection. The present study indicated that RSV-induced IL-8 secretion from HEp-2 cells was up-regulated by SP-A (170% of control) but down-regulated by LF (23% of control). RSV infectivity determined by viral titers and the uptake of FITC-labeled RSV were also increased by SP-A, but decreased by LF. To clarify the mechanism of these opposite effects, we examined the interactions of SP-A and LF with RSV F protein, the most important surface glycoprotein for viral penetration. RSV F protein was found to be the ligand for both SP-A and LF, but the manners of binding were different. LF directly interacted with the F(1) subunit, which involved antigenic sites of F protein. Contrarily, SP-A associated with the F(2) subunit, which was highly glycosylated. SP-A but not LF failed to interact with deglycosylated F protein. Moreover, SP-A initiated the hemolyzing fusion activity of F protein. These results suggest that SP-A and LF modulate RSV infection by different binding specificity to F protein.

Genetic variability and molecular epidemiology of respiratory syncytial virus subgroup a strains in Japan determined by heteroduplex mobility assay.

We used heteroduplex mobility assay (HMA) to determine the genetic variability of 118 respiratory syncytial virus (RSV) field isolates from 19 epidemics occurring in a Japanese urban area between 1980 and 2000. Nucleotides 1 to 584 of the attachment G glycoprotein gene were amplified by reverse transcription-PCR, and the PCR amplicons were analyzed by HMA by using the earliest isolate from 1980 as the reference throughout. We also performed PCR-restriction fragment length polymorphism (RFLP) analysis and phylogenetic analysis on the same nucleotide sequence. PCR-RFLP revealed 9 patterns, whereas HMA produced 31 distinct patterns. The RFLP patterns were divided into two to seven distinct HMA genotypes. Field strains with similar degrees of G gene nucleotide differences from the reference strain often showed distinct HMA types. The RSV genetic heterogeneity detected by direct sequencing of the PCR amplicon was usually identical to HMA analysis. Analysis of the molecular epidemiology of RSV subgroup A isolates obtained by HMA showed that new RSV variants emerged with each epidemic and that previously dominant variants seldom recurred in subsequent epidemics. HMA is useful in detecting genetic variants of RSV subgroup A and has some advantages over other conventional methods.

Comparison of an immunochromatography test with multiplex reverse transcription-PCR for rapid diagnosis of respiratory syncytial virus infections.

A new commercial rapid 10-min one-step immunochromatography (IC) test, SAS RSV test, was compared to another IC test, Directigen EZ RSV, employing RT-PCR as the "gold standard" for detecting respiratory syncytial virus. Of 102 clinical samples, 79 were positive by RT-PCR, 66 (82.5%) were positive with the SAS RSV test, and 55 (69.6%) were positive with Directigen EZ RSV. The specificity of the new test was 91.3% (21 of 23), similar to that of Directigen EZ RSV (100% [23 of 23]). This test performs well enough to be used for patient care.

Nosocomial outbreak of respiratory syncytial virus subgroup B variants with the 60 nucleotides-duplicated G protein gene.

In January 2001, 20 children among 40 residents under 2 years old at a nursery home in Sapporo, Japan had respiratory symptoms and were confirmed as having respiratory syncytial virus (RSV) infection by a conventional diagnostic kit. Nasopharyngeal aspirates were collected from four RSV-positive patients and total RNA was extracted directly from the specimens for the analysis of RSV grouping and genotyping. All four RSV strains had the same G protein gene sequence of subgroup B and were assigned to identical strains. Interestingly, the G protein gene had a duplication of 60 nucleotides at the C-terminal third of the G protein gene in which three nucleotides differed each other. The predicted polypeptide is lengthened by 20 amino acids. The clinical picture of these cases was not different from those of patients with other RSV strains. These novel mutations were thought to be introduced in vivo.

Progressive liver fibrosis in late-onset argininosuccinate lyase deficiency.

A 4-month-old boy, with late-onset argininosuccinate lyase (ASL) deficiency with hepatomegaly, was treated by protein restricted diet and arginine supplementation; he was followed for 3 years. Hepatomegaly and mild liver dysfunction persisted without significant hyperammonemia. He maintained normal psychomotor development to the age of 12 months, but, at 3 years of age, his developmental status is in the borderline normal range. Liver biopsy performed at 12 months of age demonstrated swollen and pale hepatocytes with abnormal glycogen deposition and mild periportal fibrosis. A subsequent liver biopsy at 3 years of age showed progressive liver fibrosis in the periportal and central areas, which extended into the liver lobule. These findings suggest that liver impairment in ASL deficiency may advance without significant hyperammonemia and underline the importance of repeated liver biopsy in this disorder, even when the plasma ammonia level is well controlled.

Hemilabile amidomonophosphine ligand-rhodium(I) complex-catalyzed asymmetric 1,4-addition of arylboronic acids to cycloalkenones.

The asymmetric 1,4-addition reaction of arylboronic acids with cycloalkenones was catalyzed by 1 mol % of an amidomonophosphine-rhodium(I) catalyst in a 10:1 mixture of 1,4-dioxane and water at 100 degrees C, affording 3-arylcycloalkanones in reasonably high enantioselectivity and high yields. It was revealed by NMR, IR, and X-ray spectroscopies that this bidentate amidomonophosphine behaves as a hemilabile ligand that contains a hard donor site in addition to the soft donor in a molecule. Phosphorus atom strongly bonds to rhodium(I), and the amide carbonyl oxygen is coordinatively labile. The reaction efficacy of phenylboronic acid with cyclopent-2-en-1-one was significantly dependent on the possibility of coordination of the amide carbonyl oxygen to rhodium(I).

Asymmetric alkylation of N-toluenesulfonylimines with dialkylzinc reagents catalyzed by copper-chiral amidophosphine.

The synthetic procedure of a chiral amidophosphine ligand 5 bearing two bulky substituents, 2,4,6-trimethylphenylmethyl or 2,4,6-triisopropylphenylmethyl groups, on the pyrrolidine ring was improved by employing the borane-THF reduction of the lactam-alcohol intermediate 8. The resulting amino alcohol was selectively acylated to give an amide-alcohol 11, which was then converted to the chloride 12 in 55-73% yields by the treatment with methanesulfonyl chloride in collidine. The reaction of the chloride 12 with NaPPh(2) in dioxane-THF gave an amidophosphine 5 in an acceptably high 82-83% yields. Addition of a hexane solution of dialkylzinc reagent to a mixture of catalytic amount of an amidophosphine 5, copper species, and N-toluenesulfonylimine 1a of benzaldehyde in toluene provided a solution which gave the alkylated amide 3 in high yield and enantioselectivity up to 96%. A survey of copper sources and solvents concluded that copper(II) ditriflate and copper(I) triflate-benzene complex as good copper sources and toluene as a choice of solvent. N-Toluenesulfonylimines 1a-e of arylaldehydes, furfural, and alkanals were successfully ethylated with diethylzinc to give the corresponding N-toluenesulfonylamides 3aE-eE in satisfactorily good 69-97% yields and high 86-96% enantioselectivities.