Anti-Ascaris IgE as a Risk Factor for Asthma Symptoms among 5-Year-Old Children in Rural Bangladesh with Even Decreased Ascaris Infection Prevalence.

BACKGROUND: Epidemiological studies have indicated that anti-Ascaris IgE enhances asthma and allergies under specific conditions although the association between them is still controversial. The association of anti-Ascaris IgE with increased asthma symptoms among children from a general population with a mild to moderate Ascaris infection prevalence was investigated. METHODS: A total of 126 children aged 5 years with wheezing during the previous year and 110 children who did not have wheezing were selected randomly from the rural service area of the International Centre for Diarrhoeal Disease Research, Bangladesh. Serum levels of total, anti-Ascaris, anti-Dermatophagoides pteronyssinus, and anti-cockroach IgEs were tested, and their risks for wheezing were analyzed. The wheezing children were then classified by hierarchical cluster analysis to investigate the contribution of anti-Ascaris IgE to wheezing. RESULTS: The anti-Ascaris IgE levels in wheezing and never-wheezing children were 1.07 and 0.65 UA/mL, and it contributed to 11% of wheezing in children. Anti-Ascaris IgE was significantly associated with wheezing (odds ratio [OR] per loge increment: 1.37 [95% CI: 1.01-1.87], p = 0.046). The ORs, which were adjusted for sex, parental asthma, pneumonia history, helminth infections, Haemophilus influenzae type B combination vaccination, antibiotic use during infancy, and total and specific IgE levels, increased even when only children with more specific symptoms of asthma were included in the analysis. Namely, the ORs for wheezing with sleep disturbance, four or more attacks, and wheezing with speech difficulties during the previous 1 year were OR = 1.44/loge increment [95% CI: 1.01-2.07], OR = 1.90/loge increment [95% CI: 1.11-3.25], and OR = 1.78/loge increment [95% CI: 1.01-3.14], respectively. CONCLUSIONS: The anti-Ascaris IgE levels in wheezing and never-wheezing children in the current study significantly decreased concurrently with Ascaris infection prevalence compared with their corresponding values in 2001. The contribution of anti-Ascaris IgE to wheezing also dropped from 26% in 2001 to 11% in the current study. Despite significant decreases in the levels and the seroprevalence and its contribution to wheezing, anti-Ascaris IgE remained significantly associated with increased risk of wheezing. Anti-Ascaris IgE significantly increased the risk of wheezing in a general population with a mild to moderate Ascaris infection prevalence, suggesting robustness as a risk factor and a possible dose-response relationship.

Diversity of human sapovirus genotypes detected in Japanese pediatric patients with acute gastroenteritis, 2014-2017.

Sapovirus (SaV) is one of the pathogens related to acute gastroenteritis (AGE) in adults and children worldwide. This study reported the diversity of SaV genotypes in children with AGE in Japan from July 2014 to June 2017. Of a total of 2259 stool samples tested by using reverse transcription-PCR method and further analyzed by nucleotide sequencing, 114 (5.0%) were positive for SaV and GI.1 (83.3%) was the most predominant genotype, followed by GII.1, GIV.1, GI.2, GI.3, and GII.3 genotypes. Monthly distribution analysis demonstrated two epidemic peaks from July to December 2015 and February to May 2017. However, no detection peak was observed in 2014 and 2016. Phylogenetic analysis of the complete VP1 nucleotide sequences of these GI.1 strains revealed two major clusters of GI.1 and each of which contained GI.1 strains of both 2015 and 2017. This study suggests that the continuous surveillance of SaV is needed to monitor high genetic diversity in Japanese children with AGE.

Impact of Haemophilus influenzae type b combination vaccination on asthma symptoms and pneumonia in 5-year-old children in rural Bangladesh: a longitudinal study and comparison with a previous cross-sectional study.

BACKGROUND: Although the prevalence of bronchial asthma has been increasing worldwide since the 1970's, the prevalence among 5-year-old children was significantly lower in 2016 than in 2001 in rural Bangladesh. We aimed to determine whether the Haemophilus influenzae type b (Hib) combination vaccination (without booster) started in 2009 contributed to this decrease. METHODS: A case-control study was conducted among 1658 randomly selected 5-year-old children from Matlab, Bangladesh. Data on wheezing were collected using the International Study of Asthma and Allergies in Childhood questionnaire. The vaccination data were collected from the records of the Matlab Health and Demographic Surveillance System, while data on pneumonia were obtained from the clinical records of Matlab Hospital. Adjusted odds ratios (aORs) were calculated for the risk for wheezing. The reduction rate was calculated to determine the impact of the vaccination on pneumonia history between the present study and our previous study conducted in 2001 by using the following formula: (percentage of pneumonia cases in 2001 - percentage of pneumonia cases in 2016)/(percentage of pneumonia cases in 2001) times 100 (%). RESULTS: Hib combination vaccination was a protecting factor against wheezing (aOR: 0.50; p = 0.010), while pneumonia at 1, 2, 3-4 years of age were risk factors for wheezing (aOR: 2.86, 3.19, 2.86; p = 0.046, 0.030, 0.030, respectively). The history of pneumonia was significantly lower in the 2016 study participants than those in 2001 both in the overall cohort and the wheezing group (paired t-test: p = 0.012, p < 0.001, respectively). Whereas the history of pneumonia decreased when the children grew older in the 2001 overall cohort, it peaked at the age of 2 years in 2016 wheezing group. The reduction rate decreased when children grew older in both the overall cohort and the wheezing group, however, it decreased faster in the wheezing group. CONCLUSIONS: Hib combination vaccination was a protective factor against wheezing in 0-year-old children. However, the effects of vaccination might have attenuated at the ages of 1-4 years, because no booster dose was administered. The addition of a booster dose might further decrease the prevalence of asthma and wheezing.

The Detection of Rotavirus Antigenemia by Immunochromatographic Kits: a Case Series.

BACKGROUND: Acute gastroenteritis is the most common cause of illness and death in infants and young children worldwide. Rotaviruses (RVs) are the major viruses that cause acute gastroenteritis in young children, especially in developing countries in Asia and Africa. METHODS: The presence of rotavirus antigens in sera of four unvaccinated pediatric patients, aged between 4 and 6 years with severe diarrhea and dehydration, were detected by using three immunochromatographic (IC) kits. In addition, the presence of anti-rotavirus IgG, IgA, and IgM antibodies and their concentrations in patient sera were also determined by enzyme immunoassay (EIA). RESULTS: All three kits could detect rotavirus antigen in patient sera with different intensity of the test lines. When patient sera were pretreated with anti-VP6 rotavirus mouse monoclonal antibody prior to testing, the rotavirus positive test lines disappeared, suggesting that all patient sera contained VP6 protein antigen of rotavirus. Assessment of antibody concentration in these patient sera revealed that all patient sera contained IgG, IgA, and IgM antibodies against rotavirus antigen at different concentrations. CONCLUSIONS: The sensitivity of rotavirus protein detection in the patient sera of one IC kit brand was comparable to those of the EIA, suggesting this IC kit could be an alternative screening method for rapid diagnosis of rotavirus infection.

Molecular epidemiology of rotavirus gastroenteritis in Japan during 2014-2015: Characterization of re-emerging G2P[4] after rotavirus vaccine introduction.

Rotavirus vaccines have been available in Japan since 2011. This study conducted to monitor the trend of group A rotavirus (RVA) genotypes 3 years after vaccine introduction. A total of, 539 fecal samples were collected from children with acute gastroenteritis in six regions during July 2014-June 2015. Among them, 178 samples (33.0%) were positive for RVA. The most predominant genotype was G1P[8] (35.9%) followed by G2P[4] (26.4%), G9P[8] (21.3%), G3P[8] (4.5%), and G3P[9] (4.5%). The detection rate of G2P[4] was increased soon after vaccine introduction. Sequence analyses of VP7 and VP4 genes of the representative G2P[4] strains were found to be clustered in sub-lineage IVa of lineage IV. It is noteworthy that one amino acid substitution in the antigenic epitope (Q114P) of VP4 gene was found in representative G2P[4] strains of the current study. However, it is unclear whether the change in antigenic epitope is due to the effect of vaccination or due to natural variation, warranting further continuous monitoring of rotavirus evolution after vaccine introduction.

Evaluation of Immunochromatographic Test for Dual Detection of Noroviruses and Group A Rotaviruses in Stool Samples.

BACKGROUND: Viral enteric infections, such as noroviruses and rotaviruses are considered as the major causes of acute gastroenteritis in young children and elderly people all over the world. These viruses are responsible for numerous outbreaks of nonbacterial gastroenteritis in several settings such as hospitals, day care centers, nursing homes, and restaurants. Therefore, a rapid and sensitive diagnostic tool for virus detections could be helpful for disease control. METHODS: A new immunochromatographic test for the dual detection of noroviruses and group A rotaviruses was evaluated by using specimens that were known to be positive for noroviruses and rotaviruses, as well as other diarrheal viruses. RESULTS: The sensitivity of detections for noroviruses and group A rotaviruses were 89.5% and 100%, respectively, while the specificity was 100% for both viruses. This immunochromatographic test was reactive to several norovirus and group A rotavirus genotypes (NoV GII.2, GII.3, GII.4, GII.6, GII.7, GII.17 and RVA G1P[8], G2P[4], G3P[8], G8P[8], G9P[8]). CONCLUSIONS: The speed and ease of use of the immunochromatographic test makes this kit particularly attractive as an alternative method for the detections of noroviruses and group A rotaviruses in the primary care unit.

Multiplex RT-PCR for rapid detection of viruses commonly causing diarrhea in pediatric patients.

Multiplex RT-PCR method using five sets of panel primers was developed for the detection of diarrheal viruses, including rotavirus A, B, and C, adenovirus, astrovirus, norovirus GI and GII, sapovirus, Aichi virus, parechovirus, enterovirus, cosavirus, bocavirus, and Saffold virus. The sensitivity of the method was evaluated and tested with 751 fecal specimens collected from Japanese children with acute diarrhea. Several kinds of viruses were detected in 528 out of 751 (70.3%) fecal specimens. Mixed-infection with different viruses in clinical specimens could also be effectively detected. The method proved to be reliable with highly sensitive and specific and useful for routine diagnosis. J. Med. Virol. 89:818-824, 2017. © 2016 Wiley Periodicals, Inc.

Molecular Epidemiological Traits of Group A Rotaviruses in Japanese Children During Transitional Period of Rotavirus Vaccine Implementation, 2011 - 2014.

BACKGROUND: Group A rotavirus (RVA) vaccines have been introduced in Japan since 2011. To investigate the molecular epidemiological traits of RVA during the transitional period of rotavirus vaccine implementation in Japan, this study was undertaken by following up three-decade long surveillance conducted in the same regions. METHODS: RVA were screened and genotyped by RT-PCR from diarrheal samples collected from non-hospitalized patients in six localities (Hokkaido, Tokyo, Shizuoka, Osaka, Kyoto, and Saga) during 2011 - 2014. Selected samples were sequenced to elucidate the evolutionary trend. RESULTS: Among 1858 specimens, the detection rate of RVA declined to 4.0% in 2013 - 2014 from 17.9% in 2011 - 2012 and 22.1% in 2012 - 2013. G1P[8] was the most predominant genotype in the first two years accounting for more than half, and G9P[8] showed the highest detection rate as 35.0% in the last year. Interestingly, the proportional rate of G2 strains in the studied period increased from 0% to 25%. VP6 genotyping revealed that DS-1 like reassortant G1P[8] strains were detected all over Japan and their prevalence fluctuated greatly from 35.0% to 89.5%. Sequence analysis of VP6 showed that strains in the current strains were closely related but distinct from the original reference strains, namely Wa and DS-1. CONCLUSIONS: The detection rates of RVA, their GP combinations, prevalence of reassortant strains varied greatly after the introduction of rotavirus vaccines in Japan. Continuous monitoring is warranted to refine future vaccine strategy.

Cosavirus (family Picornaviridae) in pigs in Thailand and Japan.

Cosavirus is a recently established genus in the family Picornaviridae. The present study investigated the prevalence and genetic diversity of cosaviruses in stool samples collected from piglets and pigs with and without diarrhea in Thailand and Japan. It was observed that the cosavirus-positive rate in Thailand was higher than in Japan (55.4 % vs. 18.9 %). Phylogenetic analysis of a portion of the 5' untranslated region showed that porcine cosavirus strains clustered together in the same branch with members of the species Cosavirus A. These strains showed 97.0 to 100 % nucleotide sequence identity to each other. The virus concentration of cosavirus was very low compared with that detected in a infant with diarrhea. These results demonstrated that cosaviruses were circulating in the swine populations of both countries during the study term; however, it remains unclear whether the virus causes diarrhea in piglets and pigs.

Anti-Ascaris immunoglobulin E associated with bronchial hyper-reactivity in 9-year-old rural Bangladeshi children.

BACKGROUND: Studies have addressed the immunomodulatory effects of helminths and their protective effects upon asthma. However, anti-Ascaris IgE has been reported to be associated with an increased risk of asthma symptoms. We examined the association between serum levels of anti-Ascaris IgE and bronchial hyper-responsiveness (BHR) in children living in rural Bangladesh. METHODS: Serum anti-Ascaris IgE level was measured and the BHR test done in 158 children aged 9 years selected randomly from a general population of 1705 in the Matlab Health and Demographic Surveillance Area of the International Centre for Diarrhoeal Disease Research, Bangladesh. We investigated wheezing symptoms using a questionnaire from the International Study of Asthma and Allergies in Childhood. BHR tests were successfully done on 152 children (108 'current wheezers'; 44 'never-wheezers'). We examined the association between anti-Ascaris IgE level and wheezing and BHR using multiple logistic regression analyses. RESULTS: Of 108 current-wheezers, 59 were BHR-positive; of 44 never-wheezers, 32 were BHR-negative. Mean anti-Ascaris IgE levels were significantly higher (12.51 UA/ml; 95% confidence interval (CI), 9.21-17.00) in children with current wheezing with BHR-positive than in those of never-wheezers with BHR-negative (3.89; 2.65-5.70; t test, p < 0.001). A BHR-positive test was independently associated with anti-Ascaris IgE levels with an odds ratio (OR) = 7.30 [95% CI, 2.28-23.33], p = 0.001 when adjusted for total IgE, anti-Dermatophagoides pteronyssinus IgE, pneumonia history, parental asthma, Trichuris infection, forced expiratory volume in one second, eosinophilic leukocyte count, and sex. CONCLUSIONS: Anti-Ascaris IgE level is associated with an increased risk of BHR among 9-year-old rural Bangladeshi children.

Four-year study of viruses that cause diarrhea in Japanese pediatric outpatients.

Acute gastroenteritis continues to be a major public health problem worldwide. A wide variety of viruses associated with diarrhea disease is being reported continually. This study investigated the epidemiological situation of viruses that cause diarrhea in Japanese pediatric patients. This study enrolled a total of 2,381 fecal specimens collected between 2009 and 2013 from Japanese children with acute gastroenteritis. There is currently a 70.4% prevalence of viruses causing diarrhea among these Japanese pediatric outpatients. Norovirus was detected in 39.3% of the patients, whereas the prevalence of rotavirus, human parechovirus, enterovirus, adenovirus, sapovirus, astrovirus, and Aichi virus was 20.1, 6.6, 6.1, 5.6, 4.8, 2.3, and 0.1%, respectively. Co-infections were observed at the prevalence rates of 13.4 and 0.5% for double infections and triple infections, respectively. Mixed viral infections were found commonly in Japanese outpatients, and the norovirus seemed to play a major role in co-infections. Viral diarrhea cases were detected mostly in children younger than 3 years of age. The norovirus and rotavirus can be detected throughout the year, with a peak during the cold and dry seasons, whereas other common viruses are found during no specific season. Surveillance data revealed that a wide variety of viruses has caused diarrhea to circulate currently in Japanese pediatric outpatients, with very high detection rates; and norovirus and rotavirus are the most important pathogens. The data obtained from this study are valuable for compiling the overall picture of several viruses that causes diarrhea and associates with acute gastroenteritis in the Japanese pediatric population.

Rapid diagnostic tests apply for pediatric infections at outpatient clinic setting.

BACKGROUND: Early identification of the etiology of infection is beneficial. Most infections are treated as outpatients. However, facilities for rapid diagnosis are not available in clinic settings. METHODS: We applied Immunochromatography (IC) and Loop-mediated Isothermal Amplification (LAMP) methods to rapidly diagnose pathogens among 31 children with respiratory infection and 12 with gastroenteritis at a clinic in Saitama prefecture, Japan. Pathogens were then screened by multiplex conventional and real-time PCRs and bacterial culture. RESULTS: Respiratory pathogens were found in 64.5%. Despite the narrow spectrum, rapid tests identified pathogens in 28.6% of cases with a high agreement rate of 89.3% with PCR. Gastroenteritis pathogens were found in 66.7%. E. coli was positive in 3 cases and all were negative for verotoxin by LAMP. The agreement rate of IC and PCR assay was high, 100%. CONCLUSIONS: IC and LAMP are reliable and suitable methods in limited-resource settings for early pathogenic identification, which will help appropriate management, avoid unnecessary intervention, and cost saving.

Failure of propagation of human norovirus in intestinal epithelial cells with microvilli grown in three-dimensional cultures.

Human noroviruses (HuNoVs) are a leading cause of acute gastroenteritis. Establishment of a cell culture system for in vitro HuNoV growth remains challenging. Replication of HuNoVs in human intestinal cell lines (INT-407 and Caco-2) that differentiate to produce microvilli in rotation wall vessel (RWV) three-dimensional cultures has been reported (Straub et al. in Emerg Infect Dis 13:396-403, 2007; J Water Health 9:225-240, 2011, and Water Sci Technol 67:863-868, 2013). We used a similar RWV system, intestinal cell lines, and the same (Genogroup [G] I.1) plus additional (GII.4 and GII.12) HuNoV strains to test the system's reproducibility and to expand the earlier findings. Apical microvilli were observed on the surface of both cell lines by light and electron microscopy. However, none of the cell types tested resulted in productive viral replication of any of the HuNoV strains, as confirmed by plateau or declining viral RNA titers in the supernatants and cell lysates of HuNoV-infected cells, determined by real-time reverse transcription PCR. These trends were the same when culture supplements were added that have been reported to be effective for replication of other fastidious enteric viruses in vitro. Additionally, by confocal microscopy and orthoslice analysis, viral capsid proteins were mainly observed above the actin filament signals, which suggested that the majority of viral antigens were on the cell surface. We conclude that even intestinal cells displaying microvilli were not sufficient to support HuNoV replication under the conditions tested.

A Pediatric Case of Encephalopathy With Hypoglycemia Induced by Coxsackievirus A4 Infection.

We report a pediatric case developing hypoglycemic encephalopathy during the acute phase of coxsackievirus (CV)-A4 infection. A part of the sequence of the virus detected from our patient was completely identical to that in other CV-A4 strain reported as a recombinant strain with lethal CV-A2, suggesting that the properties of CV-A4 might be associated with the severe hypoglycemic encephalopathy.

National seroepidemiological study of COVID-19 after the initial rollout of vaccines: Before and at the peak of the Omicron-dominant period in Japan.

Background: Based on routine surveillance data, Japan has been affected much less by COVID-19 compared with other countries. To validate this, we aimed to estimate SARS-CoV-2 seroprevalence and examine sociodemographic factors associated with cumulative infection in Japan. Methods: A population-based serial cross-sectional seroepidemiological investigation was conducted in five prefectures in December 2021 (pre-Omicron) and February-March 2022 (Omicron [BA.1/BA.2]-peak). Anti-nucleocapsid and anti-spike antibodies were measured to detect infection-induced and vaccine/infection-induced antibodies, respectively. Logistic regression was used to identify associations between various factors and past infection. Results: Among 16 296 participants (median age: 53 [43-64] years), overall prevalence of infection-induced antibodies was 2.2% (95% CI: 1.9-2.5%) in December 2021 and 3.5% (95% CI: 3.1-3.9%) in February-March 2022. Factors associated with past infection included those residing in urban prefectures (Tokyo: aOR 3.37 [95% CI: 2.31-4.91], Osaka: aOR 3.23 [95% CI: 2.17-4.80]), older age groups (60s: aOR 0.47 [95% CI 0.29-0.74], 70s: aOR 0.41 [95% CI 0.24-0.70]), being vaccinated (twice: aOR 0.41 [95% CI: 0.28-0.61], three times: aOR 0.21 [95% CI: 0.12-0.36]), individuals engaged in occupations such as long-term care workers (aOR: 3.13 [95% CI: 1.47-6.66]), childcare workers (aOR: 3.63 [95% CI: 1.60-8.24]), food service workers (aOR: 3.09 [95% CI: 1.50-6.35]), and history of household contact (aOR: 26.4 [95% CI: 20.0-34.8]) or non-household contact (aOR: 5.21 [95% CI:3.80-7.14]) in February-March 2022. Almost all vaccinated individuals (15 670/15 681) acquired binding antibodies with higher titers among booster dose recipients. Conclusions: Before Omicron, the cumulative burden was >10 times lower in Japan (2.2%) compared with the US (33%), the UK (25%), or global estimates (45%), but most developed antibodies owing to vaccination.

Specific COVID-19 risk behaviors and the preventive effect of personal protective equipment among healthcare workers in Japan.

As coronavirus disease 2019 (COVID-19) outbreaks in healthcare facilities are a serious public health concern, we performed a case-control study to investigate the risk of COVID-19 infection in healthcare workers. We collected data on participants' sociodemographic characteristics, contact behaviors, installation status of personal protective equipment, and polymerase chain reaction testing results. We also collected whole blood and assessed seropositivity using the electrochemiluminescence immunoassay and microneutralization assay. In total, 161 (8.5%) of 1,899 participants were seropositive between August 3 and November 13, 2020. Physical contact (adjusted odds ratio 2.4, 95% confidence interval 1.1-5.6) and aerosol-generating procedures (1.9, 1.1-3.2) were associated with seropositivity. Using goggles (0.2, 0.1-0.5) and N95 masks (0.3, 0.1-0.8) had a preventive effect. Seroprevalence was higher in the outbreak ward (18.6%) than in the COVID-19 dedicated ward (1.4%). Results showed certain specific risk behaviors of COVID-19; proper infection prevention practices reduced these risks.

Updates on Coronavirus Disease 2019 in Children in Japan.

This review provides updates on coronavirus disease 2019 (COVID-19) in children in Japan by summarizing published data. By the end of March 2022, Japan had experienced 6 waves of COVID-19 outbreaks. Over this time, the clinical features presented among children have changed in the context of the predominant variants. Although the COVID-19 pandemic affected children in terms of medical, physical and psychosocial aspects, the clinical outcomes have been favorable in Japan compared with those in some European countries and the United States, which may be partly due to a lower incidence of multisystem inflammatory syndromes in children and obesity. The COVID-19 vaccine has been available for children; however, the vaccination rate in children 5-11 years of age is lower than that in older children due to the government's lack of an active approach in this specific population. Further action is needed to improve the overall vaccination rates in children.

Detection of Rotavirus Strains in Freshwater Clams in Japan.

Bivalve molluscan shellfish like clams and oysters, etc., are capable to bioaccumulate surrounding contaminants from waters into their digestive systems and posing serious threats of food poisoning. Detection of rotaviruses (RVs) in shellfish is of particular importance because RVs are prone to genome reassortment resulting in the emergence of new RV variants that may compromise vaccine safety. Herein, we have detected the wild-type RVs and Rotarix/RotaTeq vaccine strains in freshwater clams collected on the riverside, Kawasaki city, from July 2019 to January 2020 and correlated the detected genotypes with that of gastroenteritis cases of nearby clinics to understand the transmission of RVs in the environment. The wild-type RVs were detected in 62 (64.6%) out of 96 freshwater clams in every study month: July, September, November, and January that are considered as off-season for RV infections. The most frequent genotypes were G2 (42.9%), G8 (28.6%), G3 (14.3%), G1 (7.1%), and G10 (7.1%), which remained comparable with genotypic distribution found in the clinical samples over the last few years indicating that these RVs may accumulate in clams since a long time. However, G10 genotype was detected in clam but not in clinical samples suggesting the presence of asymptomatic infection or RVs could be carried out from a long distance. Importantly, vaccine strains, RotaTeq (1%) but not Rotarix (0%), were also detected in a clam. Attention must be paid to monitoring the potential transmission of wild-type and vaccine RV strains in the environment to prevent the emergence of new variants generated from genome reassortment with vaccine strains.