Aug 2026· Viruses· Vol 18, pp. 903· 0 citations· 31 references
Medicine
TL;DR
It is revealed EV-D68 circulated endemically in this pediatric population, establishing a high population immune baseline (>90.0%) with distinct age-dependent patterns and providing key reference data for ongoing serosurveillance, outbreak risk assessment, and the evaluation of future vaccines or immunoprophylactic strategies should they become available.
Abstract
Enterovirus D68 (EV-D68) is a re-emerging pathogen associated with severe acute flaccid myelitis (AFM) and pneumonia, predominantly in children but also capable of causing severe disease in immunocompromised adults. Seroprevalence data are essential for understanding population immunity, age-specific susceptibility, and viral transmission dynamics; yet, such data for the period after the COVID-19 pandemic are scarce. We conducted a cross-sectional serological survey to characterize the neutralizing antibody profile of EV-D68 among children in Xiamen, China, in 2022. A total of 453 children aged 0–16 years (217 with acute respiratory tract infection [ARTI] and 236 without) were enrolled. Neutralizing antibody (NtAb) titers against the EV-D68 STL strain were measured using a microneutralization assay, seropositivity was defined as a titer ≥1:16. Multivariable regression and analysis of covariance were used to adjust for age and sex. Overall seroprevalence was 96.0% (435/453), exceeding 90.0% in every age subgroup (0–1 y: 100%; 1–3 y: 97.6%; 3–5 y: 92.6%; ≥5 y: 96.2%). The geometric mean titer (GMT) was 76.78 (95% CI: 68.32–85.24). After adjustment, ARTI status was not significantly associated with seropositivity (adjusted OR = 1.42, 95% CI: 0.46–4.41, p = 0.542). In an exploratory comparison, children with ARTI showed nominally higher antibody titers than those without (Mann–Whitney U test, p = 0.003), although the absence of EV-D68-specific PCR testing precludes etiologic attribution of respiratory symptoms to EV-D68 infection. Infants < 1 year showed the highest GMT (86.31), while children aged 1–3 years had the lowest GMT (63.52) and the largest low-titer fraction, indicating a susceptibility gap. Our study revealed EV-D68 circulated endemically in this pediatric population, establishing a high population immune baseline (>90.0%) with distinct age-dependent patterns. These findings provide key reference data for ongoing serosurveillance, outbreak risk assessment, and the evaluation of future vaccines or immunoprophylactic strategies should they become available.
BACKGROUND
Enterovirus D68 (EV-D68) causes acute respiratory illnesses and has also implicated in acute flaccid myelitis. Neutralizing antibodies (NtAbs) represent key components of the adaptative immunity. However, the dynamics of EV-D68 NtAbs in adults remain poorly characterized. We evaluated EV-D68 NtAb levels in retail workers in Canada during the COVID-19 pandemic.
METHODS
NtAbs were measured in paired serum samples (N=194), from retail workers (≥ 18 years) enrolled in a prospective SARS-CoV-2 cohort at the Centre Hospitalier Universitaire de Québec-Université Laval, in Quebec City. Samples collected 48 weeks apart, between June 2021 to October 2022, were tested by microneutralization assays.
RESULTS
EV-D68 NtAb seroprevalence was high (>85%). Over the 48-weeks follow-up, the vast majority of patients (97%) had stable or reduced titers with a statistically significant overall reduction in geometric mean titer (GMT), p<0.001. Furthermore, a small subset of participants 6/194 (3%) showed a marked increase of titers (≥4-fold) with the GMT rising from 21 (10-57) at the first visit to 593 (57-7241) at follow-up visit.
CONCLUSIONS
Neutralizing antibody titers declined in most participants over 48 weeks. However, six individuals had significantly increased NtAb titers during the study period, which is consistent with potential ongoing EV-D68 or other enterovirus circulation in Quebec following sequential non-pharmaceutical interventions lift. This is in line with documented EV-D68 resurgence in the United States at the same period. Our work complements pediatric data on EV-D68 immunity and highlights the serological surveillance importance in adults.
V. L. Rahajamanana, H. Rabezanahary, Andrea Arroyave et al.· International Journal of Inf...· 0 citations
Varicella continues to pose a significant public health challenge for children and adolescents in China. Although vaccination is available, the disease remains highly prevalent among children in Fujian. This study aimed to evaluate the seroepidemiology of varicella-zoster virus (VZV) and to explore the factors contributing to its high incidence in individuals aged 0–17 years.
A cross-sectional serosurvey was conducted in 2023. Serum samples from 2,675 eligible individuals were tested for VZV IgG using ELISA. Demographic and vaccination data were collected via questionnaire.
A total of 2,675 participants, aged between 2 days and 17 years with a median age of 6.5 years, were included. The overall seropositivity rate of VZV IgG was 47.7% (95% CI: 45.5–49.3), with a geometric mean concentration (GMC) of 81.3 mIU/mL (95% CI: 77.0–85.9). Marked variations in these immunity markers were observed across age groups, genders, and vaccination statuses. Notably, varicella vaccination coverage was substantially low: only 54.9% of children aged 1–17 years had received one dose, and merely 17.4% were fully vaccinated with two doses. A clear post-vaccination antibody waning pattern was also evident. Both seropositivity rate and GMC began to decline one year after vaccination, decreasing by more than 50% after four years.
The seropositivity rates and GMC of varicella antibodies were low among individuals aged 0–17 years in Fujian Province, and vaccination coverage was insufficient, particularly for the second dose (< 20%). Antibody titers declined markedly over time, which may be partly associated with the high incidence of varicella in this region. To ensure the continuity of surveillance data, further efforts are needed to strengthen epidemiological surveillance of varicella in younger age groups and to promote the timeliness and completeness of vaccination.
Not applicable.
Objective Norovirus (NoV) is a major pathogen causing acute gastroenteritis (AGE) worldwide, imposing a substantial disease burden. This study aimed to investigate the epidemiological, clinical and genotypic characteristics of NoV infection in pediatric patients with AGE in Ezhou, central China. Methods Between January 2023 and June 2025, we enrolled pediatric AGE patients from Ezhou Maternal and Child Health Hospital and collected their demographic profiles, clinical records and stool specimens, together with matched local meteorological data. All stool samples were screened for NoV using a commercial colloidal gold immunoassay kit. A randomly selected subset of NoV−positive samples was further subjected to genetic sequencing. Results Among the 8,435 enrolled pediatric patients, 422 (5.0%) tested positive for NoV, with annual positivity rates of 4.24% (2023), 5.89% (2024), and 4.57% (January-June 2025). The positive cases comprised 259 males and 163 females. Children aged 1–2 years had the highest NoV positivity rate. The epidemic period spanned winter to spring, corresponding to ambient humidity of 66.5%–69.95%. Typical clinical presentations included fever, vomiting, watery diarrhea, dehydration, abdominal pain, convulsions, lethargy and electrolyte disturbances. Genetic sequencing identified three NoV genotypes across the 2.5-year surveillance period: GII.17, GII.3 and GII.4. Conclusions NoV infection prevalence rose continuously in Ezhou during the 2.5-year study period, with seasonal peaks in winter and spring. GII.17 was the dominant genotype among sequenced isolates. Children aged 1–2 years constitute the highest-risk population and exhibit a wide range of clinical manifestations. Fecal colloidal gold immunoassay serves as a practical screening tool for NoV detection in pediatric populations at primary medical institutions.
Dan Luo, Siyue Tang, Yingru Liu et al.· Frontiers in Physiology· 0 citations
Enterovirus D68 (EV-D68) primarily causes respiratory illness in children but is also associated with serious neurological outcomes. Although EV-D68 circulation has historically demonstrated a biennial pattern, with peaks during summer and fall, infections can occur year-round, with unpredictable outbreaks. Notable outbreaks occurred in the U.S. in 2014, in Canada in 2022, and more recently in Senegal in late 2023, leading to increased hospitalizations in affected children. However, data are lacking in the Middle East. This study aims to describe EV-D68 circulation and clinical severity among hospitalized children in Amman, Jordan.
Data were obtained from a prospective viral surveillance study conducted at Al-Bashir Hospital, the largest public hospital in Amman, from January 2023 to April 2024. The study population included children under 5 years hospitalized with fever or respiratory symptoms. Nasal and throat swabs were collected and tested for EV-D68 and other respiratory viruses using RT-qPCR. Demographic and clinical information were gathered through parental interviews and medical chart reviews.
Of the 2,168 children enrolled, we identified 14 (0.6%) cases of EV-D68, with 13 occurring in January 2023 and one in February 2023. Table 1 compares EV-D68–positive children to EV-D68–negative children. The median age of EV-D68–positive children was 5.2 months (IQR, 1.3–15.4), and most were female (64.3%). The majority were previously healthy (78.6%) and born at term (85.7%). The most common presenting symptoms were cough (100.0%), congestion or runny nose (78.6%), and shortness of breath (78.6%). Fever, reported in two cases (14.3%), was significantly more common in children negative for EV-D68 (59.7%). Another virus was co-detected with EV-D68 in 6 cases (42.9%). Children with EV-D68 were more likely to receive supplemental oxygen during hospitalization (64.3% vs 37.2%, p=0.047). Intensive care was required for three EV-D68-positive cases (21.4%). Among them, one child with adenovirus co-detection was intubated and subsequently died. Figure 1 provides a detailed visual breakdown of the clinical characteristics, presenting symptoms, co-detections, and in-hospital outcomes of the 14 EV-D68–positive cases.
Our findings underscore that EV-D68, while infrequent, can lead to significant clinical severity among young children. As global circulation patterns of EV-D68 remain insufficiently understood, ongoing surveillance is critical. With monoclonal antibodies in development, monitoring EV-D68 circulation and identifying children at higher risk could enable timely preventive interventions, potentially mitigating EV-D68-associated morbidity and improving clinical outcomes.
Haya Hayek, J. Amarin, Olla Hamdan et al.· Journal of the Pediatric Inf...· 0 citations
Objectives: This study aimed to investigate the levels of varicella antibodies in Zhejiang, China, after a decade of implementing the two-dose varicella vaccine (VarV) strategy. Methods: Healthy participants aged 1 to 69 years from Zhejiang, China, were recruited from January to April 2024 using multistage stratified random sampling, and varicella zoster virus (VZV) IgG antibodies were detected by ELISA. We assessed the seroprevalence and geometric mean concentration (GMC) of VZV IgG and analyzed related factors using Logistic and linear regression models. Results: A total of 807 participants were included in the study. The overall seropositivity rate for VZV IgG in the healthy population was 73.08% (95%CI: 69.87–76.11), with a corresponding GMC of 200.97 mIU/mL (95%CI: 182.75 mIU/mL–221.01 mIU/mL). Multivariate analysis identified age group, VarV immunization history, and history of varicella disease as factors significantly associated with both VZV IgG seropositivity and GMC levels (p < 0.05). The seropositivity rate for VZV IgG in children aged 1–14 years was 42.67% (95%CI: 36.22–49.31), with a corresponding GMC of 82.10 mIU/mL (95%CI: 69.14 mIU/mL–97.48 mIU/mL). Furthermore, a significant decline in both seropositivity and GMC was observed over time following vaccination among vaccinated children aged 1–14 years (p < 0.05). Conclusions: Two-dose VarV vaccination may be considered for inclusion in the national immunization program.
Yingying Yang, Yan Liu, C. Zheng et al.· Vaccines· 0 citations
BACKGROUND
Acute gastroenteritis (AGE) is a primary cause of death in children less than five years old in low- and middle-income countries (LMIC), mostly caused by viral intestinal infections. While the disease poses a significant global burden, further investigation is needed to clarify the role of enteric viruses in disease pathogenesis. This work aimed to study the frequency of five major enteropathogenic viruses-Rotavirus (RV), Norovirus (NoV), Adenovirus (AdV), Sapovirus (SaV), and Astrovirus (AstV)- in stool samples of young children in Tehran, Iran, during 2023-2024.
METHODS
A cross-sectional study was conducted on 203 stool samples collected from children under 5 years of age clinically diagnosed with AGE. Viral genomic RNA was extracted and amplified for the most common AGE viruses using the RT-qPCR assay.
RESULTS
Out of 203 tested samples, 101 (49.8%) were positive for at least one of the viruses assessed. The most frequently detected enteropathogenic viral agents in children under 5 years were RV and AdV, while AstV was rarely detected. The positivity rate varies by age, gender, and season. Mixed infections were determined in 16 (7.9%) patients, with a predominance of RV and AdV. Infection with enteric viruses can occur throughout the year (peaking during mild-to-cold months), with fever, diarrhea, and nausea/vomiting being the most common symptoms among children.
CONCLUSIONS
Enteric viruses, particularly AdV and RV, contribute greatly to AGE among children in Iran. Continuous surveillance and long-term monitoring of enteropathogenic agents is essential to provide insight into the local circulation and characterization of AGE-causing viruses, guiding the implementation of targeted interventions and public health strategies to mitigate the risk of future outbreaks in the region.
