Impact of rotavirus vaccine in reducing hospitalization rates in pediatric patients: a single center experience in Italy

Molecular Evolution of GII.P31/GII.4_Sydney_2012 Norovirus over a Decade in a Clinic in Japan

Norovirus (NoV) genogroup II, polymerase type P31, capsid genotype 4, Sydney_2012 variant (GII.P31/GII.4_Sydney_2012) has been circulating at high levels for over a decade, raising the question of whether this strain is undergoing molecular alterations without demonstrating a substantial phylogenetic difference. Here, we applied next-generation sequencing to learn more about the genetic diversity of 14 GII.P31/GII.4_Sydney_2012 strains that caused epidemics in a specific region of Japan, with 12 from Kyoto and 2 from Shizuoka, between 2012 and 2022, with an emphasis on amino acid (aa) differences in all three ORFs. We found numerous notable aa alterations in antigenic locations in the capsid region (ORF2) as well as in other ORFs. In all three ORFs, earlier strains (2013-2016) remained phylogenetically distinct from later strains (2019-2022). This research is expected to shed light on the evolutionary properties of dominating GII.P31/GII.4_Sydney_2012 strains, which could provide useful information for viral diarrhea prevention and treatment.

Rates and determinants of Rotavirus vaccine uptake among children in Italy: a cross-sectional study within the 2022 OBVIOUS* project

INTRODUCTION

The World Health Organization defines rotavirus as among the most severe causes of viral gastroenteritis affecting children under 5 year old. Italy and other European countries do not release disaggregated data on rotavirus vaccination coverage. This study aimed to assess the uptake and drivers of rotavirus vaccination in Italy.

METHODS

We administered a survey to 10,000 Italian citizens recruited via an online panel and proportionate to key demographic strata. We examined rotavirus vaccine uptake among parents whose youngest child was aged 6 weeks to 4 years, their sociodemographic characteristics, their beliefs about vaccine administration, and who recommended the rotavirus vaccination.

RESULTS

A total of 711 respondents met the inclusion criteria for the rotavirus vaccine questionnaire. The uptake was estimated at 60.3% nationwide (66.4% among mothers and 50.2% among fathers). Being a mother and living in cities/suburbs was significantly associated with a higher likelihood of vaccine uptake, while fathers were more likely to be uncertain of their children's vaccine status. Living in Central Italy and having friends/relatives opposed to vaccination were found to be significantly associated with a lower likelihood of vaccine uptake, while parents' education level and children's demographics were not found to correlate with any outcomes. In 90.3% of cases, the rotavirus vaccination was recalled as being recommended by a paediatrician.

CONCLUSIONS

Consistent collection of behavioural preferences and socioeconomic characteristics of recipients of rotavirus vaccine campaigns, their epidemiological information, cost-benefit, and national policy data are crucial for designing effective vaccination strategies in Italy and other European countries with similar social profiles to reach the target uptake.

Incidence of Rotavirus-Related Hospitalizations in an Italian Southern Region from 2015 to 2021

(1) Background: Rotavirus is one of the leading causes of severe diarrhea and dehydration in infants and young children worldwide. The economic and social burden of rotavirus-related hospitalizations, particularly among children, remains a pressing concern for healthcare systems across the globe. Healthcare infrastructure and access to medical care can vary significantly within the region. Differences in the availability of healthcare facilities and the quality of care may influence the management and outcomes of rotavirus cases. (2) Methods: This was a retrospective study performed in the Abruzzo region, Italy. The study considered all hospitalization due to rotavirus gastroenteritis that occurred in the Abruzzo region from the year 2015 to 2021. Data were extracted from the hospital discharge records. The trend in hospital admissions, hospitalization costs and length of stay were evaluated and analyzed. (3) Results: A total of 664 admissions were reported during the study period. The incident rate grew till year 2019 with an annual percentage change of +13.9% (95%CI 12.6-15.2, p < 0.001). During the pandemic years, the incident rate showed a significant decrease with an annual percentage change of 12.5% (95%CI 15.5-9.3, p = 0.004). The length of stay of admissions was significantly higher among patients aged less than 1 year. (4) Conclusions: Rotavirus admission represents a heavy burden even in a high-income country such as Italy. These findings have the potential to inform targeted public health interventions, including vaccination strategies, and improve the overall well-being of children.

The Impact of Rotavirus Vaccination on Discharges for Pediatric Gastroenteritis in Italy: An Eleven Year (2009-2019) Nationwide Analysis

In Italy, despite the documented positive effects of rotavirus (RV) vaccination on reducing the burden of RV disease, an updated national assessment of its impact on clinical outcomes is still lacking. This study aims to analyze the implementation of RV vaccination in Italy, evaluating its impact on discharges for acute pediatric gastroenteritis (AGE). A retrospective analysis, including hospital discharge records and data on vaccination coverage for children aged 0-71 months from 2009 to 2019, was conducted. We examined trends in hospital discharge standardized incidence before and after vaccine introduction using a negative binomial mixture model with fixed effects to evaluate the impact of universal vaccination. The percentage of vaccination coverage increased over the years, from <5% between 2009 and 2013 to 26% in 2017, reaching 70% in 2019. The standardized incidence of discharges decreased over the period from 16.6/100,000 inhabitants in 2009-2013 to 9.9/100,000 inhabitants in 2018-2019. In this phase, about 15% of the estimated hospital discharges were avoided compared with those estimated in the first phase. The implementation of RV vaccination reduced AGE incidence discharges in children aged 0-71 months. Further efforts are needed to continue monitoring the vaccination effect over time and to increase vaccination coverage.

Differentiation between Wild-Type Group A Rotaviruses and Vaccine Strains in Cases of Suspected Horizontal Transmission and Adverse Events Following Vaccination

Human group A rotaviruses (RVA) are important enteric pathogens, as they are a leading cause of acute gastroenteritis (AGE) in children worldwide. Since 2013, the German Standing Committee on vaccination recommended the routine rotavirus vaccination for infants in Germany. While vaccination has significantly decreased RVA cases and worldwide mortality, in some cases, infants can develop acute gastroenteritis as an adverse reaction after immunization with an attenuated live vaccine. Pediatricians, as well as clinicians and diagnostic laboratories, contacted the Consultant Laboratory for Rotaviruses and inquired whether cases of RVA-positive AGE after vaccination were associated with vaccine or with wild-type RVA strains. A testing algorithm based on distinguishing PCRs and confirmative sequencing was designed, tested, and applied. Diagnostic samples from 68 vaccinated children and six cases where horizontal transmission was suspected were investigated in this study. Using a combination of real-time PCR, fragment-length analysis of amplicons from multiplex PCRs and confirmative sequencing, vaccine-like virus was detected in 46 samples and wild-type RVA was detected in 6 samples. Three mixed infections of vaccine and wild-type RVA were detectable, no RVA genome was found in 19 samples. High viral loads (>1.0 × 107 copies/g stool) were measured in most RVA-positive samples. Furthermore, information on co-infections with other AGE pathogens in the vaccinated study population was of interest. A commercial multiplex PCR and in-house PCRs revealed three co-infections of vaccinated infants with bacteria (two samples with Clostridioides difficile and one sample with enteropathogenic E. coli) and six co-infections with norovirus in a subset of the samples. Human astrovirus was detected in one sample, with suspected horizontal transmission. The cases of suspected horizontal transmission of vaccine RVA strains could not be confirmed, as they either involved wild-type RVA or were RVA negative. This study shows that RVA-positive AGE after vaccination is not necessarily associated with the vaccine strain and provides a reliable workflow to distinguish RVA vaccine strains from wild-type strains.