[Prospective epidemiological study of rotavirus gastroenteritis in Europe (REVEAL study). Results in the French area of the study]

Benefit Versus Risk Assessment of Rotavirus Vaccination in France: A Simulation and Modeling Analysis

Introduction

Two vaccines against rotavirus gastroenteritis (RVGE) in young children, Rotarix and RotaTeq, have been available in Europe since 2006. Vaccination against rotaviruses significantly reduces the burden of RVGE, but it is also associated with a very small increased risk of intussusception. In a benefit–risk analysis, the prevented RVGE burden is weighed against the possible excess of intussusception.

Purpose

The aim was to compare the estimated benefits and risks of Rotarix vaccination in France.

Methods

We estimated the benefits (vaccine-preventable RVGE hospitalizations and deaths) and risks (vaccine-caused intussusception hospitalizations and deaths) following two doses of Rotarix in a birth cohort of 791,183 followed for 3–5 years in France. We used data from peer-reviewed clinical and epidemiological studies or publications, and government statistics.

Results

Within the total number of French children below 5 years of age, we estimate vaccination could prevent a median 11,132 [95% credible interval (CI) 7842–14,408] RVGE hospitalizations and 7.43 (95% CI 3.27–14.68) RVGE deaths. At the same time, vaccination could cause an average of 6.86 (95% CI 2.25–38.37) intussusception hospitalizations and 0.0099 (95% CI 0.0024–0.060) intussusception deaths in the entire French birth cohort of infants below 1 year of age. Therefore, for every intussusception hospitalization and every intussusception death caused by vaccination, 1624 (95% CI 240–5243) RVGE hospitalizations and 743 (95% CI 93–3723) RVGE deaths are prevented, respectively, by vaccination.

Conclusions

The vaccine-prevented RVGE hospitalizations and deaths (benefit) greatly outweigh the excess potentially vaccination-related cases of intussusception (risk), indicating a favorable benefit–risk balance for Rotarix in France.

Electronic supplementary material

The online version of this article (10.1007/s40259-018-0273-6) contains supplementary material, which is available to authorized users.

Secular trends in incidence of acute gastroenteritis in general practice, France, 1991 to 2015

We analysed 25 years of general practitioner (GP) visits for acute gastroenteritis (AG) surveillance in France, by the GP Sentinelles network. We searched for time trends of acute gastroenteritis incidence during winter periods. Data from emergency departments and drug reimbursement were additional data sources. A time-series analysis was performed using a generalised additive model for all data sources for the winter period. Virological data were incorporated and compared with the three data sources. The cumulative incidence of GP visits for winter AG exhibited an increasing trend from 1991 until 2008, when it reached 6,466 per 100,000 inhabitants. It decreased thereafter to 3,918 per 100,000 inhabitants in 2015. This decreasing trend was observed for all age groups and confirmed by the generalised additive model. For emergency department visits a decreasing trend was observed from 2004. Drug reimbursement data analyses demonstrated a decreasing trend from when data began in 2009. The incidence reported by GPs and emergency departments was lower following the emergence of norovirus GII.4 2012 (p < 0.0001). Winter AG incidences seem to follow long-term rising and decreasing trends that are important to monitor through continuous surveillance to evaluate the impact of prevention strategies, such as future immunisation against acute viral gastroenteritis.

Cost-Effectiveness of Rotavirus Vaccination in France-Accounting for Indirect Protection

BACKGROUND

Vaccination against rotavirus has shown great potential for reducing the primary cause of severe childhood gastroenteritis. Previous economic evaluations of rotavirus vaccination in France have not modeled the potential impact of vaccines on disease burden via reduced transmission.

OBJECTIVE

To determine the cost-effectiveness of the introduction of pentavalent rotavirus vaccination into the French infant vaccination schedule.

METHODS

We developed an age-structured model of rotavirus transmission calibrated to 6 years of French gastroenteritis incidence and vaccine clinical trial data. We evaluated the cost-effectiveness of pentavalent rotavirus vaccination considering that 75% of infants would receive the three-dose vaccine course.

RESULTS

Our model predicts that rotavirus vaccination will decrease rotavirus gastroenteritis incidence and associated clinical outcomes in vaccinated and unvaccinated individuals, delay the seasonal peak of infection, and increase the age of infection. From the societal perspective, our base-case scenario predicts that vaccination coverage would be cost-effective at €115 or €135 per vaccine course at €28,500 and €39,500/quality-adjusted life-year (QALY) gained, respectively, and suggests that almost 95% of the financial benefits will be recouped within the first 5 years following vaccination implementation. From the third-party payer perspective, incremental cost-effectiveness ratios ranged from €12,500 to €20,000/QALY, respectively. Our uncertainty analysis suggests that findings were sensitive to various assumptions including the number of hospitalizations, outpatient visits, and the extent of QALY losses per rotavirus episode.

CONCLUSIONS

Introducing pentavalent rotavirus vaccination into the French infant vaccination schedule would significantly reduce the burden of rotavirus disease in children, and could be cost-effective under plausible conditions.

Community-Acquired Rotavirus Gastroenteritis Compared with Adenovirus and Norovirus Gastroenteritis in Italian Children: A Pedianet Study

Background. Rotavirus (RV) is the commonest pathogen in the hospital and primary care settings, followed by Adenovirus (AV) and Norovirus (NV). Only few studies that assess the burden of RV gastroenteritis at the community level have been carried out. Objectives. To estimate incidence, disease characteristics, seasonal distribution, and working days lost by parents of RV, AV, and NV gastroenteritis leading to a family pediatrician (FP) visit among children < 5 years. Methods. 12-month, observational, prospective, FP-based study has been carried out using Pedianet database. Results. RVGE incidence was 1.04 per 100 person-years with the highest incidence in the first 2 years of life. Incidences of AVGEs (1.74) and NVGEs (1.51) were slightly higher with similar characteristics regarding age distribution and symptoms. Risk of hospitalisation, access to emergency room (ER), and workdays lost from parents were not significantly different in RVGEs compared to the other viral infections. Conclusions. Features of RVGE in terms of hospitalisation length and indirect cost are lower than those reported in previous studies. Results of the present study reflect the large variability of data present in the literature. This observation underlines the utility of primary care networks for AGE surveillance and further studies on community-acquired gastroenteritis in children.

Global seasonality of rotavirus disease

BACKGROUND

A substantial number of surveillance studies have documented rotavirus prevalence among children admitted for dehydrating diarrhea. We sought to establish global seasonal patterns of rotavirus disease before the introduction of widespread vaccination.

METHODS

We reviewed studies of rotavirus detection in children with diarrhea published since 1995. We assessed potential relationships between seasonal prevalence and locality by plotting the average monthly proportion of diarrhea cases positive for rotavirus according to geography, country development and latitude. We used linear regression to identify variables that were potentially associated with the seasonal intensity of rotavirus.

RESULTS

Among a total of 99 studies representing all 6 geographic regions of the world, patterns of year-round disease were more evident in low- and low-middle income countries compared with upper-middle and high-income countries where disease was more likely to be seasonal. The level of country development was a stronger predictor of strength of seasonality (P = 0.001) than geographic location or climate. However, the observation of distinctly different seasonal patterns of rotavirus disease in some countries with similar geographic location, climate and level of development indicate that a single unifying explanation for variation in seasonality of rotavirus disease is unlikely.

CONCLUSION

While no unifying explanation emerged for varying rotavirus seasonality globally, the country income level was somewhat more predictive of the likelihood of having seasonal disease than other factors. Future evaluation of the effect of rotavirus vaccination on seasonal patterns of disease in different settings may help understand factors that drive the global seasonality of rotavirus disease.

[Incidence of rotavirus gastroenteritis among children under 5 years consulting a paediatrician or a general practitioner in France]

BACKGROUND

Rotavirus (RV) is the main infectious agent of severe acute gastroenteritis (AGE) in infants and children under 5 years. Given the recent availability of new vaccines, it is important to accurately assess the incidence of rotavirus gastroenteritis (GERV) and their medical and epidemiological consequences.

METHODS

This work is the French part of study program called SPRIK, a multicenter, prospective, observational study conducted from October 2005 to May 2007 to estimate the annual incidence of GERV within children under 5 years visiting a general practitioner or pediatrician. It presents data collected by 41 general practitioners and 36 paediatricians located throughout the French metropolitan territory. A stool sample was taken for every child. Rotavirus presence was sought by the physician using a rapid immunochromatographic test. French results are presented in this article.

RESULTS

A total of 1648 GEA episodes corresponding to 1463 eligible patients were included in the study mainly from December to May (peak in February-March). The incidence rate of GERV leading to consultations in general practice was 1357 cases per 100,000 patient-years (PY) (1.36%), with a 95% confidence interval of [1345-1368]. The peak incidence occurs before 2 years. GERV accounted for 21% of all GEA cases seen by paediatricians and general practitioners. Patients with GERV were younger (14.1 ± 10.8 versus 18.4 ± 13.9 months for other GEA, P<0.0001) and had more severe clinical symptoms: presence of fever (32.6% versus 20.0%, P<0.0001), behavioural symptoms (45.6% versus 20.8%, P<0.0001) and dehydration (48.7% versus 21.2%, P<0.0001). GERV episodes were considered severe in 79.7% of cases, using the Vesikari scale. More than 86% patients received oral rehydration during the episode and 13 patients (5.8%) were hospitalized. Nearly 80% GERV episodes were considered severe using the Vesikari scale. Main genotypes were G1P[8] rotavirus (44%) and G9P[8] rotavirus (35%) types.

CONCLUSION

The incidence rate reported in this study is close to results of previous studies done in Europe. The frequency and severity relative to GERV support vaccination in very young children to reduce the burden associated with this pathology.

Burden of community-acquired and nosocomial rotavirus gastroenteritis in the pediatric population of Western Europe: a scoping review

BACKGROUND

Rotavirus affects 95% of children worldwide by age 5 years and is the leading cause of severe dehydrating diarrhea. The objective of this review was to estimate the burden of rotavirus gastroenteritis (RVGE) in the Western European pediatric population.

METHODS

A comprehensive literature search (1999-2010) was conducted in PubMed and other sources (CDC; WHO, others). Data on the epidemiology and burden of RVGE among children < 5 years-old in Western Europe --including hospital-acquired disease--were extracted.

RESULTS

76 studies from 16 countries were identified. The mean percentage of acute gastroenteritis (AGE) cases caused by rotavirus ranged from 25.3%-63.5% in children < 5 years of age, peaking during winter. Incidence rates of RVGE ranged from 1.33-4.96 cases/100 person- years. Hospitalization rates for RVGE ranged from 7% to 81% among infected children, depending on the country. Nosocomial RVGE accounted for 47%-69% of all hospital-acquired AGE and prolonged hospital stays by 4-12 days. Each year, RVGE incurred $0.54- $53.6 million in direct medical costs and $1.7-$22.4 million in indirect costs in the 16 countries studied. Full serotyping data was available for 8 countries. G1P[8], G2P[4], G9P[8], and G3P[8] were the most prevalent serotypes (cumulative frequency: 57.2%- 98.7%). Serotype distribution in nosocomial RVGE was similar.

CONCLUSIONS

This review confirms that RVGE is a common disease associated with significant morbidity and costs across Western Europe. A vaccine protecting against multiple serotypes may decrease the epidemiological and cost burden of RVGE in Western Europe.

Molecular epidemiology and clinical characterization of group A rotavirus infections in Tunisian children with acute gastroenteritis

Rotaviruses are the most common cause of severe viral gastroenteritis in early childhood worldwide. Thus, the objectives of our study were to determine the molecular epidemiology and the clinical features of rotavirus gastroenteritis in Tunisia. Between January 2003 and April 2007, a prospective study was conducted on 788 stool samples collected from children under 12 years of age who were suffering from acute gastroenteritis. Rotavirus was detected by multiplex RT-PCR in 27% (n = 213) of samples, among them 79.3% (n = 169) cases were monoinfections. The frequency of rotavirus infections was significantly higher among inpatients (29%) than among outpatients (13%) (P < 0.001). The seasonal distribution of rotavirus diarrhea showed a winter peak, with an unusual peak from June to September. The mean duration of hospitalization was 6.5 ± 8.1 days and the mean age was 15.8 ± 22.8 months for rotavirus monoinfections. Fever, vomiting, abdominal pain, and dehydration were observed in 88, 98, 13, and 80 cases, respectively, in children with rotavirus monoinfections. G3P[8] (45.6%) and G1P[8] (23.9%) were the most common genotypes found in our study. The determination of rotavirus infection prevalence and the characterization of the rotavirus strains circulating will help us to better understand the molecular biology and epidemiology of the disease in our country.