All-cause Acute Gastroenteritis Research Articles

Health Care Utilization and Clinical Management of All-Cause and Norovirus-Associated Acute Gastroenteritis Within a US Integrated Health Care System.

Norovirus-associated acute gastroenteritis (AGE) exacts a substantial disease burden, yet the health care utilization for and clinical management of norovirus-associated AGE are not well characterized. We describe the health care encounters and therapeutics used for patients with all-cause and norovirus-associated AGE in the Kaiser Permanente Northwest health system from 1 April 2014 through 30 September 2016. Medical encounters for patients with AGE were extracted from electronic health records, and encounters within 30 days of one another were grouped into single episodes. An age-stratified random sample of patients completed surveys and provided stool samples for norovirus testing. In total, 40 348 individuals had 52 509 AGE episodes; 460 (14%) of 3310 participants in the substudy tested positive for norovirus. An overall 35% of all-cause AGE episodes and 29% of norovirus-associated AGE episodes had ≥2 encounters. While 80% of norovirus-associated AGE episodes had at least 1 encounter in the outpatient setting, all levels of the health care system were affected: 10%, 22%, 10%, and 2% of norovirus-associated AGE episodes had at least 1 encounter in virtual, urgent care, emergency department, and inpatient settings, respectively. Corresponding proportions of therapeutic use between norovirus-positive and norovirus-negative episodes were 13% and 10% for intravenous hydration (P = .07), 65% and 50% for oral rehydration (P < .001), 7% and 14% for empiric antibiotic therapy (P < .001), and 33% and 18% for antiemetics (P < .001). Increased health care utilization and therapeutics are likely needed for norovirus-associated AGE episodes during peak norovirus winter seasons, and these data illustrate that effective norovirus vaccines will likely result in less health care utilization.

Rotavirus Vaccine Impact Within an Integrated Healthcare Delivery System in the United States.

We assessed rotavirus vaccine impact using data on acute gastroenteritis (AGE) encounters within an integrated healthcare delivery system during 2000-2018. Following rotavirus vaccine introduction, all-cause AGE rates among children <5 years declined by 36% (95% confidence interval [CI]: 32%-40%) for outpatient and 54% (95% CI: 46%-60%) for inpatient encounters.

Risk Factors for Acute Gastroenteritis Among Patients Hospitalized in 5 Veterans Affairs Medical Centers, 2016-2019.

In the United States, ∼179 million acute gastroenteritis (AGE) episodes occur annually. We aimed to identify risk factors for all-cause AGE, norovirus-associated vs non-norovirus AGE, and severe vs mild/moderate AGE among hospitalized adults. We enrolled 1029 AGE cases and 624 non-AGE controls from December 1, 2016, to November 30, 2019, at 5 Veterans Affairs Medical Centers. Patient interviews and medical chart abstractions were conducted, and participant stool samples were tested using the BioFire Gastrointestinal Panel. Severe AGE was defined as a modified Vesikari score of ≥11. Multivariate logistic regression was performed to assess associations between potential risk factors and outcomes; univariate analysis was conducted for norovirus-associated AGE due to limited sample size. Among 1029 AGE cases, 551 (54%) had severe AGE and 44 (4%) were norovirus positive. Risk factors for all-cause AGE included immunosuppressive therapy (adjusted odds ratio [aOR], 5.6; 95% CI, 2.7-11.7), HIV infection (aOR, 3.9; 95% CI, 1.8-8.5), severe renal disease (aOR, 3.1; 95% CI, 1.8-5.2), and household contact with a person with AGE (aOR, 2.9; 95% CI, 1.3-6.7). Household (OR, 4.4; 95% CI, 1.6-12.0) and non-household contact (OR, 5.0; 95% CI, 2.2-11.5) with AGE was associated with norovirus-associated AGE. Norovirus positivity (aOR, 3.4; 95% CI, 1.3-8.8) was significantly associated with severe AGE. Patients with immunosuppressive therapy, HIV, and severe renal disease should be monitored for AGE and may benefit from targeted public health messaging regarding AGE prevention. These results may also direct future public health interventions, such as norovirus vaccines, to specific high-risk populations.

702. Risk Factors for Acute Gastroenteritis Among Patients Hospitalized in 5 Veterans Affairs Medical Centers, 2016–19

BackgroundIn the United States, an estimated 179 million acute gastroenteritis (AGE) episodes occur each year. Identifying factors contributing to AGE susceptibility and severity is important to address the high disease burden of AGE among adults. The primary objective of this analysis was to identify risk factors for all-cause AGE, norovirus-associated AGE and severe AGE among hospitalized adults. MethodsWe analyzed data from 1029 inpatient AGE cases and 624 non-AGE controls enrolled prospectively from December 1, 2016 – November 30, 2019 from 5 Veterans Affairs Medical Centers (Atlanta, Bronx, Houston, Los Angeles, Palo Alto). Standardized patient interviews and medical chart abstractions were conducted to collect demographics, exposure history, and underlying medical conditions. Stool samples from participants were tested for 22 pathogens using the BioFire Gastrointestinal Panel. Severity of AGE was determined using a 20-point modified Vesikari score (MVS) and severe AGE was defined as a MVS score of ≥ 11. Multivariate logistic regression was performed to assess associations between potential risk factors and outcomes. ResultsOf the total AGE cases, 551 (54%) had severe AGE; 44 (4%) were norovirus positive. Risk factors for all-cause AGE vs. non-AGE controls included household contact with a person with AGE in the past 7 days (aOR=2.9, 95% CI:1.3-6.7), severe renal disease (aOR=3.1, 95% CI:1.8-5.2), human immunodeficiency virus (HIV) (aOR=3.9, 95% CI:1.8-8.5), and immunosuppressive therapy (aOR=5.6, 95% CI:2.7-11.7). Factors associated with norovirus positivity by univariate analysis were contact with a person with AGE outside (OR=4.4, 95% CI:1.6-12.0) and within (OR=5.0, 95% CI:2.2-11.5) the household in the past 7 days. Detection of any viral pathogen (aOR=4.0, 95% CI:1.7-9.5) was a risk factor for severe AGE.ConclusionOur findings suggest that inpatients with HIV or severe renal disease, on immunosuppressive therapy, or in contact with a person with AGE within household are at higher risk for all-cause AGE. Patients with these medical conditions should be monitored for AGE related hospitalizations and may benefit from targeted AGE prevention messaging. Disclosures Vincent Marconi, MD, Bayer (Consultant, Scientific Research Study Investigator)Eli Lilly (Consultant, Scientific Research Study Investigator)Gilead Sciences (Consultant, Scientific Research Study Investigator)ViiV (Consultant, Scientific Research Study Investigator)

A major decrease in viral acute gastroenteritis in hospitalized Finnish children as rotavirus returns as the most detected pathogen

IntroductionThis study was performed to assess the prevalence and circulating genotypes of rotavirus, norovirus, and sapovirus in children. The results were compared to those of previous surveillance studies covering the years 2006–2008, 2009–2011, and 2012–2014 with similar methodology and setting, encompassing the start of universal vaccination with RotaTeq in 2009. MethodsStool samples were collected from children aged <16 years with acute gastroenteritis at Tampere University Hospital, Finland, from January 1, 2017 to December 31, 2018. The samples were analysed using reverse transcription PCR and positive amplicons were sequenced. ResultsA total of 178 stool samples were collected from 214 children. Rotavirus was detected in 56 (32%) stool samples, norovirus in 48 (27%), and sapovirus in 11 (6.3%). Rotavirus G9P[8] and G12P[8] were the most detected genotypes in vaccinated and unvaccinated children. GII.4 comprised 96% of the norovirus detections. ConclusionsThe prevalence of all-cause acute gastroenteritis in a hospital setting decreased by 51% compared to 2012–2014, and by 88% compared to 2006–2008 . Rotavirus returned as the most common cause of viral acute gastroenteritis in children, but the prevalence remains at a low level. No considerable changes were seen in the genotyping results of norovirus and sapovirus.

Burden and Trends of Severe Rotavirus Infections and Allcause Acute Gastroenteritis Hospital Episodes in Children Under Five Years Old in Mainland Portugal

Introduction: Rotavirus infections are a leading cause of severe acute gastroenteritis in children under five years old. In December 2019, Portugal announced the inclusion of the rotavirus vaccine, already available for private purchase, in the National Immunization Program. We present the first nationwide analysis of the burden and trends of rotavirus and acute gastroenteritis hospital episodes in children under five years old in mainland Portugal (2014 - 2017).Material and Methods: We used the hospital morbidity database and the Death Certificate Information System to identify hospital episodes and deaths of rotavirus and acute gastroenteritis based on the codes of the International Classification of Diseases. We described the number and rates of hospital episodes disaggregated by age group, sex, geographical units, and the seasonality and trends over the study period.Results: On average, during the study period, there were 1985 annual hospital episodes among children under five years old. The annual rate was 48.0/10 000 children (95% CI 46.9 - 49.0). Rates were consistently higher in younger children, and 67.8% episodes occurred in children under 24 months. We found a seasonal pattern with a major peak in the early spring.Discussion: Our results were consistent with the current knowledge on rotavirus and acute gastroenteritis hospital episodes in Europe. Additional studies are needed to identify the risk factors and high-risk groups for hospital attendance.Conclusion: Rotavirus and acute gastroenteritis hospital episodes in children under five years old in mainland Portugal represent an important health and economic burden. In the future, monitoring this burden and these trends in relation with rotavirus vaccine coverage could be useful in order to assess the impact of the vaccination programme on the change in hospital episodes.

Impact of Rotavirus Vaccines on Gastroenteritis Hospitalizations in Western Australia: A Time-series Analysis.

BackgroundRotavirus vaccination was introduced into the Australian National Immunisation Program in mid-2007. We aimed to assess the impact of the rotavirus vaccination program on the burden of hospitalizations associated with all-cause acute gastroenteritis (including rotavirus gastroenteritis and non-rotavirus gastroenteritis) in the Aboriginal and non-Aboriginal population in Western Australia.MethodsWe identified all hospital records, between July 2004 and June 2012, with a discharge diagnosis code for all-cause gastroenteritis. Age-specific hospitalization rates for rotavirus and non-rotavirus acute gastroenteritis before and after the introduction of the rotavirus vaccination program were compared. Interrupted time-series models were used to examine differences in the annual trends of all-cause gastroenteritis hospitalization between the two periods.ResultsBetween July 2004 and June 2012, there were a total of 106,974 all-cause gastroenteritis-coded hospitalizations (1,381 rotavirus-coded [15% among Aboriginal] and 105,593 non-rotavirus gastroenteritis-coded [7% among Aboriginal]). Following rotavirus vaccination introduction, significant reductions in rotavirus-coded hospitalization rates were observed in all children aged <5 years (up to 79% among non-Aboriginal and up to 66% among Aboriginal). Among adults aged ≥65 years, rotavirus-coded hospitalizations were 89% (95% confidence interval, 16–187%) higher in the rotavirus vaccination program period. The time-series analysis suggested reductions in all-cause gastroenteritis hospitalizations in the post-vaccination period among both vaccinated and unvaccinated (age-ineligible) children, with increases observed in adults aged ≥45 years.ConclusionsRotavirus vaccination has been associated with a significant decline in gastroenteritis hospitalizations among children. The increase in the elderly requires further evaluation, including assessment of the cost-benefits of rotavirus vaccination in this population.

Sustained Declines in Age Group-Specific Rotavirus Infection and Acute Gastroenteritis in Vaccinated and Unvaccinated Individuals During the 5 Years Since Rotavirus Vaccine Introduction in England.

The introduction of an oral live-attenuated monovalent rotavirus vaccine (Rotarix®) into the UK infant immunization program in July 2013 was associated with large reductions in laboratory-confirmed rotavirus infections and hospitalizations due to acute gastroenteritis (AGE) within 12 months. Here we report the 5-year impact of the program in England. Individuals with laboratory-confirmed rotavirus infections during 2000-2018 and all-cause hospitalizations for AGE during 2007-2018 were identified using national electronic records. Age-specific incidence rate ratios (IRR) and estimated numbers of cases averted in each of the 5 postvaccination years were calculated. There were 206 389 laboratory-confirmed rotavirus infections and 3 657 651 hospitalizations for all-cause AGE. Reductions of 69-83% in laboratory-confirmed rotavirus infections in all age groups and 77-88% in infants aged <1 year in each of the 5 postvaccine years are reported, with 11 386-11 633 cases averted annually. All-cause AGE hospitalizations were reduced by 12-35% across all age-groups and by 25-48% in <1 year-olds in the 5 postvaccine years, with 24 474-49 278 hospitalizations averted annually. There was strong evidence of indirect (herd) protection, with at least 50% and up to 80% of the non-specific end point of all-cause gastroenteritis (AGE) hospitalizations averted being in unvaccinated age-groups, primarily older adults. Seasonal changes include a possible shift from annual to biennial peaks with lower peak incidence and longer seasons. There were large and sustained declines in both laboratory-confirmed rotavirus infections and AGE hospitalizations across all age groups in each of the 5 years since the introduction of the UK rotavirus program.

Clinical Characteristics, Risk Factors, and Population Attributable Fraction for Campylobacteriosis in a Nicaraguan Birth Cohort.

Campylobacteriosis is an important contributor to the global burden of acute gastroenteritis (AGE). In Nicaragua, the burden, risk factors, and species diversity for infant campylobacteriosis are unknown. Between June 2017 and December 2018, we enrolled 444 infants from León, Nicaragua, in a population-based birth cohort, conducting weekly household AGE surveillance. First, we described clinical characteristics of symptomatic Campylobacter infections, and then compared clinical characteristics between Campylobacter jejuni/coli and non-jejuni/coli infections. Next, we conducted a nested case-control analysis to examine campylobacteriosis risk factors. Finally, we estimated the population attributable fraction of campylobacteriosis among infants experiencing AGE. Of 296 AGE episodes in the first year of life, Campylobacter was detected in 59 (20%), 39 were C. jejuni/coli, and 20 were non-jejuni/coli species, including the first report of Campylobacter vulpis infection in humans. Acute gastroenteritis symptoms associated with C. jejuni/coli lasted longer than those attributed to other Campylobacter species. In a conditional logistic regression model, chickens in the home (odds ratio [OR]: 3.8, 95% CI: 1.4-9.8), a prior AGE episode (OR: 3.3; 95% CI: 1.4-7.8), and poverty (OR: 0.4; 95% CI: 0.2-0.9) were independently associated with campylobacteriosis. Comparing 90 infants experiencing AGE with 90 healthy controls, 22.4% (95% CI: 11.2-32.1) of AGE episodes in the first year of life could be attributed to Campylobacter infection. Campylobacter infections contribute substantially to infant AGE in León, Nicaragua, with non-jejuni/coli species frequently detected. Reducing contact with poultry in the home and interventions to prevent all-cause AGE may reduce campylobacteriosis in this setting.

Spatio-temporal impact of self-financed rotavirus vaccination on rotavirus and acute gastroenteritis hospitalisations in the Valencia region, Spain

BackgroundSeveral studies have shown a substantial impact of Rotavirus (RV) vaccination on the burden of RV and all-cause acute gastroenteritis (AGE). However, the results of most impact studies could be confused by a dynamic and complex space-time process. Therefore, there is a need to analyse the impact of RV vaccination on RV and AGE hospitalisations in a space-time framework to detect geographical-time patterns while avoiding the potential confusion caused by population inequalities in the impact estimations.MethodsA retrospective population-based study using real-world data from the Valencia Region was performed among children aged less than 3 years old in the period 2005–2016. A Bayesian spatio-temporal model was constructed to analyse RV and AGE hospitalisations and to estimate the vaccination impact measured in averted hospitalisations.ResultsWe found important spatio-temporal patterns in RV and AGE hospitalisations, RV vaccination coverage and in their associated adverted hospitalisations. Overall, ~ 1866 hospital admissions for RV were averted by RV vaccination during 2007–2016. Despite the low-medium vaccine coverage (~ 50%) in 2015–2016, relevant 36 and 20% reductions were estimated in RV and AGE hospitalisations respectively.ConclusionsThe introduction of the RV vaccines has substantially reduced the number of RV hospitalisations, averting ~ 1866 admissions during 2007–2016 which were space and time dependent. This study improves the methodologies commonly used to estimate the RV vaccine impact and their interpretation.

Cost of pediatric hospitalizations in Burkina Faso: A cross-sectional study of children aged

IntroductionDiarrheal illness is a leading cause of hospitalizations among children <5 years. We estimated the costs of inpatient care for rotavirus and all-cause acute gastroenteritis (AGE) in two Burkina Faso hospitals. MethodsWe conducted a cross-sectional study among children <5 years from December 2017 to June 2018 in one urban and one rural pediatric hospital. Costs were ascertained through caregiver interview and chart abstraction. Direct medical, non-medical, and indirect costs per child incurred are reported. Costs were stratified by rotavirus results. Results211 children <5 years were included. AGE hospitalizations cost 161USD (IQR 117–239); 180USD (IQR 121–242) at the urban and 154USD (IQR 116–235) at the rural site. Direct medical costs were higher in the urban compared to the rural site (140USD (IQR 102–182) vs. 90USD (IQR 71–108), respectively). Direct non-medical costs were higher at the rural versus urban site (15USD (IQR 10, 15) vs. 11USD (IQR 5–20), respectively). Indirect costs were higher at the rural versus urban site (35USD (IQR 8–91) vs. 0USD (IQR 0–26), respectively). Rotavirus hospitalizations incurred less direct medical costs as compared to non-rotavirus hospitalizations at the rural site (79USD (IQR 64–103) vs. 95USD (IQR 80–118)). No other differences by rotavirus testing status were observed. The total median cost of a hospitalization incurred by households was 24USD (IQR 12–49) compared to 75USD for government (IQR 59–97). Direct medical costs for households were higher in the urban site (median 49USD (IQR 31–81) versus rural (median 14USD (IQR 8–25)). Households in the lowest wealth quintiles at the urban site expended 149% of their monthly income on the child’s hospitalization, compared to 96% at the rural site. ConclusionsAGE hospitalization costs differed between the urban and rural hospitals and were most burdensome to the lowest income households. Rotavirus positivity was not associated with greater household costs.

Effects of rotavirus vaccine on all-cause acute gastroenteritis and rotavirus hospitalizations in Israel: A nationwide analysis

BackgroundIn December 2010, the pentavalent rotavirus vaccine (RotaTeq) was added to the national immunization program in Israel. The study aim was to examine national reductions in all-cause acute gastroenteritis (AGE) and rotavirus gastroenteritis (RVGE) hospitalizations among children aged 0–59 months following the introduction of universal rotavirus immunization in Israel. MethodsWe extracted data from the Israel National Hospital Discharge Database. Hospitalization rates were calculated by dividing the annual number of all-cause AGE and RVGE hospitalizations by the number of children aged 0–59 months residing Israel. To assess rate reductions, we compared the mean hospitalization rate for the pre-vaccine years (2002–2008) with that for the universal vaccination years (2011–2017). Interrupted time-series analyses were undertaken. During 2008–2010 rotavirus vaccines were partially available. ResultsA total of 131,116 AGE hospitalizations were reported, of which 13,111 (10.0%) were coded as RVGE hospitalizations. The average annual all-cause AGE hospitalization rate during the pre-vaccine period was 147.9 (95% CI 146.7–149.0) per 10,000 children aged 0–59 months, and declined by 38.7–53.0% during the universal vaccination years. The average annual pre-vaccine RVGE hospitalization rate was 16.9 (95% CI 16.5–17.3) per 10,000 children, and declined by 89.1% during 2016–2017.Findings from interrupted time-series analyses showed significant impact of introducing universal rotavirus immunization on the declines of all-cause AGE and RVGE hospitalizations rates. A multivariable Autoregressive Integrated Moving Average model showed that the variable “immunization period” was a significant predictor of RVGE hospitalizations (t = 7.3, p < 0.001) for the universal vaccination years.The declines in hospitalizations rates of all-cause AGE were lower among Arab children compared to Jewish children, but the declines in RVGE rates were similar between the groups. ConclusionsNational hospitalization data demonstrated substantial and consistent reductions in all-cause AGE and RVGE hospitalizations following the implementation of universal rotavirus vaccination program.

Rotavirus Epidemiology and Vaccine Effectiveness: Continuing Successes and Ongoing Challenges.

* Abbreviations: AGE — : acute gastroenteritis ORV — : oral rotavirus vaccine RVGE — : rotavirus-associated gastroenteritis VE — : vaccine effectiveness The success of live-attenuated oral rotavirus vaccines (ORVs) in high-income countries has been extraordinary. In this issue of Pediatrics , Maguire et al1 provide an important addition to this literature with an analysis of Rotarix (GlaxoSmithKline, Brentford, United Kingdom) vaccine effectiveness (VE) and rotavirus epidemiology among children in New South Wales, Australia, from 2010 to 2017 (including during a 2017 outbreak). They found high 1-year VE of 89.5%, which decreased to 77.0% among those vaccinated 5 to 10 years previously. The median age of infection increased from 3.9 to 7.1 years over the study period. Interestingly, during the 2017 outbreak, the emerging equine-like G3P[8] and novel G8P[8] strains predominated in most age groups. Rotaviruses are the leading global cause of dehydrating acute gastroenteritis (AGE) in young children.2 Rotaviruses are segmented, double-stranded RNA viruses categorized according to the structural proteins VP7 and VP4, which define G and P genotypes, respectively. The introduction of Rotarix and RotaTeq (Merck & Co, Inc, Kenilworth, NJ) into national immunization programs in the mid-2000s led to dramatic, sustained reductions in rotavirus incidence, hospitalizations for all-cause AGE and rotavirus-associated gastroenteritis (RVGE), and diarrheal mortality.3 High VE (≥80%) in preventing RVGE hospitalizations among children younger than 5 years and evidence of herd immunity are consistently demonstrated in high-income countries,4,5 where today’s pediatric trainees may complete residency without having diagnosed a single case … Address correspondence to Benjamin Lee, MD, Department of Pediatrics, Larner College of Medicine, University of Vermont, 95 Carrigan Dr, Stafford Hall 308, Burlington, VT 05405. E-mail: benjamin.lee.1{at}med.uvm.edu

National rotavirus vaccination programme implementation and gastroenteritis presentations: the paediatric emergency medicine perspective.

Throughout the developed world, the introduction of rotavirus vaccination has led to reductions in the incidence and severity of acute gastroenteritis (AGE) in young children and consequently to reductions in paediatric emergency department (PED) attendances with AGE. Rotavirus vaccination was added to the Irish National Immunisation Schedule in November 2016. To assess the impact of vaccine introduction on citywide PED attendances and hospital admissions with all-cause AGE during rotavirus season. In an observational study, a retrospective search was performed of electronic records in three independent PEDs in Dublin. Weekly presentations and admissions with AGE in the first 30weeks (gastroenteritis season) of the years 2012-2018 were counted and stratified by age. Median weekly presentations in 2017-2018, 126 (interquartile range (IQR) 103-165) were significantly lower than in 2012-2016, 160 (IQR 128-214) (p < 0.001). A reduction in presentations was seen across the three hospitals and in those aged less than 5years. In one PED,median admissions in 2017-2018 were 10 (IQR 7-13) in comparison with nine (IQR 7-13) in 2012-2016, (p = 0.463). The emergency department AGE presentations to hospital ward admission rate was 6.7:1. A reduction in PED presentations with AGE is demonstrated post-rotavirus vaccine introduction into the Irish National Immunisation Schedule. No significant change in paediatric hospital admissions was demonstrated.

Effects of the rotavirus vaccine program across age groups in the United States: analysis of national claims data, 2001\u20132016

BackgroundThe direct effectiveness of infant rotavirus vaccination implemented in 2006 in the United States has been evaluated extensively, however, understanding of population-level vaccine effectiveness (VE) is still incomplete.MethodsWe analyzed time series data on rotavirus gastroenteritis (RVGE) and all-cause acute gastroenteritis (AGE) hospitalization rates in the United States from the MarketScan® Research Databases for July 2001–June 2016. Individuals were grouped into ages 0–4, 5–9, 10–14, 15–24, 25–44, and 45–64 years. Negative binomial regression models were fitted to monthly RVGE and AGE data to estimate the direct, indirect, overall, and total VE.ResultsA total of 9211 RVGE and 726,528 AGE hospitalizations were analyzed. Children 0–4 years of age had the largest declines in RVGE hospitalizations with direct VE of 87% (95% CI: 83, 90%). Substantial indirect effects were observed across age groups and generally declined in each older group. Overall VE against RVGE hospitalizations for all ages combined was 69% (95% CI: 62, 76%). Total VE was highest among young children; a vaccinated child in the post-vaccine era has a 95% reduced risk of RVGE hospitalization compared to a child in the pre-vaccine era. We observed higher direct VE in odd post-vaccine years and an opposite pattern for indirect VE.ConclusionsVaccine benefits extended to unvaccinated individuals in all age groups, suggesting infants are important drivers of disease transmission across the population. Imperfect disease classification and changing disease incidence may lead to bias in observed direct VE.Trial registrationNot applicable.

Effectiveness of oral rotavirus vaccination in England against rotavirus-confirmed and all-cause acute gastroenteritis

BackgroundThe monovalent oral rotavirus vaccine Rotarix® was introduced into the UK infant immunisation programme in 2013. We estimated vaccine effectiveness (VE) in the first two years of the programme. MethodsWe used a test-negative case-control design and enhanced national surveillance data for 1869 vaccine-eligible children tested for rotavirus infection to obtain adjusted odds ratios and VE against laboratory-confirmed rotavirus infections. Linked anonymised UK primary care and hospitalisation data from the Clinical Practice Research Datalink (40,723 children) and random-effects Poisson regression were used in a cohort study to estimate VE against all-cause acute gastroenteritis (AGE) and AGE hospitalisations. ResultsVE against laboratory-confirmed infection was 69% (95% Confidence Interval: 40–84%) for one dose and 77% (95%CI: 66–85%) for two doses. Two-dose VE in children aged <12 months and ≥12 months was 85% (95%CI: 74–91%) and 54% (95%CI: 15–75%), respectively. In contrast, we found no evidence that the vaccine was effective against all-cause AGE (VE = −20%, 95%CI: −36% to −5%), or against AGE hospitalisations (VE = 35%, 95% CI: −86% to 77%). ConclusionsIn this first detailed assessment of VE of the Rotarix® vaccine in the English national programme, we show that Rotarix® was highly effective in preventing laboratory-confirmed rotavirus infection in young children. This provides reassurance about the vaccine’s performance in real-life settings and gives key information for future cost-effectiveness analyses. The high VE against rotavirus-specific AGE, and the exceptionally successful implementation of the national rotavirus vaccine programme (with >90% vaccine coverage), explains the lack of VE against all-cause AGE because most AGE in the post-vaccine era would not have been due to rotavirus, although some underestimation of VE could also have occurred due to differential healthcare utilisation by vaccinated and unvaccinated infants. This highlights the importance of using specific vaccine-preventable endpoints for these scenarios.

Impact assessment of the incorporation of the rotavirus vaccine in the province of San Luis - Argentina.

Rotavirus (RV) is the main cause of acute gastroenteritis (AGE) in young children. The San Luis province of Argentina introduced RV vaccination in May 2013. We estimate vaccine impact (RVI) using real-world data. Data on all-cause AGE cases and AGE-related hospitalisations for San Luis and the adjacent Mendoza province (control group) were obtained and analysed by interrupted time-series methods. Regardless of the model used for counterfactual predictions, we estimated a reduction in the number of all-cause AGE cases of 20-25% and a reduction in AGE-related hospitalisations of 55-60%. The vaccine impact was similar for each age group considered (<1 year, <2 years and <5 years). RV vaccination was estimated to have reduced direct medical costs in the province by about 4.5 million pesos from May 2013 to December 2014. Similar to previous studies, we found a higher impact of RV vaccination in preventing severe all-cause AGE cases requiring hospitalisation than in preventing all-cases AGE cases presenting for medical care. An assessment of the economic value of RV vaccination could take other benefits into account in addition to the avoided medical costs and the costs of vaccination.

2154. How Well Are We Estimating the True Burden of Acute Gastroenteritis? Validation of Acute Gastroenteritis-Related ICD Codes in Pediatric and Adult U.S. Populations

BackgroundInternational Classification of Diseases (ICD) diagnostic codes from acute gastroenteritis (AGE)-associated medical encounters are used for AGE disease burden estimates, yet the validity of AGE-related ICD codes in both pediatric and adult populations is unknown. We estimated the validity of AGE-related diagnostic codes in these populations using two different multi-regional AGE active surveillance platforms.MethodsDiagnostic codes, demographic and clinical characteristics, and stool pathogen results from AGE-associated medical encounters were obtained for enrolled children <5 years old from seven sites in NVSN from December 1, 2011 to June 30, 2016, and for adult Veterans in four sites from SUPERNOVA from December 1, 2016 to February 28, 2018. SUPERNOVA also enrolled age- and time-matched non-AGE controls. Using AGE cases from the active surveillance networks, sensitivity and specificity of AGE ICD codes were estimated overall and stratified by age and health care setting using exact binomial tests.ResultsICD codes were collected from 14,952 enrolled children <5 years old with AGE, and 625 enrolled adults (525 AGE cases and 100 controls). The sensitivity of all-cause AGE codes in children was 54% (9,127/14,952, 95% confidence interval [CI] 54–55%), and in adults was 54% (283/525; 95% CI 50–58%), with a specificity of 100% (100/100; 95% CI 97–100%). Stratified analyses demonstrated higher sensitivity of all-cause AGE codes in children in the inpatient as compared with outpatient setting: 59% (417/675; 95% CI 57–61%) vs. 53% (934/1827; 95% CI 52–54%). In adults, this trend was reversed; all-cause AGE codes had a higher sensitivity in the outpatient as compared with the inpatient setting: 72% (50/69; 95% CI 60–83%), vs. 51% (233/456; 95% CI 46–56%), respectively.ConclusionAcross two different AGE active surveillance platforms, one enrolling only children and one enrolling only adults, the estimated sensitivity of all-cause AGE ICD codes were similarly low. This suggests that current national estimates for AGE disease burden may be underestimating the true burden of AGE pathogens in the United States, and emphasizes the importance of active, prospective surveillance.Disclosures All authors: No reported disclosures.

Evaluation of the Impact of a Rotavirus Vaccine Program on Pediatric Acute Gastroenteritis Hospitalizations: Estimating the Overall Effect Attributable to the Program as a Whole and as a Per-Unit Change in Rotavirus Vaccine Coverage.

Estimation of the overall effect of a vaccine program is essential, but the effect is typically estimated for a whole program. We estimated the overall effect of the Quebec rotavirus vaccine program, launched in November 2011, and the effect for each 10% increase in rotavirus vaccine coverage on pediatric hospitalizations for all-cause acute gastroenteritis. We implemented negative binomial regressions adjusted for seasonality, long-term trends, and infection dynamics, to estimate the effect of the vaccine program as: 1) a dichotomous variable, representing program presence/absence, and linear term to account for changes in trend in the period after the program began; and 2) a continuous variable, representing rotavirus vaccine coverage. Using exposure 1, the vaccine program was associated with a 51.2% (95% confidence interval (CI): 28.5, 66.7) relative decline in adjusted weekly hospitalization rates for all-cause acute gastroenteritis as of December 28, 2014. Using exposure 2, a 10% increase in rotavirus ≥1-dose coverage was associated with a 7.1% (95% CI: 3.5, 10.5) relative decline in adjusted weekly rates, with maximum coverage of 87.0% associated with a 47.2% (95% CI: 26.9, 61.9) relative decline. Estimation of the overall effect attributable to a change in vaccine coverage might be a useful addition to standard measurement of the overall effect.

Evidence of the impact of monovalent rotavirus vaccine on childhood acute gastroenteritis hospitalization in Togo

BackgroundMonovalent rotavirus vaccine (RV1) was introduced in the immunization schedule of Togo in June 2014. We evaluated the impact of rotavirus vaccines on acute gastroenteritis (AGE) and rotavirus-associated hospitalizations in Togolese children. MethodsSentinel surveillance for AGE (defined as ≥3 liquid or semi-liquid stools/24 h lasting <7 days) hospitalizations among children <5 years of age was conducted in two sites in the capital city, Lome. ELISA was used for diagnosis of rotavirus infection in children with AGE. Additionally, review of hospitalization registers was performed at five hospitals to assess trends in AGE hospitalizations among children aged <5 years. For the vaccine impact assessment, pre-rotavirus vaccine introduction (July 2010-June 2014) and post-rotavirus vaccine introduction (July 2014-June 2016) periods were compared for annual changes in proportions of hospitalizations associated with AGE and rotavirus. ResultsDuring the pre-vaccine period, sentinel surveillance showed that 1017 patients were enrolled and 57% (range, 53–62%) tested positive for rotavirus, declining to 42% (23% reduction) in the first post-vaccine year and to 26% (53% reduction) in the second post-vaccine year; declines were most marked among infants. The patient register review showed that, compared with pre-vaccine rotavirus seasons, declines in hospitalizations due to all-cause AGE during post-vaccine rotavirus seasons were 48% among <1 year age-group in both first and second years following vaccine introduction. Among 1–4 year olds no reduction was noted in the first year and a 19% decline occurred in the second year. ConclusionsWe report rapid and marked reduction in the number of AGE hospitalizations and the proportion of AGE hospitalizations attributable to rotavirus in the first two years post- RV1 implementation in Togo. It is necessary to monitor long-term vaccine impact on rotavirus disease burden through continued surveillance.