Rotavirus-associated acute gastroenteritis hospitalizations among Japanese children aged <5 years: active rotavirus surveillance in Mie Prefecture, Japan

Two effective vaccines for rotavirus infection will be available near future in Japan and data on the burden of rotavirus disease and the circulating rotavirus strains are urgently needed. To obtain these data, we set up active rotavirus hospitalization surveillance in three cities, Tsu, Matsusaka, and Ise in Mie Prefecture, Japan. From November 1, 2007 through October 31, 2009, we enrolled children <5 years of age who were hospitalized with a diagnosis of acute gastroenteritis (AGE) and collected information on age, sex, month of admission, city of residence, and symptoms at the time of hospitalization. Stool samples were also obtained for rotavirus testing and genotype investigation. Rotavirus infection accounted for approximately 40% to 50% of hospitalized AGE cases in each city, and approximately 63% of those hospitalized were 2 years of age or younger. Matsusaka had the highest incidence rate at 4.7 rotavirus hospitalizations per 1,000 children <5 years of age (95% confidence interval [CI]: 3.6-5.9), followed by Tsu City (4.4 per 1,000; 95% CI: 3.6-5.3), and Ise City (2.8 per 1,000; 95% CI: 2.0-4.0). The most dominant rotavirus genotype was G3P[8], which accounted for 73.1% of cases. Our findings confirm the substantial health burden of rotavirus AGE hospitalization among Japanese children <5 years of age.     

Population-based estimates of the cumulative risk of hospitalization potentially associated with rotavirus diarrhea among children living in two cities in Akita Prefecture, Japan

A 4-year retrospective population-based survey was conducted in two cities in Akita Prefecture, Japan, to estimate the incidence rate and the cumulative risk of hospitalization potentially associated with rotavirus diarrhea. At monthly occasions of the 3-year-old checkup, we asked each parent if his or her child had ever been hospitalized because of rotavirus diarrhea. Based on 3-year follow-up of the four consecutive birth cohorts (1996-1999), we calculated the incidence rate and the cumulative risk of rotavirus-associated hospitalizations by the age of 3 years. The incidence rates of rotavirus-associated hospitalization in 1-year-old children in Akita city and Honjo city were 9.7 and 16 hospitalizations per 1,000 children per year, respectively, whereas 1.9% of children in Akita city and 3.3% of children in Honjo city were hospitalized by their third birthday because of rotavirus-associated diarrhea. The burden of rotavirus diarrhea in this region of Japan, and probably across the nation, appears substantially large.     

Cost-effectiveness analysis of a universal rotavirus immunization program in Japan

In anticipation of the imminent licensure of rotavirus vaccine, we evaluated the cost-effectiveness of rotavirus vaccine in Japan by taking into account the considerable variations in the incidence of rotavirus-associated hospitalizations previously reported in the literature. We assumed that the variation was due to local differences in healthcare utilization practices rather than a true difference in the incidence of severe rotavirus gastroenteritis. Thus, a Markov model was constructed such that the sum of rotavirus-associated hospitalizations and outpatient visits was set a constant value of 129 cases per 1,000 child-years. We calculated the direct medical cost, the indirect cost, and the quality-adjusted life year (QALY) loss in children aged less than 5 years. For the base case scenario, the incremental cost-effectiveness ratio (ICER) per QALY gained was 9.8 million Japanese yen from the healthcare perspective, but it was 900,000 Japanese yen from the societal perspective, making the program of universal immunization against rotavirus highly cost-effective. Furthermore, the universal immunization program was found to be cost-effective from the societal perspective for any of the previously reported incidence rates of rotavirus-associated hospitalization. Thus, the introduction of the rotavirus vaccine into the childhood immunization schedule and its co-administration with other childhood vaccines will be a cost-effective public health intervention in Japan.     

Epidemiological profile of rotavirus infection in the Republic of Korea: results from prospective surveillance in the Jeongeub District, 1 July 2002 through 30 June 2004

To facilitate future decisions regarding the usefulness of rotavirus vaccines in the Republic of Korea, active surveillance was conducted in a network of clinics, emergency departments, and hospitals serving Jeongeub District, Korea. Children with diarrhea underwent standard clinical evaluations, and stool specimens were collected to test for the presence of rotavirus. Parents were interviewed to collect demographic and family information. From 1 July 2002 through 30 June 2004, a total of 4106 children, representing 1 (50%) of every 2 children <5 years old in the study population, were evaluated for rotavirus diarrhea. Of the 2232 stool specimens obtained throughout the year, 460 (20.6%) were rotavirus positive; however, the monthly prevalence of rotavirus infection peaked at 49.5% in February 2004. Of the 460 rotavirus-positive stool specimens, 366 were obtained from children who visited outpatient clinics, and 94 were obtained from children who were hospitalized. By extrapolating the proportion of rotavirus-positive patients to all children with diarrhea in the surveillance system, we calculate that 882 children in Jeongeub District had rotavirus infection (which would predict that there would be 702 associated clinic visits and 180 hospitalizations). Genotyping of rotavirus strains showed that 39% of strains were type G9P[8], 24% were type G1P[8], 17% were type G3P[8], and 13% were type G2P[4]. The incidence of rotavirus diarrhea peaked at age 13-24 months, and 94% of cases occurred during the first 3 years of life. The annual incidence of all rotavirus disease-associated outcomes was 56.9 cases/1000 children <5 years old (95% confidence interval [CI], 51.9-62.2 cases/1000 children <5 years old). The incidence of rotavirus disease-associated hospitalizations was 11.6 cases/1000 children <5 years old (95% CI, 9.5-14.2 cases/1000 children <5 years old). In Korea, diarrhea is common during childhood, and the incidence of diarrhea due to rotavirus infection suggests that improved programs for the prevention and control of both rotavirus diarrhea and diarrhea due to other causes are needed.     

Estimation of annual incidence, age-specific incidence rate, and cumulative risk of rotavirus gastroenteritis among children in Japan

Rotavirus gastroenteritis is a common childhood infection, but the exact morbidity of the disease is not well described in Japan. We aimed at estimating morbidity measures to determine the magnitude of rotavirus gastroenteritis. An estimate for acute infectious gastroenteritis of all causes, to which rotavirus gastroenteritis belongs, has been available since the enactment in 1999 of the Law concerning the Prevention of Infectious Diseases and Medical Care of Patients with Infectious Diseases. Using this estimate and another estimate for the detection proportion of rotavirus among outpatients with acute infectious gastroenteritis, we calculated the annual incidence, the age-specific annual incidence rate, and the cumulative risk by the age of 6 years for rotavirus gastroenteritis. The latter estimate was obtained by a meta-analysis of four independent studies previously performed in Japan. According to our estimates, approximately 800,000 children in Japan under the age of 6 years visit pediatric practices or the outpatient department of hospitals because of rotavirus gastroenteritis at a rate of 11 cases/100 persons/year, and one in two children will visit pediatricians before they go to primary school. Such pediatrician visits most frequently occur at the age of 1 year (27 cases/100 persons/year). Thus, the magnitude of the burden of rotavirus disease among Japanese children is substantial.     

Hospitalizations and deaths from diarrhea and rotavirus among children <5 years of age in the United States, 1993-2003

Recently a new rotavirus vaccine was licensed in the United States and recommended for universal immunization of American children. The impact of the vaccine on a decrease in hospitalizations will take several years to assess and will be based on the availability of good baseline data on the disease. We used the largest US hospital discharge database available, the Healthcare Cost and Utilization Project (HCUP), to study national rates, trends, and risk factors for diarrhea- and rotavirus-associated hospitalizations and deaths among children <5 years of age, to establish a baseline against which vaccine implementation can be measured. Rotavirus remained the most important cause of pediatric diarrhea throughout the study period (1993-2003). When the data were extrapolated to the US population, rotavirus was estimated to be the cause of approximately 60,000 hospitalizations and 37 deaths annually. Black infants had a significantly higher risk of being hospitalized with and dying from rotavirus disease early in life, compared with white infants (risk ratio [RR] for hospitalization by 12 months of age was 2.4, with a 95% confidence interval [CI] of 1.2-4.7; RR for death was 2.0, with a 95% CI of 1.7-2.5). Such racial differences in age and risk of rotavirus-associated hospitalization and death highlight the importance of timely and early rotavirus immunization of minority children. The HCUP database serves as a sensitive and robust data source for monitoring the impact of a rotavirus-immunization program in the United States.     

Cost impact of COPD in Japan: Opportunities and challenges?

OBJECTIVE: The Global Initiative for Obstructive Lung Disease highlights the importance of COPD from public health, health policy and clinical perspectives. In countries such as the USA, the economic impact of COPD exceeds that of many chronic conditions. There is a paucity of data on the economic burden of COPD in Japan. METHODOLOGY: Based upon publicly available information, a prevalence-based approach was used to construct a deterministic model to estimate the total direct and indirect costs of care for COPD in Japan. Data sources included a spirometry-based epidemiological study, the peer-reviewed literature, and governmental and industrial surveys. The most current data that addressed direct and indirect costs of care were utilized. RESULTS: In Japan, the estimated total cost of COPD is 805.5 billion yen (US 6.8 billion dollars) per year; 645.1 billion yen (US 5.5 billion dollars) in direct costs and 160.4 billion yen (US 1.4 billion dollars) in indirect costs. In direct costs, inpatient care accounted for 244.1 billion yen (US 2.1 billion dollars), outpatient care 299.3 billion yen (US 2.5 billion dollars), and home oxygen therapy 101.7 billion yen (US 0.9 billion dollars). The average annual total cost per patient for moderate/severe COPD is estimated to be 435,876 yen (US 3694 dollars); 349,080 yen (US 2958 dollars) per COPD patient in direct costs and 86,797 yen (US 795 dollars) in indirect costs. CONCLUSION: COPD imposes a high economic burden on the Japanese healthcare system. Health policy makers should direct urgent attention to increasing prevention, early diagnosis, and appropriate treatment of COPD.     

Incidence of diarrhea caused by rotavirus infections in rural Zhengding, China: prospective, population-based surveillance

Rotavirus is the pathogen most commonly associated with severe gastroenteritis in young children in the People's Republic of China, yet there are few population-based data on the incidence of rotavirus infection. The present study investigated the burden of rotavirus diarrhea and rotavirus infections in rural China, according to age. Population-based surveillance was used to study the incidence of rotavirus infection among children <5 years of age in 4 townships of Zhengding County, Hebei Province, China. The total population in the catchment area in 2002 was 75,630 individuals, including 2997 children aged <5 years. Stool samples were obtained and were tested for rotavirus antigen by use of an enzyme-linked immunosorbent assay. During 2002, a total of 2010 cases of diarrhea were detected among children <5 years of age. The incidence of treated cases of diarrhea was 671 cases/1000 children/year for children <5 years of age, and it was highest for children <12 months of age (1467 cases/1000 children/year). The estimated incidence of rotavirus infection was 151 cases/1000 children/year for children <5 years of age. The highest incidence of rotavirus infection was among children aged 1-2 years (340 cases/1000 children/year). Widespread immunization of children against rotavirus before 6 months of age should be considered for the control of rotavirus diarrhea.     

Infant rotavirus vaccination may provide indirect protection to older children and adults in the United States

Following the introduction of rotavirus vaccination in the United States, rotavirus and cause-unspecified gastroenteritis discharges significantly decreased in 2008 in the 0-4, 5-14, and 15-24-year age groups, with significant reductions observed in March, the historic peak rotavirus month, in all age groups. We estimate that 15% of the total 66 000 averted hospitalizations and 20% of the $204 million in averted direct medical costs attributable to the vaccination program were among unvaccinated 5-24 year-olds. This study demonstrates a previously unrecognized burden of severe rotavirus in the population >5 years and the primacy of very young children in the transmission of rotavirus.     

Epidemiology and strain characterization of rotavirus diarrhea in Malaysia.

OBJECTIVES: The objectives of the study were to describe the epidemiology and strain characterization of rotavirus (RV), to determine the proportion of hospitalizations for diarrhea attributable to RV among children under 5 years of age, and to estimate the disease burden of RV diarrhea in Malaysia. METHODS: All children 0-59 months of age admitted for acute gastroenteritis to Kuala Lumpur Hospital (KLH) or Hospital Umum Sarawak (HUS) were surveyed. The periods of surveillance were from February 1, 2001 to April 30, 2003 in KLH and April 1, 2001 to March 31, 2003 for HUS. RESULTS: The highest rate of RV-associated diarrhea was among children aged 6-17 months, accounting for 55% of RV-associated diarrhea. There was no seasonality observed in either hospital. P[8]G9 strains were predominant, accounting for 73% of all strains in both hospitals, 80% from KLH and 61% from HUS. There was no mortality. CONCLUSIONS: RV was responsible for 38% of hospitalizations for diarrhea. It was most common in the 6-17 months age group. There was no seasonality observed for RV-associated diarrhea. The most prevalent strain of RV was P[8]G9. The estimated incidence of RV-associated diarrhea was 27 per 10000 population under the age of 5 years per year.     

Sentinel hospital surveillance for rotavirus diarrhea in Taiwan, 2001-2003

We examined the epidemiological profile of rotavirus infection among children hospitalized for diarrhea in Taiwan, to assess the burden of this disease. From 1 April 2001 through 31 March 2003, children <5 years old with gastroenteritis admitted to 4 sentinel hospitals were enrolled in a surveillance study and had stool specimens tested for the presence of rotavirus, enteric adenovirus, and the bacterial pathogens for which routine screening is performed. For 52% of patients, a recognized enteric pathogen was identified, including rotavirus (43% of patients), bacteria (11%), enteric adenovirus (2.5%), and a mixture of pathogens (3.9%). Rotavirus was detected year-round, but great month-to-month variability made it difficult to identify a distinct seasonal pattern. Rotavirus disease was most common among children 7-23 months old, but the rate of rotavirus detection varied little between the youngest and oldest age groups. The novel strain P[8]G9 was detected most commonly (37% of strains), followed by strains P[8]G1 (31%), P[4]G2 (10%), P[8]G3 (9.3%), and P[8]G4 (3.7%). Rotavirus infection is the most important cause of diarrhea among hospitalized children in Taiwan, and a rotavirus vaccination program for young children might significantly reduce this problem.     

Prospective Study of the Burden of Acute Gastroenteritis and Rotavirus Gastroenteritis in Children Less Than 5 Years of Age, in Padova, Italy

BACKGROUND: : Data on the burden of rotavirus gastroenteritis in Europe are needed to help understand the potential impact of introducing new rotavirus vaccines. MATERIALS AND METHODS: : As part of prospective observational study (Rotavirus gastroenteritis Epidemiology and Viral types in Europe Accounting for Losses in Public Health and Society Study, REVEAL) conducted in 2004-2005 in seven European countries, we studied, the characteristics of acute gastroenteritis and rotavirus gastroenteritis in children less than 5 years in primary care, emergency room and hospital settings (Padova, Italy). RESULTS: : A total of 757 children with acute gastroenteritis were included and enzyme-linked immunoabsorbent assay (ELISA) results were available for 725 cases. The overall estimated annual incidence for rotavirus gastroenteritis was 4.7%. Overall, rotavirus gastroenteritis was estimated to account for 43.6% of acute gastroenteritis cases. Among children with acute gastroenteritis (AGE) aged 6-23 months, 61.2% were rotavirus positive. Rotavirus gastroenteritis (RVGE) was responsible for 68.8% of hospitalizations, 61% of emergency consultations, and 33% of primary care consultations. The most prevalent serotype was G9 (84.4%) followed by G1 (11.8%). The relative risk for rotavirus gastroenteritis of being referred to hospital after an initial consultation in primary care was 3.37 (95% CI: 1.77-6.43) and 3.38 (95% CI: 2.28-5.01) for emergency room referral. Children with rotavirus gastroenteritis generally had more severe disease than children with rotavirus-negative gastroenteritis. CONCLUSION: : Rotavirus accounts for a significant proportion of acute gastroenteritis cases in children less than 5 years in Italy, many of whom require frequent primary care consultations, or care in emergency room or hospital settings.     

Estimating hospital admissions due to rotavirus gastroenteritis from hospital episode statistics

OBJECTIVES: To determine the proportion of hospital admissions, in children < 5 years old, coded for intestinal infectious disease or non-infectious gastroenteritis, using ICD-10 codes, that were due to rotavirus infection. To assess how many children admitted with rotavirus gastroenteritis were given the specific ICD-10 code (A080) for this disease. METHODS: Sixteen-month prospective, observational study of children < 5 years old, admitted to district general hospital with: acute gastroenteritis (> or =3 loose stools/day), proven rotavirus infection and those coded as intestinal infectious disease or non-infectious gastroenteritis. RESULTS: Four hundred and twenty children < 5 years old were admitted with acute gastroenteritis. Rotavirus was detected in 170 children's stools. Acute rotavirus gastroenteritis accounted for 81/397 (20%) children coded as having non-infectious gastroenteritis and 32/81 (40%) coded for intestinal infectious disease. Only 18 children were coded for rotavirus gastroenteritis. Potentially preventable rotavirus gastroenteritis occurred in 122 children; 78 coded as non-infectious gastroenteritis (20%) and 26 coded for intestinal infectious disease (34%). CONCLUSIONS: The proportion of children coded with diarrhoeal diseases and found to have rotavirus is less than previously estimated. Using the specific code for rotavirus infection to estimate hospital admissions would be a gross underestimate. Hospital episode statistics cannot reliably estimate the burden of disease due to rotavirus.     

Incidence of severe rotavirus diarrhea in New Delhi, India, and G and P types of the infecting rotavirus strains

A total of 62,475 children <5 years old from a defined population of approximately 500,000 children and adults from slums in New Delhi, India, were assessed for 1 year by means of passive surveillance, to identify children who were hospitalized for diarrhea. The incidence of severe rotavirus diarrhea was estimated, and the G and P types of the infecting rotavirus strains were determined and were correlated with the clinical severity of diarrhea. Of 584 children who were hospitalized with diarrhea, 137 (23.5%) had rotavirus detected in stool specimens (incidence of rotavirus diarrhea-associated hospitalizations, 337 hospitalizations/100,000 children <5 years of age). Most cases of diarrhea (98%) occurred during the first 2 years of life, peaking at 9-11 months of age. Rotavirus-associated diarrhea occurred year-round but was predominant in winter. Among the strains that could be G-typed, G1 was the most common serotype, followed by G9 and G2; 10% of cases of diarrhea were due to mixed G-type infections. Common strains identified in the present surveillance study were P[8]G1, P[4]G2, P[8]G9, P[6]G1, P[6]G9, and P[6]G3. Children infected with G1 strains had a greater risk of developing more-severe cases of diarrhea than did children infected with other rotavirus strains (odds ratio, 2.95; 95% confidence interval, 1.3-6.67).     

A Prospective Hospital-based Surveillance to Estimate Rotavirus Disease Burden in Bhutanese Children under 5 Years of Age

As part of efforts to develop an informed policy for rotavirus vaccination, this prospective study was conducted to estimate the burden of rotavirus diarrhea among children less than 5 years old attended to the Department of Pediatrics, Jigme Dorji Wangchuk National Referral Hospital (JDWNRH), Thimphu, Bhutan. The duration of the study was three years, extending from February 2010 through December 2012. We estimated the frequency of hospitalization in the pediatric ward and dehydration treatment unit (DTU) for diarrhea and the number of events attributable to rotavirus infection among children under 5 years of age. During the study period, a total of 284 children (1 in 45) were hospitalized in the pediatric ward, and 2,220 (1 in 6) in the DTU with diarrhea among children residing in the Thimphu district. Group A rotavirus was detected in 32.5% and 18.8% of the stool samples from children hospitalized in the pediatric ward, respectively. Overall, 22.3% of the stool samples were rotavirus-positive, and the majority (90.8%) of them was detected in children under 2 years of age. From this study, we estimated that the annual incidence of hospitalization in the pediatric ward and DTU due to rotavirus diarrhea was 2.4/1000 (95% CI 1.7–3.4) and 10.8/1000 (95% CI 9.1–12.7) children, respectively. This study revealed that rotavirus is a major cause of diarrhea in Bhutanese children in Thimphu district and since no study has been performed previously, represents an important finding for policy discussions regarding the adoption of a rotavirus vaccine in Bhutan.     

Hospitalizations for diarrhea in Quebec children from 1985 to 1998: Estimates of rotavirus-associated diarrhea

OBJECTIVE:

To characterize the incidence and duration of hospitalization due to diarrhea and to assess the proportion of hospitalizations that are attributed to rotavirus-associated diarrhea.

DESIGN:

Retrospective study of hospitalization data.

SETTING:

Hospitals located in Quebec.

POPULATION STUDIED:

Children from one to 59 months of age who were discharged from hospital from April 1, 1985 to March 31, 1998.

MAIN RESULTS:

There were 63,827 hospitalizations for diarrhea over the study period, for an average of 4910 hospitalizations/year. The epidemic curve showed a periodicity with regular alternation of high and low annual peaks. The number of hospitalizations for rotavirus-associated diarrhea was estimated according to three different methods. The estimates varied between 1353 and 1849 hospitalizations due to rotavirus-associated diarrhea/year over the 13-year period, with good agreement between the results of the three methods for a one-month to five years of age incidence of 320 hospitalizations for rotavirus-associated diarrhea/100,000 children. The average duration of hospital stay decreased from 5.2 days in 1985 to 3.3 days in 1998.

CONCLUSIONS:

The present article shows the importance of diarrhea hospitalizations among children and the alternating peak-year periodicity.Key Words: Children, Diarrhea, Hospitalization, Quebec, RotavirusDiarrhea is an important public health problem in children. Although no longer a frequent cause of death in developed countries, rotavirus remains the major cause of hospitalizations for diarrhea among children (1). Although the first commercial vaccine was withdrawn quickly from the market because of an association with intussusception (2), other vaccines are being developed and are expected soon. The benefits that are expected from these vaccines are a contentious issue in developed nations (3). Before considering the universal use of a new rotavirus vaccine, it is essential to estimate the benefit that may be expected from its introduction. Outpatient consultations and hospitalizations are the main contributors to the burden of diarrhea. The purpose of the present study was to estimate the number of hospitalizations that may be associated with rotavirus. These data are not directly available because routine microbiological testing is not performed for all children who are hospitalized for diarrhea.In Quebec, complete computerized hospitalization data have been available since 1985. In the present study, three different methods were used to estimate the proportion of all hospitalizations with a diagnosis of diarrhea that could be attributable to rotavirus.     

The effect of routine rotavirus vaccination on healthcare utilization for diarrhea in US children

Cortes et al. thoroughly analyzed the effect of the introduction of mass rotavirus vaccination on healthcare utilization in a population of approximately 2 million US children under 5 years of age. According to the results of the study, hospitalization has been reduced from prevaccination periods by 89% for rotavirus diarrhea and by 44% for diarrheal disease. The estimated reduction of hospitalizations during the two (single-year) periods amounted to 64,855 and the respective savings in treatment costs were US$278 million. The significance of this paper is its approach to the estimation of vaccine efficacy by the assessment of vaccination coverage and hospitalization, as well as emergency department and outpatient visits in a large population of children without any 'selection' (e.g., hospitalization) bias.     

Hospital-based surveillance for rotavirus diarrhea in children in Yangon, Myanmar

Diarrhea is a common childhood illness in Myanmar, and rotavirus is the single most important etiological agent of diarrhea. Surveillance for rotavirus diarrhea in children <5 years of age was conducted in a tertiary pediatric hospital in Yangon, Myanmar, from January 2002 through December 2003. Stool specimens obtained from children admitted to the hospital for acute diarrhea were tested for the presence of rotavirus by use of an enzyme-linked immunosorbent assay. Diarrhea was the cause of 5671 (18%) of all hospitalizations of children <5 years of age during the 2-year study period (n = 30,869). Rotavirus was identified in 923 (53%) of the 1736 stool specimens tested, and rotavirus infection was associated with approximately 10% of all hospitalizations of children. Rotavirus diarrhea most frequently occurred in children 6-17 months of age, and it was more commonly identified in boys (62% of children with rotavirus diarrhea were boys). The seasonal pattern of rotavirus disease mimicked that of diarrheal illness due to all causes, with the peak season for rotavirus disease occurring from November through February (i.e., during the cool, dry season). During the study period, 53 of the children who were hospitalized for diarrhea died. The present study confirms the importance of the etiological role that rotavirus plays in childhood diarrhea.     

Burden of rotavirus disease: A population-based study in Eastern Townships,Quebec

BACKGROUND:

Since July 2010, the National Advisory Committee on Immunization of Canada has recommended rotavirus vaccination for all healthy infants. However, before implementing this vaccine in routine health programs, Canadian provinces need to establish current epidemiological data on rotavirus-associated acute gastroenteritis (AGE).

METHODS:

A retrospective cohort study of children <5 years of age with AGE from 2002 to 2008 was performed in Eastern Townships, Quebec (population in 2006: 298,780). Data were collected on visits to outpatient clinics, emergency department (ED) visits, hospitalizations (standard and short-stay units) and nosocomial AGE. The winter residual estimation and Brandt methods were used to estimate the proportion of AGE attributable to rotaviruses.

RESULTS:

During the six-year study period, a total of 1435 hospitalizations, 3631 ED visits and 6220 ambulatory care visits were attributed to AGE. The specific rotavirus burden was estimated to be 449 to 666 for hospitalizations, 1050 to 1361 for ED visits and 1633 to 1687 for outpatient visits. The epidemic curve showed a periodicity with higher incidence in March and April. Short-stay unit hospitalizations represented 58% of all hospitalizations. The annual incidence rate of rotaviruses was estimated to be 50 to 74 per 10,000 children for hospitalizations, 117 to 152 per 10,000 children for ED visits and 182 to 188 per 10,000 children for outpatient visits.

CONCLUSION:

Most available retrospective studies probably underestimate rotavirus-associated hospitalizations because they do not take into account short-stay unit hospitalizations. Furthermore, these data on emergency and outpatient visits provide an exhaustive appraisal of the rotavirus burden, which serves as crucial information for the evaluation of immunization programs.