Impact of rotavirus disease in Spain: an estimate of hospital admissions due to rotavirus

Socio-demographic, Clinical and Laboratory Features of Rotavirus Gastroenteritis in Children Treated in Pediatric Clinic

AIM

The aim of work was presentation of several socio-demographic, clinical and laboratory characteristics of gastroenteritis caused by rotavirus.

THE EXAMINEES AND METHODS

The examinees were children under the age of five years treated at the Pediatric Clinic due to acute gastroenteritis caused by rotavirus. Rotavirus is isolated by method chromatographic immunoassay by Cer Test Biotec.

RESULTS

From the total number of patients (850) suffering from acute gastroenteritis, feces test on bacteria, viruses. protozoa and fungi was positive in 425 (49.76%) cases. From this number the test on bacteria was positive in 248 (58.62%) cases, on viruses it was positive in 165 (39.0%), on protozoa in 9 (2.12%) cases and on fungi only one case. Rotavirus was the most frequent one in viral test, it was isolated in 142 (86.06%) cases, adenoviruses were found in 9 (5.45%) cases and noroviruses in only one case. The same feces sample that contained rotavirus and adenoviruses were isolated in five cases, whereas rotavirus with bacteria was isolated in the same feces sample in five cases. The biggest number of cases 62 (43.66%) were of the age 6-12 months, whereas the smallest number 10 (7.04%) cases were of the age 37-60 months. There were 76 (53.52%) of cases of male gender, from rural areas there were 81 (57.04%) cases and there were 58 (40.80%) cases during the summer period. Among the clinical symptoms the most prominent were diarrhea, vomiting, high temperature, whereas the different degree of dehydration were present in all cases (the most common one was moderate dehydration). The most frequent one was isonatremic dehydration in 91 (64.08%) cases, less frequent one was hypernatremic dehydration in 14 (9.85%) cases. The majority of cases (97.89%) had lower blood pH values, whereas 67 (47.17%) cases had pH values that varied from 7.16 -7.20 (curve peak), normal values were registered in only 3 (2.11%) cases. Urea values were increased in 45 (31.07%) cases (the maximum value was 26.5 mmol/L), whereas creatinine value was increased in 41 (28.87%) cases (maximum value was 302 mmol/L).

CONCLUSION

The results show the high frequency of rotavirus infections in children hospitalized with acute gastroenteritis. Rotavirus may cause different dehydration degree with electrolyte, acid-base and other biochemical disorders. Preventing the infection caused by rotavirus is of a great importance.

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.

Hospitalizations due to rotavirus gastroenteritis in Catalonia, Spain, 2003-2008

Background

Rotavirus is the most common cause of severe gastroenteritis among young children in Spain and worldwide. We evaluated hospitalizations due to community and hospital-acquired rotavirus gastroenteritis (RVGE) and estimated related costs in children under 5 years old in Catalonia, Spain.

Results

We analyzed hospital discharge data from the Catalan Health Services regarding hospital admissions coded as infectious gastroenteritis in children under 5 for the period 2003-2008. In order to estimate admission incidence, we used population estimates for each study year published by the Statistic Institut of Catalonia (Idescat). The costs associated with hospital admissions due to rotavirus diarrhea were estimated for the same years. A decision tree model was used to estimate the threshold cost of rotavirus vaccine to achieve cost savings from the healthcare system perspective in Catalonia. From 2003 through 2008, 10655 children under 5 years old were admitted with infectious gastroenteritis (IGE). Twenty-two percent of these admissions were coded as RVGE, yielding an estimated average annual incidence of 104 RVGE hospitalizations per 100000 children in Catalonia. Eighty seven percent of admissions for RVGE occurred during December through March. The mean hospital stay was 3.7 days, 0.6 days longer than for other IGE. An additional 892 cases of presumed nosocomial RVGE were detected, yielding an incidence of 2.5 cases per 1000 child admissions. Total rotavirus hospitalization costs due to community acquired RVGE for the years 2003 and 2008 were 431,593 and 809,224 €, respectively. According to the estimated incidence and hospitalization costs, immunization would result in health system cost savings if the cost of the vaccine was 1.93 € or less. At a vaccine cost of 187 € the incremental cost per hospitalization prevented is 195,388 € (CI 95% 159,300; 238,400).

Conclusions

The burden of hospitalizations attributable to rotavirus appeared to be lower in Catalonia than in other regions of Spain and Europe. The relatively low incidence of hospitalization due to rotavirus makes rotavirus vaccination less cost-effective in Catalonia than in other areas with higher rotavirus disease burden.

Is Rotavirus contributing to an increase of diarrhoea in a region of Spain?

Diarrhoeal illnesses are the most frequent of notifiable diseases in Aragon. Physicians notify diarrhoea cases with presumed infectious origin on a weekly basis. Following an increase in 2005-2006, we aimed to identify the responsible organism(s) in order to inform control measures. We described seasonality of diarrhoea notifications for 1998-2004 and 2005-2006. We calculated correlations between diarrhoea notifications and enteric pathogens diagnosed in two Aragonese laboratories, and applied linear regression using coefficients of determination (r2). In 2005-2006 the winter peak of diarrhoea notifications increased from 2494 to 3357 weekly cases (34.6%) and the peak in Rotavirus diagnoses from 15 to 39 weekly cases. The correlation of diarrhoea notifications with Rotavirus was 0.05 in 1998-2004 and 0.42 in 2005-2006. The model for 1998-2004 included Salmonella enterica, Giardia lamblia and Clostridium difficile (r2=0.08) and for 2005-2006 Rotavirus and Astrovirus (r2=0.24). Our results suggest that Rotavirus contributed to the increase of diarrhoea notifications. We recommend determining the disease burden of Rotavirus in order to guide vaccination policies.

Estimated mortality and hospital admission due to rotavirus infection in the WHO European region

In 2006 two rotavirus vaccines were licensed for use in young children in Europe. This study aimed to estimate the mortality and hospital admissions due to rotavirus in children aged <5 years in the WHO European region using data from routine sources and published literature. We grouped 49/52 countries in the region by their World Bank Gross National Income (GNI) per capita. We obtained for children aged <5 years: populations, hospital discharges for diarrhoeal disease, estimated mortality rates and the percentage of deaths attributable to diarrhoeal disease, from WHO data sources or published literature, and combined them to estimate country-specific diarrhoeal disease mortality. Rotavirus-attributable percentages of hospital admissions due to diarrhoeal disease were obtained through a literature search, and an income-group median applied to countries in each GNI category. In the countries we studied in the WHO European region, rotavirus infection causes an estimated 6550 deaths (range 5671–8989) and 146 287 (range 38 374–1 039 843) hospital admissions each year in children aged <5 years. Hospital admission rates were similar across income groups (medians 2·0, 2·8, 4·2 and 1·9/1000 per year in low-, lower-middle-, upper-middle- and high-income countries, respectively). Seven countries, mostly in the low- and lower-middle-income groups, accounted for 93% of estimated deaths. Disease burden varied dramatically by income level in the European region. Rotavirus vaccination in Azerbaijan, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan and Turkey could potentially prevent 80% of all regional rotavirus deaths. Data from low-income countries is still sparse, and improved disease burden studies are required to better inform regional vaccine policy.

Gastroenteritis by rotavirus in Spanish children. Analysis of the disease burden

Rotavirus is one of the most common causes of gastroenteritis worldwide. With the commercialisation of effective rotavirus vaccines in Europe in sight, it is necessary to provide studies which evaluate the disease burden. The aim of this study is two-fold, on one hand, to determine the burden of the rotavirus disease in Spanish children under the age of five, and on the other, to estimate the economic cost of these hospitalizations. The study was undertaken during a 5 year period (2000-2004). The rotavirus hospitalization rate was determined using the Minimum Basic Data Set of the national hospital discharge register. The observed data were compared with those expected by applying a model developed by the Centers for Disease Control and Prevention (CDC) adapted for European Countries. The financial expense of these hospitalizations was estimated. Of all admissions coded as gastroenteritis, 31.6% were due to rotavirus. The hospitalization rate by rotavirus was 480 cases per 100,000 children under five. These data are within the confidence range proposed by the adapted CDC model. The financial expense due to hospitalizations reaches 123,262 euros yearly in a Spanish University Hospital. In conclusion, rotavirus contributes significantly to the hospitalization of acute gastroenteritis. The rate of hospitalization by rotavirus is higher compared to other studies carried out in Spain. In view of future commercialisation of rotavirus vaccines, more in-depth analysis considering direct and indirect costs are necessary.

Rotavirus vaccines: considerations for successful implementation in Europe

A group of European experts in infectious diseases and vaccinology has met on several occasions to assess the rationale for universal vaccination against rotavirus infection of infants in Europe. On the basis of the available data, we concluded that vaccination was the best approach to prevent severe rotavirus gastroenteritis, and that European countries should consider implementing rotavirus vaccination in their routine immunisation programmes. The main barrier to the implementation of rotavirus vaccination in Europe is a general lack of awareness of stakeholders, policymakers, health-care professionals, and parents about rotavirus disease and the advantages of vaccination. Further studies on the cost of the disease and the benefit of vaccination, together with raising awareness are necessary steps to ensure successful implementation of rotavirus vaccination in Europe.

[Burden of hospitalizations attributable to rotavirus infection in children in the Autonomous Region of Madrid, Spain, period 1999-2000]

OBJECTIVE

To assess rotavirus infection requiring hospitalization in children aged < or = 5 years between 1999 and 2000 in the Autonomous Region of Madrid (Spain).

MATERIAL AND METHOD

A retrospective study was conducted, based on the hospital data surveillance system (Conjunto Mínimo Básico de Datos [CMBD]) and on the Spanish national microbiological information system (Sistema de Información Microbiológica [SIM]). CMBD data for all hospital admissions in children aged < or = 5 years with a first-listed diagnosis of intestinal infectious disease (ICD-9-CM codes: 001-009) or non-infective gastroenteritis (ICD-9-CM code: 558) and the reports to the SIM of the major pathogen groups responsible for acute gastroenteritis were analyzed.

RESULTS

The annual incidence of hospitalizations for acute gastroenteritis was 69 cases per 10,000 children aged < or = 5 years. Fourteen percent of the 32,541 infections produced by pathogens responsible for acute gastroenteritis reported to the SIM were rotavirus. The estimated annual incidence of hospitalizations due to rotavirus infections was 12 cases per 10,000 children aged (3/4) 5 years. The mean length of stay was 4.0 days, the annual mean number of days of hospitalization was 1,382 days, and the annual cost was 565,907 J. During the rotavirus epidemic months (December and January), the percentage of excess hospitalizations was 67 %.

CONCLUSIONS

Rotavirus causes a significant proportion of hospital admissions due to acute gastroenteritis in children aged < or = 5 years in the Autonomous Region of Madrid.

The paediatric burden of rotavirus disease in Europe

Rotaviruses are a major cause of hospitalizations for acute gastroenteritis in developed countries. This review shows the burden of rotavirus disease in < 5-year-old children in Europe. An estimated 72,000-77,000 hospitalizations for community-acquired rotavirus disease occur annually in the 23 million under-fives living in the European Union (EU-25), with a median cost of Euro 1417 per case. Annual hospitalization incidence rates range from 0.3 to 11.9/1000 children < 5 years old (median 3/1000). The median proportion of hospital-acquired rotavirus disease among all cases of hospitalization for rotavirus disease is estimated to be 21%. Countries of the EU-25 require information on the burden of rotavirus disease to support introduction of rotavirus vaccines. Data on cases treated at home, medical visits, and emergency wards as well as rotavirus-associated deaths are limited. To fully evaluate the impact and effectiveness of rotavirus vaccination programmes in Europe, additional epidemiological studies will be critical and desirable.

Nosocomial rotavirus infection in European countries: a review of the epidemiology, severity and economic burden of hospital-acquired rotavirus disease

The data currently available on the epidemiology, severity and economic burden of nosocomial rotavirus (RV) infections in children younger than 5 years of age in the major European countries are reviewed. In most studies, RV was found to be the major etiologic agent of pediatric nosocomial diarrhea (31-87%), although the number of diarrhea cases associated with other virus infections (eg, noroviruses, astroviruses, adenoviruses) is increasing quickly and almost equals that caused by RVs. Nosocomial RV (NRV) infections are mainly associated with infants 0-5 months of age, whereas community-acquired RV disease is more prevalent in children 6-23 months of age. NRV infections are seasonal in most countries, occurring in winter; this coincides with the winter seasonal peak of other childhood virus infections (eg, respiratory syncytial virus and influenza viruses), thus placing a heavy burden on health infrastructures. A significant proportion (20-40%) of infections are asymptomatic, which contributes to the spread of the virus and might reduce the efficiency of prevention measures given as they are implemented too late. The absence of effective surveillance and of reporting of NRV infections in any of the 6 countries studied (France, Germany, Italy, Poland, Spain and the United Kingdom) results in severe underreporting of NRV cases in hospital databases and therefore in limited awareness of the importance of NRV disease at country level. The burden reported in the medical literature is potentially significant and includes temporary reduction in the quality of children's lives, increased costs associated with the additional consumption of medical resources (increased length of hospital stay) and constraints on parents'/hospital staff's professional lives. The limited robustness and comparability of studies, together with an evolving baseline caused by national changes in health care systems, do not presently allow a complete and accurate overview of NRV disease at country level to be obtained. RV is highly contagious, and the efficiency of existing prevention measures (such as handwashing, isolation and cohorting) is variable, but low at the global level because of the existence of numerous barriers to implementation (eg, lack of staff, high staff turnover, inadequate hospital infrastructure). Prevention of RV infection by mass vaccination could have a positive impact on the incidence of NRV by reducing the number of children hospitalized for gastroenteritis, therefore reducing the number of hospital cross-infections and associated costs.

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.

Childhood diarrhoea in Ankara, Turkey: epidemiological and clinical features of rotavirus-positive versus rotavirus-negative cases

Published reports dealing with rotavirus infections in Turkey are very scarce. This study included 1099 consecutive paediatric patients with diarrhoea, who sought care at 3 hospitals in Ankara, Turkey between 1999 and 2002 and were investigated for the presence of rotavirus antigen in faeces. Rotavirus antigen was detected by an immunochromatographic test, Simple Rotavirus (Operon, Spain). Other clinical and laboratory data were extracted from patient journals. A total of 404 (36.8%) patients were positive for rotavirus antigen. Rotavirus antigen was more frequently detected in boys than girls (40.8 vs 31.8%) and in children younger than 2 y (62.7%). The proportion of rotavirus-positive children was higher in the winter season (49.6%; November to April) and the highest proportion was observed in December (55.4%). Rotavirus-associated diarrhoea had a more severe clinical presentation than non-rotaviral diarrhoea; 55.3% of all patients who required hospitalization were rotavirus-positive. The seasonal and epidemiological characteristics of rotavirus diarrhoea in Ankara were similar to those in the USA and Europe. For reliable nationwide information about the epidemiology of rotavirus-associated disease in Turkey, more individual studies and reliable official statistics of gastroenteritis cases are needed.

Diversity of group A human rotavirus types circulating over a 4-year period in Madrid, Spain

The incidence and distribution of human rotavirus G types among children under 5 years old with acute gastroenteritis were determined over a 4-year period (1998 to 2002) by using monoclonal antibodies and reverse transcription-PCR methods. Rotavirus was detected in 1,155 (31%) of 3,760 specimens tested. Rotavirus was studied in every month of the 48-month survey period. Rotavirus activity occurred mainly (51%) in the typically cooler months in Spain (November to February). The age distribution of rotavirus-positive cases showed that 90% of patients (1,038 of 1,155) were under 2 years old. Rotavirus types were determined for 576 of 1,155 patients (50%). G1 was the main genotype detected (53%), and the second most common was G4 (24%). The G2, G9, and G3 rotavirus types were detected in 14, 6, and 2% of the cases, respectively. Dual infections were detected in only 0.6%. The seasonal distribution of genotypes showed a significant genotypic shift: whereas G4 strains predominated (57%) during the 1998 to 2000 seasons, the G1 gradually increased to account for 75% in the 2000 to 2002 seasons. In addition, the present study reports the first detection of the G9 genotype in human fecal samples in Spain. Therefore, additional types may be required for vaccine development strategies that currently target only types G1 to G4.

Burden of hospitalizations attributable to rotavirus infection in children in Spain, period 1999–2000

The aim of this study is to provide estimates on the incidence of rotavirus infection requiring hospitalization in children <or=5 years of age during the 1999-2000 period in Spain and the associated direct cost of these hospitalizations. Hospital admissions attributable to rotavirus were estimated by using data on confirmed laboratory reports of rotavirus and hospital admissions due to acute gastroenteritis. During the study period a total of 32541 cases of pathogens responsible for acute gastroenteritis were reported to the microbiological information national system (SIM) and 14.0% were rotavirus. The proportion of laboratory-confirmed rotavirus cases was extrapolated to the total number of hospitalizations for acute gastroenteritis in children <or=5 years of age. An annual incidence of 1.0 hospital admissions attributable to rotavirus per 1000 persons <or=5 years of age was found, although during the winter season it reached 2.5 hospitalizations per 1000. Overall, the estimated annual number of days of hospitalization attributable to rotavirus was 8742 days that results in a cost of 3.6 million per year.

Global illness and deaths caused by rotavirus disease in children

To estimate the global illness and deaths caused by rotavirus disease, we reviewed studies published from 1986 to 2000 on deaths caused by diarrhea and on rotavirus infections in children. We assessed rotavirus-associated illness in three clinical settings (mild cases requiring home care alone, moderate cases requiring a clinic visit, and severe cases requiring hospitalization) and death rates in countries in different World Bank income groups. Each year, rotavirus causes approximately 111 million episodes of gastroenteritis requiring only home care, 25 million clinic visits, 2 million hospitalizations, and 352,000-592,000 deaths (median, 440,000 deaths) in children <5 years of age. By age 5, nearly every child will have an episode of rotavirus gastroenteritis, 1 in 5 will visit a clinic, 1 in 65 will be hospitalized, and approximately 1 in 293 will die. Children in the poorest countries account for 82% of rotavirus deaths. The tremendous incidence of rotavirus disease underscores the urgent need for interventions, such as vaccines, particularly to prevent childhood deaths in developing nations.

Rotavirus vaccines: development, current issues and future prospects

The potential benefit of safe and effective rotavirus vaccination in reducing morbidity and especially mortality from rotavirus gastroenteritis among children in developing countries has long been recognised. More recently, the focus of attention shifted to developed countries, where cost-effectiveness analyses justified the routine introduction of rotavirus vaccines into childhood immunisation schedules. The recent withdrawal in the U.S.A. of the first licensed rotavirus vaccine (the tetravalent rhesus reassortant rotavirus vaccine), following investigation into reports of intussusception among a number of vaccinees, has directed attention once more towards rotavirus vaccine use in developing countries. However, issues relating to vaccine safety, efficacy, and cost, remain to be overcome before widespread introduction of rotavirus vaccines can be anticipated.

Epidemiology of pneumonia hospitalizations in Spain, 1995-1998

OBJECTIVES

This epidemiological survey was undertaken to estimate the burden of hospital admissions for pneumonia in Spain during a four-year period (1995-1998).

METHODS

Data were obtained from the national surveillance system for hospital data.

RESULTS

There were 231,512 hospital admissions for pneumonia (ICD 9 CM 480-486; first listed diagnosis) during this period, that is an annual incidence of 177 cases per 100,000 population. The incidence was higher in children <5 years of age and in persons >or=65 years compared with other age groups. The annual cost of these hospitalizations to the National Health Care System was of 127 million ECUS.

CONCLUSIONS

Preventive measures, such as vaccination of population groups at high risk, to reduce pneumonia-related morbidity could result in large cost savings to the National Health Care System.

Epidemiology of primary varicella hospitalizations in Spain

An approach to the burden of varicella can be obtained from information on the hospitalizations. Data were obtained from the national surveillance system for hospital data. All hospital discharges for varicella were analyzed for the 1995-1998 period. A total of 3632 primary varicella-related discharges were identified, representing an annual incidence of 2.8 per 100,000 population. A total of 58% of cases were <10 years of age and 33% were 21-50 years old. Each year primary varicella will be responsible for 6174 days of hospitalization, representing an annual cost of 1.6 million euros. There is substantial severe morbidity each year from varicella that, to reduce, would require vaccination of infants and susceptible adults.

Hospital admissions for pertussis in Spain, 1995-1998

This epidemiological survey was undertaken to estimate the annual burden of hospitalizations for pertussis in Spain during a four-year period 1995-1998. Data were obtained from the national surveillance system for hospital data. All hospital discharges for pertussis (ICD-9- CM 033) were analyzed. The annual incidence of hospitalization for pertussis was 1.7 per 100,000 population. Eighty-nine percent of the cases were < 1 year of age (incidence of 78 per 100,000) and 95% were < or =5 years of age (incidence of 28 per 100,000). During the study period, 14 deaths were reported among patients hospitalized by pertussis. Despite of the high immunization rates, many pertussis cases occur each year, mostly of them among very young children.

Hospital admissions for rotavirus infection in the Netherlands

The development of a vaccine against rotavirus (RV) infection has necessitated the estimation of the number of hospitalizations for RV infection in the Netherlands. During 1998, pediatricians have reported all hospitalizations with RV infection and supplied information on the duration of admission, clinical picture, indication for admission, and treatment. Also, data from the National Disease Registry on hospitalizations for gastroenteritis (International Classification of Disease codes 006.6. 006.8, 009, and 558.9) and laboratory surveillance data for 1996-1998 were combined in a linear regression model to indirectly estimate the incidence and proportion of hospitalizations attributable to RV infection. The direct estimate of admissions for RV infection in children aged <5 years was 0.9 per 1000, and the indirect estimate was 2.7 per 1000 in 1998 (1996, 3.4; 1997, 1.6). The proportion of hospitalizations for gastroenteritis attributable to RV ranged from 32% in 1997 to 58% in 1996.

VP7 and VP4 genotypes among rotavirus strains recovered from children with gastroenteritis over a 3-year period in Valencia, Spain

Between September 1996 and May 1999, the incidence and distribution of the main human rotavirus G genotypes (VP7 associated: G1-G4) and P genotypes (VP4 associated: P[8], P[4], P[6] and P[9]) among children with rotavirus gastroenteritis were determined using reverse transcription and polymerase chain reaction (RT-PCR)-based genotyping methods. From a total of 145 rotavirus strains examined, we identified the G type in 131 (90.3%) and the P type in 127 (87.5%) of the samples. An overall predominance of genotypes P[8] G1 (42.7%) and P[8] G4 (32.4%) was found during the period of study, with much lower incidence of genotypes P[4] G2 (5.5%) and P[8] G3 (2%). P[6] and P[9] types were not detected, neither were unusual combinations of P and G types. A significant genotypic shift was observed: whereas P[8] G4 was the most prevalent genotype during the first year of the study (60%), the genotype P[8] G1 gradually increased to account for 62.3% of the strains analysed in the following winter season. Mixed G types revealing dual infections G1/G4 and G3/G4 were found at low frequency (2%).

Seasonality and diversity of Group A rotaviruses in Europe

Group A rotaviruses are a major cause of severe gastroenteritis in children under 4 y of age worldwide. Group A rotaviruses have been identified in many animal and bird species, they are antigenically complex, and multiple serotypes infect humans. Re-assortant rotavirus vaccines are now available which confer protection against severe illness due to rotavirus serotypes G1-4. Before vaccines are introduced it is necessary to establish the diversity of rotavirus in the target population to ensure efficacy and to establish a baseline for future surveillance strategies. The purpose of this review is to describe our current knowledge of the diversity of rotaviruses across Europe. Since multinational studies with standardized methodology have not been performed, this review is based on the available published studies. In Europe, more than 90% of Group A rotavirus strains that have been typed are of serotypes G1-4, with an average 8% of non-G1-4 strains in published studies. The percentage of non-typeable strains may fluctuate from one year to another, and has been as high as 18% in one study in Great Britain, indicating the need for a more systematic study. Group A rotavirus infection typically occurs as a winter peak in the European countries studied. Comparison of seasonality data from national laboratory surveillance systems showed seasonal differences, with the annual rotavirus peak occurring first in Spain, usually in December, followed by France in February, and ending in Northern Europe in England and Wales in February or March, and the Netherlands and Finland in March.