Prospective population-based study on rotavirus disease in Germany

Review of Over 15 Years Postmarketing Safety Surveillance Spontaneous Data for the Human Rotavirus Vaccine (Rotarix) on Intussusception

Introduction

Rotavirus (RV) is the most common cause of acute gastroenteritis in children <5 years of age worldwide, and vaccination reduces the disease burden. Evidence from postmarketing surveillance studies suggested an increased risk of intussusception (IS) in infants post-RV vaccination. An overall positive benefit–risk balance for the human RV vaccine (HRV) Rotarix (GlaxoSmithKline [GSK], Belgium) has been established and recent findings indicate an indirect effect of reduced IS over the long term.

Objective

The aim of this study was to discuss spontaneous data from the GSK worldwide safety database on IS post-Rotarix administration.

Methods

The database was reviewed for all spontaneous IS cases from 2004 to 2020. Additionally, an observed versus expected (O/E) analysis was done for adverse events attributed to IS. Data were reviewed as overall worldwide and stratified by region (Europe/USA/Japan) and dose.

Results

A male predominance of IS patients was observed, consistent with earlier reports. The most frequently reported events in confirmed IS cases (Brighton Collaboration Working Group [BCWG] level 1) with time to onset ≤ 30 days post-vaccination were vomiting (55.8%), haematochezia (47.2%), and crying (21.1%). The observations from the IS spontaneous cases review and results of the O/E analysis are consistent with the known IS safety profile of RV vaccines: a transient increased incidence of IS post-vaccination (primarily in Europe/Japan/worldwide), mostly within 7 days postdose 1.

Conclusion

Since the outcomes of early IS management are favourable over delayed management, healthcare professionals should inform parents about the importance of seeking immediate medical advice in case of unusual behaviour of the vaccinated infant. GSK continues to monitor the IS risk post-Rotarix administration through routine pharmacovigilance activities.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s40264-021-01141-4.

Rotavirus (RV) is the most common cause of acute gastroenteritis and a major cause of death in young children worldwide. Vaccination has been instrumental in reducing the impact of RV disease. Real-world evidence suggests an increased risk of intussusception (an infrequent type of bowel obstruction) in infants following RV vaccination. We reviewed IS cases reported spontaneously worldwide in children following a two-dose vaccination with the human RV vaccine (Rotarix, GlaxoSmithKline [GSK]) since its launch in 2004. We observed that (1) IS occurred more frequently 7 days after the first dose and, to a lesser extent, after the second dose; (2) boys were more frequently affected than girls (56.3%); (3) of 862 confirmed reported cases, 557 required hospitalisation; and (4) surgical intervention was required for 294 of 557 hospitalised cases. We used statistical analysis to assess whether the number of cases observed would be higher or lower than the natural occurrence of IS (irrespective of vaccination). These results were in line with the known RV vaccine safety profile. It is important to constantly monitor the real-world safety profile of RV vaccines in the postmarketing setting. Since the outcomes of early management of IS are favourable compared with delayed management, healthcare professionals should inform parents to seek immediate medical advice if they observe unusual behaviour in their vaccinated child. In conclusion, our analyses on data of a large patient pool for this rare event reinforce the favourable safety profile of human RV vaccine and the benefits of vaccination in young children.

Sentinel hospital-based surveillance for assessment of burden of rotavirus gastroenteritis in children in Pakistan

Objectives

To determine the burden and molecular epidemiology of rotavirus gastroenteritis in children hospitalized with severe acute watery diarrhea in Pakistan prior to introduction of rotavirus vaccine.

Methods

A cross-sectional study was carried out over a period of two years from 2006 – 2008 at five sentinel hospitals in the cities of Karachi, Lahore, Rawalpindi, and Peshawar. Stool samples collected from children under five years of age hospitalized with severe acute watery diarrhea were tested for rotavirus antigen via enzyme immunoassay (EIA) (IDEA REF K6020 Oxoid Ltd (Ely), Cambridge, United Kingdom). A subset of EIA positive stool samples were further processed for genotyping.

Results

6679 children were enrolled and stool specimens of 2039 (30.5%) were positive for rotavirus. Rotavirus positivity ranged from 16.3% to 39.4% in the 5 hospitals with highest positivity in Lahore. 1241 (61%) of all rotavirus cases were in infants under one year of age. Among the strains examined for G-serotypes, the occurrence of G1, G2, G9 and G4 strains was found to be 28%, 24%, 14% and 13%, respectively. Among P-types, the most commonly occurring strains were P6 (31.5%) followed by P8 (20%) and P4 (12%). Prevalent rotavirus genotype in hospitalized children of severe diarrhea were G1P[8] 11.6% (69/593), followed by G2P[4] 10.4% (62/593), and G4P[6] 10.1% (60/593).

Conclusions

Approximately one third of children hospitalized with severe gastroenteritis in urban centers in Pakistan have rotavirus. Introduction of rotavirus vaccine in Pakistan's national immunization program could prevent many severe episodes and diarrheal deaths.

Breastfeeding protects against acute gastroenteritis due to rotavirus in infants

To assess whether breastfeeding protects against acute gastroenteritis (AGE) due to rotavirus (RV) infection compared to RV-negative AGE (RV-) in children age 0-12 months. Data from a community-based study of children with AGE from 30 pediatric practices in Germany, Switzerland, and Austria were evaluated. A case-control design was conducted with RV-positive AGE (RV+) cases and RV- AGE as controls. Odds ratios and 95% confidence intervals were estimated using log-linear regression models adjusting for child's age, family size, number of siblings, child care attendance, and nationality. A total of 1,256 stool samples were collected from infants with AGE; 315 (25%) were RV+ and 941 RV-. Being breastfed in the period of disease inception reduced the risk of AGE due to RV+ (OR, 0.53; 95% CI, 0.37-0.76). In infants 0-6 months of age, the protective effect was stronger (OR, 0.33; 95% CI, 0.19-0.55) than in 7-12-month-old children. Our study adds to the evidence of a protective concurrent effect of breastfeeding against rotavirus infection in infants, particularly in children 6 months and younger. Breastfeeding is important to diminish rotavirus-related gastroenteritis in infants before vaccination can be introduced.

Acute gastroenteritis: from guidelines to real life

Acute gastroenteritis is a very common disease. It causes significant mortality in developing countries and significant economic burden to developed countries. Viruses are responsible for approximately 70% of episodes of acute gastroenteritis in children and rotavirus is one of the best studied of these viruses. Oral rehydration therapy is as effective as intravenous therapy in treating mild to moderate dehydration in acute gastroenteritis and is strongly recommended as the first line therapy. However, the oral rehydration solution is described as an underused simple solution. Vomiting is one of the main reasons to explain the underuse of oral rehydration therapy. Antiemetics are not routinely recommended in treating acute gastroenteritis, though they are still commonly prescribed. Ondansetron is one of the best studied antiemetics and its role in enhancing the compliance of oral rehydration therapy and decreasing the rate of hospitalization has been proved recently. The guidelines regarding the recommendation on antiemetics have been changed according to the evidence of these recent studies.

Incidence and risk factors for community-acquired acute gastroenteritis in north-west Germany in 2004

In developed countries, acute gastroenteritis (AGE) is a major source of morbidity. However, only a few studies have estimated its incidence and the associated medical burden. This population-based study determined the incidence of community-acquired AGE patients seeking medical care and the relative role of various pathogens. Stool samples from patients with AGE presenting to a general practitioner (GP), pediatrician, or specialist in internal medicine for that reason were screened for various bacterial and viral enteropathogens. A control group was established as well. Incidences were calculated by the number of positive patients divided by the general population. The study was performed in north-west Germany in 2004. The incidence of AGE patients requiring medical consultation was 4,020/100,000 inhabitants. Children (<5 years of age) were at the highest risk (13,810/100,000 inhabitants). Of the patients, 6.6% were tested positive for an enteropathogenic bacteria and 17.7% for a viral agent. The predominant pathogens were norovirus (626/100,000) and rotavirus (270/100,000). Salmonella was the most frequently detected bacteria (162/100,000). The results presented confirm AGE and, specifically, AGE of viral origin as a major public health burden in developed countries.

Infantile gastroenteritis in the community: a cost-of-illness study

Rotavirus infections are the main cause of gastroenteritis in infants and children and it is expected that by the age of 5 years, nearly every child will have experienced at least one episode of rotavirus gastroenteritis. While severe cases are hospitalized, milder disease is either treated at home or by the GP, and as such the true prevalence of rotavirus infection in the community, and the burden of disease, is unknown. This paper reports the results of a cost-of-illness study which was conducted alongside a structured community surveillance study. Forty-eight percent of our sample was found to have rotavirus acute gastroenteritis; and the average total cost of a child presenting with rotavirus gastroenteritis ranged between pound sterling 59 and pound sterling 143 per episode, depending on the perspective. Given the prevalence and severity of the disease, the estimated burden of rotavirus gastroenteritis to society is pound sterling 11.5 million per year.

Group A rotavirus genotypes in Germany during 2005/2006

During the 2005/2006 winter season a total of 802 group A positive rotavirus specimens of patients from different regions throughout Germany were genotyped. Amplicons from a one-tube RT-PCR were typed by analysis of their (type-specific) size using type-specific primers, fluorescent consensus primers and a capillary sequencer for detection. While G1P[8] was predominant (45.8%), G9P[8] has emerged as the second most frequent genotype combination (37.7%). The distribution of genotypes was heterogeneous, regional frequencies regarding G1 and G9 were ranging from 15.0 to 89.3% and from 7.1 to 67.7%, respectively. Furthermore, a few human rotavirus G10P[6] and G10P[8] infections were observed.

Rotavirus and not age determines gastroenteritis severity in children: a hospital-based study

BACKGROUND

The severity of childhood gastroenteritis is generally believed to be age-related rather than aetiology-related. Rotavirus-induced gastroenteritis is more severe than gastroenteritis caused by other enteric pathogens and is also age-related. We thus addressed the question of whether the increased severity of rotavirus-induced gastroenteritis is related to age or to features intrinsic to the agent.

STUDY DESIGN

In this multicentre, hospital-based, prospective survey, we evaluated the severity of diarrhoea in rotavirus-positive and rotavirus-negative children up to 4 years of age. Severity was assessed with a score in four groups of age-matched children.

RESULTS

Rotavirus was detected in 381 of 911 children. Disease severity was evaluated in 589 cases for which clinical data were complete. The rotavirus-positive and rotavirus-negative groups differed with regards to diarrhoea duration, hospital stay, degree of dehydration and the number of episodes of vomiting. Gastroenteritis was more severe in rotavirus-positive than in rotavirus-negative children. In contrast, none of the main severity parameters differed in the four age groups, irrespective of the presence of rotavirus.

CONCLUSIONS

These data provide the evidence that aetiology and not age determines diarrhoeal severity. The demonstration that diarrhoea was more severe in rotavirus-positive children supports the need for a rotavirus vaccine and for studies that address the duration of vaccine protection.

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.

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.

Serotype diversity and reassortment between human and animal rotavirus strains: implications for rotavirus vaccine programs

The development of rotavirus vaccines that are based on heterotypic or serotype-specific immunity has prompted many countries to establish programs to assess the disease burden associated with rotavirus infection and the distribution of rotavirus strains. Strain surveillance helps to determine whether the most prevalent local strains are likely to be covered by the serotype antigens found in current vaccines. After introduction of a vaccine, this surveillance could detect which strains might not be covered by the vaccine. Almost 2 decades ago, studies demonstrated that 4 globally common rotavirus serotypes (G1-G4) represent >90% of the rotavirus strains in circulation. Subsequently, these 4 serotypes were used in the development of reassortant vaccines predicated on serotype-specific immunity. More recently, the application of reverse-transcription polymerase chain reaction genotyping, nucleotide sequencing, and antigenic characterization methods has confirmed the importance of the 4 globally common types, but a much greater strain diversity has also been identified (we now recognize strains with at least 42 P-G combinations). These studies also identified globally (G9) or regionally (G5, G8, and P2A[6]) common serotype antigens not covered by the reassortant vaccines that have undergone efficacy trials. The enormous diversity and capacity of human rotaviruses for change suggest that rotavirus vaccines must provide good heterotypic protection to be optimally effective.

Genetic variability among serotype G4 Italian human rotaviruses

A total of 254 serotype GH rotavirus strains were detected in Palermo, Italy, from 1985 to 2003. Out of 38 serotype G4 strains selected for genetic analysis, 14 were recognized by genotyping as type G9. Strains confirmed to belong to the G4 type showed temporal patterns of genetic evolution in their VP7 and VP4 gene sequences, and the latest Italian G4 strains were distantly related to the reference vaccinal ST3 strain.