Rotavirus symptomatic infection among unvaccinated and vaccinated children in Valencia, Spain

BACKGROUND

Human group A rotavirus is the leading cause of severe acute gastroenteritis in young children worldwide. Immunization programs have reduced the disease burden in many countries. Vaccination coverage in the Autonomous Region of Valencia, Spain, is around 40%, as the rotavirus vaccine is not funded by the National Health System. Despite this low-medium vaccine coverage, rotavirus vaccination has substantially reduced hospitalizations due to rotavirus infection and hospital-related costs. However, there are very few studies evaluating symptomatic rotavirus infections not requiring hospitalization in vaccinated children. The objective of this study was to investigate symptomatic rotavirus infections among vaccinated children in the health area served by the Hospital Clínico Universitario of Valencia, Spain, from 2013 to 2015.

METHODS

A total of 133 children younger than 5 years of age with rotavirus infection were studied. Demographic and epidemiological data were collected and informed consent from their caretakers obtained. Rotavirus infection was detected by immunological methods and G/P rotavirus genotypes were determined by RT-PCR, following standard procedures from the EuroRotaNet network.

RESULTS

Forty infants (30.1%; 95% CI: 22.3-37.9) out of 133 were diagnosed with symptomatic rotavirus infection despite having been previously vaccinated, either with RotaTeq (85%) or with Rotarix (15%). Children fully vaccinated against rotavirus (24.8%), partially vaccinated (5.3%) and unvaccinated (69.9%) were found. The infecting genotypes showed high G-type diversity, although no significant differences were found between the G/P genotypes infecting vaccinated and unvaccinated children during the same time period. G9P[8], G12P[8] and G1P[8] were the most prevalent genotypes. Severity of gastroenteritis symptoms required 28 (66.6%) vaccinated and 67 (73.6%) unvaccinated children to be attended at the Emergency Room.

CONCLUSION

Rotavirus vaccine efficacy in reducing the incidence of severe rotavirus infection has been well documented, but symptomatic rotavirus infection can sometimes occur in vaccinees.

Rotavirus vaccination in Europe: drivers and barriers

Rotavirus gastroenteritis is a vaccine-preventable disease that confers a high medical and economic burden in more developed countries and can be fatal in less developed countries. Two vaccines with high efficacy and good safety profiles were approved and made available in Europe in 2006. We present an overview of the status of rotavirus vaccination in Europe. We discuss the drivers (including high effectiveness and effect of universal rotavirus vaccination) and barriers (including low awareness of disease burden, perception of unfavourable cost-effectiveness, and potential safety concerns) to the implementation of universal rotavirus vaccination in Europe. By February, 2014, national universal rotavirus vaccination had been implemented in Belgium, Luxembourg, Austria, Finland, Greece, Luxembourg, Norway, and the UK. Four other German states have issued recommendations and reimbursement is provided by sickness funds. Other countries were at various stages of recommending or implementing universal rotavirus vaccination.

A reverse evidence of rotavirus vaccines impact

In 2010, and due to a quality problem identified in the vaccine manufacture, the rotavirus (RV) vaccination was withheld in Spain during 5 months. Our study aimed to evaluate the impact that this sudden cease had on rotavirus acute gastroenteritis (RAGE) hospitalizations. An increase in RAGE hospitalization was observed in parallel to the drop in vaccine coverage. Here, we report the first reverse evidence of rotavirus vaccine impact.

Effectiveness of one and two doses of varicella vaccine in preventing laboratory-confirmed cases in children in Navarre, Spain

Varicella vaccine effectiveness was evaluated in a case-control study in Navarre, Spain, in 2010-2012. The cases were 54 children aged 15 months to 10 years with a diagnosis of varicella confirmed by polymerase-chain-reaction. Each case was matched with eight controls by pediatric practice, district of residence and date of birth. The effectiveness was 87% (95% confidence interval: 60% to 97%) for one dose of vaccine and 97% (80% to 100%) for two doses. A single dose was 93% (34% to 100%) effective in the first year, which declined to 61% (95% CI: -64% to 94%) after the third year. In conclusion, varicella vaccine is highly effective in preventing confirmed cases, although this effect declines over time since the first dose. A second dose helps to reestablish very high levels of effectiveness and to reduce the risk of breakthrough varicella.

[Early presentation of breakthrough varicella in vaccinated children]

INTRODUCTION

The introduction of a routine varicella vaccination program for children has achieved a significant reduction in morbidity and mortality due to varicella. However, there is still an incidence of chickenpox in those vaccinated, called "varicella breakthrough" (VB). This has led to the inclusion of a 2nd dose vaccination schedule, at an age which could be too late.

PATIENTS AND METHODS

This study presents 23 cases of children diagnosed with VB (mean age at diagnosis 4.85 years) who had been vaccinated with one dose of varicella vaccine (mean age of vaccination 2.37 years).

RESULTS

The mean time between the vaccine and the disease was 2.48 years, with a median of 2.0 years. VB was diagnosed in 13% of children who had been vaccinated the previous year, and 52% diagnosed in the previous two. Therefore many of these patients had suffered the disease before the recommended time of administration of the second dose of vaccine according to the current vaccine schedules.

CONCLUSIONS

To avoid these vaccine failures, it would be appropriate to bring the two doses of varicella vaccine closer, or even assess the pattern of two consecutive doses.

Multicenter prospective study analysing the role of rotavirus on acute gastroenteritis in Spain

BACKGROUND

Paediatric rotavirus gastroenteritis is the most frequent cause of acute gastroenteritis (AGE) in children up to 5 years of age worldwide.

AIM

To analyse the clinical characteristics of AGE caused by rotavirus comparing to AGE caused by other agents.

METHODS

The study was conducted in 30 health-care centers in Spain (25 hospitals and five primary centers) between January and March 2006. Children with AGE up to 2 years of age were included. Stool samples were analysed using immunochromatographic test to identify rotavirus infection. Clinical and epidemiological data were analysed.

RESULTS

A total of 1192 children were enrolled (mean age: 11.2 months). Fever, Vomiting, weakness and dehydration were more frequent in rotavirus-positive AGE cases. Severity score was higher and hospitalization was likely in AGE caused by rotavirus. Family AGE illness was more frequent in children with rotavirus-positive AGE. Breastfeeding was found as a protective factor against Rotavirus AGE.

CONCLUSION

Rotavirus is the primary causal agent of AGE in children under 2 years of age in Spain, causing more severe symptoms and more hospital admissions than other causal agents. Our data support the interest of the introduction of the available rotavirus vaccines in the Spanish immunization schedule.

Epidemiologic impact of blood culture practices and antibiotic consumption on pneumococcal bacteraemia in children

This study examined the roles of two different diagnostic approaches to children with fever of unknown origin in determining the patterns of pneumococcal bacteraemia in two Spanish regions by comparing their main epidemiologic characteristics. Whereas a blood culture is routinely obtained in this setting in Navarre, this is not generally the case in Majorca. Additionally, the potential role of antibiotic consumption in each region was also analysed. Cumulative incidences in children under the age of 14 years were 26.6 per 100,000 child-years in Navarre (121.1 in children <2 years of age) and 7.3 per 100,000 child-years in Majorca (33.3 in children <2 years of age). In contrast, the incidences per 1,000 blood cultures were similar in both regions. The relative risks of occult bacteraemia, bacteraemic pneumonia and meningitis among the children of Navarre compared to Majorcan children were 11.8, 2.6 and 0.8, respectively. The risk for less virulent (vaccine serotypes plus 6A, 19A and 23A) and for more virulent serotypes (1 and 7) was 4.9 and 3.1 times higher in Navarre, respectively. The number of 7-valent pneumococcal conjugate vaccine (PCV7) doses administered between 2003 and 2004 were also higher in Navarre. Conversely, antibiotic resistance and paediatric prescriptions for broad-spectrum antibiotics were greater in Majorca. Although the most salient differences between both regions, including the effectiveness of pneumococcal conjugate vaccine in Navarre, appeared to be confounded by the higher frequency of blood cultures taken there, certain differences in serotype composition may be explained by the higher antibiotic consumption in Majorca.