Racecadotril in the Management of Rotavirus and Non-rotavirus Diarrhea in Under-five Children: Two Randomized, Double-blind, Placebo-controlled Trials.

OBJECTIVE: To study the effect of racecadotril on reduction in the duration of acute rotavirus and non-rotavirus diarrhea. DESIGN: Two randomized double-blind placebo-controlled trials. SETTING: Community-based trial in an urban area in Vellore, hospital-based trial at a secondary hospital in Vellore. PARTICIPANTS: 199 and 130 3-59 month old children in the community- and hospital-based trials, respectively. METHODS: Racecadotril (1.5 mg/kg/dose, thrice a day for three days) or placebo were given to manage acute diarrhea in both trials. MAIN OUTCOME MEASURE: Median duration of diarrhea. RESULTS: Among 124 children completing the hospital trial, the median duration of diarrhea was 25 h in both arms (P=0.5); median total stool weight was 74 g/kg and 53.5 g/kg in racecadotril group and placebo group, respectively (P=0.4); and average fluid intake per day was 3.6 mL/kg/h and 3mL/kg/h in racecadotril and placebo arms, respectively (P=0.3). Among rotavirus-positive children, median duration of diarrhea was 26.9 h and 30.2 h in racecadotril and placebo arms, respectively (P=0.7). In the community, 196 completed the trial, the median duration of diarrhea was 2 days for both arms (P=0.8) and rotavirus positive children had similar outcomes with median diarrheal duration of 3 d in both arms (P=0.4). CONCLUSIONS: Treatment with racecadotril did not reduce diarrheal duration, stool volume or the requirement for fluid replacement in children with acute gastroenteritis, both with and without rotavirus infection.

Unsuspected glucose-6-phosphate dehydrogenase deficiency presenting as symptomatic methemoglobinemia with severe hemolysis after fava bean ingestion in a 6-year-old boy.

We report the occurrence of symptomatic methemoglobinemia in a previously healthy boy, who presented with severe acute hemolysis after fava bean ingestion. The methemoglobinemia revealed a previously unrecognized glucose-6-phosphate dehydrogenase (G6PD) deficiency. We discuss the pathophysiology of severe methemoglobinemia when associated with acute hemolysis, favism, and the common African G6PD A-variant [G6PD, VAL68MET, ASN126ASP]. In conclusion, screening for G6PD deficiency must be considered in symptomatic methemoglobinemia, especially in young boys, when associated with intravascular hemolysis.

The European Paediatric Life Support course improves assessment and care of dehydrated children in the emergency department.

We tested the hypothesis that application of the principles learned from the European Paediatric Life Support (EPLS) course improves child health assessment and care. In a retrospective study, residents from five paediatric emergency departments were included. For each of them, we analysed five medical records of infants and children suffering from diarrhoea; three were in ambulatory care and two were in-hospital care with IV hydration. Two independent observers analysed the records using a standardized checklist of 14 clinical points, as well as three items to evaluate the adequacy of treatment according to hydration status. Agreement between readers was evaluated the kappa coefficient of concordance. Statistical associations between each item and the EPLS course status was assessed by logistic regression taking into account the clustered data structure. Fifty residents and 240 medical records were included. Twenty-six residents were EPLS trained (intervention group) and 24 residents were not (control group). The results of the analyses of the medical records by the observers were concordant (kappa >0.91). Medical records in the intervention group contained more clinical information on circulatory status (P < 0.0001). Residents in the intervention group prescribed goal-directed therapy more often (P = 0.006). For children with shock, they administered volume resuscitation (P = 0.01) with goal-directed therapy more often (P = 0.003). This is the first evaluation of an educational program focusing on the actions of "learners" in the clinical environment. Our findings highlight that the EPLS course is associated with a better clinical analysis of hydration and circulation status as well as with goal-directed therapy.

Hospital-based surveillance to estimate the burden of rotavirus gastroenteritis among European children younger than 5 years of age.

OBJECTIVES: Rotavirus is the leading cause of acute gastroenteritis requiring hospitalization in young children. Data on the burden of rotavirus gastroenteritis are needed to guide recommendations for rotavirus vaccine use. This study was undertaken to estimate the burden of rotavirus gastroenteritis in European children <5 years of age. METHODS: This prospective, study was conducted in 12 hospitals in France, Germany, Italy, Spain, and the United Kingdom. A sample of all children aged <5 years presenting to emergency departments or hospitalized because of community-acquired acute gastroenteritis was enrolled for parental interview and stool collection. Acute gastroenteritis was defined as diarrhea (>/=3 loose stools per 24 hours) for <14 days. Rotavirus was detected by enzyme-linked immunosorbent assay and typed by reverse-transcriptase polymerase chain reaction. RESULTS: Between February 2005 and August 2006, 3734 children with community-acquired acute gastroenteritis were recruited and retained for analysis (55.9% via the emergency department, 41.8% hospitalized). Of the 2928 community-acquired acute gastroenteritis cases for which stool samples were available, 43.4% were rotavirus-positive by enzyme-linked immunosorbent assay (32.8% emergency department, 56.2% hospitalized). Of these rotavirus gastroenteritis cases 80.9% occurred in children aged <2 years and 15.9% among infants aged <6 months. Acute gastroenteritis was more severe in rotavirus-positive subjects (Vesikari score >/= 11 in 53.3% compared with 31.0% of rotavirus-negative subjects). All 1271 rotavirus-positive strains were genotyped (G1P[8]: 40.3%; G9P[8]: 31.2%; G4P[8]: 13.5%; G3P[8]: 7.1%). CONCLUSIONS: Rotavirus gastroenteritis places high demands on European health care systems, accounting for 56.2% of hospitalizations and 32.8% of emergency department visits because of community-acquired acute gastroenteritis in children aged <5 years. Most community-acquired rotavirus gastroenteritis occurs in children aged <2 years, and a high proportion occurs in infants aged <6 months. Cases were also observed among very young infants <2 months of age. Rotavirus vaccination is expected to have a major impact in reducing morbidity and the pressure on hospital services in Europe.

Papular-purpuric gloves and socks syndrome associated with B19V infection in a 6-year-old child.

A 6 year-old girl was admitted for evaluation of a fever associated with a petechial rash of 2 days' duration. She was in good general condition with no acute distress. Inspection of the skin revealed an amazing papular and purpuric rash of predominantly acral and symmetrical distribution and sharply demarcated on the ankles. All laboratory tests were found normal. Rash and fever completely resolved in less than 3 days. Serological testing for parvovirus B19 (B19V) antibodies was positive for IgM but negative for IgG. Moreover, B19V DNA was detected in serum with a viral load of 2.24 x 10(8) copies per mL. So we concluded of a paediatric case of popular-purpuric gloves and socks syndrome (PPGSS) associated with B19V infection. PPGSS is an idiosyncratic reaction to viral infection. The syndrome has been associated with several viruses such as HHV6, measles, coxsackie B6, and above all B19V. PPGSS occurs mostly in young adults. It is characterised by a typical papular and purpuric rash with an acral distribution and a sharp demarcation on the wrists and ankles. The rash is often pruritic and can be accompanied by mucosal lesions and/or systemic symptoms such as fever, asthenia and lymphadenopathy. Most of the time, the disease is self-limited with a short course and a benign prognosis. A very similar disease has been described in some children. The distinctive clinical characteristics of PPGSS in children should be recognized by paediatrician in particular at the emergency room in order to avoid superfluous explorations.

Rearrangements of rotavirus genomic segment 11 are generated during acute infection of immunocompetent children and do not occur at random.

Group A rotaviruses are the main cause of viral gastroenteritis in infants. The viral genome consists of 11 double-stranded RNA (dsRNA) segments. Dysfunction of the viral RNA polymerase can lead to gene rearrangements, which most often consist of partial sequence duplication of a dsRNA segment. Gene rearrangements have been detected in vivo during chronic infection in immunodeficient children or in vitro during passages at a high multiplicity of infection in cell culture, suggesting that these replication conditions lead to selective advantages favoring the recovery of viruses with rearranged genes. During acute rotavirus infection, the replication level is high, but the occurrence of rearrangement events has never been reported. By the use of a reverse transcription-PCR assay specifically designed to detect small numbers of copies of rearranged forms of segment 11 in a high background of its standard counterpart, we detected 12 rearrangement events among 161 cases (7.5%) of acute rotavirus infection in immunocompetent children. Strikingly, in all but one case, rearrangement took place at the same location within the short direct repeat AUGU sequence. For the unique case with a different rearrangement pattern, the rearrangement occurred within the direct repeat ACAAGUC that was specific for this isolate. In conclusion, we report the occurrence of segment 11 rearrangements during acute rotavirus infection in immunocompetent children. We show that under such conditions of infection, the viral RNA polymerase generates rearrangements which occur not at random but within direct repeats which might constitute hot spots for RNA recombination.

Cost-effectiveness analysis of vaccination against rotavirus with RIX4414 in France.

BACKGROUND: It is estimated that annually 300 000 cases of rotavirus-induced gastroenteritis (RVGE) occur in children aged up to 5 years in France. A two-dose vaccine against rotavirus infection (RIX4414; Rotarix, GlaxoSmithKline), has been shown to be highly effective against severe RVGE. OBJECTIVE: This study evaluated the cost effectiveness of general vaccination against rotavirus using RIX4414 in France. METHODS: A Markov model simulated RVGE events and the associated outcomes and costs relating to general vaccination of infants against rotavirus infection using RIX4414 (Rotarix) in a birth cohort of children aged up to 5 years in France with a combined adjustment for age distribution with the seasonality of the infection. Costs and outcomes were estimated from a limited societal perspective, including direct medical costs paid out of pocket or by third-party payers, as well as the proportion of direct medical costs reimbursed by the health authorities. Indirect costs were not included in the base-case analysis. The primary outcome measure was the incremental cost per QALY. RESULTS: Vaccination with RIX4414 incurred an incremental cost of 44 583 Euro per QALY at a public price of 57 Euro per vaccine dose. Univariate sensitivity analyses showed that the parameters with the largest influence on the results were the transition probabilities of severe diarrhoea, seeking medical advice and emergency visits, utility scores of diarrhoea (mild) in children and infants, and the discount rate for benefits. Probabilistic multivariate sensitivity analysis confirmed these results. The acceptability curve indicated that 94% of the results were under an informal threshold of 50 000 Euro per QALY. Comparing our results with those of a recently published study using pooled data for two rotavirus vaccine products in France, the main differences are explained by differences in model structure and in data input values. They include a different age distribution of the infection, shorter duration of the at-risk period (3 years instead of 5 years), different vaccine efficacy, different unit cost data, different disease duration, and different disutility values for the health states in the model. There is a need for agreed standards to improve comparability of results from different studies. CONCLUSIONS: The results demonstrate that a generalized vaccination strategy with RIX4414 would be cost effective in France from a limited societal perspective, depending on the baseline assumptions for disease progression and on utility scores selected.

Rotavirus gastroenteritis: why to back up the development of new vaccines?

Rotaviruses (RVs) are the main aetiologic agent of severe acute diarrhoea in children under the age of 5, worldwide. Given that the currently available preventive measures to fight against the transmission of RV disease are not sufficiently effective, vaccination likely represents the only efficacious adapted response to the massive impact of this infection. Although the two current RV vaccines have shown good tolerance and significant efficacy to protect infant against severe RV disease, their development have raised key questions that are still unanswered regarding their cost, efficacy and safety. These two vaccines have in common the disadvantages related to the use of oral attenuated live viruses which limit their implementation in both developed and developing countries. In order to overcome these hurdles, it is important to support the development of new, non-replicating vaccines which will not suffer the potential disadvantages of the present vaccines. New approaches and other routes of administration are being tested in animal models and soon will be evaluated in humans. Among those are viral-like particle-based vaccines which have provided the most promising results. Finally, the epidemiology of the disease which differs in developed and developing countries can affect decisions about vaccine composition and delivery. The answer brought by the development of new RV vaccines could reside in developing several types of RV vaccines specifically designed to be used in different settings.

Recombinant rotavirus inner core proteins produced in the milk of transgenic rabbits confer a high level of protection after intrarectal delivery.

Development of a safe, cheap and efficient vaccine against rotavirus is important to reduce the morbidity and mortality associated with gastroenteritis in infants worldwide. High quantities of two inner core rotavirus-derived proteins (VP2 and a nonglycosylated mutant VP6 (VP6(NG)) from the RF81 bovine strain) were produced in the milk of transgenic rabbits. We show here that rectal administration of partially purified milk-derived VP2 and VP6(NG) proteins with the detoxified LT(R192G) adjuvant almost completely prevented fecal shedding induced by a highly infectious challenge in mice with the murine ECw strain. The vaccine generated rotavirus-specific fecal secretory IgA, systemic IgG and IgA and a rotavirus-specific Th1 response. We thus demonstrate in clinically feasible settings that mass production of viral protein in transgenic milk is a promising way to generate subunit vaccine against rotavirus.

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.

Rotavirus anti-VP6 secretory immunoglobulin A contributes to protection via intracellular neutralization but not via immune exclusion.

Immunoglobulin A (IgA) monoclonal antibodies (MAbs) directed at the conserved inner core protein VP6 of rotavirus, such as the IgA7D9 MAb, provide protective immunity in adult and suckling mice when delivered systemically. While these antibodies do not have traditional in vitro neutralizing activity, they could mediate their antiviral activity either by interfering with the viral replication cycle along the IgA secretory pathway or by acting at mucosal surfaces as secretory IgA and excluding virus from target enterocytes. We sought to determine the critical step at which antirotaviral activity was initiated by the IgA7D9 MAb. The IgA7D9 MAb appeared to directly interact with purified triple-layer viral particles, as shown by immunoprecipitation and immunoblotting. However, protection was not conferred by passively feeding mice with the secretory IgA7D9 MAb. This indicates that the secretory IgA7D9 MAb does not confer protection by supplying immune exclusion activity in vivo. We next evaluated the capacity of polymeric IgA7D9 MAb to neutralize rotavirus intracellularly during transcytosis. We found that when polymeric IgA7D9 MAb was applied to the basolateral pole of polarized Caco-2 intestinal cells, it significantly reduced viral replication and prevented the loss of barrier function induced by apical exposure of the cell monolayer to rotavirus, supporting the conclusion that the antibody carries out its antiviral activity intracellularly. These findings identify a mechanism whereby the well-conserved immunodominant VP6 protein can function as a target for heterotypic antibodies and protective immunity.

Rectal immunization with rotavirus virus-like particles induces systemic and mucosal humoral immune responses and protects mice against rotavirus infection.

To evaluate whether the rectal route of immunization may be used to provide appropriate protection against enteric pathogens such as rotaviruses (RV), we studied the antibody response and the protection induced by rectal immunization of mice with RV virus-like particles (VLP). For this purpose, 6-week-old BALBc mice were rectally immunized twice with RV 8-2/6/7-VLP derived from the bovine RV RF81 strain either alone or combined with various adjuvants including four toxins [cholera toxin (CT) and three attenuated Escherichia coli-derived heat-labile toxins (LTs), LT(R192G), LT(R72), and LT(K63)] and two Toll-like receptor-targeting adjuvants (CpG and resiquimod). Six weeks after the second immunization, mice were challenged with murine RV strain ECw. RV VLP administered alone were not immunogenic and did not protect mice against RV challenge. By contrast, RV VLP combined with any of the toxin adjuvants were immunogenic (mice developed significant titers of anti-RV immunoglobulin A [IgA] in both serum and feces and of anti-RV IgG in serum) and either efficiently induced complete protection of the mice (no detectable fecal virus shedding) or, for LT(K63), reduced the amount of fecal virus shedding after RV challenge. When combined with RV VLP, CpG and resiquimod failed to achieve protection, although CpG efficiently induced an antibody response to RV. These results support the consideration of the rectal route for the development of new immunization strategies against RV infection. Rectal delivery of a VLP-based vaccine might allow the use of adjuvants less toxic than, but as efficient as, CT.

The VP6 protein of rotavirus interacts with a large fraction of human naive B cells via surface immunoglobulins.

Immunity to human group A rotavirus (RV), a major cause of viral gastroenteritis in infants, involves B lymphocytes that provide RV-specific antibodies. Additionally, some arguments suggest that naive B cells could be implicated in the first steps of the immune response against RV. The aim of our study was to analyze the interaction of VP6 and VP7 RV capsid proteins with human B cells depending on the immune status of the individual, i.e., naive or RV experienced. For this purpose, a two-color virus-like particle flow cytometry assay was devised to evaluate the blood B-lymphocyte reactivity to VP6 and VP7 proteins from healthy RV-exposed adults, recently infected infants, and neonates at birth. Both VP6 and VP7 interactions with B cells were mediated by surface immunoglobulins and probably by their Fab portions. VP7-reactive B lymphocytes were mainly detected from RV-experienced patients and almost exclusively in the CD27-positive memory cell fraction. Conversely, VP6-reactive B lymphocytes were detected at similar and high frequencies in adult, infant, and neonate samples. In adult samples, VP6 reacted with about 2% of the CD27-negative (CD27(neg)) naive B cells. These results demonstrated that the VP6 RV protein interacted with a large fraction of naive B lymphocytes from both adults and neonates. We propose that naive B cell-VP6 interaction might influence the strength and quality of the acquired immune response and should be considered for elaborating RV vaccine strategies.