Health perception and adherence with blood pressure control among rural Chinese adults with hypertension

AIM

The aim of this study was to examine associations among blood pressure, personal and illness characteristics, illness perception and medication and self-management adherence among adults with hypertension in rural mainland China.

BACKGROUND

Despite the high prevalence of hypertension in China, the control rate is only 20%. Identifying factors associated with blood pressure control is critical.

DESIGN

Cross-sectional survey.

METHODS

Data were collected from 163 hypertensive adults in two rural villages in mainland China. Measures included a demographic questionnaire, the Chinese Illness-Perception Questionnaire-Revised, Medication Adherence Inventory and the Inventory of Adherence to Self-management. Height, weight, and blood pressure were also measured using standard approaches. Hierarchical linear regression was used to assess the association between blood pressure and significant variables identified in bivariate analysis.

FINDINGS

The mean systolic pressure observed in this sample was 147 mmHg and the diastolic mean was 81 mmHg. None of the variables analysed were associated with systolic blood pressure. Gender, age, and household annual income were associated with diastolic blood pressure, explaining 23% of the variance in the regression model. Illness coherence contributed an additional 2%.

CONCLUSION

These findings suggest: (a) healthcare providers should focus on educating rural hypertensive adults about healthful diets and behaviours to manage hypertension, especially for those with high household income; (b) knowledge-based health education alone is not adequate; (c) illness perception may not be directly associated with blood pressure; and (d) the Chinese Illness-Perception Questionnaire-Revised and the Inventory of Adherence to Self-management require validation and potential revision for use with rural Chinese populations.

The Relationship Between Mutuality and Health-Related Quality of Life in Adult Child Caregivers in China

The strain inherent in caregiving relationships between adult children and aging parents is a prominent issue in contemporary China due to a combination of demographic and socioeconomic changes. The purpose of this study was to explore how mutuality, a positive quality of caregiving relationships, contributes to the physical health and mental health (health-related quality of life [HRQoL]) of adult child caregivers [ACCs] of parent stroke survivors. A cross-sectional correlational study was conducted on a nonproportional quota sample of 126 ACCs, using questionnaires of demographics, the 15-item Mutuality Scale, and the Second Version of the Standard 12-Item Health Survey (SF-12v2). Higher mutuality was found to be correlated with better caregiver physical health and mental health. However, after adjusting for the covariates, mutuality significantly explained 4.6% of the variance of caregiver physical health (β = .22, ΔR² = .046, p < .01) but it did not significantly explain the variance of caregiver mental health. Although multiple factors correlate with Chinese family caregivers' HRQoL, this was the first study exploring the impact of caregiver-care receiver dyadic relationships on caregiver HRQoL in mainland China by using a mutuality scale with SF-12v2. Despite the fact that the Chinese tradition of filial piety can facilitate mutuality, socioeconomic changes and legislation that require adult children to care for aging parents appear to create high stress among family caregivers. Higher levels of mutuality contribute to better physical health in Chinese family caregivers. Therefore, culturally appropriate family nursing strategies and social policies in China could enhance caregiver mutuality and potentially promote their HRQoL, in particular physical health.

Clinical severity and molecular characteristics of circulating and emerging rotaviruses in young children attending hospital emergency departments in France

Group A rotavirus (RVA) is the leading cause of acute gastroenteritis in young children worldwide. A prospective surveillance network has been set up to investigate the virological and clinical features of RVA infections and to detect the emergence of potentially epidemic strains in France. From 2009 to 2014, RVA-positive stool samples were collected from 4800 children <5 years old attending the paediatric emergency units of 16 large hospitals. Rotaviruses were then genotyped by RT-PCR with regard to their outer capsid proteins VP4 and VP7. Genotyping of 4708 RVA showed that G1P[8] strains (62.2%) were predominant. The incidence of G9P[8] (11.5%), G3P[8] (10.4%) and G2P[4] (6.6%) strains varied considerably, whereas G4P[8] (2.7%) strains were circulating mostly locally. Of note, G12P[8] (1.6%) strains emerged during the seasons 2011-12 and 2012-13 with 4.1% and 3.0% prevalence, respectively. Overall, 40 possible zoonotic reassortants, such as G6 (33.3%) and G8 (15.4%) strains, were detected, and were mostly associated with P[6] (67.5%). Analysis of clinical records of 624 hospitalized children and severity scores from 282 of them showed no difference in clinical manifestations or severity in relation to the genotype. The relative stability of RVA genotypes currently co-circulating and the large predominance of P[8] type strains may ensure vaccine effectiveness in France. The surveillance will continue to monitor the emergence of new reassortants that might not respond to current vaccines, all the more so as all genotypes can cause severe infections in infants.

Detection and genotyping of group A rotaviruses isolated from sewage samples in Monastir, Tunisia between April 2007 and April 2010

AIMS

To ascertain the viral load, the distribution of G and P types of group A rotaviruses (RV-A) in sewage samples and to compare strains in clinical, animal and environmental samples.

METHODS AND RESULTS

During our study from April 2007 to April 2010, 518 samples of raw and treated sewage were collected from two biological sewage treatment plants (STPs) located in the Monastir region, Tunisia. RV-A was detected by real-time RT-PCR in 375 (72·4%) sewage samples. According to the quantification results of RV-A, it appears that the viral load in raw and treated sewage of the two STPs was quite similar (P = 0·735). The genotyping of RV-A strains detected in sewage samples showed a great diversity with 10 G types and 8 P types. Most of them were described as common in humans, but we also detected genotypes commonly found in animals. All the genotypes detected in two previous studies performed in our laboratory on clinical and bovine samples were also found in environmental samples. However, some genotypes commonly found in animal were only found in sewage samples.

CONCLUSION

The comparison of environmental, clinical and animal data suggests that STPs may convey not only human sewage but also animal wastes, both of them contaminated with numerous RV-A strains which are not efficiently eliminated by the sewage treatment process and may spread to surface waters.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work demonstrates the potential release of human and animal RV-A into water sources, representing a public health risk, by inducing gastroenteritis in population, but also by increasing the risk of zoonotic transmission and formation of reassortant viruses which could get a higher infectious potential. Our findings also suggest that monitoring of sewage may provide an additional tool to determine the epidemiology of RV-A circulating in a given community.

Relationship between GII.3 norovirus infections and blood group antigens in young children in Tunisia

Noroviruses (NoVs) constitute a major cause of gastroenteritis in Tunisia. One hundred and fourteen matched saliva and stool samples were collected from children (n = 114) suffering from acute gastroenteritis at the hospital of Monastir during the winter season 2011-2012. For 98 of 114 children, blood samples were collected for secretor genotyping. NoVs were associated with 36.8% (n = 42/114) of the gastroenteritis cases. The GII.3 genotype was the most common (69% of all NoVs). For patients who were phenotyped (n = 114) for human blood group antigens (HBGAs), the secretor and non-secretor phenotypes represented 79% and 21%, respectively. Of the NoV infections, 83% were detected in all ABO groups. Five GII.3 isolates, one GII.1 isolate and one GII.7 isolate were detected in Lewis-positive non-secretors, confirmed by genotyping of the FUT2 gene. Even though our data showed that GII.3 NoVs could infect non-secretors, no binding was observed with saliva and GII.3 baculovirus-expressed virus-like particles from the same symptomatic non-secretor individual. This suggests that other factors might also participate in NoV attachment in children and newborns.

The burden of norovirus gastroenteritis: an important foodborne and healthcare-related infection

Human norovirus (NoV) is now recognized as one of the most important causative agents of gastroenteritis in all age groups worldwide. During the course of NoV infection, symptoms are usually mild and disappear within 48 h after onset. The incidence of NoV infection is high, with hundreds of cases per 10 000 of the population, although the number of infections is still underestimated. Epidemiological surveys conducted in Europe and North America have shown that NoV infections constitute a major disease burden, especially for young children and the elderly, in whom NoV infection leads to high rates of hospitalization and mortality. NoV infections are also of concern in hospitals, where viral infections can be persistent in immunocompromised patients. Although the cost of NoV infection in the hospital community has not yet been clearly established, it appears that NoV infections could cost hundreds of thousands of euros in terms of unit closure, and NoV-related sickness in patients and health workers. Besides their clinical burden, NoVs, as foodborne pathogens, also cause to millions of dollars of losses for the healthcare system and the food industry. Recent estimates in the USA showed that, annually, NoV illness cost $2 billion and led to a loss of approximately 5000 quality-adjusted life-years, making NoV one of the top five pathogens causing enteric illnesses. The highest cost among 14 foodborne pathogens is also attributed to human NoV in The Netherlands. This accumulation of evidence underlines the enormous impact of NoV on populations.

Gastroenteritis outbreaks in elderly homes in the east of France during winter 2009/10: aetiology research for a series of 37 outbreaks

Binary file ES_Abstracts_Final_ECDC.txt matches

Gastroenteritis outbreaks in elderly homes in the east of France during winter 2009/10: aetiology research for a series of 37 outbreaks

Although acute gastroenteritis is a common cause of morbi-mortality in care homes, there is no national surveillance system in France except for food-borne gastroenteritis. Since 2008, a specific surveillance system has been operating in nursing homes in Alsace, a region in eastern French. In the winter season 2009/10 we had the opportunity to study 37 outbreaks, collecting data on attack rate, duration and aetiology as well as epidemic management in nursing homes. We noticed the responsiveness of the institutions, with a mean period of 1.6 days between the onset of first symptoms and the implementation of management measures (95% confidence interval (CI): 1.0–2.2). One or several stool samples were taken in 27 of the 37 described outbreaks. The only pathogen detected was norovirus, and the positive samples were from outbreaks with a very typical pattern: vomiting in 36 of the outbreaks, a high average attack rate of 36.8% (95% CI: 31.5–42.2) and a short average duration of 8.9 days (95% CI: 5.8–7.0). No severe cases, hospitalisations or deaths were reported. The high frequency of norovirus isolation indicated that systematic bacteriological analysis in local laboratories is not cost-effective. Consequently, Cire Est recommends to test for bacteria and viruses only in cases presenting with fever or atypical symptoms. Nevertheless, Cire Est also recommends to continue sending stool samples to the French National Centre for enteric viruses, more for the benefit of the virological surveillance programme than for diagnostic purposes.

Detection and molecular characterization of enteric viruses in environmental samples in Monastir, Tunisia between January 2003 and April 2007

AIMS

A prospective study was performed to characterize the main human enteric viruses able to persist in sewage samples and in shellfish tissues, and to establish the correlation between environmental strains and viral infantile diarrhoea observed in the same area during the same period.

METHODS AND RESULTS

A total of 250 sewage (raw and treated) and 60 shellfish samples were collected between January 2003 and April 2007 in Monastir region, Tunisia. Group A rotavirus (RVA) was detected in 80 (32%) sewage samples, norovirus (NoV) in 11 (4·4%) and enteric adenovirus (AdV) in 1 (0·4%). Among 60 shellfish samples collected near sewage effluents, one was contaminated by NoV (1·6%).

CONCLUSION

Our data represent the first documentation in Tunisia, combining gastroenteritis viruses circulating in the environment and in clinical isolates. We observed a correlation between environmental strains and those found in children suffering from gastroenteritis during the same period study. This suggests the existence of a relationship between water contamination and paediatric diarrhoea.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results address the potential health risks associated with transmission of human enteric viruses through water-related environmental routes. The research findings will aid in elucidating the molecular epidemiology and circulation of enteric viruses in Tunisia and in Africa, where data are rare.

Presence of enteric hepatitis viruses in the sewage and population of Greater Cairo

In Egypt, the disease burden of viral hepatitis is one of the heaviest worldwide. We conducted a survey of hepatitis A virus (HAV) and hepatitis E virus (HEV) in patients and sewage in Cairo. Our data showed that HAV (genotype IB) was predominant over HEV (genotype 3) and was circulating in the population and the environment.

Epidemiology and clinical features of gastroenteritis in hospitalised children: prospective survey during a 2-year period in a Parisian hospital, France

Rotavirus is recognised as the most important agent of severe acute gastroenteritis (AGE) in young children. In a 2-year prospective survey, we investigated the epidemiology and clinical features of the viral and bacterial pathogens in children hospitalised for AGE. The study was performed in a Parisian teaching hospital from November 2001 to May 2004. Clinical data were prospectively collected to assess the gastroenteritis severity (20-point Vesikari severity score, the need for intravenous rehydration, duration of hospitalisation). Stools were systematically tested for group A rotavirus, norovirus, astrovirus and adenovirus 40/41, sapovirus and Aichi virus and enteropathogenic bacteria. A total of 457 children (mean age 15.9 months) were enrolled. Viruses were detected in 305 cases (66.7%) and bacteria in 31 cases (6.8%). Rotaviruses were the most frequent pathogen (48.8%), followed by noroviruses (8.3%) and adenoviruses, astroviruses, Aichi viruses and sapoviruses in 3.5%, 1.5%, 0.9% and 0.4%, respectively. Cases of rotavirus gastroenteritis were significantly more severe than those of norovirus with respect to the Vesikari score, duration of hospitalisation and the need for intravenous rehydration. Rotaviruses were the most frequent and most severe cause in children hospitalised for AGE, and noroviruses also account for a large number of cases in this population.

Evidence of the co-circulation of enteric viruses in sewage and in the population of Greater Cairo

AIMS

To characterize major enteric viruses (enterovirus, rotavirus, norovirus, astrovirus and adenovirus) in the sewage of Greater Cairo and to compare the results with clinical data collected during the same period.

METHODS AND RESULTS

Seventy-two sewage samples from two waste water treatment plants were collected from April 2006 through February 2007. Enteroviruses, noroviruses (NoVs) and rotaviruses (RVs) were detected by RT-PCR in 22%, 18% and 8.3% of the samples, respectively. No adenovirus and astrovirus was detected. G2P[8], G9P[8], G1P[8], G2P[4] and rare G12 RV isolates were detected in the environment as well as a bovine RV. The environmental NoV strains mostly belonged to genogroup I (84%). Rotaviruses and some of the NoVs were similar to those found in the clinical samples at the same time.

CONCLUSIONS

The comparison of environmental and clinical data suggests that similar RV and NoV isolates were circulating in the environment and in the population during the same period.

SIGNIFICANCE AND IMPACT OF THE STUDY

Few studies have investigated the prevalence and the epidemiology of RVs and NoVs in Cairo. This work is the first to establish a correlation between viral gastroenteritis and the concomitant presence of enteric viruses in the environment for Greater Cairo where combined environmental and clinical surveys should help to prevent infections caused by these major pathogens.

Import of norovirus infections in the Netherlands and Ireland following pilgrimages to Lourdes, 2008--preliminary report

Between mid-September and 19 October 2008, nine clusters of norovirus infection involving around 90 primary cases and over a hundred secondary cases were identified in patients from the Netherlands, Ireland, Italy and France, linked to pilgrimage to Lourdes, France.

Import of norovirus infections in the Netherlands and Ireland following pilgrimages to Lourdes, 2008 – preliminary report

Between mid-September and 19 October 2008, nine clusters of norovirus infection involving around 90 primary cases and over a hundred secondary cases were identified in patients from the Netherlands, Ireland, Italy and France, linked to pilgrimage to Lourdes, France.

Unexpected substitution of dominant rotavirus G genotypes in French hospitalized children over five consecutive seasons

The study was designed to evaluate the circulation of group A rotaviruses in French hospitalized children, and to detect unusual strains. This prospective study was conducted from 2001 to 2006 in children consulting for acute diarrhea at the pediatric emergency department in three French University Hospitals. The rotaviruses were detected by rapid test and genotyped by RT-PCR on the basis of their outer capsid proteins VP4 (P-type) and VP7 (G-type). The stools from 757 children were analyzed. G1P[8] strains were predominant (44.0%), followed by G9P[8] (17.7%), G3P[8] 13.1%, G4P[8] (9.5%), and G2P[4] (1.8%); mixed rotavirus infections occurred in 2.3%. G9 rotaviruses emerged during the 2004-2005 season (73.4%) and remained the second most prevalent strains. Few unusual strains, G6, G8, G12 and P[6]-types, were detected. The monitoring of rotavirus infections should be maintained to document strain distribution and to assess the emergence of new reassortants that may not respond to current rotavirus vaccines.

[Sensitivity and specificity of the VIKIA Rota-Adeno immuno-chromatographic test (bioMérieux) and the ELISA IDEIA Rotavirus kit (Dako) compared to genotyping]

The performances of two diagnostic tests for rotavirus infection in stool samples were evaluated during a prospective study in children of less than 36 months in child-care centers of Lyon from November 2004 to May 2005. The VIKIA Rota-Adeno immuno-chromatographic test (bioMérieux) and the ELISA IDEIA Rotavirus kit (Dako) were compared with a referral method, the genotyping. Fifty-seven stool samples were collected and analyzed by RT-PCR. The virus genome was detected in 29 samples. The most frequent genotypic combinations were G9P[8] with a prevalence of 75.9%. Sensitivity and specificity of the VIKIA Rota-Adeno test and the ELISA IDEIA Rotavirus kit were strictly comparable and very good: 96.6% (83.0; 99.9) and 96.4% (81.6; 99.9), respectively. The immuno-chromatographic technique were in concordance with the ELISA tests in 93.6% of cases. Thus, the VIKIA Rota-Adeno test is a good alternative for the occasional analysis of stool samples in ambulatory practice.

[Prospective epidemiological study of rotavirus gastroenteritis in Europe (REVEAL study). Results in the French area of the study]

PRIMARY OBJECTIVE

To estimate the incidence of acute gastroenteritis (AGE) and rotavirus acute gastroenteritis (RVAGE) in children less than 5 years of age seeking medical care in primary care, emergency department, and hospital settings.

SECONDARY OBJECTIVES

To compare the clinical profile of RVAGE and non-RVAGE and to describe the distribution of RV serotypes among RVAGE cases.

METHODS

A prospective primary care, emergency ward and hospital-based observational study was conducted during 1 year in a selected city of France with 250,000 inhabitants. Children less than 5 years of age presenting with symptoms of AGE were included. Rotavirus was identified using an Elisa test in stools.

RESULTS

The estimated annual incidence of RVAGE was 1.56% for AGE and 0.87% for RVAGE in hospital, 5.87% for AGE and 2.65% for RVAGE in emergency-wards, 7.39% for AGE and 1.45% for RVAGE in primary care. Total incidence was 14.82% for AGE and 4.96% for RVAGE among children less than 5 years of age. RVAGE were more clinically severe than the AGE: dehydration (26.8% vs. 14.7%, p<0.0001), vomiting 84.9% vs. 60.9%, p<0.0001), fever (74.3% vs. 44.4%, p<0.0001), lethargy (84.9% vs. 70.2%, p<0.0001). G9 serotype was the most frequent serotype encountered (54.7%) during the study period followed by G3 serotype (33.6%) and G2 serotype (7.9%).

CONCLUSION

In this study, RVAGE, caused by serotypes G9 and G3, represented about 1/3 of AGE and were more severe than non-RV AGE with twice as high dehydration rate. These results underline the need for continued promotion on the use of oral rehydration fluids and provide some arguments on the benefits of vaccination against rotavirus and also permanent virological monitoring of circulating serotypes.

[Epidemiology and burden of rotavirus diarrhea in day care centers in Lyon, France]

Rotavirus is the main cause of severe, dehydrating diarrhoea in infants and young children. In industrialized countries, pediatric rotavirus gastroenteritis (PRGE) is responsible for high morbidity, particularly among children under 3 years of age attending day care centers (DCCs). The objectives of this study were to estimate the incidence, management and cost of PRGE in DCCs. We also described the nature of group A rotavirus genotypes. This study also compared the performance of different diagnostic techniques. The study was conducted from November 2004 to May 2005. Children aged less than 36 months, attending a participating DCC at least 4 times a week were included in the study. For any episode of acute gastroenteritis (AGE), defined as the occurrence of 3 or more watery or looser than normal stools and/or forceful vomiting within a 24 h period, a fecal specimen was tested by Elisa test IDEIA Rotavirus (Dako) and the immunochromatographic test VIKIA Rota-Adeno (BioMérieux). Sequencing by RT-PCR was performed to identify the rotavirus genotype. Among the 41 DCCs contacted, 18 (43.9%) agreed to participate. Out of 966 children, 547 attended a participating DCC at least 4 times a week and met the inclusion criteria. A total of 302 were included in the study. The clinical diagnosis of AGE was confirmed and validated, by the Elisa test, in 63 fecal specimens, of which 29 (46%) were positive for rotavirus antigen, with a predominance of P[8]G9 (86%). Our results showed good sensitivity and specificity for the VIKIA and Elisa methods when compared to RT-PCR. Among the PRGE cases, 36% were male and the median age was 12.2 months. The first rotavirus case was observed in December 2004 with a peak in January 2005. The incidence of PRGE cases was 2.2 [1.4-3.0] per 100 child-months in children aged less than 36 months of age, increasing to 3.4 per 100 child-months among children aged less than 24 months. Vomiting (P<0.0005) and behavior modification (P<0.001) were significantly more frequent for PRGE cases. A total of 85.7% PRGE cases sought medical attention. In 58.3% of these cases, at least one parent had to miss work for a mean duration of 2.1 days. The total cost of rotavirus cases seeking medical attention (with or without prescribed medication, days off work for parents or additional diaper consumption) was estimated at 275.54 euros/case. The PRGE incidence rate is similar to that estimated in European studies conducted in DDC. These findings confirm that rotavirus transmission occurs not only in DCCs but within the family. This is the first study to give an estimate of the incidence and the cost of rotavirus infection in DCCs in France.

Intranasal immunization of mice with VP2 DNA of human rotavirus a induces cellular and humoral immunity

DNA vaccination using a plasmid encoding Human rotavirus A (HuRV-A) inner capsid VP2 was examined in a mouse model. BALB/c mice were immunized intranasally (i.n.) with a VP2 DNA vaccine that induced cellular and humoral immune response to HuRV-A. The increased levels of cytokines IFN-gamma and IL-4 and the production of anti-VP2 IgG antibodies were detected. In addition, splenocyte proliferation detected by MTT test was enhanced in the mice treated with the vaccine. These results may encourage the development of a HuRV-A DNA vaccine derived from the inner layer of viral capsid that can be administered i.n.

Data quality of 5 years of central norovirus outbreak reporting in the European Network for food-borne viruses

BACKGROUND

The food-borne viruses in Europe (FBVE) network database was established in 1999 to monitor trends in outbreaks of gastroenteritis due to noroviruses (NoVs), to identify major transmission routes of NoV infections within and between participating countries and to detect diffuse international food-borne outbreaks.

METHODS

We reviewed the total of 9430 NoV outbreak reports from 13 countries with date of onset between 1 January 2002 and 1 January 2007 for representativeness, completeness and timeliness against these objectives.

RESULTS

Rates of reporting ranged from a yearly average of 1.8 in 2003 to 11.6 in 2006. Completeness of reporting of an agreed minimum dataset improved over the years, both for epidemiological and virological data. For the 10 countries that provided integrated (epidemiological AND virological) reporting over the 5-year period, the completeness of the minimum dataset rose from 15% in 2003 to 48% in 2006. Two countries have not been able to combine both data types due to the structure of the national surveillance system (England and Wales and Germany). Timeliness of reporting (median days between the onset of an outbreak and the date of reporting to the FBVE database) differed greatly between countries, but gradually improved to 47 days in 2006.

CONCLUSION

The outbreaks reported to the FBVE reflect the lack of standardization of surveillance systems across Europe, making direct comparison of data between countries difficult. However, trends in reported outbreaks per country, distribution of NoV genotypes, and detection of diffuse international outbreaks were used as background data in acute questions about NoV illness and the changing genotype distribution during the 5-year period, shown to be of added value. Integrated reporting is essential for these objectives, but could be limited to sentinel countries with surveillance systems that allow this integration. For successful intervention in case of diffuse international outbreaks, completeness and timeliness of reporting would need to be improved and expanded to countries that presently do not participate.

Évaluation de sept réactifs d'immunochromatographie pour détecter les rotavirus humains dans les selles

Seven commercially available immunochromatographic assays were tested for the rapid detection of group A rotaviruses in fecal samples compared to a enzyme immunoassay (Argene). Detection of rotaviruses in 80 ELISA positive frozen stool samples showed rates superior to 90% for three reagents (Rota Strip (Cypress Diagnostics), 98.8%; Rotascreen (Microgen), 95.0%; VIKIA Rota/Adeno (bioMérieux), 92.5%); from 82.5% to 88.8% for three others (Diarlex with centrifugation (Orion Diagnostica), 88.8%; Combo Rota/Adeno (All Diag), 87.5%; Rota/Adeno Combi Stick (bmd), 82.5%) and only 70.0% for Diarlex with filtration vial (Orion Diagnostica). The evaluation of the specificity, performed on one hundred fresh rotavirus negative stools, did not show any false positives with any assay. Analysis of the different technical features of these tests showed that they are quick and suitable for a clinical laboratory and do not require expensive equipment.

[Investigation of an outbreak of norovirus gastroenteritis in a geriatric hospital]

In aged-care facilities, gastroenteritis outbreaks are responsible for big trouble in the management of cares to the elderly. In November 2002, a gastroenteritis outbreak was observed in 5 of the 6 wards of the geriatric hospital La Charité, University Hospital of Saint-Etienne, France, with an attack rate of 38.5% in the elderly (70 infected from 182 patients) and of 26.0% in the nursing staff (40 infected from 154 agents). The outbreak lasted 30 days with a peak corresponding to 79.8% of the cases between the 11(th) and the 20(th) of November. The first cases were observed in the two short-term-care wards; then, the outbreak spread rapidly to 3 of the 4 long-term care units. Health care workers were contaminated later than the elderly (P < 0.001 by Kruskal-Wallis test). A self-administered questionnaire was documented by most of the nursing staff; the most frequently observed clinical symptoms in this population were nausea (82.5%), abdominal pain (80.0%), diarrhoea (70.5%), asthenia (67.5%) and vomiting (62.5%). Thirty-five percent of the health care workers ceased their work. The causative agent of the gastroenteritis was identified by RT-PCR in the stools of 5 aged persons as a norovirus close to the Lordsdale strain (genogroup II). These findings illustrate the respective role of elderly and health care workers in the spread of the gastroenteritis outbreak inside the geriatric hospital.

Molecular epidemiology of caliciviruses detected in sporadic and outbreak cases of gastroenteritis in France from December 1998 to February 2004

We compiled sequence and epidemiological data from 172 caliciviruses detected in France from December 1998 to February 2004 in sporadic and outbreak cases. The results showed a cocirculation of strains with a majority of genogroup II (GII) noroviruses. Three groups of noroviruses, not detected before in our laboratory, emerged and spread during the period: the recombinant GGIIb and Norwalk-related strains not amplified in the polymerase gene in 2000 and a new Lordsdale variant in 2002. We observed that (i) GII-4 noroviruses were predominant in nursing home and hospital outbreaks but rare in oyster- and water-related outbreaks despite continuous circulation in the population; (ii) at the opposite, genogroup I strains were detected in the majority of environmental outbreaks; (iii) several strains were frequently found in oyster- and water-linked outbreaks (up to seven), whereas one single strain was detected when transmission was from person to person; and (iv) whereas GII noroviruses were predominant in sporadic cases where patients were under 15 years of age, GI strains were more frequent in outbreaks occurring in this age group. Finally, from a methodology point of view, this compilation shows that detection and characterization in the polymerase gene are not adequate in a significant number of cases and should be completed by amplification and sequencing in the capsid gene.

Characterization of new recombinant noroviruses

Noroviruses are important etiologic agents of acute gastroenteritis and show great genetic diversity. To characterize more fully previously detected strains that could not be assigned unequivocally to one particular genotype based on the RNA polymerase, we have sequenced a region in the capsid gene and, in some cases, in the junction between open reading frame 1 (ORF 1) and ORF 2. The results allowed us to identify several recombinant noroviruses: GGIIb viruses were detected for the first time in France in August 2000 and then spread through France and to Europe during the following winter. Here we present the characterization of three other probable GII recombinants which showed different phylogenetic positions depending on their ORF 1 and ORF 2 sequences. Analysis of the region located between ORF 1 and ORF 2 by a nucleotide identity window search showed a sudden shift in similarities. Moreover, recombination breakpoints were identified upstream and downstream of the beginning of ORF 2 by using a statistical test, thus confirming the involvement of this region in recombination. Unlike GGIIb, the three recombinants described here do not seem to have diffused widely in the community: one was found in a waterborne outbreak, and the other two were found in sporadic cases. Recombination is important for the evolution of RNA viruses and has already been described for noroviruses. Our results suggest that recombination is not a rare phenomenon among noroviruses, but not all these presumed recombinants that formed during RNA replication are able to spread widely.

Development and evaluation of a new commercial test allowing the simultaneous detection of noroviruses and sapoviruses by reverse transcription-PCR and microplate hybridization

This work describes the design and initial evaluation of a commercial test allowing the detection of noroviruses and sapoviruses by reverse transcription-PCR (RT-PCR) in a single tube followed by microplate hybridization, as well as the detection of PCR inhibitors. The test was shown to be broadly reactive (except for Melksham-like strains), sensitive, and specific and thus should be useful for calicivirus detection in clinical practice.

Sewage impact on shellfish microbial contamination

Coastal areas are frequently contaminated by microorganisms of human origin, due to high population density and low seawater renewal. To evaluate the impact of wastewater input on shellfish quality, a study was conducted in Brittany (France) over a period of 20 months. A hydrodynamic model was used to simulate wastewater impact on microbial water quality. To validate the model, wastewater from the three main sewage treatment plants and shellfish from three sites were sampled monthly. Bacterial indicators (E. coli), F-RNA phages were searched for by culture and noroviruses by RT-PCR and hybridisation. These microorganisms were detected in the three effluents and clams, with no marked seasonal variation. The microbial concentrations in the two oyster beds, distant from the effluent outfall, were low, and only three of the samples were positive for norovirus. For simulation, the winter wastewater inputs of E. coli and phages were calculated and an estimation for norovirus flux was made from the epidemic situation in the population. The microbial behaviour was included in the model by a decay-rate factor. Results from the model calculations were found to be very similar to E. coli and phage concentrations observed in shellfish. For noroviruses, the model indicated that shellfish distant from the wastewater input were under the detection limit of the RT-PCR method. This study demonstrated the use of modelisation to interpret norovirus contamination in various areas.

Cytosolic free Ca2+ concentration in canine aortic endothelial cells lining the polyester arterial prosthesis

A rise in baseline cytosolic free Ca2+ in canine vascular endothelial-like cells (VEC) lining the luminal surface of the polyester arterial prosthesis is described. In one, three and six month implantation experiments we employed six adult mongrel dogs, polyester arterial prostheses Arteknit Ra K, fluorescent Ca2+ indicator Fura-2 and digital imaging microscopy to study cytosolic free Ca2+ in cultured VEC. The electron microscopy scanning of the luminal surface in different regions of the graft were also performed. A rise in cytosolic free Ca2+ in the VEC lining the luminal surface of the prosthesis is probably the result of the immunologic reaction and mechanical stress which stimulate the proliferation activity of the endothelial cells. It seems that the baseline cytosolic free Ca2+ reflects the course of the endothelization process on the polyester arterial prosthesis.

Rotavirus 2/6 virus-like particles administered intranasally in mice, with or without the mucosal adjuvants cholera toxin and Escherichia coli heat-labile toxin, induce a Th1/Th2-like immune response

We investigated the rotavirus-specific lymphocyte responses induced by intranasal immunization of adult BALB/c mice with rotavirus 2/6 virus-like particles (2/6-VLPs) of the bovine RF strain, by assessing the profile of cytokines produced after in vitro restimulation and serum and fecal antibody responses. The cytokines produced by splenic cells were first evaluated. Intranasal immunization with 50 microg of 2/6-VLPs induced a high serum antibody response, including immunoglobulin G1 (IgG1) and IgG2a, a weak fecal antibody response, and a mixed Th1/Th2-like profile of cytokines characterized by gamma interferon and interleukin 10 (IL-10) production and very low levels of IL-2, IL-4, and IL-5. Intranasal immunization with 10 microg of 2/6-VLPs coadministered with the mucosal adjuvants cholera toxin and Escherichia coli heat-labile toxin (LT) considerably enhanced the Th1/Th2-like response; notably, significant levels of IL-2, IL-4, and IL-5 were observed. Since rotavirus is an enteric pathogen, we next investigated the production of IL-2 and IL-5, as being representative of Th1 and Th2 responses, by Peyer's patch and mesenteric lymph node cells from mice immunized intranasally with 2/6-VLPs and LT. The results were compared to those obtained from splenic and cervical lymph node cells. We found that both cytokines were produced by cells from each of these lymphoid tissues. These results confirm the Th1/Th2-like response observed at the systemic level and show, on the assumption that T cells are the primary cells producing the cytokines after in vitro restimulation, that rotavirus-specific T lymphocytes are present in the intestine after intranasal immunization with 2/6-VLPs and LT.

Antibody inhibition of the transcriptase activity of the rotavirus DLP: a structural view

On entering the host cell the rotavirus virion loses its outer shell to become a double-layered particle (DLP). The DLP then transcribes the 11 segments of its dsRNA genome using its own transcriptase complex, and the mature mRNA emerges along the 5-fold axis. In order to better understand the transcription mechanism and the role of VP6 in transcription we have studied three monoclonal antibodies against VP6: RV-238 which inhibits the transcriptase activity of the DLP; and RV-133 and RV-138 which have no effect on transcription. The structures obtained by cryo-electron microscopy of the DLP/Fab complexes and by X-ray crystallography of the VP6 trimer and the VP6/Fab-238 complex have been combined to give pseudo-atomic structures. Steric hindrance between the Fabs results in limited Fab occupancy. In particular, there are on average only three of a possible five Fabs-238 which point towards the 5-fold axis. Thus, Fabs-238 are not in a position to block the exiting mRNA, nor is there any visible conformational change in VP6 on antibody binding at a resolution of 23 A. However, the epitope of the inhibiting antibody involves two VP6 monomers, whereas, those of the non-inhibiting antibodies have an epitope on only one VP6. Thus, the inhibition of transcription may be a result of inhibition of a possible change in the VP6 conformation associated with the transcription of mRNA.

[Epidemiology of viral nosocomial infections in pediatrics]

Nosocomial viral infections account for at least 5% of the total of NI and reach 23% in pediatric wards. The nosocomial infection (NI) incidence rate varies from 0.59 to 0.72 per 100 patients in pediatric wards. Many viruses have been associated with NI in pediatric wards. Rotavirus and respiratory syncytial virus (RSV) are the most frequent. Other viruses frequently identified are: calicivirus, adenovirus, astrovirus, influenza et para-influenza, rhinovirus and coronavirus. Asymptomatic infections occur frequently. The period of communicability varies and depends on the virus. It often begins before the clinical signs appear and ends after the healing. Viral shedding may be intermittent. Children and hospital environment and less frequently hospital staff are the main source for the virus. Poor handwashing results in direct spread to patient or self-inoculation even for respiratory viruses like RSV and rhinovirus. The main risk factors for NI are prolonged hospital stay, past history of prematurity and low age. Immunocompromised patients constitute a special high-risk group. Understaffing is also a risk factor. Minimal infective doses depend on the route of inoculation and the kind of virus. Low doses are for example sufficient for rotavirus, adenovirus and calicivirus. Viral inactivation is all the more easy when there is an envelope. Handwashing and appropriate isolation (technical and geographical) are the mainstay of prevention of viral NI. Vaccines are promising, especially for rotavirus.

G and P genotyping of rotavirus strains circulating in france over a three-year period: detection of G9 and P[6] strains at low frequencies. The AZAY Group

Rotavirus G and P types from 716 children with acute diarrhea in Dijon from 1995 to 1998 and throughout France during the winter of 1997-1998 were analyzed by reverse transcription-PCR. P[8],G1 predominated, followed by P[8],G4, which emerged during the last winter. G9 and P[6] strains were detected at low frequencies.

Prevalence of group A rotavirus, human calicivirus, astrovirus, and adenovirus type 40 and 41 infections among children with acute gastroenteritis in Dijon, France

Group A rotaviruses, human caliciviruses, astroviruses, and adenovirus types 40 and 41 were detected by enzyme immunoassay or reverse transcription-PCR in 61, 14, 6, and 3% of stool specimens from 414 children consulting for gastroenteritis between 1995 and 1998. These data highlight the importance of caliciviruses in infantile gastroenteritis. Among these, Norwalk-like viruses belonging to genogroup II were predominant.

Dose-dependent effects of IL-12 treatment to immune response induced after immunization with a recombinant respiratory syncytial virus (RSV) fusion protein fragment

The amino acid (aa) sequence 190-289 of the RSV fusion (F) glycoprotein expressed in insect cells (bF(190-289)) has been shown to partially protect BALB/c mice and to prime for a Th2 cell response. We evaluated the effects of IL-12 treatment during antigen priming of bF(190-289) on immune response and protective efficacy. Low doses of IL-12 (10 ng) reduced IL-4 and IL-5 secretion (but did not affect IL-10 production) and decreased inflammatory signs whereas high doses of IL-12 had no effects. In addition, IL-12 treatment did not improve resistance to RSV replication. These results suggest that IL-12 treatment attenuates Th2 response and Th2 associated pulmonary inflammatory response in a dose-dependent manner, without improving protective efficacy.