Norovirus detection in environmental samples in norovirus outbreaks in closed and semi-closed settings

BACKGROUND

Environmental surfaces are a potential vehicle for the transmission of norovirus outbreaks in closed and semi-closed settings. Testing of environmental samples may help control outbreaks.

AIM

To assess the level of environmental contamination by norovirus in acute gastroenteritis outbreaks in closed or semi-closed settings (nursing homes, schools, kindergartens, youth accommodations, hospitals and social health centres) in the Barcelona region between January 2017 and March 2019.

METHODS

A prospective surveillance study was carried out. Environmental samples (529) were collected in 46 of the 50 outbreaks of acute norovirus gastroenteritis from environmental surfaces of common areas, bathrooms and kitchens in closed and semi-closed settings when the outbreak was notified and 10 days later. Instructions for taking environmental samples were distributed to public health inspectors. Norovirus was detected by reverse transcription polymerase chain reaction.

FINDINGS

Environmental samples were positive for norovirus in 31 (67.4%) outbreaks. Norovirus was most frequently detected on elevator buttons (4/17, 24%), toilet handles (16/66, 24%) and handrail bars (7/34, 21%). Positive samples from the first sampling were mainly found in bathrooms and greater viral persistence in the second sampling was found on elevator buttons and TV remote controls. Nursing homes were the setting with the most types of environmental surfaces contaminated (82% in first samples and 55% in second samples).

CONCLUSION

The probability of virus detection is independent of the time between notification of the outbreak or symptom onset and sample collection. Our results suggest possible defects in cleaning protocols and disinfection in closed and semi-closed settings.

Virological surveillance of influenza and other respiratory viruses during six consecutive seasons from 2006 to 2012 in Catalonia, Spain

Most attention is given to seasonal influenza and respiratory syncytial virus outbreaks, but the cumulative burden caused by other respiratory viruses (RV) is not widely considered. The aim of the present study is to describe the circulation of RV in the general population during six consecutive seasons from 2006 to 2012 in Catalonia, Spain. Cell culture, immunofluorescence and PCR-based assays were used for the RV laboratory-confirmation and influenza subtyping. Phylogenetic and molecular characterizations of viral haemagglutinin, partial neuraminidase and matrix 2 proteins were performed from a representative sampling of influenza viruses. A total of 6315 nasopharyngeal samples were collected, of which 64% were laboratory-confirmed, mainly as influenza A viruses and rhinoviruses. Results show the significant burden of viral aetiological agents in acute respiratory infection, particularly in the youngest cases. The study of influenza strains reveals their continuous evolution through either progressive mutations or by segment reassortments. Moreover, the predominant influenza B lineage was different from that included in the recommended vaccine in half of the studied seasons, supporting the formulation and use of a quadrivalent influenza vaccine. Regarding neuraminidase inhibitors resistance, with the exception of the 2007/08 H275Y seasonal A(H1N1) strains, no other circulating influenza strains carrying known resistance genetic markers were found. Moreover, all circulating A(H1N1)pdm09 and A(H3N2) strains finally became genetically resistant to adamantanes. A wide knowledge of the seasonality patterns of the RV in the general population is well-appreciated, but it is a challenge due to the unpredictable circulation of RV, highlighting the value of local and global RV surveillance.

Prevalence of anti-rubella, anti-measles and anti-mumps IgG antibodies in neonates and pregnant women in Catalonia (Spain) in 2013: susceptibility to measles increased from 2003 to 2013

Non-immune neonates and non-immune pregnant women are at risk of developing rubella, measles and mumps infections, including congenital rubella syndrome. We describe the seroepidemiology of measles, mumps and rubella (MMR) in neonates and pregnant women in Catalonia (Spain). Anti-rubella, anti-measles and anti-mumps serum IgG titres were assessed using enzyme-linked immunosorbent assay (ELISA) tests in 353 cord blood samples from neonates of a representative sample of pregnant women obtained in 2013. The prevalence of protective antibody titres in neonates was 96 % for rubella IgG (≥8 IU/ml), 90 % for measles IgG (>300 IU/ml) and 84 % for mumps IgG (>460 EU/ml). Slightly lower prevalences of protective IgG titres, as estimated from the cord blood titres, were found in pregnant women: 95 % for rubella IgG, 89 % for measles IgG and 81 % for mumps IgG. The anti-measles and anti-mumps IgG titres and the prevalences of protective IgG titres against measles and mumps increased significantly (p < 0.001) with maternal age. The prevalence of protective anti-measles IgG titres decreased by 7 % [odds ratio (OR) = 0.15, p < 0.001), the prevalence of protective anti-rubella IgG titres increased by 3 % (OR = 1.80, p < 0.05) and the MMR vaccination coverage (during childhood) in pregnant women increased by 54 % (OR = 2.09, p < 0.001) from 2003 to 2013. We recommend to develop an MMR prevention programme in women of childbearing age based on mass MMR vaccination or MMR screening and vaccination of susceptible women to increase immunity levels against MMR.

Lack of detection of Middle East respiratory syndrome coronavirus in mild and severe respiratory infections in Catalonia, northeastern Spain

Surveillance of Middle East respiratory syndrome coronavirus (MERS-CoV) was conducted to explore the possible introduction and circulation of this novel virus in Catalonia, northeastern Spain. Five hundred and sixty-three samples from mild and severe respiratory infections collected between January 2012 and April 2013 were screened using real-time RT-PCR. All samples were negative, suggesting that MERS-CoV is not circulating silently in Catalonia.

Type 1 diabetes and perinatal factors in Catalonia (Spain)

AIM

To identify perinatal risk factors associated with the development of type 1 diabetes.

METHODS

The research was designed as a retrospective study of cases and controls. Catalan Register of Diabetes and the Register of Newborn Screening for Metabolic Diseases were the data sources used in this study. The variables studied include sex, birth weight, age of onset of type 1 diabetes, maternal age at delivery, type of delivery, and type of feeding at birth. Anthropometric growth patterns of Carrascosa have been used to classify birth weight as small for gestational age: weight <10th percentile; appropriate for gestational age: weight ≥10th percentile and ≤90th percentile; and large for gestational age (LGA): weight >90th percentile. Statistical analysis was carried out using bivariate analysis (chi-squared test), and odds ratios and 95% confidence intervals were predicted.

RESULTS

A total of 1530 infants were analyzed (306 type 1 diabetes cases, 1224 control subjects). A significantly greater percentage of LGA babies were observed among diabetics (16.3% compared with 11.3% of the control group). The risk of having type 1 diabetes in children who were LGA was 1.45 times greater than that shown in children with normal and low birth weight.

CONCLUSIONS

Only being born LGA was significantly associated with developing type 1 diabetes.

[Impact of smoking and alcohol consumption on mortality in the population of Barcelona [Spain]: 1983-1998]

OBJECTIVES

To analyze the mortality attributable to smoking and alcohol consumption in the city of Barcelona from 1983 to 1998.

METHODS

All deaths among residents of the city of Barcelona from 1983 to 1998 were included. Population data were obtained from the city inhabitants register. The mortality attributable to smoking and alcohol consumption was calculated by population attributable fractions using relative risks from previous studies in the US population.

RESULTS

In 1998, 2,205 deaths were attributable to smoking, representing 13.8% of all deaths among the population aged 35 years or older and a decrease of 9.6% compared with deaths in 1983. From 1983 to 1998 there was an increase in smoking-attributable adjusted mortality rates for lung cancer (155.84/100,000 inhabitants in men and 9.39/100,000 in women in 1998) and chronic obstructive pulmonary disease (COPD) (95.89/100,000 in men and 11.29/ 100,000 in women in 1998). In 1998, deaths attributed to alcohol consumption accounted for 4.3% of total mortality, representing a reduction of 26% since 1983. Among men, the primary cause of alcohol-attributable mortality was liver cirrhosis (17.1%), although its relative importance decreased (accounting for 17.1% of alcohol-attributable mortality in 1998 compared with 24.3% in 1983).

CONCLUSIONS

The mortality attributable to smoking and alcohol consumption decreased in the city of Barcelona during the study period. Smoking-attributable mortality from lung cancer and COPD increased in both sexes. Alcohol consumption-attributable mortality from liver cirrhosis decreased in men.

[Determinant factors of smoking cessation during pregnancy]

BACKGROUND

To investigate sociodemographic factors and smoking habit characteristics associated with spontaneous smoking cessation during pregnancy.

DESIGN

SUBJECTS AND METHODS

Cross-sectional study including 726 pregnant smoking women who attended the antenatal clinic of the Vall d'Hebron University Hospital in Barcelona between July and December 1997 and who agreed to participate were studied. Information was obtained by a structured questionnaire which included items on age, educational level, marital status, previous and current smoking habit, partner smoking habit and partner's attitude towards the smoking habit of the pregnant woman.

RESULTS

At the first antenatal visit, 19.7% of women had given up smoking spontaneously. Light smokers (between 1 and 9 daily cigarettes; OR = 4.74) or moderate smokers (between 10 and 19 daily cigarettes; OR = 2.20) were more likely to stop smoking compared to heavy smokers (more than 20 daily cigarettes). If the partner did not smoke, smoking cessation was more likely among pregnant women (OR = 1.78). At the first antenatal visit, among those women who carried on smoking during pregnancy, there was a significative reduction in cigarette consumption of about half the usual daily number of cigarettes smoked.

CONCLUSIONS

One out of five pregnant women give up smoking spontaneously during pregnancy from the moment they know they were pregnant until the first antenatal visit. Women who are less likely to stop smoking during pregnancy are those who smoke a larger number of cigarettes. Family environment is an important influential factor in the smoking habit of the pregnant woman.

[Evaluation of a simple rapid polymerase chain reaction (PCR) technique for the diagnosis of Helicobacter pylori infection in childhood]

BACKGROUND

The purpose of this study was to evaluate the use of polymerase chain reaction (PCR) applied to the diagnosis Helicobacter pylori infection in the pediatric population, by means of a rapid and simple method of extraction and posterior detection by a colorimetric hybridation of amplified H. pylori DNA.

METHODS

Fifty three gastric biopsies, obtained through upper gastrointestinal endoscopy from 53 patients with gastric pathology (45 recidivant abdominal pain and eight hematemesis), were processed from october 1995 to july 1996. Three non invasive tests were performed: detection of IgG by (Cobas) Core Anti-H. pylori EIA (Roche), breath test with 13C-urea and PCR of dental plaque, as well as four invasive ones: histologic study, culture into selective (Pylori Agar, bioMérieux) and non selective media (Columbia Agar with 5% sheep blood, bioMérieux), test of rapid urease and PCR of gastric biopsies. A 20% solution of Chelex 100 resin (DNA Extraction Reagen, Perkin Elmer) was used for DNA extraction, amplification was performed from gen ureA (Clayton, 1992) and amplified DNA was detected by colorimetric hybridation (PCR ELISA, Boehringer, Mannheim). Duration of the PCR process was: extraction 25 min, amplification two hours and detection three hours.

RESULTS

Results of culture and PCR from gastric biopsies agreed in 84.3% of cases (27 positives, 16 negatives and two not determined). Two samples were positive by culture and negative by PCR, and were considered as PCR false negatives due to positivity of three or more other tests. Six samples were negative by culture and positive by PCR, being considered as culture false negatives due to positivity of three or more other tests. Sensitivity of PCR and culture was 94.2 and 82.8%. Specificity was 100% for both tests. None of the dental plaque samples was positive.

CONCLUSIONS

When invasive techniques are to be done for microbiologic diagnose of H. pylori, PCR increases the confirmation rate of infection; the present procedure enables daily routine work due to its simplicity and its short turnaround time.