George Kafatos - Academia.edu (original) (raw)
Papers by George Kafatos
In 2008, acute hepatitis E infection was confirmed in 4 passengers returning to the United Kingdo... more In 2008, acute hepatitis E infection was confirmed in 4 passengers returning to the United Kingdom after a world cruise. Epidemiologic investigation showed that of 789 persons who provided blood samples, 195 (25%) were seropositive, 33 (4%) had immunoglobulin (Ig) M levels consistent with recent acute infection (11 of these persons were symptomatic), and 162 (21%) had IgG only, consistent
BMJ Open, 2012
To cite: Clarke S, Keshishian C, Murray V, et al. Screening for carbon monoxide exposure in selec... more To cite: Clarke S, Keshishian C, Murray V, et al. Screening for carbon monoxide exposure in selected patient groups attending rural and urban emergency departments in England: a prospective observational study.
Surprisingly little is known regarding the human mixing patterns relevant to the spread of closec... more Surprisingly little is known regarding the human mixing patterns relevant to the spread of closecontact infections, such as measles, influenza and meningococcal disease. This study aims to estimate the number of partnerships that individuals make, their stability and the degree to which mixing is assortative with respect to age. We defined four levels of putative at-risk events from casual (physical contact without conversation) to intimate (contact of a sexual nature), and asked university student volunteers to record details on those they contacted at these levels on three separate days. We found that intimate contacts are stable over short time periods whereas there was no evidence of repeat casual contacts with the same individuals. The contacts were increasingly assortative as intimacy increased. Such information will aid the development and parameterisation of models of close contact diseases, and may have direct use in outbreak investigations.
Journal of Bone and Joint Surgery - British Volume, 2005
We wished to estimate the incidence of surgical-site infection (SSI) after total hip replacement ... more We wished to estimate the incidence of surgical-site infection (SSI) after total hip replacement (THR) and hemiarthroplasty and its strength of association with major risk factors. The SSI surveillance service prospectively gathered clinical, operative and infection data on inpatients from 102 hospitals in England during a four-year period. The overall incidence of SSI was 2.23% for 16,291 THRs, 4.97% for 5769 hemiarthroplasty procedures, 3.68% for 2550 revision THRs and 7.6% for 198 revision hemiarthroplasties. Staphylococcus aureus was identified in 50% of SSIs; 59% of these isolates were methicillin-resistant (MRSA). In the single variable analysis of THRs, age, female gender, American Society of Anesthesiologists (ASA) score, body mass index, trauma, duration of operation and pre-operative stay were significantly associated with the risk of SSI (p < 0.05). For hemiarthroplasty, the ASA score and age were significant factors. In revision THRs male gender, ASA score, trauma, wound class, duration of operation and pre-operative stay were significant risk factors. The median time to detection of SSI was eight days for superficial incisional, 11 days for deep incisional and 11 days for joint/bone infections. For each procedure the mean length of stay doubled for patients with SSI. The multivariate analysis identified age group, trauma, duration of operation and ASA score as significant, independent risk factors for SSI. There was significant interhospital variation in the rates of SSI. MRSA was the most common pathogen to cause SSI in hip arthroplasty, especially in patients undergoing hemiarthroplasty, but coagulase-negative Staph. aureus may be more important in deep infections involving the joint.
European Journal of Epidemiology, 2010
A source of infection is rarely identified for sporadic cases of Legionnaires' disease. We found ... more A source of infection is rarely identified for sporadic cases of Legionnaires' disease. We found that professional drivers are five times more commonly represented among community acquired sporadic cases in England and Wales than expected. We therefore investigated possible risk exposures in relation to driving or spending time in a motor vehicle. A case control study including all surviving community acquired sporadic cases in England and Wales with onset between 12 July 2008 and 9 March 2009 was carried out. Cases were contacted by phone and controls were consecutively recruited by sequential digital dialling matched by area code, sex and age group. Those who consented were sent a questionnaire asking questions on driving habits, potential sources in vehicles and known risk factors. The results were analysed using logistic regression. 75 cases and 67 controls were included in the study. Multivariable analysis identified two exposures linked to vehicle use associated with an increased risk of Legionnaires' disease: Driving through industrial areas (OR 7.2, 95%CI 1.5-33.7) and driving or being a passenger in a vehicle with windscreen wiper fluid not containing added screenwash (OR 47.2, 95%CI 3.7-603.6). Not adding screenwash to windscreen wiper fluid is a previously unidentified risk factor and appears to be strongly associated with community acquired sporadic cases of Legionnaires' disease. We estimated that around 20% of community acquired sporadic cases could be attributed to this exposure. A simple recommendation to use screenwash may mitigate transmission of Legionella bacteria to drivers and passengers.
Epidemiology and Infection, 2007
We investigated the comparative seroepidemiology of varicella zoster virus (VZV) in pregnant wome... more We investigated the comparative seroepidemiology of varicella zoster virus (VZV) in pregnant women of two ethnic groups, white British and Bangladeshi, living in an inner city area of London, United Kingdom. Women aged 16-45 years were recruited from antenatal clinics of the Royal London Hospital in the Borough of Tower Hamlets. Complete data were obtained from 275 white British and 765 Bangladeshi women. VZV antibody prevalence was 93 . 1% (95 % CI 89 . 4-95 . 8) and 86 . 0% (95 % CI 83 . 3-88 . 4) respectively. Women who were born in Bangladesh and lived there at least until the age of 15 years had the lowest odds of being immune (OR 0 . 37, 95 % CI 0 . 22-0 . 63). This implies they will have an increased risk of varicella during pregnancy. Women arriving in the United Kingdom in adulthood should be screened routinely during pregnancy and vaccination offered postpartum if they are susceptible.
Epidemiology and Infection, 2013
Indigenously acquired hepatitis E infections have increased substantially in England and Wales si... more Indigenously acquired hepatitis E infections have increased substantially in England and Wales since 2010. Epidemiological investigations were undertaken to determine risk factors for the acquisition of infection. A case-control study (25 cases, 75 controls) was used to test the hypothesis that hepatitis E infection was related to consumption of pork products. In a multivariable model, consumption of pork pie [odds ratio (OR) 6·33, 95% confidence interval (CI) 1·41-28·48, P = 0·009] and consumption of ham and sausages purchased from a major UK supermarket chain (OR 10·12, 95% CI 1·68-60·81, P = 0·023) were significantly associated with indigenous infection. The consumption of sausages and ham purchased from the supermarket was highly correlated; however. separate models showed that each variable was significantly associated with infection (OR 7·59, 95% CI 1·81-31·84, P = 0·004 and OR 10·98, 95% CI 1·84-65·35, P = 0·003, respectively). Although contamination of sausages with HEV has previously been shown this study also raises concerns about other processed pork products and whether current practice in preparing these products is sufficient to prevent transmission of HEV.
Emerging Infectious Diseases, 2009
In 2008, acute hepatitis E infection was confi rmed in 4 passengers returning to the United Kingd... more In 2008, acute hepatitis E infection was confi rmed in 4 passengers returning to the United Kingdom after a world cruise. Epidemiologic investigation showed that of 789 persons who provided blood samples, 195 (25%) were seropositive, 33 (4%) had immunoglobulin [Ig] M levels consistent with recent acute infection (11 of these persons were symptomatic), and 162 (21%) had IgG only, consistent with past infection. Passenger mean age was 68 years. Most (426/789, 54%) passengers were female, yet most with acute infection (25/33, 76%) were male. Sequencing of RNA from 3 case-patients identifi ed hepatitis E virus genotype 3, closely homologous to genotype 3 viruses from Europe. Signifi cant association with acute infection was found for being male, drinking alcohol, and consuming shellfi sh while on board (odds ratio 4.27, 95% confi dence interval 1.23-26.94, p = 0.019). This was probably a common-source foodborne outbreak.
Critical Care Medicine, 2011
To determine the effect of enhanced cleaning of the near-patient environment on the isolation of ... more To determine the effect of enhanced cleaning of the near-patient environment on the isolation of hospital pathogens from the bed area and staff hands.
Eurosurveillance: bulletin europeen sur les maladies transmissibles = European communicable disease bulletin
Vaccine, 2005
The aim of the European Sero-Epidemiology Network 2 (ESEN2) is to compare standardised serologica... more The aim of the European Sero-Epidemiology Network 2 (ESEN2) is to compare standardised serological results of vaccine preventable diseases across Europe. In order to adjust for laboratory and assay differences, the participant laboratories tested a standardisation panel for each disease and the results were plotted against those of a reference centre in order to obtain standardisation equations. We describe an algorithm for obtaining these equations which took into account outliers, censored data and model selection, and needed to be robust due to the variety of assays and diseases under investigation. If the standardisation equations explained sufficient variability, these were used to convert each country&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s main serum bank results to a common unitage, thereby allowing international comparisons to be made.
Epidemiology and infection, Jan 25, 2014
SUMMARY The aim of the European Sero-Epidemiology Network 2 (ESEN2) project was to estimate age-s... more SUMMARY The aim of the European Sero-Epidemiology Network 2 (ESEN2) project was to estimate age-specific seroprevalence for a number of vaccine-preventable diseases in Europe. To achieve this serosurveys were collected by 22 national laboratories. To adjust for a variety of laboratory methods and assays, all quantitative results were transformed to a reference laboratory's units and were then classified as positive or negative to obtain age-specific seroprevalence. The aim of this study was to assess the value of standardization by comparing the crude and standardized seroprevalence estimates. Seroprevalence was estimated for measles, mumps, rubella, diphtheria, varicella zoster and hepatitis A virus (HAV) and compared before and after serological results had been standardized. The results showed that if no such adjustment had taken place, seroprevalence would have differed by an average of 3·2% (95% bootstrap interval 2·9-3·6) although this percentage varied substantially by an...
Disaster Medicine and Public Health Preparedness, 2013
Objective: This study examined homemade masks as an alternative to commercial face masks. Methods... more Objective: This study examined homemade masks as an alternative to commercial face masks. Methods: Several household materials were evaluated for the capacity to block bacterial and viral aerosols.
Vaccine, 2007
The European sero-epidemiology network (ESEN2) aims to standardise serological surveillance of va... more The European sero-epidemiology network (ESEN2) aims to standardise serological surveillance of varicella zoster virus (VZV) in 11 participant countries. In each country, serum banks were collected between 1996 and 2003 and tested for VZV antibodies. Assay results were standardised so that international comparisons could be made. Age-specific forces of infection were calculated for three age groups (<5, 5-9 and ≥10 years of age) and used to estimate the base reproduction number (R 0 ) and the herd immunity threshold (H). Most VZV infection occurred in childhood, but there was a wide variation in transmissibility, with R 0 ranging from 16.9 in the Netherlands to 3.3 in Italy. Herd immunity thresholds varied from 70% in Italy to 94% in the Netherlands. There are substantial differences in VZV sero-epidemiology within the European region, which will need to be taken into account in designing national policies regarding VZV vaccination.
Journal of Medical Microbiology, 2013
The impact was assessed of censored serological measurements on regression equations fitted to da... more The impact was assessed of censored serological measurements on regression equations fitted to data from panels of sera tested by different laboratories, for the purpose of standardizing serosurvey results to common units. Several methods that adjust for censoring were compared, such as deletion, simple substitution, multiple imputation and censored regression. Simulations were generated from different scenarios for varying proportions of data censored. The scenarios were based on serological panel comparisons tested by different national laboratories and assays as part of the European Sero-Epidemiology Network 2 project. The results showed that the simple substitution and deletion methods worked reasonably well for low proportions of data censored (,20 %). However, in general, the censored regression method gave estimates closer to the truth than the other methods examined under different scenarios, such as types of equations used and violation of regression assumptions. Interval-censored regression produced the least biased estimates for assay data resulting from dilution series. Censored regression produced the least biased estimates in comparison with the other methods examined. Moreover, the results suggest using interval-censored regression methods for assay data resulting from dilution series.
Journal of Hospital Infection, 2013
Healthcare-associated infections in long-term care facilities (LTCFs) are of increasing importanc... more Healthcare-associated infections in long-term care facilities (LTCFs) are of increasing importance. To develop consensus national performance indicators (NPIs) for infection control (ICPI) and antimicrobial stewardship (ASPI) in LTCFs, and assess the performance of 32 European countries against these NPIs. Previously established European standards were the basis for consensus and the same iterative approach with national representatives from the 32 countries. A World Health Organization scoring system recorded how close each country was to implementing each standard. The 42 agreed component indicators were grouped into six NPI categories: 'national programme', 'guidelines', 'expert advice', 'IC structure' (not present in the ASPI), 'surveillance' and 'composite'. 'Guidelines' scored the highest mean total possible score (60%, range 20-100%), followed by 'composite' (53%, range 30-100%), 'expert advice' (48%, range 20-100%), 'surveillance' (47%, range 20-83%), 'national programme' (42%, range 20-100%) and 'IC structure' (39%, range 20-100%). Although several scores were low, some countries were able to implement all NPIs, indicating that this was feasible. Most NPIs were very significantly related, indicating that they were considered to be important by the countries. 'Guidelines' and 'IC structure' were significantly related to European region (P ≤ 0.05). Accreditation/inspection was not evident in seven (22%) countries, nine (28%) countries had accreditation/inspection that included IC assessments, and seven (22%) countries had accreditation/inspection that included IC and antimicrobial stewardship assessments. Multi-variable analysis found that only the NPI and the ICPI 'expert advice' were associated with accreditation/inspection which included IC and antimicrobial stewardship. The identified gaps represent significant potential patient safety issues. The NPIs should serve as a basis for monitoring improvements over the coming years.
Journal of Clinical Virology, 2006
Journal of Clinical Virology, 2012
Recently, a commercial, standardised VZV IgG glycoprotein EIA, Binding Site VaccZyme™VZV glycopro... more Recently, a commercial, standardised VZV IgG glycoprotein EIA, Binding Site VaccZyme™VZV glycoprotein IgG low level EIA (VaccZyme™EIA) has become available. The VaccZyme™EIA is more robust and user friendly than the reference VZV time-resolved fluorescence immunoassay (VZV TRFIA). To assess the usefulness of the VaccZyme™EIA in the diagnostic laboratory by comparing VZV IgG levels generated by both assays on serum panels representing, non-vaccinated, and vOka vaccinated populations. Sera from non-vaccinated individuals were tested; 248 from pregnant women, 117 from various patient groups referred to the Virus Reference Department for confirmatory VZV IgG testing and 102 from healthcare workers enrolled in a study (ROVE) of antibody/IgG response to vOka. From the ROVE study, 282 post vaccination sera were tested; 108 and 101 collected at six weeks post first and second doses of vOka, respectively, and 73 collected at 18 month follow-up. Sensitivities and specificities (equivocals treated as negatives) of the VaccZyme™EIA for sera from pregnant women were 97.8% (95% CI: [94.6%, 99.4%]) and 96.8% (95% CI: [89.0%, 99.6%]), respectively, and for sera referred for confirmatory testing were 81.2% (95% CI: [71.2%, 88.8%]) and 96.9% (95% CI: [83.8%, 99.9%]), respectively, and for ROVE baseline sera were 54.2% (95% CI: [32.8%, 74.4%]) and 100% (95% CI: [95.4%, 100.0%]), respectively. For the post vOka serum panels sensitivities of the VaccZyme™EIA ranged from 65.3% (95% CI: [50.4%, 78.3%]) to 80.4% (95% CI: [71.1%, 87.8%]). Specificities were all 100%. Correlation with VZV TRFIA was high and agreement varied between the serum panels tested. VaccZyme™EIA is recommended for detecting VZV IgG in sera from non-vaccinated populations; however, caution is advised when measuring post vOka VZV IgG levels.
Influenza and Other Respiratory Viruses, 2013
Estimates of seasonal influenza vaccine effectiveness (VE) are affected by factors such as the st... more Estimates of seasonal influenza vaccine effectiveness (VE) are affected by factors such as the strain of the current circulating influenza virus and characteristics of the host. The objective of this study was to provide VE estimates for the 2010/2011 seasonal trivalent influenza vaccine (TIV) in preventing medically attended influenza in England and Wales for the season 2010/2011. A cohort study design was employed using electronic health records extracted from 104 GP practices in the Royal College of General Practitioners (RCGP) primary care sentinel network. Endpoints included influenza-like illness (ILI), lower respiratory tract infection (LTRI) as well as PCR-confirmed influenza from patients swabbed from practices participating in a swabbing scheme. Adjustment was made for age, month, underlying chronic condition, region and number of consultations in the 12 months prior to the study period. In addition to the cohort analysis, a nested test-negative case-control analysis (TNCC) was carried out using the swab-negative results as controls. In the cohort analysis, VE against LRTI was -0·5% [95% CI: (-7·0%, 7·5%)], against ILI was 37·8% [95% CI: (32·3%, 43·0%)] and against PCR-confirmed influenza was 50·0% [95% CI:(25·9%, 65·6%)] for type A and 44·4% [95% CI: (10·1%, 65·6%)] for type B. Using the TNCC design, the type A VE was 56·5% [95% CI: (30·4%, 72·7%)] and for type B was 54·0% [95% CI: (21·0%, 73·3%)]. This study shows that the 2010/2011 TIV provided moderate protection against the circulating influenza strains for the 2010/2011 season. It also suggests that VE against the less specific diagnosis of ILI can be found, but less specific endpoints such as LRTI are not useful.
In 2008, acute hepatitis E infection was confirmed in 4 passengers returning to the United Kingdo... more In 2008, acute hepatitis E infection was confirmed in 4 passengers returning to the United Kingdom after a world cruise. Epidemiologic investigation showed that of 789 persons who provided blood samples, 195 (25%) were seropositive, 33 (4%) had immunoglobulin (Ig) M levels consistent with recent acute infection (11 of these persons were symptomatic), and 162 (21%) had IgG only, consistent
BMJ Open, 2012
To cite: Clarke S, Keshishian C, Murray V, et al. Screening for carbon monoxide exposure in selec... more To cite: Clarke S, Keshishian C, Murray V, et al. Screening for carbon monoxide exposure in selected patient groups attending rural and urban emergency departments in England: a prospective observational study.
Surprisingly little is known regarding the human mixing patterns relevant to the spread of closec... more Surprisingly little is known regarding the human mixing patterns relevant to the spread of closecontact infections, such as measles, influenza and meningococcal disease. This study aims to estimate the number of partnerships that individuals make, their stability and the degree to which mixing is assortative with respect to age. We defined four levels of putative at-risk events from casual (physical contact without conversation) to intimate (contact of a sexual nature), and asked university student volunteers to record details on those they contacted at these levels on three separate days. We found that intimate contacts are stable over short time periods whereas there was no evidence of repeat casual contacts with the same individuals. The contacts were increasingly assortative as intimacy increased. Such information will aid the development and parameterisation of models of close contact diseases, and may have direct use in outbreak investigations.
Journal of Bone and Joint Surgery - British Volume, 2005
We wished to estimate the incidence of surgical-site infection (SSI) after total hip replacement ... more We wished to estimate the incidence of surgical-site infection (SSI) after total hip replacement (THR) and hemiarthroplasty and its strength of association with major risk factors. The SSI surveillance service prospectively gathered clinical, operative and infection data on inpatients from 102 hospitals in England during a four-year period. The overall incidence of SSI was 2.23% for 16,291 THRs, 4.97% for 5769 hemiarthroplasty procedures, 3.68% for 2550 revision THRs and 7.6% for 198 revision hemiarthroplasties. Staphylococcus aureus was identified in 50% of SSIs; 59% of these isolates were methicillin-resistant (MRSA). In the single variable analysis of THRs, age, female gender, American Society of Anesthesiologists (ASA) score, body mass index, trauma, duration of operation and pre-operative stay were significantly associated with the risk of SSI (p < 0.05). For hemiarthroplasty, the ASA score and age were significant factors. In revision THRs male gender, ASA score, trauma, wound class, duration of operation and pre-operative stay were significant risk factors. The median time to detection of SSI was eight days for superficial incisional, 11 days for deep incisional and 11 days for joint/bone infections. For each procedure the mean length of stay doubled for patients with SSI. The multivariate analysis identified age group, trauma, duration of operation and ASA score as significant, independent risk factors for SSI. There was significant interhospital variation in the rates of SSI. MRSA was the most common pathogen to cause SSI in hip arthroplasty, especially in patients undergoing hemiarthroplasty, but coagulase-negative Staph. aureus may be more important in deep infections involving the joint.
European Journal of Epidemiology, 2010
A source of infection is rarely identified for sporadic cases of Legionnaires' disease. We found ... more A source of infection is rarely identified for sporadic cases of Legionnaires' disease. We found that professional drivers are five times more commonly represented among community acquired sporadic cases in England and Wales than expected. We therefore investigated possible risk exposures in relation to driving or spending time in a motor vehicle. A case control study including all surviving community acquired sporadic cases in England and Wales with onset between 12 July 2008 and 9 March 2009 was carried out. Cases were contacted by phone and controls were consecutively recruited by sequential digital dialling matched by area code, sex and age group. Those who consented were sent a questionnaire asking questions on driving habits, potential sources in vehicles and known risk factors. The results were analysed using logistic regression. 75 cases and 67 controls were included in the study. Multivariable analysis identified two exposures linked to vehicle use associated with an increased risk of Legionnaires' disease: Driving through industrial areas (OR 7.2, 95%CI 1.5-33.7) and driving or being a passenger in a vehicle with windscreen wiper fluid not containing added screenwash (OR 47.2, 95%CI 3.7-603.6). Not adding screenwash to windscreen wiper fluid is a previously unidentified risk factor and appears to be strongly associated with community acquired sporadic cases of Legionnaires' disease. We estimated that around 20% of community acquired sporadic cases could be attributed to this exposure. A simple recommendation to use screenwash may mitigate transmission of Legionella bacteria to drivers and passengers.
Epidemiology and Infection, 2007
We investigated the comparative seroepidemiology of varicella zoster virus (VZV) in pregnant wome... more We investigated the comparative seroepidemiology of varicella zoster virus (VZV) in pregnant women of two ethnic groups, white British and Bangladeshi, living in an inner city area of London, United Kingdom. Women aged 16-45 years were recruited from antenatal clinics of the Royal London Hospital in the Borough of Tower Hamlets. Complete data were obtained from 275 white British and 765 Bangladeshi women. VZV antibody prevalence was 93 . 1% (95 % CI 89 . 4-95 . 8) and 86 . 0% (95 % CI 83 . 3-88 . 4) respectively. Women who were born in Bangladesh and lived there at least until the age of 15 years had the lowest odds of being immune (OR 0 . 37, 95 % CI 0 . 22-0 . 63). This implies they will have an increased risk of varicella during pregnancy. Women arriving in the United Kingdom in adulthood should be screened routinely during pregnancy and vaccination offered postpartum if they are susceptible.
Epidemiology and Infection, 2013
Indigenously acquired hepatitis E infections have increased substantially in England and Wales si... more Indigenously acquired hepatitis E infections have increased substantially in England and Wales since 2010. Epidemiological investigations were undertaken to determine risk factors for the acquisition of infection. A case-control study (25 cases, 75 controls) was used to test the hypothesis that hepatitis E infection was related to consumption of pork products. In a multivariable model, consumption of pork pie [odds ratio (OR) 6·33, 95% confidence interval (CI) 1·41-28·48, P = 0·009] and consumption of ham and sausages purchased from a major UK supermarket chain (OR 10·12, 95% CI 1·68-60·81, P = 0·023) were significantly associated with indigenous infection. The consumption of sausages and ham purchased from the supermarket was highly correlated; however. separate models showed that each variable was significantly associated with infection (OR 7·59, 95% CI 1·81-31·84, P = 0·004 and OR 10·98, 95% CI 1·84-65·35, P = 0·003, respectively). Although contamination of sausages with HEV has previously been shown this study also raises concerns about other processed pork products and whether current practice in preparing these products is sufficient to prevent transmission of HEV.
Emerging Infectious Diseases, 2009
In 2008, acute hepatitis E infection was confi rmed in 4 passengers returning to the United Kingd... more In 2008, acute hepatitis E infection was confi rmed in 4 passengers returning to the United Kingdom after a world cruise. Epidemiologic investigation showed that of 789 persons who provided blood samples, 195 (25%) were seropositive, 33 (4%) had immunoglobulin [Ig] M levels consistent with recent acute infection (11 of these persons were symptomatic), and 162 (21%) had IgG only, consistent with past infection. Passenger mean age was 68 years. Most (426/789, 54%) passengers were female, yet most with acute infection (25/33, 76%) were male. Sequencing of RNA from 3 case-patients identifi ed hepatitis E virus genotype 3, closely homologous to genotype 3 viruses from Europe. Signifi cant association with acute infection was found for being male, drinking alcohol, and consuming shellfi sh while on board (odds ratio 4.27, 95% confi dence interval 1.23-26.94, p = 0.019). This was probably a common-source foodborne outbreak.
Critical Care Medicine, 2011
To determine the effect of enhanced cleaning of the near-patient environment on the isolation of ... more To determine the effect of enhanced cleaning of the near-patient environment on the isolation of hospital pathogens from the bed area and staff hands.
Eurosurveillance: bulletin europeen sur les maladies transmissibles = European communicable disease bulletin
Vaccine, 2005
The aim of the European Sero-Epidemiology Network 2 (ESEN2) is to compare standardised serologica... more The aim of the European Sero-Epidemiology Network 2 (ESEN2) is to compare standardised serological results of vaccine preventable diseases across Europe. In order to adjust for laboratory and assay differences, the participant laboratories tested a standardisation panel for each disease and the results were plotted against those of a reference centre in order to obtain standardisation equations. We describe an algorithm for obtaining these equations which took into account outliers, censored data and model selection, and needed to be robust due to the variety of assays and diseases under investigation. If the standardisation equations explained sufficient variability, these were used to convert each country&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s main serum bank results to a common unitage, thereby allowing international comparisons to be made.
Epidemiology and infection, Jan 25, 2014
SUMMARY The aim of the European Sero-Epidemiology Network 2 (ESEN2) project was to estimate age-s... more SUMMARY The aim of the European Sero-Epidemiology Network 2 (ESEN2) project was to estimate age-specific seroprevalence for a number of vaccine-preventable diseases in Europe. To achieve this serosurveys were collected by 22 national laboratories. To adjust for a variety of laboratory methods and assays, all quantitative results were transformed to a reference laboratory's units and were then classified as positive or negative to obtain age-specific seroprevalence. The aim of this study was to assess the value of standardization by comparing the crude and standardized seroprevalence estimates. Seroprevalence was estimated for measles, mumps, rubella, diphtheria, varicella zoster and hepatitis A virus (HAV) and compared before and after serological results had been standardized. The results showed that if no such adjustment had taken place, seroprevalence would have differed by an average of 3·2% (95% bootstrap interval 2·9-3·6) although this percentage varied substantially by an...
Disaster Medicine and Public Health Preparedness, 2013
Objective: This study examined homemade masks as an alternative to commercial face masks. Methods... more Objective: This study examined homemade masks as an alternative to commercial face masks. Methods: Several household materials were evaluated for the capacity to block bacterial and viral aerosols.
Vaccine, 2007
The European sero-epidemiology network (ESEN2) aims to standardise serological surveillance of va... more The European sero-epidemiology network (ESEN2) aims to standardise serological surveillance of varicella zoster virus (VZV) in 11 participant countries. In each country, serum banks were collected between 1996 and 2003 and tested for VZV antibodies. Assay results were standardised so that international comparisons could be made. Age-specific forces of infection were calculated for three age groups (<5, 5-9 and ≥10 years of age) and used to estimate the base reproduction number (R 0 ) and the herd immunity threshold (H). Most VZV infection occurred in childhood, but there was a wide variation in transmissibility, with R 0 ranging from 16.9 in the Netherlands to 3.3 in Italy. Herd immunity thresholds varied from 70% in Italy to 94% in the Netherlands. There are substantial differences in VZV sero-epidemiology within the European region, which will need to be taken into account in designing national policies regarding VZV vaccination.
Journal of Medical Microbiology, 2013
The impact was assessed of censored serological measurements on regression equations fitted to da... more The impact was assessed of censored serological measurements on regression equations fitted to data from panels of sera tested by different laboratories, for the purpose of standardizing serosurvey results to common units. Several methods that adjust for censoring were compared, such as deletion, simple substitution, multiple imputation and censored regression. Simulations were generated from different scenarios for varying proportions of data censored. The scenarios were based on serological panel comparisons tested by different national laboratories and assays as part of the European Sero-Epidemiology Network 2 project. The results showed that the simple substitution and deletion methods worked reasonably well for low proportions of data censored (,20 %). However, in general, the censored regression method gave estimates closer to the truth than the other methods examined under different scenarios, such as types of equations used and violation of regression assumptions. Interval-censored regression produced the least biased estimates for assay data resulting from dilution series. Censored regression produced the least biased estimates in comparison with the other methods examined. Moreover, the results suggest using interval-censored regression methods for assay data resulting from dilution series.
Journal of Hospital Infection, 2013
Healthcare-associated infections in long-term care facilities (LTCFs) are of increasing importanc... more Healthcare-associated infections in long-term care facilities (LTCFs) are of increasing importance. To develop consensus national performance indicators (NPIs) for infection control (ICPI) and antimicrobial stewardship (ASPI) in LTCFs, and assess the performance of 32 European countries against these NPIs. Previously established European standards were the basis for consensus and the same iterative approach with national representatives from the 32 countries. A World Health Organization scoring system recorded how close each country was to implementing each standard. The 42 agreed component indicators were grouped into six NPI categories: 'national programme', 'guidelines', 'expert advice', 'IC structure' (not present in the ASPI), 'surveillance' and 'composite'. 'Guidelines' scored the highest mean total possible score (60%, range 20-100%), followed by 'composite' (53%, range 30-100%), 'expert advice' (48%, range 20-100%), 'surveillance' (47%, range 20-83%), 'national programme' (42%, range 20-100%) and 'IC structure' (39%, range 20-100%). Although several scores were low, some countries were able to implement all NPIs, indicating that this was feasible. Most NPIs were very significantly related, indicating that they were considered to be important by the countries. 'Guidelines' and 'IC structure' were significantly related to European region (P ≤ 0.05). Accreditation/inspection was not evident in seven (22%) countries, nine (28%) countries had accreditation/inspection that included IC assessments, and seven (22%) countries had accreditation/inspection that included IC and antimicrobial stewardship assessments. Multi-variable analysis found that only the NPI and the ICPI 'expert advice' were associated with accreditation/inspection which included IC and antimicrobial stewardship. The identified gaps represent significant potential patient safety issues. The NPIs should serve as a basis for monitoring improvements over the coming years.
Journal of Clinical Virology, 2006
Journal of Clinical Virology, 2012
Recently, a commercial, standardised VZV IgG glycoprotein EIA, Binding Site VaccZyme™VZV glycopro... more Recently, a commercial, standardised VZV IgG glycoprotein EIA, Binding Site VaccZyme™VZV glycoprotein IgG low level EIA (VaccZyme™EIA) has become available. The VaccZyme™EIA is more robust and user friendly than the reference VZV time-resolved fluorescence immunoassay (VZV TRFIA). To assess the usefulness of the VaccZyme™EIA in the diagnostic laboratory by comparing VZV IgG levels generated by both assays on serum panels representing, non-vaccinated, and vOka vaccinated populations. Sera from non-vaccinated individuals were tested; 248 from pregnant women, 117 from various patient groups referred to the Virus Reference Department for confirmatory VZV IgG testing and 102 from healthcare workers enrolled in a study (ROVE) of antibody/IgG response to vOka. From the ROVE study, 282 post vaccination sera were tested; 108 and 101 collected at six weeks post first and second doses of vOka, respectively, and 73 collected at 18 month follow-up. Sensitivities and specificities (equivocals treated as negatives) of the VaccZyme™EIA for sera from pregnant women were 97.8% (95% CI: [94.6%, 99.4%]) and 96.8% (95% CI: [89.0%, 99.6%]), respectively, and for sera referred for confirmatory testing were 81.2% (95% CI: [71.2%, 88.8%]) and 96.9% (95% CI: [83.8%, 99.9%]), respectively, and for ROVE baseline sera were 54.2% (95% CI: [32.8%, 74.4%]) and 100% (95% CI: [95.4%, 100.0%]), respectively. For the post vOka serum panels sensitivities of the VaccZyme™EIA ranged from 65.3% (95% CI: [50.4%, 78.3%]) to 80.4% (95% CI: [71.1%, 87.8%]). Specificities were all 100%. Correlation with VZV TRFIA was high and agreement varied between the serum panels tested. VaccZyme™EIA is recommended for detecting VZV IgG in sera from non-vaccinated populations; however, caution is advised when measuring post vOka VZV IgG levels.
Influenza and Other Respiratory Viruses, 2013
Estimates of seasonal influenza vaccine effectiveness (VE) are affected by factors such as the st... more Estimates of seasonal influenza vaccine effectiveness (VE) are affected by factors such as the strain of the current circulating influenza virus and characteristics of the host. The objective of this study was to provide VE estimates for the 2010/2011 seasonal trivalent influenza vaccine (TIV) in preventing medically attended influenza in England and Wales for the season 2010/2011. A cohort study design was employed using electronic health records extracted from 104 GP practices in the Royal College of General Practitioners (RCGP) primary care sentinel network. Endpoints included influenza-like illness (ILI), lower respiratory tract infection (LTRI) as well as PCR-confirmed influenza from patients swabbed from practices participating in a swabbing scheme. Adjustment was made for age, month, underlying chronic condition, region and number of consultations in the 12 months prior to the study period. In addition to the cohort analysis, a nested test-negative case-control analysis (TNCC) was carried out using the swab-negative results as controls. In the cohort analysis, VE against LRTI was -0·5% [95% CI: (-7·0%, 7·5%)], against ILI was 37·8% [95% CI: (32·3%, 43·0%)] and against PCR-confirmed influenza was 50·0% [95% CI:(25·9%, 65·6%)] for type A and 44·4% [95% CI: (10·1%, 65·6%)] for type B. Using the TNCC design, the type A VE was 56·5% [95% CI: (30·4%, 72·7%)] and for type B was 54·0% [95% CI: (21·0%, 73·3%)]. This study shows that the 2010/2011 TIV provided moderate protection against the circulating influenza strains for the 2010/2011 season. It also suggests that VE against the less specific diagnosis of ILI can be found, but less specific endpoints such as LRTI are not useful.