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This study investigated the ability of second-grade children to employ initial and final consonant substitution as a technique in word identification. An instrument of 44 one-syllable simulated words and a measurement to ascertain consonant phoneme knowledge were used to study 90 second-grade pupils, approximately equal in general characteristics. The children were asked to recall a known word visually similar to an unknown word, except for an initial or final consonant, and to pronounce the unknown word by association with the known one. Significant relationships were found in the following cases: (1) between the student's abilities to recall a known word visually similar to the simulated word and to correctly identify the simulated word by means of single consonant substitution, (2) between the abilities to substitute initial consonants and to substitute final consonants, and (3) between reading achievement and ability to employ consonant substitution to identify simulated words. It was concluded that second-grade children can effectively employ single consonant substitution to identify unknown one-syllable words. (LH)

Background Many people use handwashing and hand-drying facilities in public washrooms under the impression that these amenities are hygienic. However, such facilities may be potential sites for the transmission of pathogenic bacteria. This study aimed to examine the hygiene facilities provided including handwashing and hand-drying facilities in public washrooms. Total bacterial counts and species identification were determined for hand-drying facilities. Antimicrobial susceptibilities were performed. Methods The bacterial contamination levels of 55 public washrooms ranging in category from low class communities to high end establishments, were examined. The hygienic environment and facilities of the washrooms were analysed using an electronic checklist to facilitate immediate data entry. Pre-moistened sterile swabs were used to collect samples from areas around the outlet of paper towel dispensers, air outlet of air dryers, exit door handles and paper towels in the washrooms. Total bacterial counts were performed and isolates identified using matrix-assisted laser desorption ionisation time-of-flight mass spectrometry. Antimicrobial susceptibility was determined by disk diffusion. Results The high and middle-income categories washrooms generally had cleaner facilities and environment followed by those in low categories. Fifty-two bacterial species were identified from the 55 investigated washrooms. Over 97% of the pathogenic Staphylococcus spp. tested were resistant to at least one first-line antimicrobial therapeutic agent, including penicillin, cefoxitin, erythromycin, co-trimoxazole, clindamycin and gentamicin, and 22.6% demonstrated co-resistance to at least three antimicrobial agents, with co-resistance to penicillin, erythromycin and clindamycin being the most common. Conclusion Our findings suggest that hand-drying facilities in public washrooms can act as reservoirs of drug-resistant bacteria. The importance of frequent cleaning and maintenance of public washrooms to promote safe hand hygiene practices for the public are emphasised. Electronic supplementary material The online version of this article (10.1186/s13756-019-0500-z) contains supplementary material, which is available to authorized users.

There are no existing affordable diagnostics for sensitive, rapid, and on-site detection of pathogens in milk. To this end, an on-site colorimetric-based sustainable assay has been developed and optimized using an L16 (54) Taguchi design to obtain results in hours without PCR amplification. To determine the level of Escherichia coli (E. coli) contamination, after induction with 150 &micro, L of breast milk, the B-Per bacterial protein extraction kit was added to a solution containing an alginate-based microcapsule assay. Within this 3 mm spherical novel sensor design, X-Gal (5-Bromo-4-Chloro-3-Indolyl &beta, d-Galactopyranoside) was entrapped at a concentration of 2 mg/mL. The outward diffusing X-Gal was cleaved by &beta, galactosidase from E. coli and dimerized in the solution to yield a blue color after incubation at 40 &deg, C. Color intensity was correlated with the level of E. coli contamination using a categorical scale. After an 8 h incubation period, a continuous imaging scale based on intensity normalization was used to determine a binary lower limit of detection (LOD), which corresponded to 102 colony forming unit per mL (CFU/mL) and above. The cost of the overall assay was estimated to be $0.81 per sample, well under the $3 benchmark for state-of-the-art immune-based test kits for pathogen detection in biofluids. Considering the reported binary LOD cutoff of 102 CFU/mL and above, this proposed hydrogel-based assay is suited to meet global requirements for screening breast milk or milk for pathogenic organisms of 104 CFU/mL, with a percentage of false positives to be determined in future efforts.

Background The adequate fit of an N95 respirator is important for health care workers to reduce the transmission of airborne infectious diseases in the clinical setting. This study aimed to evaluate whether adequately sealed N95 respirators may provide consistent protection for the wearer while performing nursing procedures. Methods Participants were a group of nursing students (N = 120). The best fitting respirator for these participants was identified from the 3 common models, 1860, 1860S, and 1870+ (3M), using the quantitative fit test (QNFT) method. Participants performed nursing procedures for 10-minute periods while wearing a backpack containing the portable aerosol spectrometers throughout the assessment to detect air particles inside the respirator. Results The average fit factor of the best fitting respirator worn by the participants dropped significantly after nursing procedures (184.85 vs 134.71) as detected by the QNFT. In addition, significant differences in particle concentration of different sizes (>0.3, >0.4, >1.0, and >4.0 µm) inside the respirator were detected by the portable aerosol spectrometers before, during, and after nursing procedures. Conclusions Body movements during nursing procedures may increase the risk of face seal leakage. Further research, including the development of prototype devices for better respirator fit, is necessary to improve respiratory protection of users.

Tick-borne disease in dogs is common in South-east Asia and includes babesiosis and ehrlichiosis. These diseases can be largely prevented by compliant use of tick preventive products. This study investigated knowledge of ticks and tick-borne disease and use of tick preventive agents by a large sample of dog owners in Hong Kong. A total of 492 valid questionnaires were completed by owners attending veterinary practices, approached by researchers at common dog-walking areas, or targeted via local social media sites for pet owners. A high proportion of respondents were aware of tick-borne disease (79%) and this correlated well with use of preventive products. However, 18% of owners did not use any protection, mainly due to lack of knowledge of the risk of disease. Targeted advice stressing the importance of tick protection use and frequent follow-up at veterinary clinics could help reduce the risk of tick-borne disease. It would be beneficial if veterinarians provided training of frontline staff at the clinics to ensure they provide essential information to clients in an easily understandable format.

The study aimed to describe the lived experiences of SDMC Registered Nurses, using the existential phenomenological method espoused by Van Manen (2014) in analyzing the experiences. The experiential themes (first reflection) from textual transcription of 4 Registered Nurses revealed: Nurse S shares, “When I am with the patient, I immerse myself in the totality of patient care”. Thus, the theme: Commitment and Compassionate Care. Nurse D verbalized; I have a feeling of satisfaction when I see that the patient loneliness subsides”. Thus, the theme: Gratification in Action. Nurse M expressed, “I felt fulfilled when the patient and family treats me as part of the family. Thus, the theme, Patient and Compassionate Nurse equals Family. Nurse C voiced, “When you are equipped with basic information to answer patient’s questions rapport is easy to establish”. The theme: Cognitive Aspect of Care. The second refection describes caring at the core, inner compass of care, nurturing begets belonging and confidence in knowing. The third reflection sums up the details into “Authentic Caring and Rapport as central to relationship. Hence, the gist of the lived experiences outlined that in every Nurse- Patient relationship, there is a caring moment and human interaction.

For physicians, the early career phase spans medical training (medical school, residency, fellowship) through the initial years of post-training employment. While the transition out of the trainee role marks an important inflection point, this period is unified by a focus on developing knowledge, clinical skills, and scope of practice and by establishing greater professional authority and identity. Several issues may uniquely affect the risk for burnout in women during this phase, including the realities of negotiating work obligations with the demands of relationship-, community-, and family-building which are common during this chronological and developmental timeframe. Issues related to reproduction are often salient. Productivity expectations—particularly those established in academic settings within a historical context that was male-dominated—may need adjustment to account for these factors. Additionally, the evolution of authority that must occur during this phase can be impacted by gendered expectations of performance in the workplace. This chapter proposes both individual and organizational solutions to prevent and manage burnout in women during this critical early phase of career development. To organize these solutions, we utilize the Stanford School of Medicine wellness framework which conceptualizes three major domains that impact wellness: Culture, Efficiency of Practice, and Resiliency.

Background Hand hygiene is a critical component of infection control. Much of the focus on improving hand hygiene in healthcare settings has been directed towards healthcare worker compliance but its importance for patients, including those in long-term care facilities (LTCFs), is increasingly being recognised. Alcohol-based hand rub (ABHR) can lead to improved compliance. We aimed to determine acceptability and tolerability of two ABHRs for hand hygiene of elderly LTCF residents using a modified version of the WHO protocol. Methods Thirty six elderly LTCF residents participated in this crossover study. A modified and translated (Chinese) version of the WHO protocol for evaluation of two or more ABHRs was used to determine product acceptability and tolerability for one gel (bottle with reclosable cap) and one foam (pump). During the 3-day testing period, participants were provided with their own portable bottle of ABHR. A research nurse objectively assessed the skin integrity of the hands at baseline and throughout the study. Skin moisture content was determined using a Scalar Moisture Checker Probe (Science Technology Resources, Ca, USA). Participants rated ABHR tolerability and acceptability using the WHO checklist at the end of each test period. Results Both products passed the WHO criteria for acceptability and tolerability. The foam (86%) scored higher than the gel (51%) for ease of use possibly because some participants found the cap of the gel bottle difficult to open due to finger stiffness. No evidence of damage to skin integrity was observed. Overall, skin moisture content had improved by the end of the study. Residents preferred either of the test products to the liquid formulation currently in use by the LTCF. Conclusions Overall, the elderly were willing to use ABHR for hand hygiene. Both products were well tolerated and preferred over the usual product provided by the LTCF. However, forgetfulness and difficulty rubbing the product over the hands due to finger stiffness posed a challenge for some residents. This could be overcome by using healthcare worker-assisted hand hygiene at specified times each day and prompts to serve as reminders to perform hand hygiene.

Lycopene and green tea consumption have been observationally associated with reduced prostate cancer risk, but the underlying mechanisms have not been fully elucidated. We investigated the effect of factorial randomisation to a 6‐month lycopene and green tea dietary advice or supplementation intervention on 159 serum metabolite measures in 128 men with raised PSA levels (but prostate cancer‐free), analysed by intention‐to‐treat. The causal effects of metabolites modified by the intervention on prostate cancer risk were then assessed by Mendelian randomisation, using summary statistics from 44,825 prostate cancer cases and 27,904 controls. The systemic effects of lycopene and green tea supplementation on serum metabolic profile were comparable to the effects of the respective dietary advice interventions (R 2 = 0.65 and 0.76 for lycopene and green tea respectively). Metabolites which were altered in response to lycopene supplementation were acetate [β (standard deviation difference vs. placebo): 0.69; 95% CI = 0.24, 1.15; p = 0.003], valine (β: −0.62; −1.03, −0.02; p = 0.004), pyruvate (β: −0.56; −0.95, −0.16; p = 0.006) and docosahexaenoic acid (β: −0.50; −085, −0.14; p = 0.006). Valine and diacylglycerol were lower in the lycopene dietary advice group (β: −0.65; −1.04, −0.26; p = 0.001 and β: −0.59; −1.01, −0.18; p = 0.006). A genetically instrumented SD increase in pyruvate increased the odds of prostate cancer by 1.29 (1.03, 1.62; p = 0.027). An intervention to increase lycopene intake altered the serum metabolome of men at risk of prostate cancer. Lycopene lowered levels of pyruvate, which our Mendelian randomisation analysis suggests may be causally related to reduced prostate cancer risk., What's new? Prostate cancer incidence varies by geographic region, suggesting that environmental factors, such as diet, play a role. Here, the authors investigated how green tea and lycopene intake affects prostate cancer risk. They conducted a 6‐month intervention on men with raised PSA levels but no cancer, testing levels of 159 serum metabolites by NMR. Lycopene supplementation, they found, reduced levels of circulating pyruvate, and Mendelian randomisation analysis suggests pyruvate may boost PC risk. These results suggest a possible mechanism of action by which consuming dietary lycopene may reduce prostate cancer risk.

This chapter contains case studies for a wide range of mental health scenarios pertinent to active military service members and veterans. Each clinical case study is followed by a self-study review, which includes a set of questions and assignments regarding diagnoses, treatment plans, ethical considerations, and military and veteran systems of care. These self-study reviews are designed to help the learner understand the unique needs of military and veteran populations and to practice applications of the fundamental principles for mental health care of these populations. The learner may refer back to relevant chapters from the book to build a conceptual framework for understanding these cases and their implications for care.

BACKGROUND The goal of antiretroviral therapy (ART) is to reduce HIV-related morbidity and mortality by suppressing HIV replication. The prognostic value of persistent low-level viremia (LLV), particularly for clinical outcomes, is unknown. OBJECTIVE Assess the association of different levels of LLV with virological failure, AIDS event, and death among HIV-infected patients receiving combination ART. METHODS We analyzed data from 18 cohorts in Europe and North America, contributing to the ART Cohort Collaboration. Eligible patients achieved viral load below 50 copies/ml within 3-9 months after ART initiation. LLV50-199 was defined as two consecutive viral loads between 50 and 199 copies/ml and LLV200-499 as two consecutive viral loads between 50 and 499 copies/ml, with at least one between 200 and 499 copies/ml. We used Cox models to estimate the association of LLV with virological failure (two consecutive viral loads at least 500 copies/ml or one viral load at least 500 copies/ml, followed by a modification of ART) and AIDS event/death. RESULTS Among 17 902 patients, 624 (3.5%) experienced LLV50-199 and 482 (2.7%) LLV200-499. Median follow-up was 2.3 and 3.1 years for virological and clinical outcomes, respectively. There were 1903 virological failure, 532 AIDS events and 480 deaths. LLV200-499 was strongly associated with virological failure [adjusted hazard ratio (aHR) 3.97, 95% confidence interval (CI) 3.05-5.17]. LLV50-199 was weakly associated with virological failure (aHR 1.38, 95% CI 0.96-2.00). LLV50-199 and LLV200-499 were not associated with AIDS event/death (aHR 1.13, 95% CI 0.81-1.68; and aHR 0.95, 95% CI 0.62-1.48, [corrected] respectively). CONCLUSION LLV200-499 was strongly associated with virological failure, but not with AIDS event/death. Our results support the US guidelines, which define virological failure as a confirmed viral load above 200 copies/ml.

SUMMARYA longitudinal study of nasal colonization and hand contamination of food handlers withStaphylococcus aureuscommenced in 2002 prior to the outbreak of severe acute respiratory syndrome. In the follow-up in 2003 when hygiene measures were strictly implemented, significant reductions in carriage were observed. To investigate if this change was sustained, nasal and hand carriage rates were compared between the earlier studies and a further sampling in 2011. The initial nasal carriage rate was 35% and hand contamination 41·2%, decreasing to 23·5% and 11·6%, respectively in 2003 (P< 0·001). In 2011, nasal carriage was similar to 2003 (22·9%), while hand contamination dropped further to 3·7% (P< 0·001).Spa-typing revealed 39 types in 2002 and 42 in 2011. This study reveals that the marked reduction in colonization had been sustained. This may be attributed to reduced opportunities for spread due to enhanced hygiene and reinforces its importance for control of disease.

We aimed to identify the source of Staphylococcus aureus contaminating hands of food handlers. Nasal samples and direct fingertip imprints were collected on 2 occasions from food handlers and characterized to determine likely sources of hand contamination. Most hand contamination was attributable to nasal isolates of persistently colonized coworkers who had presumably contaminated the environment. Regular handwashing should be supplemented by effective environmental disinfection., Highlights • We aimed to identify the source of S. aureus contaminating hands of food handlers. • Persistently colonized co-workers indirectly contaminated hands of others. • Regular handwashing should be supplemented by effective environmental disinfection.

Conventional lubricants are formulated using mineral base stocks, which are refined from petroleum and contain many chemical species. Although mineral base stocks serve general-purpose lubricants well, they cannot be optimized for specific performance features. Modern machines and equipment are increasingly designed to operate under more severe conditions, to require less maintenance, to have improved longevity and better energy efficiency. Sometimes, conventional lubricants based on mineral base stocks fail to meet these elevated performance requirements. Synthetic lubricants using tailored synthetic base stocks are designed to meet these higher performance needs and can provide superior performance and economic benefits over conventional lubricants.

Background Whilst numerous studies have investigated nurses’ compliance with hand hygiene and use of alcohol-based hand rub (ABHR), limited attention has been paid to these issues in allied health staff. Reports have linked infections to breaches in infection control in the radiography unit (RU). With advances in medical imaging, a higher proportion of patients come into contact with RU staff increasing the need for good hand hygiene compliance. This study aimed to evaluate effectiveness on compliance of an intervention to improve awareness of hand hygiene in the RU of a district hospital. Methods A quasi-experimental study design including questionnaires assessing knowledge and attitudes of hand hygiene and direct observation of participants was used to evaluate an educational programme on hand hygiene of the RU of a large district hospital. All healthcare workers (HCW), comprising 76 radiographers, 17 nurses, and nine healthcare assistants (HCA), agreed to participate in the study. Of these, 85 completed the initial and 76 the post-test anonymous questionnaire. The hand hygiene compliance of all 102 HCW was observed over a 3-week period prior to and after the intervention. The 2-month intervention consisted of talks on hand hygiene and benefits of ABHR, provision of visual aids, wall-mounted ABHR dispensers, and personal bottles of ABHR. Results Before the intervention, overall hand hygiene compliance was low (28.9 %). Post-intervention, compliance with hand hygiene increased to 51.4 %. This improvement was significant for radiographers and HCA. Additionally, knowledge and attitudes improved in particular, understanding that ABHR can largely replace handwashing and there is a need to perform hand hygiene after environmental contact. The increased use of ABHR allowed HCW to feel they had enough time to perform hand hygiene. Conclusions The educational intervention led to increased awareness of hand hygiene opportunities and better acceptance of ABHR use. The reduced time needed to perform hand rubbing and improved access to dispensers resulted in fewer missed opportunities. Although radiographers and other allied HCW make frequent contact with patients, these may be mistakenly construed as irrelevant with respect to healthcare associated infections. Stronger emphasis on hand hygiene compliance of these staff may help reduce infection risk.

Background Influenza often causes winter and summer epidemics in subtropical regions, but few studies have investigated the difference in healthcare seeking behavior of patients with influenza-like illness (ILI) between these two epidemics. Methods Household telephone surveys were conducted using random digit dialing in Hong Kong during July-August 2014 and March-April 2015. One adult from each household was interviewed for ILI symptoms and associated healthcare seeking behaviour of themselves and one child in the household (if any), during the preceding 30 days. Healthcare seeking behavior of respondents with self-reported ILI was compared between summer and winter influenza. Logistic regression was used to explore the factors associated with healthcare seeking behavior. Results Among 516 and 539 adult respondents in the summer and winter surveys, 22.6 and 38.0 % reported ILI symptoms, and 40.9 and 46.8 % of them sought medical care, respectively. There was no significant difference in healthcare seeking behavior between the summer and winter epidemics, except a higher proportion of self-medication in summer in the adult respondents. Among 155 and 182 children reported by the adults in both surveys, the proportion of self-reported ILI was 32.9 and 40.1 % in the summer and winter surveys, respectively. Of these children, 47.1 and 56.2 % were brought for medical consultation in summer and winter, respectively. Women, adults with diabetes and those with symptoms of cough, shortness of breath, and runny nose were more likely to seek medical consultations for ILI symptoms. The factors associated with seeking medical consultations in children with ILI symptoms included being female, age under 10 years, and with symptoms of sore throat or vomiting. Those older than 60 years were less likely to self-medicate, whereas regular smokers and those with symptom of sore throat were more likely to do so. Conclusion Healthcare seeking behavior of the general public was not significantly different between these two epidemics. However ILI was associated with increased healthcare utilization in both winter and summer epidemics in Hong Kong. Electronic supplementary material The online version of this article (doi:10.1186/s12879-016-1821-7) contains supplementary material, which is available to authorized users.

Chinese roasted pork has been implicated as a major source of food poisoning caused by Staphylococcus aureus. Establishing the source, either as contaminants from raw meat or from food handlers, could facilitate drafting more appropriate guidelines for better prevention of food poisoning. To determine the rate and source of staphylococcal contamination, roasted pork purchased from 50 sui-mei shops in Hong Kong was sampled for presence of S. aureus by enrichment and subsequent culture. Isolates were characterized for methicillin sensitivity, spa type, and presence of Panton-Valentine leukocidin (PVL) and staphylococcal enterotoxins (SEs). Methicillin-resistant isolates were confirmed by presence of mecA and SCCmec type and sensitivity to vancomycin investigated. S. aureus was isolated from 25 (50%) samples, with 3 yielding two colony types. Of the 28 isolates, 3 were resistant to cefoxitin, but only 2 were mecA positive and belonged to SCCmec type V. The mecA negative isolate also lacked mecC, but had a penicillin minimum inhibitory concentration of 10 mg/L. A livestock-associated spa type (t034) was only observed in one methicillin-sensitive strain, all other isolates appearing to be of human origin, with 30% belonging to t189. One isolate was PVL positive and five carried genes for classical SEs. The high rate of staphylococcal contamination observed was probably associated with food handlers, as the strains belonged to spa types previously reported in clinical and nasal carriage isolates. The presence of enterotoxins in 18% of isolates confirms the risk of food poisoning associated with this product and emphasizes the need for improved guidelines for handling after preparation. Use of refrigerated display areas should be considered.

INTRODUCTION:Efficacious and cost-efficient non-pharmacologic treatments, i.e., therapist guided exposure therapy for penetration disorders (GET-PEN), are available and in widespread use outside of the U.S. While therapists commonly provide guided desensitization therapy for other phobias, the GET-P

Contains fulltext : 70499.pdf (Publisher’s version ) (Closed access) OBJECTIVE: To determine whether differences in short-term virologic failure among commonly used antiretroviral therapy (ART) regimens translate to differences in clinical events in antiretroviral-naive patients initiating ART. DESIGN: Observational cohort study of patients initiating ART between January 2000 and December 2005. SETTING: The Antiretroviral Therapy Cohort Collaboration (ART-CC) is a collaboration of 15 HIV cohort studies from Canada, Europe, and the United States. STUDY PARTICIPANTS: A total of 13 546 antiretroviral-naive HIV-positive patients initiating ART with efavirenz, nevirapine, lopinavir/ritonavir, nelfinavir, or abacavir as third drugs in combination with a zidovudine and lamivudine nucleoside reverse transcriptase inhibitor backbone. MAIN OUTCOME MEASURES: Short-term (24-week) virologic failure (>500 copies/ml) and clinical events within 2 years of ART initiation (incident AIDS-defining event, death, and a composite measure of these two outcomes). RESULTS: Compared with efavirenz as initial third drug, short-term virologic failure was more common with all other third drugs evaluated; nevirapine (adjusted odds ratio = 1.87, 95% confidence interval (CI) = 1.58-2.22), lopinavir/ritonavir (1.32, 95% CI = 1.12-1.57), nelfinavir (3.20, 95% CI = 2.74-3.74), and abacavir (2.13, 95% CI = 1.82-2.50). However, the rate of clinical events within 2 years of ART initiation appeared higher only with nevirapine (adjusted hazard ratio for composite outcome measure 1.27, 95% CI = 1.04-1.56) and abacavir (1.22, 95% CI = 1.00-1.48). CONCLUSION: Among antiretroviral-naive patients initiating therapy, between-ART regimen, differences in short-term virologic failure do not necessarily translate to differences in clinical outcomes. Our results should be interpreted with caution because of the possibility of residual confounding by indication.

Gram-negative bacteria possess an outer membrane (OM) containing lipopolysaccharide (LPS). Proper assembly of the OM not only prevents certain antibiotics from entering the cell, but also allows others to be pumped out. To assemble this barrier, the seven-protein lipopolysaccharide transport (Lpt) system extracts LPS from the outer leaflet of the inner membrane (IM), transports it across the periplasm and inserts it selectively into the outer leaflet of the OM. As LPS is important, if not essential, in most Gram-negative bacteria, the LPS biosynthesis and biogenesis pathways are attractive targets in the development of new classes of antibiotics. The accompanying paper (Simpson BW, May JM, Sherman DJ, Kahne D, Ruiz N. 2015 Phil. Trans. R. Soc. B 370 , 20150029. ( doi:10.1098/rstb.2015.0029 )) reviewed the biosynthesis of LPS and its extraction from the IM. This paper will trace its journey across the periplasm and insertion into the OM.

This study investigated the association between the presence of staphylococcal enterotoxin (SE) genes and nasal carriage status, and determined temporal changes in the prevalence of these genes in Staphylococcus aureus strains isolated from healthy carriers between 2002 and 2011. Three large samples of food handlers recruited in 2002, 2003 and 2011 were nasally sampled on two occasions to determine S. aureus colonisation status. Those carrying the same spa type on both occasions were defined as persistent carriers. Genes for SEs SEA–SEU were amplified and associations between carriage status and presence of SE genes were investigated. Although 80 % of nasal isolates harboured at least one SE gene over the sampling period, persistent carriers were significantly more likely to harbour enterotoxigenic S. aureus than transiently colonised subjects [odds ratio (OR) 2.52–3.06]. Strains from persistent carriers more commonly harboured sea, seb and sem. The prevalence of classical SE genes and sej, sem, sen, seo, seq and ses was stable over time, but seh, sel, sep, ser, set and selu increased significantly. Increased toxigenicity of isolates from persistent carriers is consistent with the elevated antibody levels to classical SEs previously reported in persistent carriers, supporting the hypothesis that superantigen production in the nasal cavity may enhance colonisation.