Hepatitis A outbreak in British Columbia, Canada: the roles of established surveillance, consumer loyalty cards and collaboration, February to May 2012

Non-travel-related hepatitis A is rare in Canada. We describe a hepatitis A outbreak investigation in British Columbia in February to May 2012 in which exposure history was collected from nine confirmed non-travel-related cases. Suspected foods were tested for hepatitis A virus (HAV): a frozen fruit blend was identified as a common exposure for six of the nine cases using supermarket loyalty cards. Consumption of the product was confirmed in each case. Genetic analysis confirmed HAV genotype 1B in the six exposed cases. Of the three non-exposed cases, the virus could not be genotyped for two of them; the virus from the other case was found to be genotype 1A and this case was therefore not considered part of the outbreak. HAV was detected by PCR from pomegranate seeds, a component of the identified frozen fruit blend. Historically low levels of HAV infection in British Columbia triggered early recognition of the outbreak. Loyalty card histories facilitated product identification and a trace-back investigation implicated imported pomegranate seeds.

Asenapine induces differential regional effects on serotonin receptor subtypes

Asenapine, a novel psychopharmacologic agent being developed for the treatment of schizophrenia and bipolar disorder, has high affinity for a wide range of receptors, including the serotonergic receptors 5-HT(1A), 5-HT(1B), 5-HT(2A), 5-HT( 2B), 5-HT(2C), 5-HT(5A), 5-HT(6) and 5-HT( 7). We examined the long-term effects in rat brain of multiple doses of asenapine on representative serotonin receptor subtypes: 5-HT(1A), 5-HT(2A) and 5-HT(2C). Rats were given asenapine (0.03, 0.1 or 0.3 mg/kg) subcutaneously twice daily or vehicle for 4 weeks. Brain sections were collected from the medial prefrontal cortex (mPFC), dorsolateral frontal cortex (DFC), caudate putamen, nucleus accumbens, hippocampal CA( 1) and CA(3) regions, and entorhinal cortex and processed for in-vitro receptor autoradiography. Asenapine 0.1 and 0.3 mg/kg significantly increased 5-HT(1A) binding in mPFC (by 24% and 33%, respectively), DFC (27%, 31%) and hippocampal CA(1) region (23%, 25%) (all P < 0.05). All three asenapine doses (0.03, 0.1 and 0.3 mg/kg) significantly decreased 5-HT(2A) binding by a similar degree in mPFC (40%, 44%, 47%, respectively) and DFC (45%, 51%, 52%) (all P < 0.05), but did not alter 5-HT(2A) binding in the other brain regions studied. In contrast to the effects on 5-HT(1A) and 5-HT(2A) receptors, asenapine did not alter 5-HT(2C) binding in any brain region examined at the doses tested. Our results indicate that repeated administration of asenapine produces regional-specific effects on 5-HT(1A) and 5-HT(2A) receptors in rat forebrain regions, which may contribute to the distinctive psychopharmacologic profile of asenapine.

Investigation of the second wave (phase 2) of severe acute respiratory syndrome (SARS) in Toronto, Canada. What happened?

BACKGROUND

Severe acute respiratory syndrome (SARS) was introduced to Toronto on 23 February, 2003. The outbreak was believed to be over in early May after two incubation periods had passed with no newly identified cases. However, on 20 May, 2003 a cluster of respiratory illnesses occurred in a rehabilitation facility in Toronto. These cases were later identified as SARS but not until a community hospital in which one of these cases was previously hospitalized (Hospital X) had already experienced nosocomial transmission. This report describes the outbreak investigation of nosocomial transmission of SARS at Hospital X.

METHODS

An investigation of 90 probable and suspect cases of SARS associated with a hospital outbreak was performed. The investigation included death record reviews, chart reviews, case finding and contact tracing. Nursing cohorts who worked on the specific ward in which nosocomial transmission occurred had work-shift and patient-assignment records reviewed to determine source of infection.

RESULTS

The greatest number of cases occurred within hospital employees (42.5%) with an average age of 51 years and 69% being female. The mean incubation period for one time exposure patients was 6.3 days (range 4 to 10 days). Twelve (13.8%) of the cases died. Five of seven nurses who cared for a specific SARS patient during this period acquired SARS. Twelve of 17 (70.6%) nursing staff who developed SARS worked with another nursing staff who was symptomatic for SARS. Staff members who worked the evening shift or the morning shift and therefore likely attended a nursing appreciation breakfast were five times more likely to acquire SARS than those who did not attend.

INTERPRETATION

What was believed to be the end of the Toronto SARS outbreak led the Provincial Operations Centre (POC) to issue a directive allowing a more relaxed use of infection-control precautions during the beginning of Phase 2 of the outbreak. These relaxations of precautions were temporally associated with the nosocomial transmission of SARS to hospital staff, other patients and visitors at Hospital X. As a result of this outbreak significant changes have been made with respect to infection-control practices within Canada.

46. INNOVATION AND DESIGN: IMPROVING CONTACT TRACING IN SEXUAL HEALTH CLINICS

Contact tracing (CT) is an integral part of sexually transmitted infection (STI) management. Although routinely conducted in most sexual health clinics (SHCs), the methods used may vary. To improve CT required novel approaches. First we audited the outcomes of current contact tracing methods. A major finding of this audit was that while CT was routinely recommended, outcomes were poorly recorded. We developed a sticker to be placed in the charts of clients with a traceable STI. This indicated the number of contacts requiring notification, and how many had been notified and treated at our clinic. This enabled a standardised approach to CT records and improved ability to audit outcomes. It also focused clinicians on the need to ensure followup of CT and to offer assistance when CT had not been done. Next, a brochure was developed to give to clients when diagnosed with a traceable STI. This brochure mentioned the reasons for contacting patterns, dispelled some myths that have been found in previous studies about telling partners and provided ideas about how to tell partners. In conjunction with this a SMS was developed, that could be sent to index cases' mobile phones, allowing them to forward the SMS to partners. This was seen as an ideal method for young people who frequently had mobile numbers of past partners but little other contact details. It was also able to be simple and quick. The next step will be reauditing the CT outcomes once the SMS and brochure are in established use.

Microdialysis sampling and the clinical determination of topical dermal bioequivalence

Our objective was to determine whether the degree of variability associated with dermal microdialysis allows its practical application to determinations of bioequivalence of topically applied agents with a reasonable number of subjects. A statistical review of literature data was conducted to estimate the variances associated with subject-to-subject variability and the probe-to-probe variability within the subjects. In order to successfully utilise dermal microdialysis to establish bioequivalence of topically applied agents, particular care must be applied to study design. Due to the inherent variability between subjects, to maintain subject numbers at reasonable levels, each subject should act as their own control, thus removing the element of subject-to-subject variability from calculations of sample sizes. It is also recommended that measurements are made in duplicate in each subject to reduce the element of variability further. It is then possible to demonstrate, within 80-125% confidence limits and a subject population of approximately 20, that two formulations are bioequivalent.

A multi-approach study of the interaction of the Cu(II) and Ni(II) ions with alanylglycylhistamine, a mimicking pseudopeptide of the serum albumine N-terminal residue

The protonation equilibria of alanylglycylhistamine (Ala-Gly-Ha) and the complexation of this ligand with Cu(II) and Ni(II) have been studied by pH-potentiometry, 1H and 14N NMR spectroscopy, electrospray ionization mass spectrometry (ESI-MS), circular dichroism (CD), UV-Vis spectrophotometry and electron paramagnetic resonance (EPR). From pH approximately 2-12, the following complexes: MLH, MLH(-1), MLH(-2) and MLH(-3) are successively formed in aqueous solutions, the ligand under its neutral form being noted L. At physiological pH, the MLH(-2) complex is predominant. The coordination in this complex is assumed by one amino, two deprotonated peptide and one imidazole nitrogen atoms. The ESI-MS study confirmed the formation of the MLH(-1), MLH(-2) and MLH(-3) complexes. The structure of MLH(-2) was determined by single crystal X-ray analysis. CD and UV-Vis techniques allowed us to propose that the imidazole-N3 nitrogen acts as the anchor group for the coordination to the metal(II) ions rather than the amino group. At high pH values, the further deprotonation of the N-H imidazole group, leading to the formation of MLH(-3), occurs, as revealed by 1H NMR spectroscopy.

A multi-laboratory evaluation of a common in vitro pepsin digestion assay protocol used in assessing the safety of novel proteins

Rationale. Evaluation of the potential allergenicity of proteins derived from genetically modified foods has involved a weight of evidence approach that incorporates an evaluation of protein digestibility in pepsin. Currently, there is no standardized protocol to assess the digestibility of proteins using simulated gastric fluid. Potential variations in assay parameters include: pH, pepsin purity, pepsin to target protein ratio, target protein purity, and method of detection. The objective was to assess the digestibility of a common set of proteins in nine independent laboratories to determine the reproducibility of the assay when performed using a common protocol. Methods. A single lot of each test protein and pepsin was obtained and distributed to each laboratory. The test proteins consisted of Ara h 2 (a peanut conglutin-like protein), beta-lactoglobulin, bovine serum albumin, concanavalin A, horseradish peroxidase, ovalbumin, ovomucoid, phosphinothricin acetyltransferase, ribulose diphosphate carboxylase, and soybean trypsin inhibitor. A ratio of 10U of pepsin activity/microg test protein was selected for all tests (3:1 pepsin to protein, w:w). Digestions were performed at pH 1.2 and 2.0, with sampling at 0.5, 2, 5, 10, 20, 30, and 60min. Protein digestibility was assessed from stained gels following SDS-PAGE of digestion samples and controls. Results. Results were relatively consistent across laboratories for the full-length proteins. The identification of proteolytic fragments was less consistent, being affected by different fixation and staining methods. Overall, assay pH did not influence the time to disappearance of the full-length protein or protein fragments, however, results across laboratories were more consistent at pH 1.2 (91% agreement) than pH 2.0 (77%). Conclusions. These data demonstrate that this common protocol for evaluating the in vitro digestibility of proteins is reproducible and yields consistent results when performed using the same proteins at different laboratories.

Risk factors for Salmonella typhimurium DT104 and non-DT104 infection: a Canadian multi-provincial case-control study

To identify risk factors for sporadic Salmonella Typhimurium definitive phage-type 104 (DT104) and non-DT104 diarrhoeal illness in Canada, we conducted a matched case-control study between 1999 and 2000. Cases were matched 1:1 on age and province of residence. Multivariate analysis suggested that recent antibiotic use [odds ratio (OR) 5.2, 95% confidence interval (CI) 1.8-15.3], living on a livestock farm (OR 4.9, 95% CI 1.9-18.9), and recent travel outside Canada (OR 4.1, 95% CI 1.2-13.8) are independent risk factors for DT104 illness. Similar analyses suggested that recent travel outside North America is a sizable risk factor for non-DT104 illness (OR 66.8, 95% CI 6.7-665.3). No food exposure was a risk factor in either analysis. Educating health-care providers and the public about appropriate antibiotic use and antimicrobial resistance is important. Appropriate administration of antibiotics to livestock, particularly cattle, and hygienic measures such as handwashing after contact with farm animals may reduce risk. Travel represents an important and probably underestimated risk factor for sporadic illness with S. Typhimurium. Improved national surveillance and detailed investigation of travel-related illness are required.