The use of multiple hypothesis-generating methods in an outbreak investigation of Escherichia coli O121 infections associated with wheat flour, Canada 2016-2017.

A Canadian outbreak investigation into a cluster of Escherichia coli O121 was initiated in late 2016. When initial interviews using a closed-ended hypothesis-generating questionnaire did not point to a common source, cases were centrally re-interviewed using an open-ended approach. The open-ended interviews led cases to describe exposures with greater specificity, as well as food preparation activities. Data collected supported hypothesis generation, particularly with respect to flour exposures. In March 2017, an open sample of Brand X flour from a case home, and a closed sample collected at retail of the same brand and production date, tested positive for the outbreak strain of E. coli O121. In total, 76% (16/21) of cases reported that they used or probably used Brand X flour or that it was used or probably was used in the home during their exposure period. Crucial hypothesis-generating techniques used during the course of the investigation included a centralised open-ended interviewing approach and product sampling from case homes. This was the first outbreak investigation in Canada to identify flour as the source of infection.

Online population control surveys: A new method for investigating foodborne outbreaks.

In foodborne outbreak investigations, case-control and cohort studies are used to test hypotheses and identify a source, but these studies are resource-intensive and may have challenges of representativeness, temporality or accessibility. We used online surveys to collect population control data for two foodborne outbreaks and compared the data collected to our cases and existing population exposure data. Online survey population controls were comparable to cases based on age and sex. Exposure data collected through online surveys were more precise than existing control data, represented the disease-specific exposure period and could be easily modified. In one outbreak the online control exposure data differed from established population data. In both outbreaks, the information from the online population control survey supported the hypothesis of the investigation. Our findings demonstrate that online surveys were a rapid and representative way to collect responses from controls during outbreak investigations.

Shiga toxin-producing Escherichia coli in British Columbia, 2011-2017: Analysis to inform exclusion guidelines.

BACKGROUND: Shiga toxin-producing Escherichia coli (STEC) can cause severe illness including bloody diarrhea and hemolytic-uremic syndrome (HUS) through the production of Shiga toxins 1 (Stx1) and 2 (Stx2). E. coli O157:H7 was the most common serotype detected in the 1980s to 1990s, but improvements in laboratory methods have led to increased detection of non-O157 STEC. Non-O157 STEC producing only Stx1 tend to cause milder clinical illness. Exclusion guidelines restrict return to high-risk work or settings for STEC cases, but most do not differentiate between STEC serogroups and Stx type. OBJECTIVE: To analyze British Columbia (BC) laboratory and surveillance data to inform the BC STEC exclusion guideline. METHODS: For all STEC cases reported in BC in 2011-2017, laboratory and epidemiological data were obtained through provincial laboratory and reportable disease electronic systems, respectively. Incidence was measured for all STEC combined as well as by serogroup. Associations were measured between serogroups, Stx types and clinical outcomes. RESULTS: Over the seven year period, 984 cases of STEC were reported. A decrease in O157 incidence was observed, while non-O157 rates increased. The O157 serogroup was significantly associated with Stx2. Significant associations were observed between Stx2 and bloody diarrhea, hospitalization and HUS. CONCLUSION: The epidemiology of STEC has changed in BC as laboratories increasingly distinguish between O157 and non-O157 cases and identify Stx type. It appears that non-O157 cases with Stx1 are less severe than O157 cases with Stx2. The BC STEC exclusion guidelines were updated as a result of this analysis.

Outbreak of Salmonella Chailey infections linked to precut coconut pieces - United States and Canada, 2017†.

Foodborne salmonellosis causes an estimated one million illnesses and 400 deaths annually in the United States (US). During March-May 2017, an outbreak of 19 cases of Salmonella Chailey associated with precut coconut pieces from a single grocery store chain occurred in the United States and Canada. The chain voluntarily recalled precut coconut pieces. This was the first time that coconut has been associated with a Salmonella outbreak in the United States or Canada. In recent years, salmonellosis outbreaks have been caused by foods not typically associated with Salmonella. Raw coconut should now be considered in investigations of Salmonella outbreaks among fresh food consumers.

Analysis of enteric disease outbreak metrics, British Columbia Centre for Disease Control, 2005-2014.

BACKGROUND: For enteric disease outbreaks, effective control depends on timely intervention. Routine collection of metrics related to outbreak identification, investigation and control can help evaluate and improve interventions and inform further analyses and modelling of intervention effectiveness. OBJECTIVE: To analyze data from enteric disease outbreaks in British Columbia, generate outbreak metrics and assess their use in evaluating the impact of outbreak interventions. METHODS: This descriptive study analyzed data from 57 provincial and national enteric disease outbreak investigations involving the British Columbia Centre for Disease Control from 2005 to 2014. Data were extracted from internal files and the Canadian Network for Public Health Intelligence. Outbreak metrics analyzed included days to initiate investigation, days to intervention, number and type of interventions, duration of investigation, duration of outbreak and the total number of cases. RESULTS: The median time to initiate an outbreak investigation was 36 days and the median duration of investigations was 39 days. The median duration of outbreaks was 40 days and the median time to intervene was 10 days. Identification of the source was associated with use of one or more interventions (P<0.0001). The duration of outbreaks was correlated with the number of days to initiate an investigation (rs =0.72, P<0.0001) and number of days to intervene (rs =0.51, P=0.025). CONCLUSION: Identification and analysis of outbreak metrics establishes benchmarks that can be compared to other jurisdictions. This may support continuous quality improvement and enhance understanding of the impact of public health activities. Date information for public health actions is essential for evaluating the timing and effectiveness of outbreak interventions.

Surveillance for Lyme disease in Canada: 2009-2015.

OBJECTIVE: To summarize seven years of surveillance data for Lyme disease cases reported in Canada from 2009 to 2015. METHODS: We describe the incidence over time, seasonal and geographic distribution, demographic and clinical characteristics of reported Lyme disease cases. Logistic regression was used to explore differences between age groups, sex and year to better understand potential demographic risk factors for the occurrence of Lyme disease. RESULTS: The number of reported Lyme disease cases increased more than six-fold, from 144 in 2009 to 917 in 2015, mainly due to an increase in infections acquired in Canada. Most locally acquired cases were reported between May and November. An increase in incidence of Lyme disease was observed in provinces from Manitoba eastwards. This is consistent with our knowledge of range expansion of the tick vectors in this region. In the western provinces the incidence has remained low and stable. All cases reported by Alberta, Saskatchewan and Newfoundland and Labrador were acquired outside of the province, either elsewhere in Canada or abroad. There was a bimodal distribution for Lyme disease by age with peaks at 5-9 and 45-74 years of age. The most common presenting symptom was a single erythema migrans rash (74.2%) and arthritis (35.7%). Variations in the frequency of reported clinical manifestations were observed among age groups and years of study. CONCLUSION: Lyme disease incidence continues to increase in Canada as does the geographic range of ticks that carry the Lyme disease bacteria. Ongoing surveillance, preventive strategies as well as early disease recognition and treatment will continue to minimize the impact of Lyme disease in Canada.

Alisertib demonstrates significant antitumor activity in bevacizumab resistant, patient derived orthotopic models of glioblastoma.

Aurora A kinase (AURKA), a member of the serine/threonine kinase family, plays a critical role in cell division, and it is widely overexpressed in a variety of tumors including glioblastoma (GBM). Alisertib (MLN8237) is an orally administered selective AURKA inhibitor with potent antiproliferative activity, currently undergoing clinical testing in different tumor types. In vitro evaluation of alisertib against the primary GBM lines, GBM6, GBM10, GBM12 and GBM39 showed significant antitumor activity with IC50s ranging between 30 and 95 nM. Orthotopic xenografts of GBM10 and the bevacizumab resistant lines GBM6 and GBM39 were established by implantating 3 × 105 cells in the caudate nucleus of nude mice; animals were randomized to treatment with either alisertib 30 mg/kg/day or vehicle. In all three models, treatment with alisertib resulted in a statistically significant prolongation of survival (p < 0.0001). In addition, alisertib administration in these mice decreased phosphorylated aurora-A, induced mitotic arrest and significantly decreased histone H3 phosphorylation in tumors. In conclusion, alisertib displays significant antitumor activity against primary GBM lines and xenografts, including patient derived GBM lines resistant to bevacizumab; these data support clinical translation in GBM.

Utility of algorithms for the analysis of integrated Salmonella surveillance data.

The objective of this study was to assess the use of statistical algorithms in identifying significant clusters of Salmonella spp. across different sectors of the food chain within an integrated surveillance programme. Three years of weekly Salmonella serotype data from farm animals, meat, and humans were used to create baseline models (first two years) and identify weeks with counts higher than expected using surveillance algorithms in the third (test) year. During the test year, an expert working group identified events of interest reviewing descriptive analyses of same data. The algorithms did not identify Salmonella events presenting as gradual increases or seasonal patterns as identified by the working group. However, the algorithms did identify clusters for further investigation, suggesting they could be a valuable complementary tool within an integrated surveillance system.

Are enteric infections sexually transmitted in British Columbia?

BACKGROUND: Enteric infections may on occasion be sexually transmitted, particularly among people who engage in oral-anal sexual contact. Although outbreaks of enteric infections have been reported among men who have sex with men (MSM) in British Columbia (BC), the epidemiology of sexually transmitted enteric infections has never been assessed. OBJECTIVE: To describe the epidemiology of enteric infections in BC to determine if sexual transmission may be occurring. METHODS: A descriptive analysis was conducted of all reported cases of shigellosis, amebiasis and giardiasis in BC for the period 2003-2012. RESULTS: For shigellosis and amebiasis, there was a high male-to-female ratio and a higher rate of infection in males aged 20-59 years as compared to all other age-sex groups. Additionally, for shigellosis, adult males were significantly more likely than females to acquire disease locally (RR 1.9; CI 1.7--.4). CONCLUSION: Analysis suggests that sexual transmission of enteric infections, particularly shigellosis and amebiasis, may be occurring in MSM in BC. Further studies are indicated.

Inhibition of the Aurora A kinase augments the anti-tumor efficacy of oncolytic measles virotherapy.

Oncolytic measles virus (MV) strains have demonstrated broad spectrum preclinical anti-tumor efficacy, including breast cancer. Aurora A kinase controls mitotic spindle formation and has a critical role in malignant transformation. We hypothesized that the Aurora A kinase inhibitor MLN8237 (alisertib) can increase MV oncolytic effect and efficacy by causing mitotic arrest. Alisertib enhanced MV oncolysis in vitro and significantly improved outcome in vivo against breast cancer xenografts. In a disseminated MDA-231-lu-P4 lung metastatic model, the MV/alisertib combination treatment markedly increased median survival to 82.5 days with 20% of the animals being long-term survivors versus 48 days median survival for the control animals. Similarly, in a pleural effusion model of advanced breast cancer, the MV/alisertib combination significantly improved outcome with a 74.5 day median survival versus the single agent groups (57 and 40 days, respectively). Increased viral gene expression and IL-24 upregulation were demonstrated, representing possible mechanisms for the observed increase in anti-tumor effect. Inhibiting Aurora A kinase with alisertib represents a novel approach to enhance MV-mediated oncolysis and antitumor effect. Both oncolytic MV strains and alisertib are currently tested in clinical trials, this study therefore provides the basis for translational applications of this combinatorial strategy in the treatment of patients with advanced breast cancer.

Enteric outbreak surveillance in British Columbia, 2009-2013.

BACKGROUND: Understanding enteric disease outbreak sources, burden of illness, mode of transmission and use of interventions informs planning, policy development and prevention programs. OBJECTIVE: To describe trends in enteric disease outbreaks investigated in British Columbia (BC) between 2009 and 2013. METHODS: An analysis was conducted of enteric disease outbreaks that had been entered into a national, secure web-enabled outbreak reporting system using the Canadian Network for Public Health Intelligence (CNPHI) and investigated in BC between January 1, 2009 and December 31, 2013. The data included information on pathogen, number of cases, hospitalizations, deaths, setting, mode of transmission, source, factors that contributed to the outbreak and interventions. Residential facility-based viral outbreaks and outbreaks associated with international travel were excluded. RESULTS: There were 104 outbreaks investigated in BC between 2009 and 2013. Ninety-three were reported by BC organizations and 11 were national outbreak investigations reported by the Public Health Agency of Canada (PHAC). There was an average of 21 outbreaks per year. Overall, the annual rate of foodborne outbreaks in BC was 2.8 per one million population. Seventy-nine (76%) outbreaks had a pathogen identified, most commonly norovirus, Salmonella and E. coli. There was a total of 108 hospitalizations (3.8% of all cases) and two deaths (0.1% of all cases); one caused by botulism, the other by E. coli O157. Food service establishments were the most common setting (33.7%), followed by the community (24.0%) and private functions (12.5%). The food types most often reported were fruits and vegetables, meat and seafood. The data showed a pathogen-food source combination between Salmonella and eggs. CONCLUSION: This is the first publication summarizing trends in enteric disease outbreaks in BC including assessing sources, burden and interventions. Ongoing reporting and analysis of outbreak data in BC will allow for improved assessment of trends in sources and pathogens over time and further understanding of the effectiveness of interventions associated with outbreaks.

Measles Edmonston vaccine strain derivatives have potent oncolytic activity against osteosarcoma.

Osteosarcoma (OS) is the most common primary bone tumor affecting children and young adults, and development of metastatic disease is associated with poor prognosis. The purpose of this study was to evaluate the antitumor efficacy of virotherapy with engineered measles virus (MV) vaccine strains in the treatment of OS. Cell lines derived from pediatric patients with OS (HOS, MG63, 143B, KHOS-312H, U2-OS and SJSA1) were infected with MV expressing green fluorescent protein (MV-GFP) and MV-expressing sodium iodide symporter (MV-NIS) strains. Viral gene expression and cytotoxicity as defined by syncytial formation, cell death and eradication of cell monolayers were demonstrated. Findings were correlated with in vivo efficacy in subcutaneous, orthotopic (tibial bone) and lung metastatic OS xenografts treated with the MV derivative MV-NIS via the intratumoral or intravenous route. Following treatment, we observed decrease in tumor growth of subcutaneous xenografts (P=0.0374) and prolongation of survival in mice with orthotopic (P<0.0001) and pulmonary metastatic OS tumors (P=0.0207). Expression of the NIS transgene in MV-NIS infected tumors allowed for single photon emission computed tomography and positron emission tomography-computed tomography imaging of virus infected tumors in vivo. Our data support the translational potential of MV-based virotherapy approaches in the treatment of recurrent and metastatic OS.

The association between campylobacteriosis, agriculture and drinking water: a case-case study in a region of British Columbia, Canada, 2005-2009.

We studied the association between drinking water, agriculture and sporadic human campylobacteriosis in one region of British Columbia (BC), Canada. We compared 2992 cases of campylobacteriosis to 4816 cases of other reportable enteric diseases in 2005-2009 using multivariate regression. Cases were geocoded and assigned drinking water source, rural/urban environment and socioeconomic status (SES) according to the location of their residence using geographical information systems analysis methods. The odds of campylobacteriosis compared to enteric disease controls were higher for individuals serviced by private wells than municipal surface water systems (odds ratio 1·4, 95% confidence interval 1·1-1·8). In rural settings, the odds of campylobacteriosis were higher in November (P = 0·014). The odds of campylobacteriosis were higher in individuals aged ⩾15 years, especially in those with higher SES. In this region of BC, campylobacteriosis risk, compared to other enteric diseases, seems to be mediated by vulnerable drinking water sources and rural factors. Consideration should be given to further support well-water users and to further study the microbiological impact of agriculture on water.

Establishing criteria to initiate enteric outbreak investigations in British Columbia.

OBJECTIVE: To establish and evaluate criteria to initiate provincial enteric outbreak investigations based on characteristics of alerts, clusters and successful outbreak investigations. METHODS: We tracked all enteric disease alerts and clusters reported to the British Columbia Centre for Disease Control (BCCDC) in 2011 and 2012. Information was collected on etiology, number of cases, geographic spread, dates reported, and method of notification. Actions were classified as no further action, review/report or investigation. Outbreak investigation outcome was classified as solved/not solved. 2011 data were used to identify characteristics of alerts and clusters more likely to lead to outbreak investigations and of solved outbreaks to establish criteria. Criteria for initiating an outbreak investigation were evaluated retrospectively using 2011 data and then implemented in 2012. RESULTS: In 2011, 251 alerts/clusters of enteric diseases were reported. Fourteen (5.6%) led to an outbreak investigation and nine (64.3%) of the outbreaks were solved. Analyzing the data retrospectively, criteria were identified from the alerts and clusters that led to outbreak investigations and successful outbreak investigations: pathogen specificity, timely notification, a common source or event, and multi-regional outbreaks or outbreaks reported by other agencies. After applying these criteria prospectively in 2012, we took action on a smaller proportion of the 244 alerts and clusters (32.0% compared to 44.6% in 2011) and 66.7% of them were solved (compared to 64.3% in 2011). CONCLUSION: Continued evaluation will identify whether this will improve outbreak investigations and use of resources in British Columbia.

The mitotic kinase Aurora--a promotes distant metastases by inducing epithelial-to-mesenchymal transition in ERα(+) breast cancer cells.

In this study, we demonstrate that constitutive activation of Raf-1 oncogenic signaling induces stabilization and accumulation of Aurora-A mitotic kinase that ultimately drives the transition from an epithelial to a highly invasive mesenchymal phenotype in estrogen receptor α-positive (ERα(+)) breast cancer cells. The transition from an epithelial- to a mesenchymal-like phenotype was characterized by reduced expression of ERα, HER-2/Neu overexpression and loss of CD24 surface receptor (CD24(-/low)). Importantly, expression of key epithelial-to-mesenchymal transition (EMT) markers and upregulation of the stemness gene SOX2 was linked to acquisition of stem cell-like properties such as the ability to form mammospheres in vitro and tumor self-renewal in vivo. Moreover, aberrant Aurora-A kinase activity induced phosphorylation and nuclear translocation of SMAD5, indicating a novel interplay between Aurora-A and SMAD5 signaling pathways in the development of EMT, stemness and ultimately tumor progression. Importantly, pharmacological and molecular inhibition of Aurora-A kinase activity restored a CD24(+) epithelial phenotype that was coupled to ERα expression, downregulation of HER-2/Neu, inhibition of EMT and impaired self-renewal ability, resulting in the suppression of distant metastases. Taken together, our findings show for the first time the causal role of Aurora-A kinase in the activation of EMT pathway responsible for the development of distant metastases in ERα(+) breast cancer cells. Moreover, this study has important translational implications because it highlights the mitotic kinase Aurora-A as a novel promising therapeutic target to selectively eliminate highly invasive cancer cells and improve the disease-free and overall survival of ERα(+) breast cancer patients resistant to conventional endocrine therapy.

Inhibition of Rho-associated coiled-coil-forming kinase increases efficacy of measles virotherapy.

RhoA and its downstream effector Rho-associated coiled-coil-forming kinase (ROCK) are known regulators of the formation of actin cytoskeleton in cells. Actin cytoskeleton is involved in paramyxovirus infection; we, therefore, examined the effect of ROCK inhibition on measles virus (MV) cytopathic effect and replication. Treatment with the ROCK inhibitor, Y27632, significantly increased syncytia size in tumor cell lines following MV infection, associated with cytoskeleton disruption as demonstrated by actin staining. Treatment of prostate cancer, breast cancer and glioblastoma tumor cell lines with Y27632 following MV infection resulted in increased cytopathic effect, as assessed by trypan blue exclusion assays. In addition, there was a significant increase in viral proliferation by at least one log or more as tested in one-step viral growth curves. Increased viral replication was also observed in athymic nude mice bearing MDA-MB-231 xenografts following combination treatment with MV and Y27632. In summary, inhibition of the ROCK kinase by Y27632 enhanced the oncolytic effect of MV and viral proliferation; this approach merits further translational investigation.

Oncolytic measles virus strains have significant antitumor activity against glioma stem cells.

Glioblastoma (GBM) is the most common primary brain tumor in adults and has a dismal prognosis despite multimodality treatment. Given the resistance of glioma stem cells (GSC) to chemotherapy and radiation therapy, their eradication could prevent tumor recurrence. We sought to evaluate the antitumor activity of measles virus (MV) derivatives against GSC. We generated neurosphere cultures from patient-derived primary tumor GBM xenografts, and we characterized them for the GSC markers CD133, SOX2, Nestin, ATF5 and OLIG2. Using the MV-strains MV-GFP, MV-CEA and MV-NIS we demonstrated infection, viral replication and significant cytopathic effect in vitro against GSC lines. In tumorigenicity experiments, GBM44 GSC were infected with MV in vitro and subsequently implanted into the right caudate nucleus of nude mice: significant prolongation of survival in mice implanted with infected GSC was observed, compared with mock-infected controls (P=0.0483). In therapy experiments in GBM6 and GBM12 GSC xenograft models, there was significant prolongation of survival in MV-GFP-treated animals compared with inactivated virus-treated controls (GBM6 P=0.0021, GBM12 P=0.0416). Abundant syncytia and viral replication was demonstrated in tumors of MV-treated mice. Measles virus derivatives have significant antitumor activity against glioma-derived stem cells in vitro and in vivo.

Investigation of the concurrent emergence of Salmonella enteritidis in humans and poultry in British Columbia, Canada, 2008-2010.

An increase in the rate of human infections with Salmonella enteritidis (SE) occurred between 2007 and 2010 in British Columbia (BC). During the same time period, an increase in SE from poultry-sourced isolates and increased clinical severity in poultry were also observed in BC. This article describes a multi-sectoral collaboration during a 3-year investigation, and the actions taken by public health and animal health professionals. Human cases were interviewed, clusters were investigated, and a case-control study was conducted. Environmental investigations were conducted in food service establishments (FSE). Suspect foods were tested. Laboratory data from poultry-sourced isolates were analysed. Five hundred and eighty-four human cases of SE with the same pulsed-field gel electrophoresis pattern were identified between May 2008 and August 2010. Seventy-three percentage of cases reported consumption of eggs. The odds of egg consumption were 2.4 times higher for cases than controls. Implicated FSE were found to use ungraded eggs, which had been distributed illegally. Investigation suggested that there were multiple suppliers of these eggs. Collaboration between public health and animal health professionals led to data sharing, improved understanding of SE, engagement with the poultry industry and public communication. Multi-disciplinary, multi-sectoral and multi-pronged investigations are recommended to identify the likely source of illness in large, protracted foodborne outbreaks caused by commonly consumed foods.

Attenuated oncolytic measles virus strains as cancer therapeutics.

Attenuated measles virus vaccine strains have emerged as a promising oncolytic vector platform, having shown significant anti-tumor activity against a broad range of malignant neoplasms. Measles virus strains derived from the attenuated Edmonston-B (MV-Edm) vaccine lineage have been shown to selectively infect, replicate in and lyse cancer cells while causing minimal cytopathic effect on normal tissues. This review summarizes the preclinical data that led to the rapid clinical translation of oncolytic measles vaccine strains and provides an overview of early clinical data using this oncolytic platform. Furthermore, novel approaches currently under development to further enhance the oncolytic efficacy of MV-Edm strains, including strategies to circumvent immunity or modulate immune system responses, combinatorial approaches with standard treatment modalities, virus retargeting as well as strategies for in vivo monitoring of viral replication are discussed.

Therapeutic potential of oncolytic measles virus: promises and challenges.

Measles virus (MV) is a negative-strand RNA virus (paramyxovirus) with oncolytic properties. The significant preclinical activity of MV vaccine strains against a variety of tumor models, their potent bystander effect, their selectivity against tumor cells, and their ability to retain their oncolytic properties when engineered and retargeted makes them a promising oncolytic platform. In this article, we review potential applications and challenges associated with use of MV strains as cancer therapeutics.