The Cutaneous Microbiome: Implications for Dermatology Practice.

The human integument is inhabited by a vast array of microorganisms known collectively as the cutaneous microbiome. As a result of advances in laboratory science, our understanding of the diversity and complexity of the human microbiome is rapidly evolving. In particular, advances in the field of genomics have enabled the study of the cutaneous microbiome with a hitherto unimaginable level of detail, resulting in a maturation of our understanding of cutaneous health and disease. Herein, we review current microbiology concepts and highlight the key features of recent laboratory advances, particularly with respect to genomics. We provide a summary of new findings related to normal skin flora, interactions between host immunity and microbial communities, and microbial relationships with common skin disorders. Finally, we review the implications for dermatologists.

Atypical clinical and laboratory features of fish-tank granuloma: A case report.

We report a case of cutaneous Mycobacterium marinum infection with the unusual reported features of pruritus and paresthesia. In addition, we report a lack of in-vivo response to antibiotics based on in-vitro susceptibility testing.

Human Activity Determines the Presence of Integron-Associated and Antibiotic Resistance Genes in Southwestern British Columbia.

The dissemination of antibiotic resistant bacteria from anthropogenic sources into the environment poses an emerging public health threat. Antibiotic resistance genes (ARGs) and gene-capturing systems such as integron-associated integrase genes (intI) play a key role in alterations of microbial communities and the spread of antibiotic resistant bacteria into the environment. In order to assess the effect of anthropogenic activities on watersheds in southwestern British Columbia, the presence of putative antibiotic resistance and integrase genes was analyzed in the microbiome of agricultural, urban influenced, and protected watersheds. A metagenomics approach and high-throughput quantitative PCR (HT qPCR) were used to screen for elements of resistance including ARGs and intI. Metagenomic sequencing of bacterial genomic DNA was used to characterize the resistome of microbial communities present in watersheds over a 1-year period. There was a low prevalence of ARGs relative to the microbial population (<1%). Analysis of the metagenomic sequences detected a total of 60 elements of resistance including 46 ARGs, intI1, and groEL/intI1 genes and 12 quaternary ammonium compounds (qac) resistance genes across all watershed locations. The relative abundance and richness of ARGs was found to be highest in agriculture impacted watersheds compared to urban and protected watersheds. A downstream transport pattern was observed in the impacted watersheds (urban and agricultural) during dry months. Similar to other reports, this study found a strong association between intI1 and ARGs (e.g., sul1), an association which may be used as a proxy for anthropogenic activities. Chemical analysis of water samples for three major groups of antibiotics was below the detection limit. However, the high richness and gene copy numbers (GCNs) of ARGs in impacted sites suggest that the effects of effluents on microbial communities are occurring even at low concentrations of antimicrobials in the water column. Antibiotic resistance and integrase genes in a year-long metagenomic study showed that ARGs were driven mainly by environmental factors from anthropogenized sites in agriculture and urban watersheds. Environmental factors such as land-use and water quality parameters accounted for 45% of the variability observed in watershed locations.

Cutaneous Nontuberculous Mycobacterial Infections in Alberta, Canada: An Epidemiologic Study and Review.

BACKGROUND: Cutaneous infections caused by nontuberculous mycobacteria (NTM) occur infrequently. Nonetheless, the incidence of NTM infections is reported to be increasing. In Canada, cutaneous NTM infections have not been well described. OBJECTIVES: A database review from 2006 to 2016 was done to assess species frequency, incidence, and trends of the most common cutaneous NTMs in the province of Alberta, Canada. We also reviewed major diagnostic and epidemiologic aspects of NTM cutaneous infections with a focus on Mycobacterium marinum. RESULTS: A database search identified 244 cases of NTM infections. Mycobacterium avium-intracellulare complex had the highest incidence, causing 64% of cases. Rapid growers ( Mycobacterium abscessus, Mycobacterium chelonae, Mycobacterium fortuitum) caused 23% and M marinum 13%. Information on infection site was available for 117 cases. There was no difference noted in sex distribution; however, differences in age groups between species were noted. CONCLUSIONS: The incidence of NTM cutaneous infections in Alberta, Canada, was reported for the first time and the incidence of M marinum was found to be similar to that reported in the worldwide literature. Patients' age groups were different between species. Knowledge of the unique microbiological features of NTMs and the role of the diagnostic laboratory are important.

Beaver Fever: Whole-Genome Characterization of Waterborne Outbreak and Sporadic Isolates To Study the Zoonotic Transmission of Giardiasis.

Giardia causes the diarrheal disease known as giardiasis; transmission through contaminated surface water is common. The protozoan parasite's genetic diversity has major implications for human health and epidemiology. To determine the extent of transmission from wildlife through surface water, we performed whole-genome sequencing (WGS) to characterize 89 Giardia duodenalis isolates from both outbreak and sporadic infections: 29 isolates from raw surface water, 38 from humans, and 22 from veterinary sources. Using single nucleotide variants (SNVs), combined with epidemiological data, relationships contributing to zoonotic transmission were described. Two assemblages, A and B, were identified in surface water, human, and veterinary isolates. Mixes of zoonotic assemblages A and B were seen in all the community waterborne outbreaks in British Columbia (BC), Canada, studied. Assemblage A was further subdivided into assemblages A1 and A2 based on the genetic variation observed. The A1 assemblage was highly clonal; isolates of surface water, human, and veterinary origins from Canada, United States, and New Zealand clustered together with minor variation, consistent with this being a panglobal zoonotic lineage. In contrast, assemblage B isolates were variable and consisted of several clonal lineages relating to waterborne outbreaks and geographic locations. Most human infection isolates in waterborne outbreaks clustered with isolates from surface water and beavers implicated to be outbreak sources by public health. In-depth outbreak analysis demonstrated that beavers can act as amplification hosts for human infections and can act as sources of surface water contamination. It is also known that other wild and domesticated animals, as well as humans, can be sources of waterborne giardiasis. This study demonstrates the utility of WGS in furthering our understanding of Giardia transmission dynamics at the water-human-animal interface.IMPORTANCEGiardia duodenalis causes large numbers of gastrointestinal illness in humans. Its transmission through the contaminated surface water/wildlife intersect is significant, and the water-dwelling rodents beavers have been implicated as one important reservoir. To trace human infections to their source, we used genome techniques to characterize genetic relationships among 89 Giardia isolates from surface water, humans, and animals. Our study showed the presence of two previously described genetic assemblages, A and B, with mixed infections detected from isolates collected during outbreaks. Study findings also showed that while assemblage A could be divided into A1 and A2, A1 showed little genetic variation among animal and human hosts in isolates collected from across the globe. Assemblage B, the most common type found in the study surface water samples, was shown to be highly variable. Our study demonstrates that the beaver is a possible source of human infections from contaminated surface water, while acknowledging that theirs is only one role in the complex cycle of zoonotic spread. Mixes of parasite groups have been detected in waterborne outbreaks. More information on Giardia diversity and its evolution using genomics will further the understanding of the epidemiology of spread of this disease-causing protozoan.

A comprehensive method for amplicon-based and metagenomic characterization of viruses, bacteria, and eukaryotes in freshwater samples.

BACKGROUND: Studies of environmental microbiota typically target only specific groups of microorganisms, with most focusing on bacteria through taxonomic classification of 16S rRNA gene sequences. For a more holistic understanding of a microbiome, a strategy to characterize the viral, bacterial, and eukaryotic components is necessary. RESULTS: We developed a method for metagenomic and amplicon-based analysis of freshwater samples involving the concentration and size-based separation of eukaryotic, bacterial, and viral fractions. Next-generation sequencing and culture-independent approaches were used to describe and quantify microbial communities in watersheds with different land use in British Columbia. Deep amplicon sequencing was used to investigate the distribution of certain viruses (g23 and RdRp), bacteria (16S rRNA and cpn60), and eukaryotes (18S rRNA and ITS). Metagenomic sequencing was used to further characterize the gene content of the bacterial and viral fractions at both taxonomic and functional levels. CONCLUSION: This study provides a systematic approach to separate and characterize eukaryotic-, bacterial-, and viral-sized particles. Methodologies described in this research have been applied in temporal and spatial studies to study the impact of land use on watershed microbiomes in British Columbia.

Exploring readiness for the adoption of new molecular water quality tests: Insights from interviews with policy makers, laboratory managers and watershed managers.

Adoption of molecular-based water quality tests has been limited despite their advantage over traditional culture-based tests. A better understanding of the factors affecting adoption of these tests is needed for effective implementation. The Consolidated Framework for Implementation Research (CFIR) was used to analyze interviews with policy makers, watershed managers and laboratory managers in British Columbia (BC), Canada about their perceptions of molecular water tests currently under development in order to assess readiness for adoption and identify factors that may impact implementation. Many of the CFIR constructs were addressed by study participants, thus confirming their validity in the water-testing context. Other constructs were not mentioned, which suggests that awareness about these constructs need to be increased to ensure that they are incorporated into implementation strategies. In general, there was much enthusiasm for the new tests, which were seen to provide valuable information that could enable improved management of watersheds and treatment of source water. However, prior to adopting the tests, stakeholders would require evidence supporting the tests' validity and reliability, would need to assess the complexity of introducing the tests into laboratories and water sampling processes, and would require support interpreting the test results. Even if all the aforementioned issues are satisfactorily addressed, the tests may not be adopted unless regulations and policies were changed to allow the use of these test results to inform decision making. The results support that implementation of new technologies, such as these water quality tests, need to address potential barriers that could hinder uptake despite the advantages of the new product.

Efficacy of common disinfectant/cleaning agents in inactivating murine norovirus and feline calicivirus as surrogate viruses for human norovirus.

BACKGROUND: The efficacies of disinfection by sodium hypochlorite, accelerated hydrogen peroxide (AHP), and quaternary ammonium compound (QUAT) commonly used in health care facilities were determined using the surrogate viruses murine norovirus (MNV-1) and feline calicivirus (FCV). METHODS: A virus suspension of known concentration (with or without a soil load) was deposited onto stainless steel discs under wet or dry load conditions and exposed to defined concentrations of the disinfectant/cleaning agent for 1-, 5-, or 10-minute contact time using the quantitative carrier test (QCT-2) method. Virus inactivation was determined by plaque assay. RESULTS: At an exposure time of 1 minute, sodium hypochlorite at 2,700 ppm was able to inactivate MNV-1 and FCV with a >5 log10 reduction. After 10 minutes, MNV-1 was inactivated by AHP at 35,000 ppm, whereas FCV was inactivated at 3,500 ppm. MNV-1 was not inactivated by QUAT at 2,800 ppm. A QUAT-alcohol formulation containing 2,000 ppm QUAT and 70% ethanol was effective in inactivating MNV-1 after 5 minutes, but resulted in only a <3 log10 reduction of FCV after 10 minutes. CONCLUSIONS: AHP and QUAT products were less effective than sodium hypochlorite for the inactivation of MNV-1 and FCV.

Giardia spp. Are Commonly Found in Mixed Assemblages in Surface Water, as Revealed by Molecular and Whole-Genome Characterization.

Giardia is the most common parasitic cause of gastrointestinal infections worldwide, with transmission through surface water playing an important role in various parts of the world. Giardia duodenalis (synonyms: G. intestinalis and G. lamblia), a multispecies complex, has two zoonotic subtypes, assemblages A and B. When British Columbia (BC), a western Canadian province, experienced several waterborne giardiasis outbreaks due to unfiltered surface drinking water in the late 1980s, collection of isolates from surface water, as well as from humans and beavers (Castor canadensis), throughout the province was carried out. To better understand Giardia in surface water, 71 isolates, including 29 from raw surface water samples, 29 from human giardiasis cases, and 13 from beavers in watersheds from this historical library were characterized by PCR. Study isolates also included isolates from waterborne giardiasis outbreaks. Both assemblages A and B were identified in surface water, human, and beavers samples, including a mixture of both assemblages A and B in waterborne outbreaks. PCR results were confirmed by whole-genome sequencing (WGS) for one waterborne outbreak and supported the clustering of human, water, and beaver isolates within both assemblages. We concluded that contamination of surface water by Giardia is complex, that the majority of our surface water isolates were assemblage B, and that both assemblages A and B may cause waterborne outbreaks. The higher-resolution data provided by WGS warrants further study to better understand the spread of Giardia.

Automated Gel Size Selection to Improve the Quality of Next-generation Sequencing Libraries Prepared from Environmental Water Samples.

Next-generation sequencing of environmental samples can be challenging because of the variable DNA quantity and quality in these samples. High quality DNA libraries are needed for optimal results from next-generation sequencing. Environmental samples such as water may have low quality and quantities of DNA as well as contaminants that co-precipitate with DNA. The mechanical and enzymatic processes involved in extraction and library preparation may further damage the DNA. Gel size selection enables purification and recovery of DNA fragments of a defined size for sequencing applications. Nevertheless, this task is one of the most time-consuming steps in the DNA library preparation workflow. The protocol described here enables complete automation of agarose gel loading, electrophoretic analysis, and recovery of targeted DNA fragments. In this study, we describe a high-throughput approach to prepare high quality DNA libraries from freshwater samples that can be applied also to other environmental samples. We used an indirect approach to concentrate bacterial cells from environmental freshwater samples; DNA was extracted using a commercially available DNA extraction kit, and DNA libraries were prepared using a commercial transposon-based protocol. DNA fragments of 500 to 800 bp were gel size selected using Ranger Technology, an automated electrophoresis workstation. Sequencing of the size-selected DNA libraries demonstrated significant improvements to read length and quality of the sequencing reads.

Personalized genetic testing and norovirus susceptibility.

BACKGROUND: The availability of direct-to-consumer personalized genetic testing has enabled the public to access and interpret their own genetic information. Various genetic traits can be determined including resistance to norovirus through a nonsense mutation (G428A) in the FUT2 gene. Although this trait is believed to confer resistance to the most dominant norovirus genotype (GII.4), the spectrum of resistance to other norovirus strains is unknown. The present report describes a cluster of symptomatic norovirus GI.6 infection in a family identified to have norovirus resistance through personalized genetic testing. CASE PRESENTATION: In January 2013, four members of a family determined by a direct-to-consumer genetic test to be homozygous for the norovirus resistance trait (A/A genotype for single nucleotide polymorphism rs601338) developed symptoms consistent with acute viral gastroenteritis. Stool and vomitus samples were submitted for enteric viral pathogen testing. Samples were positive for norovirus GI.6 in three of the four cases. CONCLUSIONS: The present report is the first to describe norovirus GI.6 infection in patients with the G428A nonsense mutation in FUT2; this cluster of cases suggests that the G428A mutation in FUT2 may not confer resistance to norovirus GI.6. Direct-to-consumer genetic testing is empowering members of the public to identify novel associations with their genetic traits. Expert consultation is important for the interpretation of personalized genetic test results, and follow-up laboratory testing can confirm any potentially novel associations.

HISTORIQUE: Les tests génétiques personnalisés destinés directement aux consommateurs permettent au public d'accéder eux-mêmes à l'information génétique et à l'interpréter. Il est ainsi possible de déterminer divers traits génétiques, y compris la résistance au norovirus par une mutation nonsens (G428A) dans le gène FUT2. Même si on pense que ce trait confère une résistance au génotype du norovirus le plus dominant (GII.4), on n'en connaît pas le spectre de résistance à d'autres souches de norovirus. Le présent rapport décrit une grappe d'infection symptomatique au norovirus GI.6 au sein d'une famille dont la résistance au norovirus avait été établie au moyen de tests génétiques personnalisés. PRÉSENTATION DU CAS: En janvier 2013, quatre membres d'une famille qui, d'après un test génétique destiné directement au consommateur, étaient homozygotes au trait de résistance au norovirus (génotype A/A du polymorphisme de nucléotide simple rs601338) ont présenté des symptômes évocateurs d'une gastroentérite virale aiguë. Des coprocultures et des prélèvements de vomissures ont été soumis à un test pour déceler un virus entéropathogène. Dans trois des quatre cas, les prélèvements étaient positifs au norovirus GI.6. CONCLUSIONS: Le présent rapport est le premier à décrire l'infection à norovirus GI.6 chez des patients présentant la mutation nonsens G428A dans le gène FUT2. Ce groupe de cas laisse croire que la mutation G428A dans le gène FUT2 ne confère pas de résistance au norovirus GI.6. Les tests génétiques destinés directement aux consommateurs permettent aux membres du public d'établir de nouvelles associations avec leurs traits génétiques. Il est important de consulter un expert pour en interpréter les résultats, et des tests de laboratoire effectués en suivi peuvent confirmer ces associations potentielles.

Assessment of Giardia and Cryptosporidium spp. as a microbial source tracking tool for surface water: application in a mixed-use watershed.

Knowledge of host specificity, combined with genomic sequencing of Giardia and Cryptosporidium spp., has demonstrated a microbial source tracking (MST) utility for these common waterborne microbes. To explore the source attribution potential of these pathogens, water samples were collected in a mixed rural-urban watershed in the Township of Langley, in southwestern British Columbia (BC), Canada, over a 2-year period. Cryptosporidium was detected in 63% of surface water samples at concentrations ranging from no positive detection (NPD) to 20,600 oocysts per 100 liters. Giardia was detected in 86% of surface water samples at concentrations ranging from NPD to 3,800 cysts per 100 liters of water. Sequencing at the 18S rRNA locus revealed that 50% of Cryptosporidium samples and 98% of Giardia samples contained species/genotypes (Cryptosporidium) or assemblages (Giardia) that are capable of infecting humans, based on current knowledge of host specificity and taxonomy. Cryptosporidium genotyping data were more promising for source tracking potential, due to the greater number of host-adapted (i.e., narrow-host-range) species/genotypes compared to Giardia, since 98% of Giardia isolates were zoonotic and the potential host could not be predicted. This report highlights the benefits of parasite genomic sequencing to complement Method 1623 (U.S. Environmental Protection Agency) and shows that Cryptosporidium subtyping for MST purposes is superior to the use of Giardia subtyping, based on better detection limits for Cryptosporidium-positive samples than for Giardia-positive samples and on greater host specificity among Cryptosporidium species. These additional tools could be used for risk assessment in public health and watershed management decisions.

Foodborne botulism in Canada, 1985-2005.

During 1985-2005, a total of 91 laboratory-confirmed outbreaks of foodborne botulism occurred in Canada; these outbreaks involved 205 cases and 11 deaths. Of the outbreaks, 75 (86.2%) were caused by Clostridium botulinum type E, followed by types A (7, 8.1%) and B (5, 5.7%). Approximately 85% of the outbreaks occurred in Alaska Native communities, particularly the Inuit of Nunavik in northern Quebec and the First Nations population of the Pacific coast of British Columbia. These populations were predominantly exposed to type E botulinum toxin through the consumption of traditionally prepared marine mammal and fish products. Two botulism outbreaks were attributed to commercial ready-to-eat meat products and 3 to foods served in restaurants; several cases were attributed to non-Native home-prepared foods. Three affected pregnant women delivered healthy infants. Improvements in botulism case identification and early treatment have resulted in a reduction in the case-fatality rate in Canada.

Identification of fecal contamination sources in water using host-associated markers.

In British Columbia, Canada, drinking water is tested for total coliforms and Escherichia coli, but there is currently no routine follow-up testing to investigate fecal contamination sources in samples that test positive for indicator bacteria. Reliable microbial source tracking (MST) tools to rapidly test water samples for multiple fecal contamination markers simultaneously are currently lacking. The objectives of this study were (i) to develop a qualitative MST tool to identify fecal contamination from different host groups, and (ii) to evaluate the MST tool using water samples with evidence of fecal contamination. Singleplex and multiplex polymerase chain reaction (PCR) were used to test (i) water from polluted sites and (ii) raw and drinking water samples for presence of bacterial genetic markers associated with feces from humans, cattle, seagulls, pigs, chickens, and geese. The multiplex MST assay correctly identified suspected contamination sources in contaminated waterways, demonstrating that this test may have utility for heavily contaminated sites. Most raw and drinking water samples analyzed using singleplex PCR contained at least one host-associated marker. Singleplex PCR was capable of detecting host-associated markers in small sample volumes and is therefore a promising tool to further analyze water samples submitted for routine testing and provide information useful for water quality management.

Identifying host sources, human health risk and indicators of Cryptosporidium and Giardia in a Canadian watershed influenced by urban and rural activities.

Cryptosporidium and Giardia were characterized in a watershed in southern Ontario, Canada, over a 2½ year period. River samples were collected every two weeks, primarily near a municipal drinking water treatment plant intake. Cryptosporidium and Giardia were frequently detected with an overall occurrence rate of 88 and 97%, respectively. Giardia concentrations were higher than Cryptosporidium, with median values of 80 cysts 100 L(-1) and 12 oocysts 100 L(-1), respectively. Although pathogens rarely show a significant relationship with fecal or water quality indicators, this study determined that Cryptosporidium, but not Giardia, was significantly correlated with Escherichia coli, turbidity and river flow. There was no correlation between the two types of protozoa, and only Giardia showed a seasonal trend with higher concentrations at cold water temperatures. Cryptosporidium genotyping of all samples found that farm animals and wildlife were an important contributor of oocysts in the watershed, and that Cryptosporidium strains/genotypes of medium to high risk for human infection (C. hominis, C. parvum and C. ubiquitum) were detected in 16% of samples. This study was able to identify Cryptosporidium host sources and human health risk, and to identify differences between Cryptosporidium and Giardia occurrence in the watershed.

Characteristics of an Acanthamoeba keratitis outbreak in British Columbia between 2003 and 2007.

OBJECTIVE: Quantify and describe Acanthamoeba keratitis (AK) cases in British Columbia (BC). DESIGN: A comparison of annual incidence rates confirms the presence of an outbreak. A case series describes characteristics of the outbreak. PARTICIPANTS: All laboratory-confirmed AK cases (persons) in BC (1988-2011; n = 68) were included in the incidence rate comparison. Of the 42 cases (persons) between 2003 and 2007, 32 were selected to interview (laboratory confirmed, 2005-2007), and the 23 who completed interviews form the case series. METHODS: A comparison of standardized annual incidence rates in historic to outbreak periods is performed by z-score test. A telephone interview and descriptive analysis detailing demographics, risk factors, and contact lens (CL) wearing habits was completed for 23 cases. MAIN OUTCOME MEASURES: We measure number of laboratory confirmed cases in BC. In addition, risk factors and potential exposures of these cases are reported. RESULTS: The annual incidence of AK increased significantly from 0.029 to 0.200 per 100 000 population between historic years (1988-2002) and outbreak years (2003-2007; P = 0.022). The annual incidence of AK has since returned to near historic levels (0.056/100 000 population). The case series identified multiple risk factors, including the use of a specific recalled solution (60.9%), daily soft CL wear (95.7%), all-in-one solutions (95.7%), showering while wearing CL (65.2%), and generally poor CL hygiene. CONCLUSIONS: A significant increase in annual AK incidence occurred between 2003 and 2007 in BC. After 2007, the incidence of AK returned to near historic levels. The recalled solution was associated with many cases; however, other risk factors were also identified, including being unaware of the recall and poor CL hygiene practices, highlighting the need for improved education about the severity of AK and consequences of improper CL hygiene. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Use of Lean response to improve pandemic influenza surge in public health laboratories.

A novel influenza A (H1N1) virus detected in April 2009 rapidly spread around the world. North American provincial and state laboratories have well-defined roles and responsibilities, including providing accurate, timely test results for patients and information for regional public health and other decision makers. We used the multidisciplinary response and rapid implementation of process changes based on Lean methods at the provincial public health laboratory in British Columbia, Canada, to improve laboratory surge capacity in the 2009 influenza pandemic. Observed and computer simulating evaluation results from rapid processes changes showed that use of Lean tools successfully expanded surge capacity, which enabled response to the 10-fold increase in testing demands.

Using centralized laboratory data to monitor trends in herpes simplex virus type 1 and 2 infection in British Columbia and the changing etiology of genital herpes.

OBJECTIVES: Understanding the regional epidemiology of genital Herpes Simplex Virus (HSV) infections is important for clinical and public health practice, due to the increasing availability of type-specific serologic testing in Canada and the contribution of genital HSV-2 infection to ongoing HIV transmission. We used centralized laboratory data to describe trends in viral identifications of genital HSV in BC and assess the utility of these data for ongoing population surveillance. METHODS: Records of viral identifications (1997-2005) were extracted from the Provincial Public Health Microbiology & Reference Laboratory database. Classification as genital or other site was based on documented specimen site. We conducted a descriptive analysis of trends over time, and calculated odds of HSV-1 infection among individuals with genital herpes. RESULTS: Of 48,183 viral identifications, 56.8% were genital, 10.0% were peri-oral and 9.1% cutaneous; site was unknown for 22.9%. Among genital identifications, HSV-1 infection was more likely in females, younger age groups, and later time periods. The proportion of genital herpes due to HSV-1 increased over time from 31.4% to 42.8% in BC. CONCLUSIONS: Our analysis of population-level laboratory data demonstrates that the proportion of genital herpes due to HSV-1 is increasing over time in BC, particularly among women and younger age groups; this has implications for clinical practice including the interpretation of type-specific serology. Provincial viral identification data are useful for monitoring the distribution of genital HSV-1 and HSV-2 infections over time. Improving clinical documentation of specimen site would improve the utility of these data.

West Nile virus finally debuts in British Columbia 10 years after its introduction to North America.

Since its first detection in New York (1999), West Nile virus (WNv) has spread across the United States and Canada with the first activity reported in Canada in 2001. By 2004, WNv had been detected almost in every province of Canada and the contiguous regions of the United States with the exception of British Columbia (BC), this despite being detected in Alberta in 2003 and Washington as early as 2002. In August 2009, two human cases were serologically found to have WNv infection. They reported mosquito bites and had only traveled in the South and Central Okanagan areas of BC before their presentation. On the basis of clinical, laboratory, and epidemiological data, these two human cases have been confirmed as the first locally acquired WNv cases in BC. Various factors may have contributed to the 10-year delay in the spread of WNv to BC, including regional weather conditions and unique topography.

Water and sewage systems, socio-demographics, and duration of residence associated with endemic intestinal infectious diseases: a cohort study.

BACKGROUND: Studies of water-related gastrointestinal infections are usually directed at outbreaks. Few have examined endemic illness or compared rates across different water supply and sewage disposal systems. We conducted a cohort study of physician visits and hospitalizations for endemic intestinal infectious diseases in a mixed rural and urban community near Vancouver, Canada, with varied and well-characterized water and sewage systems. METHODS: Cohort members and their disease events were defined via universal health insurance data from 1995 through 2003. Environmental data were derived from municipal, provincial, and federal government sources. Logistic regression was used to examine associations between disease events and water and sewage systems, socio-demographic characteristics, and temporal factors. RESULTS: The cohort included 126,499 individuals and approximately 190,000,000 person-days. Crude incidence rates were 1,353 physician visits and 33.8 hospitalizations for intestinal infectious diseases per 100,000 person-years. Water supply chlorination was associated with reduced physician visit incidence (OR: 0.92, 95% CI 0.85-1.0). Two water systems with the highest proportions of surface water had increased incidence (ORs: 1.57, 95% CI 1.39-1.78; and 1.45, 95% CI 1.28-1.64). Private well water and well depth were not associated with increased risk, likely because of residents' awareness of and attention to water quality. There was increased crude incidence with increasing precipitation in the population served by surface water supplies, but this trend did not remain with adjustment for other variables. Municipal sewer systems were associated with increased risk (OR: 1.26, 95% CI 1.14-1.38). Most socio-demographic variables had predicted associations with risk: higher rates in females, in the very young and the elderly, and in residents of low income areas. Increased duration of area residence was associated with reduced risk (OR, duration ≥ 6 years: 0.69, 95% CI 0.60-0.80 vs. < 1 year: 1.16, 95% CI 1.03-1.30). CONCLUSIONS: This large cohort study, with objective data on exposures and outcomes, demonstrated associations between endemic infectious intestinal diseases and factors related to water supply, sewage disposal, socio-demographics, and duration of residency. The results did not always follow prior expectations based on studies examining outbreaks and single systems, and underscore the importance of studying factors associated with endemic disease across water and sewage system types.