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Leptospirosis, caused by spirochetes of the genus Leptospira, is a globally widespread, neglected and emerging zoonotic disease. While whole genome analysis of individual pathogenic, intermediately pathogenic and saprophytic Leptospira species has been reported, comprehensive cross-species genomic comparison of all known species of infectious and non-infectious Leptospira, with the goal of identifying genes related to pathogenesis and mammalian host adaptation, remains a key gap in the field. Infectious Leptospira, comprised of pathogenic and intermediately pathogenic Leptospira, evolutionarily diverged from non-infectious, saprophytic Leptospira, as demonstrated by the following computational biology analyses: 1) the definitive taxonomy and evolutionary relatedness among all known Leptospira species; 2) genomically-predicted metabolic reconstructions that indicate novel adaptation of infectious Leptospira to mammals, including sialic acid biosynthesis, pathogen-specific porphyrin metabolism and the first-time demonstration of cobalamin (B12) autotrophy as a bacterial virulence factor; 3) CRISPR/Cas systems demonstrated only to be present in pathogenic Leptospira, suggesting a potential mechanism for this clade’s refractoriness to gene targeting; 4) finding Leptospira pathogen-specific specialized protein secretion systems; 5) novel virulence-related genes/gene families such as the Virulence Modifying (VM) (PF07598 paralogs) proteins and pathogen-specific adhesins; 6) discovery of novel, pathogen-specific protein modification and secretion mechanisms including unique lipoprotein signal peptide motifs, Sec-independent twin arginine protein secretion motifs, and the absence of certain canonical signal recognition particle proteins from all Leptospira; and 7) and demonstration of infectious Leptospira-specific signal-responsive gene expression, motility and chemotaxis systems. By identifying large scale changes in infectious (pathogenic and intermediately pathogenic) vs. non-infectious Leptospira, this work provides new insights into the evolution of a genus of bacterial pathogens. This work will be a comprehensive roadmap for understanding leptospirosis pathogenesis. More generally, it provides new insights into mechanisms by which bacterial pathogens adapt to mammalian hosts. [ABSTRACT FROM AUTHOR]

Methicillin-resistant Staphylococcus aureus (MRSA) is a public health threat within the general community, thereby warranting identification of MRSA reservoirs within the community. Computer terminals in schools were sampled for S. aureus and methicillin-resistant staphylococci. The overall prevalence of MRSA on computer keyboards was low: 0.68% for a postsecondary institution and 2% and 0% for two secondary institutes. The MRSA isolate from the postsecondary institution did not correspond to the Canadian epidemic clusters, but is related to the USA 700 cluster, which contains strains implicated in outbreaks within the U.S. The isolate from the secondary institute's keyboard was typed as CMRSA7 (USA 400), a strain that has been implicated in both Canadian and U.S. epidemics. Methicillin-resistant S. haemolyticus and S. epidermidis were also isolated from keyboards, indicating that a mixed community of methicillinresistant staphylococci can be present on keyboards. Although the prevalence was low, the presence of MRSA combined with the high volume of traffic on these student computer terminals demonstrates the potential for publicaccess computer terminals and computer rooms at educational institutes to act as reservoirs. [ABSTRACT FROM AUTHOR]

A reassortant influenza A(H1N1) virus of swine origin distinct from the pandemic H1N1 2009 strain was isolated from 3 patients, all of whom worked at the same large hog operation in Saskatchewan, Canada. The genomic composition of the isolates has not been previously reported, to our knowledge, and was the product of a genetic reassortment between seasonal H1N1 and triple-reassortant influenza virus that emerged in North American swine during the late 1990s. The neuraminidase and hemagglutinin genes of A/ Saskatchewan/5350/2009, A/Saskatchewan/5351/2009, and A/ Saskatchewan/5131/2009 were derived from human H1N1 virus and were closely related to those of A/Brisbane/59/2007. [ABSTRACT FROM AUTHOR]

Abstract: Background: Molecular diagnosis of Norovirus infection can be a complex multistep process, which requires significant user intervention and expertise, and is not amenable to automation without extensive validation and optimization. Objectives: To develop a real-time multiplexed RT-PCR assay with automated sample preparation that requires only a single-step and a single-tube for reverse transcription, amplification, and detection while exceeding the sensitivity of conventional PCR for broad-spectrum Norovirus detection. Study design: Limit of detection was assessed against dilutions of clinical specimens. Fifty archived extractions were used to compare TaqMan sensitivity with either a separate RT using random primers or a single-step RT-PCR. The sensitivity of the novel assay was compared with conventional RT-PCR using 100 specimens from gastroenteritis cases. Results: Automated extraction reduced RNA recovery by 0.5 logs compared to manual extraction but was more effective at removing PCR inhibitors from stool specimens. The optimized single-step real-time RT-PCR demonstrated no reduction in sensitivity. Together, the sensitivity of the novel assay was 19% higher than manual extraction with conventional RT-PCR. Conclusions: A semi-automated and simplified molecular diagnostic protocol for the rapid detection of Norovirus has been achieved. PCR inhibitors are present in human fecal specimens and cause a significant problem for Norovirus detection by RT-PCR. [Copyright &y& Elsevier]

We collected acute-phase serum samples from febrile patients at 2 major hospitals in Dhaka, Bangladesh, during an outbreak of dengue fever in 2001. A total of 18% of dengue-negative patients tested positive for leptospirosis. The case-fatality rate among leptospirosis patients (5%) was higher than among dengue fever patients (1.2%). [ABSTRACT FROM AUTHOR]

In the past decade, leptospirosis has emerged as a globally important infectious disease. It occurs in urban environments of industrialised and developing countries, as well as in rural regions worldwide. Mortality remains significant, related both to delays in diagnosis due to lack of infrastructure and adequate clinical suspicion, and to other poorly understood reasons that may include inherent pathogenicity of some leptospiral strains or genetically determined host immunopathological responses. Pulmonary haemorrhage is recognised increasingly as a major, often lethal, manifestation of leptospirosis, the pathogenesis of which remains unclear. The completion of the genome sequence of Leptospira interrogans serovar lai, and other continuing leptospiral genome sequencing projects, promise to guide future work on the disease. Mainstays of treatment are still tetracyclines and β-lactam/cephalosporins. No vaccine is available. Prevention is largely dependent on sanitation measures that may be difficult to implement, especially in developing countries. [Copyright &y& Elsevier]

Leptospiral culture, direct immunofluorescence, and the polymerase chain reaction (PCR) were used to detect leptospiral material in postmortem specimens collected from eight patients who died of leptospirosis. Diagnosis of leptospiral infection was based on clinical summary (premortem) and confirmed by serological analysis and/or culture of leptospires. Leptospiral culture was the least sensitive technique, yielding two isolates (3%) from 65 samples. Both isolates were from the aqueous humour and cerebrospinal fluid of the same patient. Direct immunofluorescence was of intermediate sensitivity for detection of leptospires, confirming the presence of leptospires in 11% (2 of 18) of tissue samples from three patients. PCR analysis was the most sensitive technique for detection of leptospiral material in tissue samples, being positive in 20% (11 of 56) of samples from eight patients. Both samples (cerebellum and liver) positive by immunofluorescence were also positive by PCR. The sensitivity of the PCR assay was 1–10 leptospires ml−1 sample, and the assay was specific for Leptospira pathogenic species. Multi-system involvement was indicated based on successful amplification of leptospiral DNA from more than one tissue sample, which corroborated with the clinical and pathologic findings. The results suggest that in acute and/or fatal leptospirosis, the pathogenesis of the pathologic features are related to the presence of the organisms in the tissues. In conclusion, PCR combined with serology appears to be a useful tool for diagnosis of leptospirosis and may be invaluable in epidemiological studies. [Copyright &y& Elsevier]

A genetic basis for asthma- and atopy-related quantitative traits, such as allergen-specific immunoglobulin E (IgE) levels, has been suggested by the observed familial aggregation of these traits in temperate climates. Less information is available for tropical climates, where different allergens may predominate. Sensitivity to the mite Blomia tropicalis is related to asthma in tropical climates, but heritability of B. tropicalis sensitivity and the impact of age, sex, and other environmental covariates on heritability have not been widely explored. Total and specific IgE levels were measured by immunochemiluminescent assay in 481 members of 29 Barbadian families (comprised of 340 parent-offspring trios or pairs) ascertained through two asthmatic siblings. Trait heritability was estimated using regression of offspring on mid-parent (ROMP) and pairwise correlation analysis of unadjusted IgE levels and on residual values after adjustment for covariates. Heritability of IgE levels to the major antigen of B. tropicalis (Blo t M) estimated by ROMP in 180 complete parent-offspring trios was 0.56. Heritability was consistently greater for male offspring than for female offspring. Similar sex-specific patterns were observed for specific IgE to Dermatophagoides pteronyssinus and total IgE levels and were relatively unaffected by adjustment for covariates. Pairwise correlational analyses of specific and total IgE levels showed similar results. Moderate heritability of Blo t M IgE levels was detected in these Barbadian families and was greater for sons than daughters. Adjustment for covariates had minimal impact. This suggests that future investigations of genetic determinants of IgE levels should include approaches that allow for potential sex differences in their expression. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has led to the influx of immunoassays for the detection of antibodies towards severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into the global market. The Canadian Public Health Laboratory Network Serology Task Force undertook a nationwide evaluation of twelve laboratory and 6 point-of-care based commercial serological assays for the detection of SARS-CoV-2 antibodies. We determined that there was considerable variability in the performance of individual tests and that an orthogonal testing algorithm should be prioritized to maximize the accuracy and comparability of results across the country. The manual enzyme immunoassays and point-of-care tests evaluated had lower specificity and increased coefficients of variation compared to automated enzyme immunoassays platforms putting into question their utility for large-scale sero-surveillance. Overall, the data presented here provide a comprehensive approach for applying accurate serological assays for longitudinal sero-surveillance and vaccine trials while informing Canadian public health policy. [ABSTRACT FROM AUTHOR]

• Sensitivities of evaluated anti-SARS-CoV-2 assays exceeded 90% ≥14 days post-onset. • Specificities and negative predictive values exceeded 90%. • Addition of serology to PCR testing for outbreaks increased case yield by 16%. SARS-CoV-2 antibody testing is required for estimating population seroprevalence and vaccine response studies. It may also increase case identification when used as an adjunct to routine molecular testing. We performed a validation study and evaluated the use of automated high-throughput assays in a field study of COVID-19-affected care facilities. Six automated assays were assessed: 1) DiaSorin LIAISONTM SARS-CoV-2 S1/S2 IgG; 2) Abbott ARCHITECTTM SARS-CoV-2 IgG; 3) Ortho VITROSTM Anti-SARS-CoV-2 Total; 4) VITROSTM Anti-SARS-CoV-2 IgG; 5) Siemens SARS-CoV-2 Total Assay; and 6) Roche ElecsysTM Anti-SARS-CoV-2. The validation study included 107 samples (42 known positive; 65 presumed negative). The field study included 296 samples (92 PCR positive; 204 PCR negative or not PCR tested). All samples were tested by the six assays. All assays had sensitivities >90% in the field study, while in the validation study, 5/6 assays were >90% sensitive and DiaSorin was 79% sensitive. Specificities and negative predictive values were >95% for all assays. Field study estimated positive predictive values at 1–10% disease prevalence were 100% for Siemens, Abbott and Roche, while DiaSorin and Ortho assays had lower PPVs at 1% prevalence, but PPVs increased at 5–10% prevalence. In the field study, addition of serology increased diagnoses by 16% compared to PCR testing alone. All assays evaluated in this study demonstrated high sensitivity and specificity for samples collected at least 14 days post-symptom onset, while sensitivity was variable 0–14 days after infection. The addition of serology to the outbreak investigations increased case detection by 16%. [ABSTRACT FROM AUTHOR]

Antivirals with broad coronavirus activity are important for treating high-risk individuals exposed to the constantly evolving SARS-CoV-2 variants of concern (VOCs) as well as emerging drug-resistant variants. We developed and characterized a novel class of active-site-directed 3-chymotrypsin-like protease (3CLpro) inhibitors ( C2-C5a ). Our lead direct-acting antiviral (DAA), C5a , is a non-covalent, non-peptide with a dissociation constant of 170 nM against recombinant SARS-CoV-2 3CLpro. The compounds C2-C5a exhibit broad-spectrum activity against Omicron subvariants (BA.5, BQ.1.1, and XBB.1.5) and seasonal human coronavirus-229E infection in human cells. Notably, C5a has median effective concentrations of 30-50 nM against BQ.1.1 and XBB.1.5 in two different human cell lines. X-ray crystallography has confirmed the unique binding modes of C2-C5a to the 3CLpro, which can limit virus cross-resistance to emerging Paxlovid-resistant variants. We tested the effect of C5a with two of our newly discovered host-directed antivirals (HDAs): N-0385, a TMPRSS2 inhibitor, and bafilomycin D (BafD), a human vacuolar H + -ATPase [V-ATPase] inhibitor. We demonstrated a synergistic action of C5a in combination with N-0385 and BafD against Omicron BA.5 infection in human Calu-3 lung cells. Our findings underscore that a SARS-CoV-2 multi-targeted treatment for circulating Omicron subvariants based on DAAs ( C5a ) and HDAs (N-0385 or BafD) can lead to therapeutic benefits by enhancing treatment efficacy. Furthermore, the high-resolution structures of SARS-CoV-2 3CLpro in complex with C2-C5a will facilitate future rational optimization of our novel broad-spectrum active-site-directed 3C-like protease inhibitors.

Background: The evolving proportion of the population considered immunologically naive versus primed for more efficient immune memory response to SARS-CoV-2 has implications for risk assessment. We sought to chronicle vaccine- and infection-induced seroprevalence across the first 7 waves of the COVID-19 pandemic in British Columbia, Canada., Methods: During 8 cross-sectional serosurveys conducted between March 2020 and August 2022, we obtained anonymized residual sera from children and adults who attended an outpatient laboratory network in the Lower Mainland (Greater Vancouver and Fraser Valley). We used at least 3 immunoassays per serosurvey to detect SARS-CoV-2 spike and nucleocapsid antibodies. We assessed any seroprevalence (vaccineor infection-induced, or both), defined by positivity on any 2 assays, and infection-induced seroprevalence, also defined by dual-assay positivity but requiring both antinucleocapsid and antispike detection. We used estimates of infection-induced seroprevalence to explore underascertainment of infections by surveillance case reports., Results: By January 2021, we estimated that any seroprevalence remained less than 5%, increasing with vaccine rollout to 56% by May-June 2021, 83% by September-October 2021 and 95% by March 2022. Infection-induced seroprevalence remained less than 15% through September-October 2021, increasing across Omicron waves to 42% by March 2022 and 61% by July-August 2022. By August 2022, 70%-80% of children younger than 20 years and 60%-70% of adults aged 20-59 years had been infected, but fewer than half of adults aged 60 years and older had been infected. Compared with estimates of infection-induced seroprevalence, surveillance case reports underestimated infections 12-fold between September 2021 and March 2022 and 92-fold between March 2022 and August 2022., Interpretation: By August 2022, most children and adults younger than 60 years had evidence of both SARS-CoV-2 vaccination and infection. As previous evidence suggests that a history of both exposures may induce stronger, more durable hybrid immunity than either exposure alone, older adults - who have the lowest infection rates but highest risk of severe outcomes - continue to warrant prioritized vaccination., Competing Interests: Competing interests: Danuta Skowronski reports grants from the Canadian Institutes of Health Research and the British Columbia Centre for Disease Control Foundation for Public Health, paid to her institution, for other SARS-CoV-2 work. Romina Reyes is chair of the BC Diagnostic Accreditation Program committee. Mel Krajden reports grants paid to his institution from Roche, Hologic and Siemens. No other competing interests were declared., (© 2022 CMA Impact Inc. or its licensors.)

SARS-CoV-2 anti-spike antibody concentrations and angiotensin converting enzyme-2 (ACE-2) inhibition have been used as surrogates to live viral neutralizing antibody titers; however, validity among vaccinated individuals is unclear. We tested the correlation of these measures among vaccinated participants, and examined subgroups based on duration since vaccination and vaccine dosing intervals. We analyzed 120 samples from two-dose mRNA vaccinees without previous COVID-19. We calculated Spearman correlation coefficients between wild-type viral neutralizing antibody titers and: anti-spike (total and IgG), anti-receptor-binding-domain (RBD), and anti-N-terminal-domain (NTD) antibodies; and ACE-2 binding by RBD. We performed three secondary analyses, dichotomizing samples by the first vaccination-to-blood collection interval, second vaccination-to-blood collection interval, and by the vaccine dosing interval (all groups divided by the median), and compared correlation coefficients (Fisher's Z test). Of 120 participants, 63 (53%) were women, 91 (76%) and 29 (24%) received BNT162b2 and mRNA-1273 vaccines, respectively. Overall, live viral neutralization was correlated with anti-spike total antibody (correlation coefficient = 0.80), anti-spike IgG (0.63), anti-RBD IgG (0.62), anti-NTD IgG (0.64), and RBD ACE2 binding (0.65). Samples with long (>158 days) first vaccination-to-blood collection and long (>71 days) second vaccination-to-blood collection intervals demonstrated higher correlation coefficients, compared with short groups. When comparing cases divided by short (≤39 days) versus long vaccine dosing intervals, only correlation with RBD-ACE-2 binding inhibition was higher in the long group. Among COVID-negative mRNA vaccinees, anti-spike antibody and ACE-2 inhibition concentrations are correlated with live viral neutralizing antibody titers. Correlation was stronger among samples collected at later durations from vaccination. IMPORTANCE Live viral neutralizing antibody titers are an accepted measure of immunity; however, testing procedures are labor-intensive. COVID-19 antibody and angiotensin converting enzyme-2 (ACE-2) levels have been used as surrogates to live viral neutralizing antibody titers; however, validity among vaccinated individuals is unclear. Using samples from 120 two-dose mRNA vaccinees without previous COVID-19, we found that live viral neutralization was correlated with COVID-19 antibody and ACE2 binding levels. When grouping samples by the time interval between vaccination and sample blood collection, samples collected over 158 days after the first vaccine and over 71 days from the second vaccine demonstrated stronger correlation between live viral neutralization titers and both antibody and ACE2 levels, in comparison to those collected earlier.

Increasing transmission of SARS-CoV-2 infection in successive waves may strain the capacity of laboratories performing molecular diagnostic testing. Alternative testing approaches may offer additional diagnostic capacity. A high throughput chemiluminescent antigen assay (Ortho VITROS SARS-CoV-2 antigen test) was evaluated using both an inactivated virus preparation and prospective clinical samples (nasopharyngeal swabs in virus transport medium). The limit of detection of the assay was approximately 0.5 TCID 50 /ml, equivalent to a Ct value of 33. The assay was linear over a wide range. When 528 clinical samples were tested with the antigen assay, the sensitivity was 84.2% and the specificity was 100% (positive predictive value 100% and negative predictive value 97.7%). High volume antigen tests might be used to supplement molecular diagnostic testing capacity., (Copyright © 2021 Elsevier B.V. All rights reserved.)

We compared neutralization assays using either the wild-type severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus or surrogate neutralization markers, using characterized sera. We found the results of the neutralization assays 75 % concordant overall and 80 % concordant for samples with high antibody levels. This demonstrates that commercial surrogate SARS-CoV-2 assays offer the potential to assess anti-SARS-CoV-2 antibodies' neutralizing capacity outside CL-3 laboratory containment., Competing Interests: The authors declare that there are no conflicts of interest., (© 2021 The Authors.)

A comparison of rapid point-of-care serology tests using finger prick and venous blood was done on 278 participants. In a laboratory setting, immunoglobulin G (IgG) sensitivity neared 100%; however, IgG sensitivity dramatically dropped (82%) in field testing. Possible factors include finger prick volume variability, hemolysis, cassette readability, and operator training., (© The Author(s) 2021. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Mycobacterium avium complex (MAC) is usually considered an opportunistic organism, which infects immunocompromised children or those with structural airway abnormalities. We present two cases of MAC infection affecting immune competent children, likely from hot tubs with primary involvement of pulmonary and urinary systems. These cases highlight the importance of asking about hot tub use in immune competent children with suspected or confirmed MAC infections., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Canadian Paediatric Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

To describe a historical baseline of antimicrobial resistance (AMR) profiles for human clinical Campylobacter species isolates obtained by laboratory surveillance in the province of Saskatchewan from 1999 to 2006; to determine if there were differences in resistance between Campylobacter jejuni and Campylobacter coli ; and to determine if there were changes in the annual resistance levels in the two species. One thousand three hundred seventy-eight Campylobacter isolates were subjected to antimicrobial susceptibility testing using the E-test method. Annual resistance levels in C. jejuni and C. coli were compared using logistic regression models. One thousand two hundred (87.1%) isolates were C. jejuni and 129 (9.4%) were C. coli . Resistance in C. jejuni isolates included ciprofloxacin (CIP: 9.4%), erythromycin (ERY: 0.5%), and tetracycline (33.3%). CIP resistance in C. jejuni was higher in 1999 (15.5%, odds ratio [OR] = 3.96, p  = 0.01), 2000 (12.7%, OR = 3.10, p  = 0.01), 2005 (10.2%, OR = 2.47, p  = 0.05), and 2006 (13.0%, OR = 3.22, p  = 0.01) compared with 2004 (4.4%). C. coli had significantly higher CIP resistance (15.5%, OR = 1.78, p  = 0.03), ERY resistance (13.2%, OR = 60.12, p  < 0.01), multidrug resistance (2.3%, OR = 36.29, p  < 0.01), and CIP-ERY resistance (3.1%, OR = 50.23, p  < 0.01) compared with C. jejuni . This represents the first and most current report of AMR of the collective human Campylobacter isolates from a province in Canada and provides a baseline against which current and future resistance patterns can be compared. Fluoroquinolone resistance in C. jejuni isolates fluctuated from 1999 to 2006, including an increased prevalence in 2005-2006, while macrolide/lincosamide resistance remained very low. Human clinical C. jejuni isolates from Saskatchewan demonstrated resistance to multiple antimicrobials but had significantly less fluoroquinolone and macrolide resistance than C. coli isolates.

Aim: To ascertain the antimicrobial resistance and strain types (STs) of Neisseria gonorrhoeae from 50 remnant Aptima urine specimens using molecular methods. Methods: Mutations predictive of resistance to six antibiotics were identified in eight genes. STs were determined using NG-MAST and NG-STAR. Results: All eight antimicrobial resistance genes could be characterized in 36 specimens. A total of 17 specimens were predicted to be susceptible to all antibiotics, including ceftriaxone. Decreased susceptibility to cefixime and ciprofloxacin resistance was predicted in 11 specimens (PBP2 type 34.001). Overall, 38/50 specimens were predicted to be ciprofloxacin susceptible; three were azithromycin resistant. Nineteen NG-MAST and 21 NG-STAR STs were noted. Conclusion: Molecular analysis of remnant Aptima specimens enabled the prediction of emerging gonococcal cefixime and azithromycin resistance which would otherwise have been undetected.

Objective: HIV incidence in the Canadian province of Saskatchewan, where Indigenous persons make up 80% of those infected, are among the highest on the continent. Reports of accelerated HIV progression, associated with carriage of certain human leukocyte antigen (HLA) alleles (including the typically protective HLA-B*51) have also emerged from the region. Given that acquisition of HIV preadapted to host HLA negatively impacts clinical outcome, we hypothesized that HIV-host adaptation may be elevated in Saskatchewan., Design: Comparative analysis of population-level HIV sequence datasets from Saskatchewan and elsewhere in Canada/USA., Methods: We analyzed 1144 HIV subtype B Pol sequences collected in Saskatchewan between 2000 and 2016, comprising ∼65% of cumulative provincial HIV cases, for the presence of 70 HLA-associated Pol mutations. Sequences from British Columbia (N = 6525) and elsewhere in Canada/USA (N = 6517) were used for comparison. HIV adaptation levels to 34 HLA alleles were also computed. Putative HIV transmission clusters were identified, and the prevalence of HLA-associated adaptations within and outside these clusters was investigated., Results: Analyses confirmed significantly elevated and temporally increasing levels of HIV adaptation to commonly expressed HLA alleles, in particular B*51. Notably, HLA-adapted HIV strains were significantly enriched among phylogenetic clusters in Saskatchewan., Conclusion: Extensive circulating HIV adaptation to HLA in Saskatchewan provides a plausible explanation for accelerated progression, while enrichment of adapted variants in phylogenetic clusters suggests they are being widely transmitted. Results highlight the utility of Pol sequences, routinely collected for drug resistance monitoring, for surveillance of HIV-host adaptation, and underscore the urgent need to expand HIV prevention and treatment programmes in Saskatchewan.

Background: Standard diagnostic testing for HIV infection has traditionally relied on a high sensitivity HIV antibody screening test using an enzyme-linked immunosorbent assay (ELISA) followed by a high specificity antibody confirmatory test such as a Western Blot. Recently several of the screening assays have been enhanced with an ability to identify p24 antigen thereby narrowing the diagnostic window., Objectives: To explore the implications of enhanced HIV screening methods that may be leading to HIV misdiagnoses., Study Design: A patient deemed to be an HIV infected 'elite controller' was found to be misdiagnosed when undergoing detailed investigations prior to initiating antiretroviral therapy. A root cause analysis was performed to identify the causative factors of this misdiagnosis. A retrospective review of all "elite controllers" in Alberta, Canada revealed challenges of current HIV testing algorithms., Results: Technical and human factors were identified as being causative in this HIV misdiagnosis including (i) high rates of false reactive results on the Abbott ARCHITECT HIV-1&2 COMBO EIA, (ii) human error in reading the initial Western blot, (iii) HIV algorithmic directives in which confirmatory (Western blot) testing was not performed on a repeatedly reactive screen test. The outcome of this analysis identified opportunities for improvement, including implementation of a newly approved (automated) confirmatory assay and improved communication between the clinician and laboratory., Conclusions: HIV testing remains problematic despite significant advances in HIV test performance and algorithm development, presenting new and unexpected issues. Ensuring a high-quality management system including implementation of the latest HIV technologies and algorithms along with human resources and policies are required to minimize the impact of false positive diagnoses, especially in the era of universal screening and 'test and treat' recommendations., (Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.)

Purpose: This study was undertaken to provide baseline HPV genotype distribution among women in Barbados before HPV immunization was introduced. This information would then be used as a denominator for post-vaccine surveillance and is expected to aid in understanding the effect of vaccination on cervical disease in Barbados., Methods: Liquid-based cytology specimens were collected from 413 women (age range 18-65 years) attending three clinics, in a pre-vaccination, population-based study. After consent was obtained, sexual behavior and socio-demographic information were acquired from self-administered questionnaires. HPV types were detected using Luminex-based HPV PCR genotyping methodology., Results: HPV was detected in 33% (135/413) of the subjects overall (95% CI 32.7, 33.37), of which 70% (95/135) were high-risk types, with 35 different types being detected in this population. Single and multiple high-risk HPV types were detected in 14% (13/95) and 31% (29/95) of the subjects, respectively. The most common high-risk HPV types detected were 45(n = 22, 23%), 16 (n = 17, 18%), 52 (n = 16, 17%), and 58 (n = 10, 11%). Persons with the highest level of infection by age were 21-25 (n = 25/135;19%; 95% CI 18.8, 19.3); 26-30 (n = 22/135;16%; 95% CI 15.9, 16.2); 31-35 (n = 19/135;14%; 95% CI 13.9, 14.2); 36-40 (n = 17/135;13%; 95% CI 12.2, 13.2), and 18-21 (n = 15/135;11%; 95% CI 10.9, 11.2). 91/413 (22%) persons had a normal cytology result., Conclusion: A high prevalence of HPV type 45 was found in the screening population of women in Barbados. The results of cytological examinations and HPV positivity suggest that both tests should be used for greater reliable diagnosis of HPV infection.

Leptospires are spirochetes that may be free-living saprophytes found in freshwater or may cause acute or chronic infection of animals. The family Leptospiraceae comprises three genera: Leptospira Leptospira Leptonema Leptonema, and Turneriella Turneriella. Within the genus Leptospira, three clades can be distinguished, of pathogens, nonpathogens, and an intermediate group. Leptospires are further divided into serovars; antigenically related serovars are clustered into serogroups for convenience.