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Background: Since the publication of the 2010 Canadian antiplatelet guidelines, several large randomized controlled trials (RCTs) have evaluated the role of aspirin (ASA) use in primary prevention. We evaluated the effect of ASA use, compared with no ASA, on ischemic and bleeding events in patients without known atherosclerotic cardiovascular diseases., Methods: We updated a published systematic review and meta-analysis by searching MEDLINE, Embase, and CENTRAL for the period up to March 2023. We included RCTs that enrolled patients for primary prevention of atherosclerotic cardiovascular diseases, and compared use of ASA to no ASA. We assessed risk of bias (RoB) using the Cochrane RoB tool, and certainty of evidence using the grading recommendations, assessment, development, and evaluation (GRADE) criteria. The primary efficacy outcome was major adverse cardiovascular events (MACE) (death, myocardial infarction, or stroke). The primary safety outcomes were intracranial hemorrhage and extracranial major bleeding events. We used a random-effects model to generate pooled risk ratios (RRs) and 95% confidence intervals (CIs)., Results: We included 14 RCTs (n = 167,587) at overall low RoB, with a median follow-up of 5 years. Compared to no ASA, ASA use reduced the incidence of MACE (RR 0.90, 95% CI 0.86-0.94), with a higher risk of intracranial hemorrhage (RR 1.33, 95% CI 1.13-1.56) and extracranial major bleeding (RR 1.67, 95% CI 1.36-2.06). In prespecified subgroups of age, sex, and diabetes, effect estimates were consistent., Conclusions: ASA use in primary prevention is associated with a consistent reduction in MACE, but at the expense of major bleeding events. Patient values and preferences should be taken into account when considering ASA use for primary prevention., (© 2023 The Authors.)

The coronavirus SARS-CoV-2, which causes Coronavirus disease 2019 (COVID-19), has infected more than 100 million people globally and caused over 2.5 million deaths in just over one year since its discovery in Wuhan, China in December 2019. The pandemic has evoked widespread collateral damage to societies and economies, and has destabilized mental health and well-being. Early in 2020, unprecedented efforts went into the development of vaccines that generate effective antibodies to the SARS-CoV-2 virus. Teams developing twelve candidate vaccines, based on four platforms (messenger RNA, non-replicating viral vector, protein/virus-like particle, and inactivated virus) had initiated or announced the Phase III clinical trial stage by early November 2020, with several having received emergency use authorization in less than a year. Vaccine rollout has proceeded around the globe. Previously, we and others had proposed a target product profile (TPP) for ideal/optimal and acceptable/minimal COVID-19 vaccines. How well do these candidate vaccines stack up to a harmonized TPP? Here, we perform a comparative analysis in several categories of these candidate vaccines based on the latest available trial data and highlight the early successes as well as the hurdles and barriers yet to be overcome for ending the global COVID-19 pandemic.

Objectives: To investigate the effects of early upstream antithrombotic therapy administration (ATTA) in ST-segment elevation myocardial infarction (STEMI) patients with prolonged transport times to primary percutaneous intervention (PPCI) on major clinical outcomes., Background: It remains unclear whether early upstream administration of aspirin, ticagrelor, and unfractionated heparin (UFH) confers additional benefits compared with in-hospital administration., Methods: Between 2015 and 2018, we performed PPCI in 709 included consecutive STEMI patients. We compared 482 STEMI patients who received aspirin, ticagrelor, and UFH loading in a non-PCI capable spoke hospital before transfer (NPHT) versus 227 prehospital triage setting (PTS) STEMI patients who received in-ambulance aspirin, followed by ticagrelor and UFH in the hub catheterization laboratory. The primary outcome was the presence of a pre-PPCI TIMI flow 2-3 in the infarct related artery (IRA). The secondary outcomes included definite acute stent thrombosis and hemorrhagic complications., Results: The median times from ticagrelor and heparin administration to angiography in the NPHT group and the PTS group were 80.5 min (Interquartile Range (IQR) 68.5-94) and 10 min (IQR 5-15) respectively (p < .0001). Using inverse probability of treatment weighting to minimize heterogeneity between groups, we showed significant differences for the primary outcome (44.6 versus 18.5%, p < .0001) and for definite acute stent thrombosis (0.6 versus 2.6%, p = .03), with no difference in the combined in-hospital BARC 2-5 bleeding events (1.9 versus 3.5%, p = .18) in the NPHT versus the PTS group, respectively., Conclusion: In this single-center retrospective cohort study, after adjusting for baseline covariates, early upstream ATTA with aspirin, ticagrelor, and UFH was associated with greater pre-PPCI TIMI flow and less definite acute stent thrombosis in STEMI patients, without increased bleeding risk., (© 2020 Wiley Periodicals LLC.)

A novel coronavirus SARS-CoV-2 causing Coronavirus disease 2019 (COVID-19) has entered the human population and has spread rapidly around the world in the first half of 2020 causing a global pandemic. The virus uses its spike glycoprotein receptor-binding domain to interact with host cell angiotensin-converting enzyme 2 (ACE2) sites to initiate a cascade of events that culminate in severe acute respiratory syndrome in some individuals. In efforts to curtail viral spread, authorities initiated far-reaching lockdowns that have disrupted global economies. The scientific and medical communities are mounting serious efforts to limit this pandemic and subsequent waves of viral spread by developing preventative vaccines and repurposing existing drugs as potential therapies. In this review, we focus on the latest developments in COVID-19 vaccine development, including results of the first Phase I clinical trials and describe a number of the early candidates that are emerging in the field. We seek to provide a balanced coverage of the seven main platforms used in vaccine development that will lead to a desired target product profile for the "ideal" vaccine. Using tales of past vaccine discovery efforts that have taken many years or that have failed, we temper over exuberant enthusiasm with cautious optimism that the global medical community will reach the elusive target to treat COVID-19 and end the pandemic., (Copyright © 2020 Funk, Laferrière and Ardakani.)

Objective: To describe the burden of pneumococcal disease and associated risk factors in the Canadian adult population, delineate available pneumococcal vaccines and associated efficacy and effectiveness data, and review current pneumococcal vaccine recommendations and community-acquired pneumonia (CAP) prevention strategies in Canada., Quality of Evidence: Pneumococcal vaccination guidelines from the Canadian National Advisory Committee on Immunization in 2013 and 2016 constitute level III evidence for CAP prevention in the Canadian adult population., Main Message: It is recommended that immunosuppressed adults of all ages receive the 13-valent pneumococcal conjugate vaccine (PCV13) (grades A and B recommendations). In 2016, the National Advisory Committee on Immunization also recommended that all adults aged 65 years and older receive PCV13 (grade A recommendation) on an individual basis, followed by the 23-valent pneumococcal polysaccharide vaccine (grade B recommendation). This update is based on a large clinical study that demonstrated PCV13 efficacy against vaccine-type CAP in this population., Conclusion: Physicians should focus on improving pneumococcal vaccination rates among adults, which remain low. Vaccination with PCV13 should also be considered for adults with chronic conditions, whose baseline risk is often higher than that for healthy individuals aged 65 years and older., (Copyright© the College of Family Physicians of Canada.)

Recent studies have reported increased levels of Legionella pneumophila (Lp) at points of use compared to levels in primary and secondary components of hot water systems, suggesting possible selection by environmental conditions. In this study, concentrations of Lp in a hospital hot water system were evaluated by profile sampling, collecting successive water samples to determine the prevalence at the faucet (distal) and upstream piping before and after a system intervention to increase temperature. Lp strain diversity was compared between different points of use and different areas of the hot water system (i.e., tap, intermediate piping and main upflow piping). In total, 47 isolates were recovered from 32 positive hot water samples collected from designated taps, showers and recirculation loops; these isolates were subsequently analyzed by sequence-based typing (SBT). Lp levels were comparable between first draw (500 mL) and flushed (2 and 5 min) samples, whereas a decrease was observed in the amount of culturable cells (1 log). Two sequence types (STs) were identified throughout the system. ST378 (sg4/10) was present in 91% of samples, while ST154-like (sg1) was present in 41%; both STs were simultaneously recovered in 34% of samples. Isolated STs displayed comparable tolerance to copper (0.8-5 mg/L) and temperature (55 °C, 1 h) exposure. The ability to replicate within THP1 cells and Acanthamoeba castellanii was similar between the two STs and a comparative environmental outbreak strain. The low Lp diversity and the detection of both Lp sequence types in repeated subsequent samples collected from positive faucets in a hospital wing suggest a minimal impact of the distal conditions on strain selection for the sampled points, as well as a possible adaptation to stressors present in the system, leading to the predominance of a few strains., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Microbial drinking water quality can be altered in large buildings, especially after stagnation. In this study, bacterial profiles were generated according to the stagnation time and the volume of water collected at the tap. Successive volumes of cold and hot water were sampled after controlled stagnation periods. Bacterial profiles revealed an important decline (> 2 log) in culturable cells in the first 500 mL sampled from the hot and cold water systems, with a steep decline in the first 15 mL. The strong exponential correlation (R2 ≥ 0.97) between the culturable cell counts in water and the pipe surface-to-volume ratio suggests the biofilm as the main contributor to the rapid increase in suspended culturable cells measured after a short stagnation of one-hour. Results evidence the contribution of the high surface-to-volume ratio at the point of use and the impact of short stagnation times on the increased bacterial load observed. Simple faucets with minimal internal surface area should be preferred to minimize surface area. Sampling protocol, including sampling volume and prior stagnation, was also shown to impact the resulting culturable cell concentration by more than 1000-fold. Sampling a smaller volume on first draw after stagnation will help maximize recovery of bacteria., Competing Interests: The authors have declared that no competing interests exist.

Objective: Serological testing guidelines for vaccine-preventable infectious diseases in pregnant women are heterogeneous. It is unclear how vaccination history influences health care workers' (HCWs) attitudes about testing. The aim of this study was to describe current practices in screening for rubella, hepatitis B, and varicella-zoster virus (VZV) in pregnant women in the province of Québec., Methods: In 2015, an electronic survey was distributed to HCWs who followed the case of at least one pregnant woman in the previous year and who could be contacted by email by their professional association., Results: A total of 363 of 1084 (33%) participants were included in the analysis: general practitioners (57%), obstetrician-gynaecologists (20%), midwives (41%), and nurse practitioners (31%). For rubella, 48% of participants inquired about vaccination status, and of these, 98% offered serological testing for unvaccinated women versus 44% for vaccinated women. Similarly, of the 48% of participants who asked about hepatitis B vaccination status before offering testing, 96% ordered testing for hepatitis B surface antigen, 28% ordered testing for hepatitis B surface antibody, and 1% ordered no serological testing to unvaccinated women versus 72%, 46%, and 8%, respectively, for vaccinated women. Among the 81% of respondents who discussed VZV during prenatal care, 13% ordered serological testing if patients had a history of VZV infection, 87% if the VZV history was uncertain, and 19% if patients had a positive history of vaccination., Conclusion: Asking about vaccination status influences HCWs' attitudes about serological testing for rubella, hepatitis B, and VZV. In the context of increasing vaccination coverage in women of child-bearing age, it is important to clarify the impact of vaccination status in serological screening guidelines in pregnant women., (Copyright © 2018 Society of Obstetricians and Gynaecologists of Canada. Published by Elsevier Inc. All rights reserved.)

Identifying environmental sources of Pseudomonas aeruginosa ( Pa ) related to hospital-acquired infections represents a key challenge for public health. Biofilms in water systems offer protection and favorable growth conditions, and are prime reservoirs of microorganisms. A comparative genotyping survey assessing the relationship between Pa strains recovered in hospital sink biofilm and isolated in clinical specimens was conducted. Environmental strains from drain, faucet and sink-surface biofilm were recovered by a culture method after an incubation time ranging from 48 to 240 h. The genotyping of 38 environmental and 32 clinical isolates was performed using a multiple-locus variable-number of tandem repeats analysis (MLVA). More than one-third of Pa isolates were only cultivable following ≥48 h of incubation, and were predominantly from faucet and sink-surface biofilms. In total, 41/70 strains were grouped within eight genotypes (A to H). Genotype B grouped a clinical and an environmental strain isolated in the same ward, 5 months apart, suggesting this genotype could thrive in both contexts. Genotype E grouped environmental isolates that were highly prevalent throughout the hospital and that required a longer incubation time. The results from the multi-hospital follow-up study support the drain as an important reservoir of Pa dissemination to faucets, sink surfaces and patients. Optimizing the recovery of environmental strains will strengthen epidemiological investigations, facilitate pathway identification, and assist in identifying and controlling the reservoirs potentially associated to hospital-acquired infections., Competing Interests: The authors declare no conflict of interest.

Coagulase-negative staphylococci (CoNS) have become the leading cause of bloodstream infections (BSIs) in intensive care units (ICUs), particularly in premature neonates. Vancomycin-intermediate heteroresistant CoNS (hVICoNS) have been identified as sources of BSIs worldwide, and their potential to emerge as significant pathogens in the neonatal ICU (NICU) remains uncertain. This study describes the molecular epidemiology of an outbreak of vancomycin-heteroresistant (hV) Staphylococcus epidermidis central-line-associated BSI (CLABSI) in a single tertiary care NICU and compares it to a second tertiary care NICU that had not been associated with an outbreak. Between November 2009 and April 2014, 119 S. epidermidis CLABSIs were identified in two tertiary care NICUs in Quebec, Canada. Decreased vancomycin susceptibility was identified in about 88% of all collected strains using Etest methods. However, discrepancies were found according to the Etest and population analysis profiling-area under the concentration-time curve (PAP-AUC) methods used. All strains were susceptible to linezolid, and a few isolates were nonsusceptible to daptomycin. Great genetic diversity was observed within the collection, with 31 pulsed-field gel electrophoresis (PFGE) patterns identified. The outbreak strains were all determined to be heteroresistant to vancomycin and were polyclonal. The study identified two major clones, PFGE patterns E and G, which were found in both NICUs across the 5-year study period. This suggests the persistence of highly successful clones that are well adapted to the hospital environment. hV S. epidermidis seems more common than currently realized in the NICU, and certain hV S. epidermidis clones can become endemic to the NICU. The reservoirs for these clones remain unknown at this time, and identification of the reservoirs is needed to better understand the impact of hV S. epidermidis in the NICU and to inform infection prevention strategies. In addition, there is a need to investigate and validate hV determination protocols for different species of CoNS., (Copyright © 2016, American Society for Microbiology. All Rights Reserved.)

Objective: To perform a post-outbreak prospective study of the Pseudomonas aeruginosa contamination at the faucets (water, aerator and drain) by culture and quantitative polymerase chain reaction (qPCR) and to assess environmental factors influencing occurrence, Setting: A 450-bed pediatric university hospital in Montreal, Canada, Methods: Water, aerator swab, and drain swab samples were collected from faucets and analyzed by culture and qPCR for the post-outbreak investigation. Water microbial and physicochemical parameters were measured, and a detailed characterization of the sink environmental and design parameters was performed., Results: The outbreak genotyping investigation identified drains and aerators as the source of infection. The implementation of corrective measures was effective, but post-outbreak sampling using qPCR revealed 50% positivity for P. aeruginosa remaining in the water compared with 7% by culture. P. aeruginosa was recovered in the water, the aerator, and the drain in 21% of sinks. Drain alignment vs the faucet and water microbial quality were significant factors associated with water positivity, whereas P. aeruginosa load in the water was an average of 2 log higher for faucets with a positive aerator., Conclusions: P. aeruginosa contamination in various components of sink environments was still detected several years after the resolution of an outbreak in a pediatric university hospital. Although contamination is often not detectable in water samples by culture, P. aeruginosa is present and can recover its culturability under favorable conditions. The importance of having clear maintenance protocols for water systems, including the drainage components, is highlighted.

Legionella pneumophila is frequently detected in hot water distribution systems and thermal control is a common measure implemented by health care facilities. A risk assessment based on water temperature profiling and temperature distribution within the network is proposed, to guide effective monitoring strategies and allow the identification of high risk areas. Temperature and heat loss at control points (water heater, recirculation, representative points-of-use) were monitored in various sections of five health care facilities hot water distribution systems and results used to develop a temperature-based risk assessment tool. Detailed investigations show that defective return valves in faucets can cause widespread temperature losses because of hot and cold water mixing. Systems in which water temperature coming out of the water heaters was kept consistently above 60 °C and maintained above 55 °C across the network were negative for Legionella by culture or qPCR. For systems not meeting these temperature criteria, risk areas for L. pneumophila were identified using temperature profiling and system's characterization; higher risk was confirmed by more frequent microbiological detection by culture and qPCR. Results confirmed that maintaining sufficiently high temperatures within hot water distribution systems suppressed L. pneumophila culturability. However, the risk remains as shown by the persistence of L. pneumophila by qPCR., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Objective: To compare Pseudomonas aeruginosa prevalence in electronic and manual faucets and assess the influence of connecting pipes and water quality., Setting: Faucets in 4 healthcare centers in Quebec, Canada., Methods: Water samples from 105 electronic, 90 manual, and 14 foot-operated faucets were analyzed for P. aeruginosa by culture and enzymatic detection, and swab samples from drains and aerators were analyzed by culture. Copper and residual chlorine concentrations, temperature, and flow rate were measured. P. aeruginosa concentrations were analyzed in 4 consecutive volumes of cold water and a laboratory study was conducted on copper pipes and flexible hoses., Results: P. aeruginosa contamination was found in drains more frequently (51%) than in aerators (1%) or water (culture: 4%, enzyme detection: 16%). Prevalence in water samples was comparable between manual (14%) and 2 types of electronic faucets (16%) while higher for foot-operated faucets (29%). However, type 2 electronic faucets were more often contaminated (31%) than type 1 (14%), suggesting that faucet architecture and mitigated volume (30 mL vs 10 mL) influence P. aeruginosa growth. Concentrations were 100 times higher in the first 250 mL than after flushing. Flexible hoses were more favorable to P. aeruginosa growth than copper and a temperature of 40°C led to higher counts., Conclusions: The types of faucets and connecting pipes, flow rate, and water quality are important parameters influencing the prevalence and the concentrations of P. aeruginosa in faucets. High concentrations of P. aeruginosa in the first 250 mL suggest increased risk of exposure when using the first flush.

Background: Beta-hemolytic Group A Streptococcus invasive disease (iGASd) has been subject to intense research since its re-emergence in the late 1980s. In Quebec, an increase in the number of severe iGASd cases has recently been observed. Because of the inter-individual variability in the severity of iGASd, a hereditary predisposition to invasive disease can be suspected. Given that iGASd occurs in MyD88- and IRAK4-deficient patients, although rarely, the increasing frequency of iGASd in the population of French-Canadian children may be associated with a deficiency in the host's innate immune response., Methods: In this report, we assessed the influence of: (i) bacterial genotype and virulence factors, (ii) immune-cellular features, and (iii) Myd88/IRAK4-dependent response to GAS in vitro on the susceptibility to iGASd in a paediatric cohort of 16 children: 11 French-Canadian and 5 from diverse origin., Findings: GAS virulence factors and genotype are not implicated in the susceptibility toward iGASd, and cellular and MyD88/IRAK4 deficiencies are excluded in our patients., Conclusions: Although it has been shown that the MyD88/IRAK4-dependent signal is involved in the response to invasive GAS, our data indicates that a MyD88/IRAK4-mediated signalling defect is not the main factor responsible for the susceptibility to severe iGASd in a paediatric population from the province of Quebec.

Background: Listeriosis is one of the most severe foodborne illnesses worldwide. Most infections with Listeria are sporadic, but outbreaks do occur. Pregnant women exposed to this organism are at increased risk of chorioamnionitis, preterm labour, prematurity and intrauterine fetal demise. Severe neonatal infection can also occur., Cases: Two recent outbreaks in Canada prompted a reassessment of the prevalence and the perinatal impact of this disease. We describe here three cases of perinatal listeriosis. The aim of our report is to demonstrate the variable clinical presentations and to emphasize the difficulty in diagnosing perinatal listeriosis., Conclusion: Perinatal listeriosis is a severe disease with many possible clinical presentations. Clinical diagnosis may be difficult, so clinicians must maintain a high index of suspicion.

Objective: To determine the prevalence of mid-trimester microbial invasion of the amniotic cavity (MIAC) in women with suspected cervical insufficiency., Methods: A prospective observational cohort study was performed in women with suspected cervical insufficiency and visible fetal membranes who were undergoing amniocentesis to rule out MIAC between 16 and 26 weeks of gestation. Women with preterm premature rupture of membranes, regular uterine contractions, or who had a cervical cerclage were excluded. Gram staining of amniotic fluid, glucose and lactate dehydrogenase (LDH) levels in amniotic fluid, and aerobic and anaerobic amniotic fluid cultures were performed, along with polymerase chain reaction (PCR) for the detection of Ureaplasma and Mycoplasma species., Results: Fifteen women with a mean gestational age of 22.6 +/- 2.3 weeks were included in the study. The diagnosis of MIAC was confirmed in 47% (7/15), of whom 20% (3/15) were infected with more than one bacterial strain and 33% (5/15) with Ureaplasma species. According to receiver-operator curve analyses, amniotic fluid levels of glucose were associated with MIAC (P = 0.02), but not amniotic fluid LDH (P = 0.25)., Conclusion: MIAC is present in approximately one half of women with suspected cervical insufficiency and visible fetal membranes at speculum examination.

From 1997 to 2006, in the province of Quebec, Canada, 15 isolates of Streptococcus pseudoporcinus from 1 urine and 14 vaginorectal cultures were recovered from the genitourinary tract of pregnant women. All these women originated from the Caribbean or sub-Saharan Africa (P=0.00045 compared with a suitable control group). The S. pseudoporcinus isolates were compared to eight isolates of Streptococcus porcinus identified in Quebec from 1995 to 2006, all from animals, of which five were swine. 16S rRNA gene sequencing was required to differentiate between S. pseudoporcinus and S. porcinus animal isolates.

Background: Microbial invasion of the amniotic cavity (MIAC) remains an important pathogenetic factor in preterm births. Although most MIACs seem to originate in vaginal microflora, other reservoirs such as the oral microflora have been suggested., Case: We report a case of successful eradication of Streptococcus mutans (a bacterium generally found in dental plaque) from the amniotic cavity, using ampicillin, gentamycin, and azythromycin in a woman who presented with threatened preterm labour and a short cervix at 25 weeks' gestation. She delivered at 34 weeks' gestation and was treated for tooth decay 12 weeks after delivery., Conclusion: Intra-amniotic infection should be suspected in the presence of a short cervix during the second trimester. Appropriate parenteral antibiotics can eradicate intra-amniotic infection and potentially prolong pregnancy.

Group B streptococcus (GBS) is a major cause of serious infections in neonates. The 2002 revised guidelines of the Centers for Disease Control and Prevention (CDC) for the prevention of perinatal GBS disease recommend that all pregnant women be screened for GBS carriage at between 35 and 37 weeks of gestation and that intrapartum antibiotic prophylaxis be given to carriers. We studied the performances of four different GBS detection assays in the context of antenatal screening. Between May and August 2004, the 605 vaginorectal swab specimens received at our bacteriology laboratory for GBS antenatal detection were tested by the four assays. The standard culture method was done according to the CDC recommendations. The three experimental assays performed with the growth from the selective enrichment (LIM) broth (Todd-Hewitt broth with 15 mug/ml nalidixic acid and 10 mug/ml colistin) after overnight incubation were a GBS antigen detection assay (PathoDx) and two PCR assays (for cfb and scpB). The most accurate assay was the scpB PCR (sensitivity, 99.6%; specificity, 100%), followed by the cfb PCR (sensitivity, 75.3%; specificity, 100%), GBS antigen detection (sensitivity, 57.3%; specificity, 99.5%), and standard culture (sensitivity, 42.3%; specificity, 100%). The GBS antigen detection assay was found to be more sensitive than the standard culture method, and moreover, the assay has a low cost and is easy to perform in all obstetrical centers which have access to the most basic of diagnostic microbiology services. We believe that antigen detection on incubated LIM broth should replace the standard culture method for screening for GBS carriage at 35 to 37 weeks of gestation. The impact of the greater sensitivities of PCR assays on the diminution of neonatal GBS infections remains to be demonstrated.

The human metapneumovirus (hMPV) was recently identified and linked to acute respiratory tract infections (ARTI). To assess the clinical importance of this virus in infants and children, we developed a rapid and efficient reverse transcription-PCR-based screening method for a large volume of samples and tested retrospectively a collection of 1,132 respiratory specimens submitted over a full year period to the virology laboratory of a large tertiary care pediatric center in Montreal, Canada. A total of 41 samples from 37 patients were positive by this method. During the winter months of 2001, up to 8% of specimens submitted for respiratory virus testing were hMPV positive. Sequencing data of the hMPV M gene revealed that two genogroups of the virus, each of which can be divided into two subgroups, cocirculated during this time period. A case-controlled study was conducted to compare the symptoms associated with hMPV infection with those involving other etiologic agents causing ARTI. Symptoms most frequently observed in hMPV-positive patients were cough, wheezing, and dyspnea, although the symptomatology could differ substantially from patient to patient. No distinct symptom profile could be associated with hMPV. Three nosocomial cases of hMPV infection were identified. Together, our data suggest that hMPV is a significant cause of symptomatic respiratory tract infections in infants and children. The incidence of the disease and the morbidity associated with the infection justify adding hMPV to the list of common respiratory viruses routinely screened for by clinical laboratories.

To study the relationship between length of pneumococcal polysaccharide and immunologic performance in rabbits we took well defined fragments of the capsular polysaccharides of S. pneumoniae types 3, 6A, 18C, 19F and 23F and pneumococcal C-polysaccharide and linked them terminally by reductive amination to tetanus toxoid. Contrary to other reports we found little variation in antibody titers with increasing length. In general the opsonophagocytic titers determined using activated HL60 cells and rabbit peritoneal cells correlated well with the antibody titers except for that of type 3, which despite the presence of high polysaccharide antibody titers gave unexpectedly low opsonophagocytic titers. The C-polysaccharide-conjugate was also immunogenic when injected in both rabbits and mice but gave low opsonophagocytic titers. It was demonstrated that opsonophagocytosis was solely dependent on the presence of phosphoryl choline-specific antibody and that the induction of these antibodies was species dependent.

Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia. The major adhesin of A. pleuropneumoniae has previously been identified as a lipopolysaccharide (LPS), and more recently, we demonstrated that high molecular mass LPS were involved in A. pleuropneumoniae adherence to porcine respiratory tract cells. We postulated that immunization with a LPS-based vaccine may confer a protective immunity. The high molecular mass O-polysaccharides obtained after acid hydrolysis and chromatographic separation were conjugated to bovine serum albumin (BSA) as a protein carrier. Groups of mice were injected twice with the following antigen preparations: whole-cell preparation, outer membrane preparation, O-polysaccharide-BSA conjugate, hydrolyzed LPS and phenol/water extracted LPS. A combination of different adjuvants was also used during these immunization procedures to induce a stronger immunological response to the polysaccharide antigen. Two weeks after the second injection, the mice were challenged intranasally with either homologous A. pleuropneumoniae serotype 1 strain or a serotype 5 strain. The highest survival rate, up to 80%, compared to the control groups (P < 0.05), was recorded when the mice were injected twice with 15 micrograms of carbohydrates of O-polysaccharide-BSA conjugate mixed with the saponin-derived adjuvant Quil A. Survival rates of between 60 and 70%, twice those observed in the control groups immunized with PBS, were recorded in mice injected with the O-polysaccharide-BSA conjugate mixed with other adjuvant preparations such as alhydrogel, peanut oil and Freund's incomplete adjuvant. However, the protection induced by the conjugate antigen preparation was serotype specific, because mice challenged with a serotype 5 strain were killed. Taken together, these results confirm the important role of A. pleuropneumoniae LPS in pathogenesis.

To determine the prevalence of antibody to Chlamydia heat-shock protein 60 (C-hsp60) in women with tubal infertility, an ELISA using purified recombinant C-hsp60 was developed. Antibody to C. trachomatis was present in 32 (72.7%) of 44 women with tubal infertility compared with 9 (32.1%) of 28 with other causes of infertility and 55 (28.9%) of 190 pregnant women (P < .001). Among the seropositive women, antibody to C-hsp60 was present in 26 (81.3%) of 32 women with tubal infertility compared with 0 of 9 with other causes of infertility and 9 (16.4%) of 55 pregnant women (P < .001). The C-hsp60 ELISA detected Chlamydia-associated tubal infertility in infertile women with a sensitivity of 81.3% and a specificity of 97.5%. There is a strong association between antibody response to the C-hsp60 and the development of Chlamydia-associated tubal infertility. Thus, a C-hsp60 ELISA may be useful as a predictor for poor fertility outcome.

We have developed a novel enzyme immunoassay (EIA) for the specific detection of Chlamydia trachomatis utilizing a monoclonal anti-idiotypic antibody to an antibody directed against a chlamydia specific epitope on 60 kDa heat-shock protein (HSP60). The basis of the assay is the inhibition of the binding of idiotype to anti-idiotype by antigen present in test samples. Two configurations of the assay were developed: a blocking EIA and a competition EIA. Greater sensitivity was observed using the competition EIA, with the assay detecting purified recombinant HSP60 and purified chlamydia in a concentration-dependent manner from 0.01 to 10 micrograms protein and from 0.5 to 12 micrograms total protein, respectively. The assay is highly specific and offers several potential advantages over currently available EIAs for the detection of this pathogen.

Multivalent forms of neoglycoproteins and polyacrylamides containing sialic acid were prepared and shown to be potent inhibitors of influenza A virus (H3N2) hemagglutinin with chick red blood cells. The synthetic sialylated glycoconjugates, although they were neuraminidase substrates, did not suppress viral neuraminidase and did not reduce infectivities in chick embryos. The copolyacrylamide conjugate containing a spacer group of approximately 11 A (1 A = 0.1 nm) between the polymer backbone and the sialic acid residues was the best hemagglutinin inhibitor. Moreover, it exhibited promising interferon-inducing properties.