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Point-of-care tests (POCTs) for syphilis have the potential to improve screening uptake and reduce barriers to care. Traditional screening methods for syphilis involve serologic laboratory testing, which can lead to delays in treatment due to lengthy test turnaround times. POCTs, on the other hand, provide results in minutes and can be performed in various settings, including clinical laboratories and outreach programs. Trained individuals, including lay testers, can administer these tests following standard infection control measures. The first POCT licensed in Canada detects treponemal antibodies, similar to traditional laboratory testing algorithms. However, it is important to note that POCTs cannot distinguish between active and prior syphilis infections, and clinical assessment is required to interpret results and determine appropriate treatment regimens. While POCTs cannot replace standard laboratory tests, they can be optimized by linking testing with clinical and laboratory services. Overall, POCTs have the potential to improve screening rates and access to care for syphilis.

Invasive meningococcal disease, caused by Neisseria meningitidis, remains a significant health threat. This study examined the genetic diversity of serogroup B (NmB) organisms and assessed the potential coverage offered by the MenB-FHbp vaccine, licensed for individuals aged 10–25 years. NmB vaccines have not yet been incorporated into most routine immunization programs in Canada, with the exception of campaigns to deal with specific outbreaks and targeted vaccination efforts for at-risk groups. From 2013 to 2020, NmB strains causing invasive meningococcal disease were collected through the Canadian Immunization Monitoring Program ACTive surveillance network. Each isolate underwent analysis to determine clonal complex (CC) and factor-H binding protein peptide (fHbp), and fHbp surface expression using the Meningococcal Antigen Surface Expression (MEASURE) assay. Of 119 isolates analyzed, 118 coded for full-length fHbp. CC-269 (48 isolates) and CC-41/44 (42 isolates) represented 75.6 % of all isolates. fHbp peptide 15 was the most prevalent peptide up until 2015 (47.4–53.9 %) but declined to 0–22.1 % afterwards. Median fHbp surface expression overall was 4270 MFI (IQR 2132–14,462). Peptides 15 and 210 (both CC-269) had the highest fHbp surface expression: peptide 15 (median: 18,446, IQR: 14,462–22,170) and peptide 210 (median: 28,306, IQR 24,935–31,678). Notably, 90.8 % of isolates had fHbp surface expression at a level associated with MenB-FHbp protection. CC-269 and CC-41/44 predominated in 2013–2020. Notably, peptide 15, the most prevalent until 2015, declined significantly thereafter. The majority of isolates expressed fHbp at a level associated with vaccine-induced protection. A wider age authorization for the vaccine may result in increased prevention of NmB disease. •The proportion of fHbp peptides 15 and 210 declined significantly after 2015.•90.8 % of NmB isolates had fHbp levels potentially covered by the MenB-FHbp vaccine.•Authorizing MenB-FHbp vaccine for more ages could enhance NmB disease protection.

BACKGROUNDThe province of Manitoba, Canada, with a population of approximately 1.3 million, has been experiencing increased incidence of syphilis cases since 2015. In this study, we examined the detection of Treponema pallidum DNA in 354 clinical samples from 2012 to 2016, and determined molecular types and mutations conferring resistance to azithromycin in the polymerase chain reaction (PCR)–positive samples. METHODST. pallidum DNA detection was done by PCR amplification of tpp47, bmp, and polA genes. Syphilis serology results were reviewed for the PCR-positive cases. Molecular typing of syphilis strains was done by analysis of the T, pallidum arp, tpr, and tp0548 gene targets as well as partial sequencing of the 23S rRNA gene for azithromycin resistance. RESULTSOf the 354 samples tested, 74 individual cases were PCR positive. A result from the treponemal antibody chemiluminescent microparticle immunoassay test was positive in 72 of these cases and that from the Venereal Disease Research Laboratory testing was positive in 66. Mutations conferring resistance to azithromycin were found in all 74 PCR-positive samples. Molecular typing was completed on 57 PCR-positive samples, and 12 molecular types were identified with 14d/g found in 63.2%. Increased strain diversity was observed with 8 molecular types detected in 2016, whereas only 2 to 3 types were found in 2012 to 2014. A patient with 2 episodes of infection 9 months apart caused by different molecular strain types was also identified. CONCLUSIONSThe finding of an increase in genetic diversity in the strains in this study and an increase in macrolide resistance compared with previous Canadian reports highlighted the need for continued surveillance including strain characterization.

•Global presence of Haemophilus influenzae serotype a (Hia).•Causes meningitis, bacteremic pneumonia, septic arthritis, epiglottitis.•High prevalence of invasive disease in indigenous children under five years old.•Genetics of Hia and clinical Hia diseases are very similar to Hib and Hib diseases.•Development of a Hia conjugate vaccine is a desirable public health investment. More than two decades after the implementation of the Hib conjugate vaccine in North America, Haemophilus influenzae serotype a (Hia) has emerged as a significant cause of invasive disease in Indigenous communities. However, little is known about the global presence of this pathogen. We interrogated the H. influenzae Multi-Locus Sequence Typing (MLST) website (https://pubmlst.org/hinfluenzae/) by selecting for serotype a records. We also updated our previous literature review on this subject matter. Hia has been reported from at least 35 countries on six major continents. However, most Hia diseases were associated with Indigenous communities. Clonal analysis identified two clonal populations with one typified as ST-23 responsible for most invasive disease in North America and being the predominant clone described on the H. influenzae MLST website. Incidence of invasive Hia disease in Indigenous communities in North America are similar to the rates of Hib disease reported prior to the Hib conjugate vaccine era. Hia causes severe clinical diseases, such as meningitis, septicaemia, pneumonia, and septic arthritis with case-fatality rates between 5.6% and 33% depending on the age of the patient and the genetic makeup of the Hia strain. Although invasive Hia disease can be found globally, the current epidemiological data suggest that this infection predominantly affects Indigenous communities in North America. The clinical disease of Hia and the clonal nature of the bacteria resemble that of Hib. The high incidence of invasive Hia disease in Indigenous communities, along with potential fatality and severe sequelae causing long-term disability in survivors, may support the development of a new Hia conjugate vaccine for protection against this infection similar in design to the one introduced in the 1990s to control invasive Hib disease.

Haemophilus influenzae, particularly H influenzae serotype b (Hib), is an important pathogen that causes serious diseases like meningitis and septicaemia. Since the introduction of Hib conjugate vaccines in the 1990s, the epidemiology of invasive H influenzae disease has changed substantially, with most infections now caused by non-Hib strains. We discuss the importance of H influenzae serotype a (Hia) as a cause of serious morbidity and mortality and its global epidemiology, clinical presentation, microbiology, immunology, prevention, and control. Much like Hib, the capsule of Hia is an important virulence factor contributing to the development of invasive disease. Molecular typing of Hia has identified distinct clonal groups, with some linked to severe disease and high case-fatality rates. Similarities between Hia and Hib capsules, their clinical presentation, and immunology of infection suggest that a bivalent Hia–Hib capsular polysaccharide-protein conjugate vaccine could offer protection against these two important serotypes of H influenzae.

This narrative review describes the public health importance of four most common bacterial meningitis agents, Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, and S. agalactiae (group B Streptococcus). Three of them are strict human pathogens that normally colonize the nasopharynx and may invade the blood stream to cause systemic infections and meningitis. S. agalactiae colonizes the genito-gastrointestinal tract and is an important meningitis agent in newborns, but also causes invasive infections in infants or adults. These four bacteria have polysaccharide capsules that protect them against the host complement defense. Currently licensed conjugate vaccines (against S. pneumoniae, H. influenza, and N. meningitidis only but not S. agalactiae) can induce protective serum antibodies in infants as young as two months old offering protection to the most vulnerable groups, and the ability to eliminate carriage of homologous serotype strains in vaccinated subjects lending further protection to those not vaccinated through herd immunity. However, the serotype-specific nature of these vaccines have driven the bacteria to adapt by mechanisms that affect the capsule antigens through either capsule switching or capsule replacement in addition to the possibility of unmasking of strains or serotypes not covered by the vaccines. The post-vaccine molecular epidemiology of vaccine-preventable bacterial meningitis is discussed based on findings obtained with newer genomic laboratory surveillance methods.

Bordetella pertussis causes pertussis, a respiratory disease that is most severe for infants. Vaccination was introduced in the 1950s, and in recent years, a resurgence of disease was observed worldwide, with significant mortality in infants. Possible causes for this include the switch from whole-cell vaccines (WCVs) to less effective acellular vaccines (ACVs), waning immunity, and pathogen adaptation. Pathogen adaptation is suggested by antigenic divergence between vaccine strains and circulating strains and by the emergence of strains with increased pertussis toxin production. We applied comparative genomics to a worldwide collection of 343 B. pertussis strains isolated between 1920 and 2010. The global phylogeny showed two deep branches; the largest of these contained 98% of all strains, and its expansion correlated temporally with the first descriptions of pertussis outbreaks in Europe in the 16th century. We found little evidence of recent geographical clustering of the strains within this lineage, suggesting rapid strain flow between countries. We observed that changes in genes encoding proteins implicated in protective immunity that are included in ACVs occurred after the introduction of WCVs but before the switch to ACVs. Furthermore, our analyses consistently suggested that virulence-associated genes and genes coding for surface-exposed proteins were involved in adaptation. However, many of the putative adaptive loci identified have a physiological role, and further studies of these loci may reveal less obvious ways in which B. pertussis and the host interact. This work provides insight into ways in which pathogens may adapt to vaccination and suggests ways to improve pertussis vaccines. IMPORTANCE Whooping cough is mainly caused by Bordetella pertussis , and current vaccines are targeted against this organism. Recently, there have been increasing outbreaks of whooping cough, even where vaccine coverage is high. Analysis of the genomes of 343 B. pertussis isolates from around the world over the last 100 years suggests that the organism has emerged within the last 500 years, consistent with historical records. We show that global transmission of new strains is very rapid and that the worldwide population of B. pertussis is evolving in response to vaccine introduction, potentially enabling vaccine escape. Whooping cough is mainly caused by Bordetella pertussis , and current vaccines are targeted against this organism. Recently, there have been increasing outbreaks of whooping cough, even where vaccine coverage is high. Analysis of the genomes of 343 B. pertussis isolates from around the world over the last 100 years suggests that the organism has emerged within the last 500 years, consistent with historical records. We show that global transmission of new strains is very rapid and that the worldwide population of B. pertussis is evolving in response to vaccine introduction, potentially enabling vaccine escape.

serotype a (Hia) has recently emerged as an important cause of invasive disease in the North American Arctic and Sub-Arctic regions, mainly affecting young Indigenous children. In this study, we addressed the question of whether the prevalence of Hia and all in the nasopharynx differed between paediatric populations from regions with high low incidence of invasive Hia disease. Nasopharyngeal specimens from children with acute respiratory tract infections (ARTI) collected for routine diagnostic detection of respiratory viruses were analysed with molecular-genetic methods to identify and serotype . In Nunavut, a region with a high incidence of invasive Hia disease, all and particularly Hia were found in the nasopharynx of 60.6% and 3.0% children. In Southern Ontario (Hamilton region), where Hia invasive disease is rare, the frequencies of all and Hia detection were 38.5% and 0.6%, respectively. In both cohorts, non-typeable was prevalent (57.0% and 37.9%, respectively). Considering that Hia is an important cause of severe invasive disease in Nunavut children, 3% prevalence of Hia among children with ARTI can reflect continuing circulation of the pathogen in the Northern communities that may result in invasive disease outbreaks.