Does the ultrasensitive HBsAg Next assay enhance Hepatitis B diagnosis? An evaluation of analytical performances.

BACKGROUND: Accurate laboratory confirmation for Hepatitis B diagnosis and monitoring are crucial. Recently an ultrasensitive immunoassay test, the HBsAg Next (HBsAgNx), has been reported approximately eight times more sensitive than current HBsAg assays. The aim of our study was to assess the analytical performances of this new test. METHODOLOGY: 253 clinical samples from Saint Louis University Hospital were analyzed, splitted into four panels: (1) routine prospectively screening serums (n = 196), (2) retrospective serum samples before HBV reactivation (HBV-R) (n = 18), (3) occult HBV infection (OBI) (n = 10) and (4) a selection of wild type HBV genotypes (n = 29) RESULTS: Panel 1, showed robust agreement with the HBsAg Qualitative II (HBsAgQII) assay (Cohen's kappa = 0.83). Despite this agreement, 7 false positive with the HBsAgQII assay were found negative with HBsAgNx. One OBI was detected only with HBsAgNx. Panel 2 showed potential time savings in diagnosing HBV-R using HBsAgNx among 4/18 HBsAg positives samples. Panel 3 highlighted the ability of HBsAgNx to detect HBsAg in OBI patients defined by negative for HBsAg with HBsAgQII assay and positive for HBV DNA. Furthermore, the HBsAgNx assay detected all different genotypes. CONCLUSION: The study highlights the effectiveness of the HBsAgNx assay, showing its performance. It excels in detecting weakly positive samples and addressing challenging cases. HBsAgNx assay demonstrates promising analytical performances, with improved sensitivity and specificity compared to standard HBsAgQII assay, able to detect all genotypes. Its potential impact on early detecting and monitoring reactivations, and occult infections could be very useful in clinical practice.

Long-term storage stability of PGL-I coated ELISA plates for anti-Mycobacterium leprae IgM detection.

The assessment of ELISA plates coated with phenolic glycolipid-I/PGL-I revealed excellent stability during eight years of storage at room temperature, promoting consistent IgM antibody detection in multibacillary leprosy patients. These stable, standardized plates can significantly contribute to efficient leprosy serology research and support its widespread distribution and use in endemic countries.

Models for predicting the risk of illness in leprosy contacts in Brazil: Leprosy prediction models in Brazilian contacts.

OBJECTIVE: This study aims to develop and validate predictive models that assess the risk of leprosy development among contacts, contributing to an enhanced understanding of disease occurrence in this population. METHODS: A cohort of 600 contacts of people with leprosy treated at the National Reference Center for Leprosy and Health Dermatology at the Federal University of Uberlândia (CREDESH/HC-UFU) was followed up between 2002 and 2022. The database was divided into two parts: two-third to construct the disease risk score and one-third to validate this score. Multivariate logistic regression models were used to construct the disease score. RESULTS: Of the four models constructed, model 3, which included the variables anti-phenolic glycolipid I immunoglobulin M positive, absence of Bacillus Calmette-Guérin vaccine scar and age ≥60 years, was considered the best for identifying a higher risk of illness, with a specificity of 89.2%, a positive predictive value of 60% and an accuracy of 78%. CONCLUSIONS: Risk prediction models can contribute to the management of leprosy contacts and the systematisation of contact surveillance protocols.

Molecular and serological prevalence of Leptospira spp. among slaughtered cattle and associated risk factors in the Bahr El Ghazal region of South Sudan.

INTRODUCTION: Leptospirosis is a neglected emerging and zoonotic disease reported worldwide. This study sought to determine the molecular and serological prevalence of Leptospira spp. and the associated risk factors in slaughtered cattle from the Bahr El Ghazal region of South Sudan. MATERIALS AND METHODS: Between January 16th and February 25th, 2023, blood and urine samples were collected from 402 cattle at the Lokoloko Municipal Slaughterhouse in Western Bahr El-Ghazal State. Serum samples were tested using the microscopic agglutination test (MAT), with a panel of 12 serovars (sv) from 12 serogroups (sg) and 4 species (spp) of Leptospira spp. These serovars had been previously identified in Sudan and the East African region. Simultaneously, 400 corresponding urine samples were screened using qualitative real-time polymerase chain reaction (PCR) to detect the shedding of Leptospira spp. in urine. To identify the associated risk factors, the age, sex, breed and body condition score of each sampled cattle was noted at the time of sampling and subsequently analysed using logistic regression models. RESULTS: Among the 402 serum samples screened, a substantial 81.8% (329/402, 95% CI 77.9-85.3) displayed seropositivity for Leptospira spp. with a MAT titre ≥ 100. The prevalence of urine shedding determined by PCR was 6% (23/400, 95% CI 3.8-8.4), while probable recent leptospirosis with a MAT ≥ 1:800 was observed in 33.1% (133/402, 95% CI 28.6-37.8) of the cattle. Multiple reactions were detected in 34.8% (140/402, 95% CI 30.6-39.5) serum samples. The seropositivity was against L. borgpetersenii sg. Tarassovi (78.6%; 316/402, 95% CI 74.4-82.3), followed by L. borgpetersenii sg. Ballum at 20.4% (82/402, 95% CI, 16.7-24.4%), L. kirschneri sg. Autumnalis At 8.7% (35/402, 95% CI 5.7-11.7), L. interrogans sg. of Pomona at 7.0% (28/402, 95% CI 4.5-9.5), and L. interrogans sg. Hebdomadis was 5.0% (20/402, 95% CI 2.8-7.2). Several risk factors are associated with seropositivity. Older animals (≥ 2 years) had 2.0 times greater odds (95% CI 1.14-3.5) of being seropositive than younger animals (< 2 years), P-value = 0.016. Female animals demonstrated 2.1 times greater odds (95% CI 1.2-3.6) of seropositivity than males did (P-value = 0.008). Additionally, Felata/Mbororo cattle exhibited 2.4 times greater odds (95% CI 1.3-4.5) of being seropositive than did local Nilotic cattle (P-value = 0.005). The agreement between the MAT and PCR results was poor, as indicated by a kappa statistic value of 0.001 and a P-value of 0.913. But there was a moderate agreement between MAT high titres ≥ 800 and PCR positivity with a kappa statistic value = 0.501 and a P-value < 0.001. CONCLUSION: In addition to the high seroprevalence, Leptospira spp. were found in the urine of slaughtered cattle, suggesting that leptospirosis is endemic to the study area. This finding underscores the significance of cattle as potential sources of infection for slaughterhouse workers, the general public, and other animal species. To address this issue effectively in the Bahr El Ghazal Region and South Sudan, a comprehensive strategy involving a multidisciplinary approach is essential to minimize disease among animals, hence reducing potential zoonotic risks to humans.

The prevalence and rate of undiagnosed celiac disease in an adult general population, the Trøndelag Health Study, Norway.

BACKGROUND & AIMS: This study aimed to determine the total prevalence of celiac disease (CeD), including undiagnosed cases, in a population-based study of adults screened for CeD. METHODS: The study utilized the fourth Trøndelag Health Study (HUNT4), conducted in 2017-2019, where 56,042 adult (aged >20 years) residents of Nord-Trøndelag County, Norway, participated. Serum samples from 54,505 participants were analysed for anti-transglutaminase 2 immunoglobulin A and G. Seropositive individuals were invited for a clinical assessment, including upper endoscopy with duodenal biopsies. Previously diagnosed and seronegative CeD cases were identified through linkage to hospital records and the Norwegian Patient Registry. RESULTS: The rate of CeD seropositivity was 2.0% (1107/54,505). Out of these, 724 individuals attended the clinical assessment. Additionally, the hospital records and registry identified individuals with a known CeD diagnosis, that were seronegative or without serology in HUNT4 or seropositive in HUNT4 but did not participate in the clinical assessment. In total, the study confirmed a new CeD diagnosis after participation in HUNT4 in 470 individuals and a known CeD diagnosis before participation in HUNT4 in 383 individuals. The total biopsy-confirmed prevalence of CeD was 1.5% (853/56,042), and the ratio of new, previously undiagnosed CeD cases (after HUNT4) to known, previously diagnosed CeD cases (before HUNT4) was 1.2:1 (470/383). CONCLUSION: The total prevalence of CeD in this population-based study of adults in Norway was high and many individuals were previously undiagnosed. Detection of CeD should be improved, as early diagnosis is crucial for effective management and prevention of complications.

Discovery of new antigens for serodiagnosis of visceral leishmaniasis in humans and dogs adds valuable tools to our arsenal.

Surveillance and sustained control of visceral leishmaniasis (VL) require reliable serodiagnostic tools. rK39, the gold standard antigen for VL diagnosis, is limited by its documented poor sensitivity in certain endemic regions, such as East Africa, and by the longevity of its antibodies, making it difficult to distinguish active from cured infections. In a recent publication in mBio, Roberts et al. (A. J. Roberts, H.B. Ong, S. Clare, C. Brandt, et al., mBio 15:e00859-24, 2024, https://doi.org/10.1128/mbio.00859-24) identified new immunogenic Leishmania candidates in dogs and humans. In dogs, combined antigens LdBPK_290790.1 + LdBPK_362700.1 (D4 +D46) distinguished symptomatic from asymptomatic infections. For humans, LdBPK_323600.1 (D36) antigen produced short-lived antibodies and performed well in patient cohorts from Bangladesh and Ethiopia, but not Kenya. This study adds promising new candidates to our serodiagnostic toolbox but highlights the need for more antigen discovery studies that may have to be focused on regional performance.

Relative Contribution of Diagnostic Testing to the Diagnosis of Respiratory Syncytial Virus in Hospitalized Adults in the United States.

BACKGROUND: Respiratory syncytial virus (RSV) is a leading cause of acute respiratory illness (ARI) in older adults. Optimizing diagnosis could improve understanding of RSV burden. METHODS: We enrolled adults ≥50 years of age hospitalized with ARI and adults of any age hospitalized with congestive heart failure or chronic obstructive pulmonary disease exacerbations at two hospitals during two respiratory seasons (2018-2020). We collected nasopharyngeal (NP) and oropharyngeal (OP) swabs (n=1558), acute and convalescent sera (n=568), and expectorated sputum (n=153) from participants, and recorded standard-of-care (SOC) NP results (n=805). We measured RSV antibodies by two immunoassays and performed BioFire testing on respiratory specimens. RESULTS: Of 1,558 eligible participants, 92 (5.9%) tested positive for RSV by any diagnostic method. Combined NP/OP PCR yielded 58 positives, while separate NP and OP testing identified 11 additional positives (18.9% increase). Compared to Study NP/OP PCR alone, the addition of paired serology increased RSV detection by 42.9% (28 vs 40) among those with both specimen types, while the addition of SOC swab RT-PCR results increased RSV detection by 25.9% (47 vs 59). CONCLUSIONS: The addition of paired serology testing, SOC swab results, and separate testing of NP and OP swabs improved RSV diagnostic yield in hospitalized adults.

Prevalence and risk factors of Toxoplasma gondii infection in dairy cattle from the Western Region of Thailand.

In total, 901 dairy cow sera and data were collected from 51 farms in Nakhon Pathom, Ratchaburi and Kanchanaburi provinces (Western Region of Thailand). Serum samples were processed via the multispecies ELISA method to detect IgG antibodies against Toxoplasma gondii infection. The results demonstrated that the calculated true prevalence was 1.48% (95% CI, 0.64-2.75%) for the individual-level and 29.41% (95% CI, 18.71-43%) for the farm-level. The univariate risk factor analysis showed that the number of total owned cats, the presence of stray cats, and the frequency of cleaning per day were significant factors (p < 0.2). These three factors were subjected to logistic regression analysis, and the results revealed that the frequency of cleaning farms per day was a potential risk factor for T. gondii-seropositive farms (OR = 2.745, 95% CI, 1.15-8.69, p = 0.02). The frequency of cleaning might increase the T. gondii oocyst distribution within the barn area, thus increasing the possibility of infection. Our findings show that T. gondii continues to circulate in the dairy cow population in the western part of Thailand. The presence of cats on farms was not found to be associated with T. gondii infection, but the high frequency of cleaning the floor was, and contributed to the potential risk of infection.

Title: Prévalence et facteurs de risque de l'infection à Toxoplasma gondii chez les bovins laitiers de la région occidentale de la Thaïlande. Abstract: Au total, 901 sérums de vaches laitières et des données ont été collectés dans 51 fermes des provinces de Nakhon Pathom, Ratchaburi et Kanchanaburi (région occidentale de la Thaïlande). Les échantillons de sérum ont été traités via la méthode ELISA multi-espèces pour détecter les anticorps IgG contre l'infection à Toxoplasma gondii. Les résultats ont démontré que la prévalence réelle calculée était de 1,48 % (IC à 95 %, 0,64­2,75 %) au niveau individuel et de 29,41 % (IC à 95 %, 18,71­43 %) au niveau des exploitations. L'analyse factorielle a montré que le nombre total de chats possédés, la présence de chats errants et la fréquence quotidienne de nettoyage étaient des facteurs significatifs (p < 0,2). Ces trois facteurs ont été soumis à une analyse de régression logistique et les résultats ont révélé que la fréquence quotidienne de nettoyage des exploitations était un facteur de risque potentiel pour les exploitations séropositives à T. gondii (OR = 2,745, IC à 95 % = 1,15­8,69, p = 0,02). La fréquence du nettoyage pourrait favoriser la répartition des oocystes de T. gondii dans les étables, augmentant ainsi le risque d'infection. Nos résultats indiquent que T. gondii continue de circuler dans la population de vaches laitières de l'ouest de la Thaïlande. La présence de chats dans les fermes n'a pas été associée à l'infection à T. gondii, mais la fréquence élevée du nettoyage du sol l'était et contribuait au risque potentiel d'infection.

Use of a diagnostic Puumala virus real-time RT-PCR in an orthohantavirus endemic region in the Netherlands.

Laboratory diagnosis of orthohantavirus infection is primarily based on serology. However, for a confirmed serological diagnosis, evaluation of a follow-up serum sample is essential, which is time consuming and causes delay. Real-time reverse transcription polymerase chain reaction (RT-PCR) tests, if positive, provide an immediate and definitive diagnosis, and accurately identify the causative agent, where the discriminative nature of serology is suboptimal. We re-evaluated sera from orthohantavirus-suspected clinical cases in the Dutch regions of Twente and Achterhoek from July 2014 to April 2016 for the presence of Puumala orthohantavirus (PUUV), Tula orthohantavirus (TULV), and Seoul orthohantavirus (SEOV) RNA. PUUV RNA was detected in 11% of the total number (n = 85) of sera tested, in 50% of sera positive for anti-PUUV/TULV IgM (n = 16), and in 1.4% of sera negative or indeterminate for anti-PUUV/TULV IgM (n = 69). No evidence was found for the presence of TULV or SEOV viral RNA. Based on these findings, we propose two algorithms to implement real-time RT-PCR testing in routine orthohantavirus diagnostics, which optimally provide clinicians with early confirmed diagnoses and could prevent possible further invasive testing and treatment. IMPORTANCE: The addition of a real-time reverse transcription polymerase chain reaction test to routine orthohantavirus diagnostics may better aid clinical decision making than the use of standard serology tests alone. Awareness by clinicians and clinical microbiologists of this advantage may ultimately lead to a reduction in over-hospitalization and unnecessary invasive diagnostic procedures.

Medium-term storage of frozen residual antenatal sera in gel separator tube is suitable for subsequent serological investigation of intrauterine infection.

AIM: We assessed the feasibility of storing sera in primary gel separator tube over medium-term for retrospective serological tests to facilitate investigation of intra-uterine infection. METHOD: 120 residual serum samples, consisting of 30 positive samples each for rubella, cytomegalovirus, parvovirus B19 and varicella zoster IgG were aliquoted into secondary propylene tubes and stored together with the original primary tubes at -20°C for 1 year. The serum was subsequently retested to compare results from both storage methods. RESULTS: Haemolysis was observed in 49.2% of serum stored in the primary tubes. However, there was no difference in both the qualitative and quantitative results after storage of serum samples in either receptacle. CONCLUSION: Sera can be stored in primary blood tube for up to 1 year without affecting serological results. For laboratories with adequate freezer space to store samples in primary blood tubes, this would streamline workflow saving manpower and time, avoid mislabelling of aliquots, reduce consumable costs and prevent unnecessary biohazard exposures.

An IgG1 single-dilution avidity ELISA predicts cross-protection against heterologous foot-and-mouth disease virus challenge after vaccination.

This study aims to analyze if the results from different serological assays, used alone or combined, could match the outcome of challenge infection with foot-and-mouth disease virus (FMDV) after vaccination in cattle. Day-of-challenge sera from animals that had been vaccinated 21 days before with monovalent formulations containing inactivated A Iran 96 or A Iran 99 virus strains were used. Challenge and serology were performed with A22 Iraq strain. IgG1 titers and total-IgG avidity indexes were significantly higher in protected animals (p < 0.01) while IgG2-titers were not related to protection (p > 0.05). An IgG1 avidity ELISA was developed to analyze in one step, IgG1 levels and avidity. This assay estimated protection with 96 % accuracy. A strong agreement with challenge results was achieved (K = 0.85), suggesting a role of high-affinity IgG1 in protection against FMDV. These results support the assessment of the single dilution IgG1-Avidity ELISA to predict cross-protection in FMDV-vaccinated cattle.

Reference Material Production and Milk Protein Concentration as Elements to Improve Bluetongue Serological Diagnosis in Bulk Tank Milk.

The serological surveillance of bluetongue in bulk tank milk is an efficient and cost-effective method for the early detection of bluetongue virus incursions in unvaccinated free areas of the disease. In addition, the availability of standardized and reliable reagents and refined diagnostic procedures with high sensitivity and specificity are essential for surveillance purposes. However, no available reference materials for bluetongue virus serological surveillance in bulk tank milk exist. This study shows the production and characterization of reference material for the implementation of a commercially available bluetongue milk ELISA test in official laboratories, as well as the evaluation of a procedure to increase the sensitivity in samples with low levels of antibodies. This procedure, based on milk protein concentration, allowed us to notably increase the ELISA test's analytical sensitivity, which is useful for milk samples from farms with low within-herd prevalence or pools of bulk tank milk samples. The standardized milk reference material produced here, together with the evaluated procedure to improve analytical sensitivity, could be applied as tools to ensure an accurate diagnosis by official laboratories in bluetongue unvaccinated free areas.

Evaluating Scope and Bias of Population-Level Measles Serosurveys: A Systematized Review and Bias Assessment.

BACKGROUND: Measles seroprevalence data have potential to be a useful tool for understanding transmission dynamics and for decision making efforts to strengthen immunization programs. In this study, we conducted a systematized review and bias assessment of all primary data on measles seroprevalence in low- and middle-income countries (as defined by World Bank 2021 income classifications) published from 1962 to 2021. METHODS: On 9 March 2022, we searched PubMed for all available data. We included studies containing primary data on measles seroprevalence and excluded studies if they were clinical trials or brief reports, from only health-care workers, suspected measles cases, or only vaccinated persons. We extracted all available information on measles seroprevalence, study design, and seroassay protocol. We conducted a bias assessment based on multiple categories and classified each study as having low, moderate, severe, or critical bias. This review was registered with PROSPERO (CRD42022326075). RESULTS: We identified 221 relevant studies across all World Health Organization regions, decades, and unique age ranges. The overall crude mean seroprevalence across all studies was 78.0% (SD: 19.3%), and the median seroprevalence was 84.0% (IQR: 72.8-91.7%). We classified 80 (36.2%) studies as having severe or critical overall bias. Studies from country-years with lower measles vaccine coverage or higher measles incidence had higher overall bias. CONCLUSIONS: While many studies have substantial underlying bias, many studies still provide some insights or data that could be used to inform modelling efforts to examine measles dynamics and programmatic decisions to reduce measles susceptibility.

Determinants of Systemic SARS-CoV-2-Specific Antibody Responses to Infection and to Vaccination: A Secondary Analysis of Randomised Controlled Trial Data.

SARS-CoV-2 infections elicit antibodies against the viral spike (S) and nucleocapsid (N) proteins; COVID-19 vaccines against the S-protein only. The BCG-Corona trial, initiated in March 2020 in SARS-CoV-2-naïve Dutch healthcare workers, captured several epidemic peaks and the introduction of COVID-19 vaccines during the one-year follow-up. We assessed determinants of systemic anti-S1 and anti-N immunoglobulin type G (IgG) responses using trial data. Participants were randomised to BCG or placebo vaccination, reported daily symptoms, SARS-CoV-2 test results, and COVID-19 vaccinations, and donated blood for SARS-CoV-2 serology at two time points. In the 970 participants, anti-S1 geometric mean antibody concentrations (GMCs) were much higher than anti-N GMCs. Anti-S1 GMCs significantly increased with increasing number of immune events (SARS-CoV-2 infection or COVID-19 vaccination): 104.7 international units (IU)/mL, 955.0 IU/mL, and 2290.9 IU/mL for one, two, and three immune events, respectively (p < 0.001). In adjusted multivariable linear regression models, anti-S1 and anti-N log10 concentrations were significantly associated with infection severity, and anti-S1 log10 concentration with COVID-19 vaccine type/dose. In univariable models, anti-N log10 concentration was also significantly associated with acute infection duration, and severity and duration of individual symptoms. Antibody concentrations were not associated with long COVID or long-term loss of smell/taste.

Temporal trends in disparities in COVID-19 seropositivity among Canadian blood donors.

BACKGROUND: In Canada's largest COVID-19 serological study, SARS-CoV-2 antibodies in blood donors have been monitored since 2020. No study has analysed changes in the association between anti-N seropositivity (a marker of recent infection) and geographic and sociodemographic characteristics over the pandemic. METHODS: Using Bayesian multi-level models with spatial effects at the census division level, we analysed changes in correlates of SARS-CoV-2 anti-N seropositivity across three periods in which different variants predominated (pre-Delta, Delta and Omicron). We analysed disparities by geographic area, individual traits (age, sex, race) and neighbourhood factors (urbanicity, material deprivation and social deprivation). Data were from 420 319 blood donations across four regions (Ontario, British Columbia [BC], the Prairies and the Atlantic region) from December 2020 to November 2022. RESULTS: Seropositivity was higher for racialized minorities, males and individuals in more materially deprived neighbourhoods in the pre-Delta and Delta waves. These subgroup differences dissipated in the Omicron wave as large swaths of the population became infected. Across all waves, seropositivity was higher in younger individuals and those with lower neighbourhood social deprivation. Rural residents had high seropositivity in the Prairies, but not other regions. Compared to generalized linear models, multi-level models with spatial effects had better fit and lower error when predicting SARS-CoV-2 anti-N seropositivity by geographic region. CONCLUSIONS: Correlates of recent COVID-19 infection have evolved over the pandemic. Many disparities lessened during the Omicron wave, but public health intervention may be warranted to address persistently higher burden among young people and those with less social deprivation.

Association between adverse events after COVID-19 vaccination and anti-SARS-CoV-2 antibody concentrations, the Netherlands, May 2021 to November 2022: a population-based prospective cohort study.

BackgroundNon-severe adverse events (AE) including pain at injection site or fever are common after COVID-19 vaccination.AimTo describe determinants of AE after COVID-19 vaccination and investigate the association between AE and pre- and post-vaccination antibody concentrations.MethodsParticipants of an ongoing prospective cohort study (VASCO) completed a questionnaire on AE within 2 months after vaccination and provided 6 monthly serum samples during May 2021-November 2022. Logistic regression analyses were performed to investigate AE determinants after mRNA vaccination, including pre-vaccination Ig antibody concentrations against the SARS-CoV-2 spike protein receptor binding domain. Multivariable linear regression was performed in SARS-CoV-2-naive participants to assess the association between AE and log-transformed antibody concentrations 3-8 weeks after mRNA vaccination.ResultsWe received 47,947 completed AE questionnaires by 28,032 participants. In 42% and 34% of questionnaires, injection site and systemic AE were reported, respectively. In 2.2% of questionnaires, participants sought medical attention. AE were reported more frequently by women, younger participants (< 60 years), participants with medical risk conditions and Spikevax recipients (vs Comirnaty). Higher pre-vaccination antibody concentrations were associated with higher incidence of systemic AE after the second and third dose, but not with injection site AE or AE for which medical attention was sought. Any AE after the third dose was associated with higher post-vaccination antibody concentrations (geometric mean concentration ratio: 1.38; 95% CI: 1.23-1.54).ConclusionsOur study suggests that high pre-vaccination antibody levels are associated with AE, and experiencing AE may be a marker for higher antibody response to vaccination.

Bartonella species bacteremia in association with adult psychosis.

Introduction: The potential role of pathogens, particularly vector-transmitted infectious agents, as a cause of psychosis has not been intensively investigated. We have reported a potential link between Bartonella spp. bacteremia and neuropsychiatric symptoms, including pediatric acute onset neuropsychiatric syndrome and schizophrenia. The purpose of this study was to further assess whether Bartonella spp. exposure or infection are associated with psychosis. Methods: In a blinded manner, we assessed the presence of anti-Bartonella antibodies by indirect immunofluorescence assays (IFA), and infection by amplification of bacterial DNA from blood by quantitative polymerase chain reaction (qPCR), digital PCR (dPCR), and droplet digital PCR (ddPCR) in 116 participants. Participants were categorized into one of five groups: 1) controls unaffected by psychosis (n = 29); 2) prodromal participants (n = 16); 3) children or adolescents with psychosis (n = 7); 4) adults with psychosis (n = 44); and 5) relatives of a participant with psychosis (n = 20). Results: There was no significant difference in Bartonella spp. IFA seroreactivity between adults with psychosis and adult controls unaffected by psychosis. There was a higher proportion of adults with psychosis who had Bartonella spp. DNA in the bloodstream (43.2%) compared to adult controls unaffected by psychosis (14.3%, p = 0.021). The Bartonella species was determined for 18 of the 31 bacteremic participants, including infection or co-infection with Bartonella henselae (11/18), Bartonella vinsonii subsp. berkhoffii (6/18), Bartonella quintana (2/18), Bartonella alsatica (1/18), and Bartonella rochalimae (1/18). Discussion: In conjunction with other recent research, the results of this study provide justification for a large national or international multi-center study to determine if Bartonella spp. bacteremia is more prevalent in adults with psychosis compared to adults unaffected by psychosis. Expanding the investigation to include a range of vector-borne and other microbial infections with potential CNS effects would enhance knowledge on the relationship between psychosis and infection.

A case for implementing an HSV1/2, VZV, and syphilis lesion panel in Manitoba, Canada.

Syphilis, caused by Treponema pallidum subsp. pallidum (TPA), is becoming a significant public health concern, with rising incidence in Manitoba exceeding the national average. The province has also seen a demographic shift leading to women representing 51.9% of cases in 2021, leading to the re-emergence of congenital syphilis. Given the similarities in lesion appearance between TPA and other pathogens such as herpesviruses, accurate diagnosis is crucial for effective management and prevention. In order to address the potential for missed TPA cases, we conducted a quality assurance study from June 2021 to March 2023, screening over 5,000 mucocutaneous lesion swabs for TPA, initially submitted for herpes simplex virus (HSV) and varicella zoster virus (VZV) testing. Positivity rates were 13% for HSV1, 13% for HSV2, 6.7% for VZV, and 6.6% for TPA. Turnaround times (TAT) for TPA testing, as a send-out to the reference laboratory, averaged 17.8 days. Of the TPA-positive specimens, 36% did not have a corresponding TPA PCR test ordered, and 19% did not have accompanying syphilis serology within 30 days of collection. Creation of a multiplex lesion panel identified high sensitivity and specificity for HSV1, HSV2, VZV, and TPA, with robust reproducibility across multiple runs. Incorporation of TPA into a lesion panel improved the TAT to 4 days. Our findings emphasize the need for improved testing strategies to combat the syphilis epidemic and enhance public health outcomes.IMPORTANCESyphilis resurgence has become a significant global public health concern. In particular, the Canadian Prairies have been struggling with high incidence since 2016, exceeding the national Canadian average. We undertook a quality assurance study that highlighted significant gaps in diagnosis of acute syphilis, which led to the development of a highly sensitive and specific multiplex lesion assay for the dual detection of herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2), varicella zoster virus (VZV), and syphilis.

Development and Diagnostic Potential of a Novel Bartonella henselae-Specific Immunoglobulin.

Bartonella henselae is a gram-negative rod-shaped bacterium and is the primary causative agent of Cat Scratch Disease (CSD). Although the prevalence of CSD is low in the human population, the possibility of developing multi-organ complications, especially in vulnerable individuals, remains a serious cause for concern. The immunofluorescent assay (IFA) is currently one of the most common laboratory tests for the detection of antibodies to B. henselae in serum, however, it has several disadvantages. The enzyme-linked immunosorbent assay (ELISA) technique offers a more quantitative, sensitive, and cost-effective alternative to conventional IFAs. Here, we report the purification of a novel bioidentical polyclonal antibody from discarded human serum for use as a standard in ELISAs against B. henselae. This novel method of antibody production overcomes the many limitations of animal-derived antibodies while also offering a more robust, reproducible, and scalable antibody production alternative for the diagnosis of CSD.