Serological Evidence Research Articles

Erysipelothrix spp. and other Erysipelotrichales detected by 16S rRNA microbial community profiling in samples from healthy conventionally reared chickens and their environment.

Outbreaks of erysipelas, a disease caused by infection with Erysipelothrix rhusiopathiae (ER), is a re-emerging problem in cage-free laying hen flocks. The source of ER infection in hens is usually unknown and serological evidence has also indicated the presence of ER or other antigenically related bacteria in healthy flocks. The aim of the present study was to evaluate sample collection, culture methods and DNA-based methodology to detect ER and other Erysipelotrichales in samples from healthy chickens and their environment. We used samples from a research facility with conventionally reared chickens with no history of erysipelas outbreaks where hens with high titres of IgY recognising ER previously have been observed. Microbial DNA was extracted from samples either directly or after pre-culture in nonselective or ER-selective medium. Real-time PCR was used for detection of Erysipelothrix spp. and high-throughput amplicon sequencing of 16S rRNA sequencing was used for detection of Erysipelotrichales. A pilot serological analysis of some Erysipelotrichales members with IgY from unvaccinated and ER-vaccinated high-biosecurity chickens, as well as conventionally reared chickens, was also performed. All samples were negative for ER, E. tonsillarum and E. piscisicarius by PCR analysis. However, 16S rRNA community profiling indicated the presence of several Erysipelotrichales genera in both environmental samples and chicken intestinal samples, including Erysipelothrix spp. that were detected in environmental samples. Sequences from Erysipelothrix spp. were most frequently detected in samples pre-cultured in ER-selective medium. At species level the presence of Erysipelothrix anatis and/or Erysipelothrix aquatica was indicated. Serological results indicated that IgY raised to ER showed some cross-reactivity with E. anatis. Hence, environmental samples pre-cultured in selective medium and analysis by 16S rRNA sequencing proved a useful method for detection of Erysipelotrichales, including Erysipelothrix spp., in chicken flocks. The observation of such bacteria in environmental samples offers a possible explanation for the observation of high antibody titres to ER in flocks without a history of clinical erysipelas.

Antibody responses to respiratory syncytial virus: a population-based cross-sectional serological study in Southern China, 2021

ObjectivesWith remarkable progress in the field of respiratory syncytial virus (RSV) prophylaxis, it is critical to understand population immunity against RSV. We aim to describe the RSV pre-F IgG antibodies across all age groups in Southern China and to evaluate the risk factors associated with lower antibody levels. MethodsWe performed a community-based cross-sectional sero-epidemiological study in Anhua County, Hunan Province, Southern China, from July 15, 2021, to November 5, 2021. Serum samples were tested for IgG antibodies against the RSV prefusion F (pre-F) protein using an enzyme-linked immunosorbent assay. We estimated the geometric mean titres (GMTs) and seropositivity rates across all age groups. The generalized linear models were built to identify factors associated with antibody levels. ResultsA total of 890 participants aged 4 months to older than 89 years were enrolled. The lowest RSV pre-F IgG GMTs were observed in infants and toddlers aged 4 months to younger than 2 years (3.0; 95% CI, 2.6–3.5). With increasing age, the RSV pre-F IgG GMT increased to 4.3 (95% CI, 4.1–4.4) between the ages of 2 and younger than 5 years and then stabilized at high levels throughout life. All the children had serological evidence of RSV infection by the age of 5 years. Age was associated with RSV pre-F antibody levels in children, with an estimated 1.9-fold (95% CI, 0.8–3.6) increase in titre per year before 5 years of age, although it was not significantly associated with antibody levels in adults aged older than 60 years. DiscussionOur findings could provide a comprehensive understanding of the gaps in RSV immunity at the population level and inform the prioritization of immunization platforms.

Establishment of human post-vaccination SARS-CoV-2 standard reference sera

There is a critical need to understand the effectiveness of serum elicited by different SARS-CoV-2 vaccines against SARS-CoV-2 variants. We describe the generation of reference reagents comprised of post-vaccination sera from recipients of different primary vaccines with or without different vaccine booster regimens in order to allow standardized characterization of SARS-CoV-2 neutralization in vitro. We prepared and pooled serum obtained from donors who received a either primary vaccine series alone, or a vaccination strategy that included primary and boosted immunization using available SARS-CoV-2 mRNA vaccines (BNT162b2, Pfizer and mRNA-1273, Moderna), replication-incompetent adenovirus type 26 vaccine (Ad26.COV2·S, Johnson and Johnson), or recombinant baculovirus-expressed spike protein in a nanoparticle vaccine plus Matrix-M adjuvant (NVX-CoV2373, Novavax). No subjects had a history of clinical SARS-CoV-2 infection, and sera were screened with confirmation that there were no nucleocapsid antibodies detected to suggest natural infection. Twice frozen sera were aliquoted, and serum antibodies were characterized for SARS-CoV-2 spike protein binding (estimated WHO antibody binding units/ml), spike protein competition for ACE-2 binding, and SARS-CoV-2 spike protein pseudotyped lentivirus transduction. These reagents are available for distribution to the research community (BEI Resources), and should allow the direct comparison of antibody neutralization results between different laboratories. Further, these sera are an important tool to evaluate the functional neutralization activity of vaccine-induced antibodies against emerging SARS-CoV-2 variants of concern. ImportanceThe explosion of COVID-19 demonstrated how novel coronaviruses can rapidly spread and evolve following introduction into human hosts. The extent of vaccine- and infection-induced protection against infection and disease severity is reduced over time due to the fall in concentration, and due to emerging variants that have altered antibody binding regions on the viral envelope spike protein. Here, we pooled sera obtained from individuals who were immunized with different SARS-CoV-2 vaccines and who did not have clinical or serologic evidence of prior infection. The sera pools were characterized for direct spike protein binding, blockade of virus-receptor binding, and neutralization of spike protein pseudotyped lentiviruses. These sera pools were aliquoted and are available to allow inter-laboratory comparison of results and to provide a tool to determine the effectiveness of prior vaccines in recognizing and neutralizing emerging variants of concern.

First Broad-Range Serological Survey of Crimean-Congo Hemorrhagic Fever among Hungarian Livestock.

(1) Background: Crimean-Congo hemorrhagic fever (CCHF) is an emerging tick-borne disease endemic in Africa, Asia, the Middle East, and the Balkan and Mediterranean regions of Europe. Although no human CCHF cases have been reported, based on vector presence, serological evidence among small vertebrates, and the general human population, Hungary lies within high evidence consensus for potential CCHF introduction and future human infection. Thus, the aim of our pilot serosurvey was to assess CCHF seropositivity among cattle and sheep as indicator animals for virus circulation in the country. (2) Methods: In total, 1905 serum samples taken from free-range cattle and sheep in 2017 were tested for the presence of anti-CCHF virus IgG antibodies using commercial ELISA and commercial and in-house immunofluorescent assays. (3) Results: We found a total of eleven reactive samples (0.58%) from five administrative districts of Hungary comprising 8 cattle and 3 sheep. The most affected regions were the south-central and northwestern parts of the country. (4) Conclusions: Based on these results, more extended surveillance is advised, especially in the affected areas, and there should be greater awareness among clinicians and other high-risk populations of the emerging threat of CCHF in Hungary and Central Europe.

The Serological Evidence of Positive Rheumatoid Factor in Morphea Patients and Its Relation to Disease Severity.

Background and objective Morphea, or localized scleroderma (LS), is an autoimmune skin disorder characterized by inflammation and sclerosis. Its potential causes include infections, genetic predisposition, and trauma. The disease involves cycles of inflammation and fibrosis, leading to skin hardening and scarring, which can cause deformities ifuntreated. Researchexploring the link between morphea and rheumatoid factor (RF), a marker associated with other autoimmune conditions, is ongoing. This study aimed to examine the less-explored role of RF, a marker typically linked to rheumatoid arthritis (RA), in the severityof morphea. It focused on assessing the levels of RFamong morphea patients and its correlation with disease severity, intending to provide deeper insights intothe condition and its management. Methods This study involved a simple randomized cross-sectional analysis to evaluate the role of the RF in measuring morphea severity among patients at the Dermatology and Venereology Department of Al-Sader Teaching Hospitalfrom October 2022 to December 2023. We included participants with clinically and laboratory-confirmed morphea while excluding those with other autoimmune dermatological diseases, recent systemic steroid or immunosuppressive therapy, and pregnant women. The assessment of disease severity was done by utilizing the Localized Scleroderma Cutaneous Assessment Tool (LoSCAT).Statistical analyses were performed using SPSS Statistics version 27 (IBM Corp., Armonk, NY), with a significance threshold of p<0.05. Results Elevated RF levels were significantly associated with increased morphea severity, with severe cases showinghigher RF levels (mean: 30.34 U/mL) compared to moderate (25.83 U/mL) and mild cases (21.56 U/mL) (p = 0.028). However, no significant correlation was found between RF levels and demographic factors such as age, gender, or occupation. Patients with high RF levels had a longer disease duration (mean: 57.15 years) compared to those with normal levels (25.83 years, p = 0.020). Significant differences were observed in lesion distribution on the back (p = 0.002). Logistic regression indicated that severe morphea patients were more likely to have elevated RF levels [odds ratio (OR): 1.158, p = 0.014]. Conclusions This study enriches our understanding of RF's role in morphea, revealing no significant correlation with demographic factors but suggesting its potential role in disease chronicity and severity.

Bordetella pertussis infection following relaxation of COVID-19 non-pharmaceutical interventions in 2021–2023 in Vancouver metropolitan area, British Columbia, Canada

BackgroundWe recently reported a near disappearance of B. pertussis and a decline in anti-B. pertussis antibodies during the peak implementation of Coronavirus disease 2019 (COVID-19) non-pharmaceutical interventions (NPI) in 2021 in British Columbia (BC), Canada. During 2021–2023, incidence of reported B. pertussis cases remained low in BC at < 1/100,000 population. This study determined how serological evidence of B. pertussis changed after the gradual relaxation of NPI between 2021–2023. MethodsRandomly selected blood samples from school staff 25–51 years old (n = 65) were collected yearly between 2021–2023 in the Vancouver metropolitan area, BC, Canada, and tested for anti-pertussis toxin (PT) IgG levels. Serological evidence of B. pertussis infection (thereafter “seroconversion”) was defined as a quantifiable anti-PT IgG levels in subjects with anti-PT IgG levels below lower limit of quantification in the preceding year or a > 4-fold increase in anti-PT IgG levels between two subsequent years. Samples were also tested for anti-diphtheria toxoid (DT) IgG, and similar seroconversion criteria were applied to exclude seroconversion due to vaccination with tetanus-diphtheria-acellular-pertussis (Tdap). ResultsThree subjects met seroconversion criteria for anti-PT IgG between 2021 and 2022 and 9 between 2022 and 2023, yielding a seroconversion rate of 4.6 /100 person-years and 14.9/100 person-years, P = 0.127, respectively. None of the subjects met the criteria for vaccination with Tdap. The geometric mean concentration of anti-PT IgG showed a statistically significant decrease in 2022 compared with 2021, 4.8 IU/mL IU/ml (95 % confidence interval [CI], 3.8–5.9) vs. 6.4 IU/ml (95 % CI, 4.9–8.2; p = 0.001), followed by a statistically significant increase in 2023 compared with 2022 6.5 IU/ml (95 % CI, 4.9–8.5) vs. 4.8 IU/ml (95 % CI, 3.8–5.9; p = 0.0006), respectively. DiscussionSerological evidence of B. pertussis increased between 2022 and 2023 despite low reported cases, which suggests that B. pertussis circulation resumed after relaxing of COVID-19 NPI.

Serological evidence of zoonotic filovirus exposure among bushmeat hunters in Guinea

Human Ebola virus (EBOV) outbreaks caused by persistent EBOV infection raises questions on the role of zoonotic spillover in filovirus epidemiology. To characterise filovirus zoonotic exposure, we collected cross-sectional serum samples from bushmeat hunters (n = 498) in Macenta Prefecture Guinea, adjacent to the index site of the 2013 EBOV-Makona spillover event. We identified distinct immune signatures (20/498, 4.0%) to multiple EBOV antigens (GP, NP, VP40) using stepwise ELISA and Western blot analysis and, live EBOV neutralisation (5/20; 25%). Using comparative serological data from PCR-confirmed survivors of the 2013-2016 EBOV outbreak, we demonstrated that most signatures (15/20) were not plausibly explained by prior EBOV-Makona exposure. Subsequent data-driven modelling of EBOV immunological outcomes to remote-sensing environmental data also revealed consistent associations with intact closed canopy forest. Together our findings suggest exposure to other closely related filoviruses prior to the 2013-2016 West Africa epidemic and highlight future surveillance priorities.

LYME AND DENGUE FEVER: FROM BANGLADESH TO ITALY

Abstract Background Dengue fever (Flavivirus) and Lyme disease (Borrelia burgdorferi) are rare tropical infectious diseases transmitted by hematophagous vectors (Aedes mosquitoes and ticks, respectively), and they are extremely uncommon in Italy. In European countries, both represent a public health concern as they manifest as imported diseases. Case Report A 54–year–old man from Bangladesh was admitted with symptoms of fever, dyspnea, and pericarditic chest pain. Laboratory and imaging examinations revealed severe acute respiratory failure secondary to left lower lobe pneumonia and pleuropericardial effusion. Broad–spectrum antibiotic therapy and anti–inflammatory treatment were initiated, suspecting para–pneumonic pleuropericarditis. During hospitalization, there was a gradual improvement with a reduction in inflammatory indices and resolution of lung consolidation. The patient was discharged after 14 days with anti–inflammatory therapy (ibuprofen and colchicine). Approximately 7 days later, the patient returned to the emergency department complaining of a recurrence of symptoms and fatigue. The EKG showed phases of 2:1 AV block, EAS and EPS, complete de novo left bundle branch block (LBBB), alternating with an escape atrial rhythm, not evident in previous EKG. During hospitalization, complete AV block emerged with prolonged asystolic phases, requiring urgent placement of a temporary pacemaker. Concurrently, blood tests revealed anemia and increased levels of inflammatory markers, troponin, creatinine, transaminases, cholestatic indices, LDH, and lipase, indicative of multiple organ failure (MOF). Acute pathologies or active bleeding were ruled out by total body CT with contrast. Blood cultures and serological tests were performed to exclude infections by Trichinella, Mycoplasma, Borrelia, Dengue, and other rare infectious diseases. Due to progressive deterioration, the patient was transferred to a tertiary care hospital. In the following days, laboratory results showed positive IgG and IgM for Dengue (without serological evidence of viral RNA) and positive IgG and IgM antibodies for Borrelia burgdorferi. Conclusion In Italy, the incidence of these diseases is low, and their coexistence in the same host is even rarer (if not anecdotal). However, coinfection cannot be excluded in patients from areas where these diseases are endemic, such as Bangladesh.

Serological Evidence of Mpox Virus Infection During Peak Mpox Transmission in New York City, July to August 2022.

The extent to which infections may have been undetected in an epicenter of the 2022 mpox outbreak is unknown. A serosurvey (July and August 2022) assessed the seroprevalence and correlates of mpox infection among a diverse sample of asymptomatic patients with no prior mpox diagnoses and no known histories of smallpox or mpox vaccination. We present seropositivity stratified by participant characteristics collected via survey. Two-thirds of 419 participants were cismen (281 of 419), of whom 59.1% (166 of 281) reported sex with men (MSM). The sample also included 109 ciswomen and 28 transgender/gender nonconforming/nonbinary individuals. Overall seroprevalence was 6.4% (95% confidence interval [CI], 4.1%-8.8%); 3.7% among ciswomen (95% CI, 1.0%-9.1%), 7.0% among cismen with only ciswomen partners (95% CI, 2.0%-11.9%), and 7.8% among MSM (95% CI, 3.7%-11.9%). There was little variation in seroprevalence by race/ethnicity, age group, HIV status, or number of recent sex partners. No participants who reported close contact with mpox cases were seropositive. Among participants without recent mpox-like symptoms, 6.3% were seropositive (95% CI, 3.6%-9.0%). Approximately 1 in 15 vaccine-naive people in our study had antibodies to mpox during the height of the NYC outbreak, indicating the presence of asymptomatic infections that could contribute to ongoing transmission.

Hepatitis B virus infection among illegal drug users in Enugu State, Nigeria: prevalence, immune status, and related risk factors

IntroductionHepatitis B virus infection poses a global health challenge, particularly in low- and middle-income African countries. Illicit drug use exacerbates the problem, with drug users having a higher HBV infection risk and maintaining a quiet transmission pool. This study aimed to determine HBV infection prevalence, immune status, and risk factors among illegal drug users in Enugu State, Nigeria.Materials and methodsA cross-sectional study was conducted in Enugu State, using privileged access interviewer methods to enroll drug users. Pre-tested structured questionnaires were administered after informed consent was obtained. Blood samples were tested for HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb using immunochromatographic rapid test kits. Statistical analysis was performed using SPSS version 25.ResultsOne hundred drug users were recruited into the study. Overall, 7% of the drug users had HBV infection. 61% were found to be susceptible to HBV infection, 15% showed serological evidence of immunity from HBV vaccination and 1% developed natural immunity from HBV exposure. Significant risk factors for HBV infection were age less than 20 years, young age (≤ 20 years) at drug initiation, being single, injecting drugs more than or equal to 20 times per month and injecting with used syringes.ConclusionThis study shows high intermediate endemicity of HBV infection among drug users, low vaccination uptake, and high susceptibility to HBV infection. This calls for the urgent inclusion of drug users in national HBV vaccination campaigns and the adoption of the World Health Organization’s recommendations on the prevention of viral hepatitis among people who inject drugs.

Serological profile of hepatitis B virus infection among traditional birth attendants and the attending pregnant women in Ibadan, Nigeria

ABSTRACT Although a sizable number of pregnant women patronize Traditional Birth Attendants (TBAs) for deliveries in Nigeria, efforts to prevent or reduce the risk of HBV transmission are not targeted at the TBAs and the pregnant women patronizing them. This may be linked to the dearth of information on the serological profiles of HBV among this cohort. We, therefore, show the serological profiles of HBV among the cohort. One hundred and seventy pregnant women and 91 TBAs participated in this study between May and July 2019. Serological markers of HBV infection were assayed using ELISA. A prevalence of, 8.0% (95% CI: 5.0% − 11.5%) for HBsAg, 0.8% (95% CI: 0.0% − 1.9%) for HBeAg, 2.7% (95% CI: 0.8% − 5.0%) for HBcIgM, 26.1% (95% CI: 20.7% − 31.4%) for anti-HBs, 21.5% (95% CI: 16.5% − 25.4%) for anti-HBe and 67.0% (95% CI: 60.9% – 72.8%) for anti-HBc was found indicating a high percentage of carriers. Although 32 (12.3%) of the entire participants claimed to be fully vaccinated, serological evidence was only detected in 4 (12.5%). The high percentage of carriers and low evidence of vaccination necessitate intensified efforts to ensure that adequate interventions are made available and accessible to the TBAs and the pregnant women patronizing them (including newborn babies).

Impact of gender on clinical features and outcomes of ocular toxoplasmosis

AimTo investigate the effect of gender on the clinical features and outcomes of ocular toxoplasmosis.Methods262 patients (139 women and 123 men) presenting to a tertiary referral uveitis service in Ribeirão...

Seroprevalence of SARS-CoV-2 in self-reported COVID-19-free children

IntroductionCOVID-19 poses risks and leads to complications for vulnerable populations, including children. Unreported cases of COVID-19 among children hinder our understanding of the true disease burden. In this study, we aimed to investigate the proportion of children who report no prior infection to SARS-CoV-2 but who nevertheless exhibit serological evidence of prior infection. MethodsBetween November 2022 and February 2023, we recruited children and adolescents under 19 years of age who lacked a prior history of SARS-CoV-2 infection. Participants underwent SARS-CoV-2 antibody testing to assess the presence of IgG antibodies specific to nucleocapsid (N) and spike (S) proteins. Demographic and contact information were also collected. ResultsAmong 260 COVID-19-free children, the overall anti-N antibody positivity rate, which varied across age groups (4%–25%), was 9.2% (24/260). Contact with individuals who were positive for COVID-19, particularly the children's mothers, significantly increased the likelihood of antibody positivity. The median age of the 34 children who remained unvaccinated against COVID-19 was lower than that of the children who were vaccinated (6.5 vs. 9 years; p < 0.001). Until January 2024, the overall infection rate was 41.9% (99/236) among children who were negative for anti-N antibodies, irrespective of vaccination status or the presence of chronic disease. ConclusionWe discovered previously undisclosed cases of SARS-CoV-2 infection among children. The risk of seropositivity increases substantially with household contact. Regarding children who report no prior exposure to COVID-19, clinicians must remain vigilant, as SARS-CoV-2 remains a concern.

P154 Male lupus characteristics from multi-ethnic cohort

Abstract Background/Aims Systemic lupus erythematous (SLE) is a chronic autoimmune (AI) disease of unknown etiology. It predominantly presents in women and only 1 in 10 of sufferers are men. We sought to examine the clinical pattern in male lupus patients in a tertiary multi-ethnic lupus centre in East London, UK. Methods Male lupus patients were identified through review of a pre-existing lupus patients database and clinic lists at Barts Trust. All patients’ electronic notes were reviewed prior to a telephone interview. All the participants fulfilled the ACR 1997 criteria for SLE. Descriptive data analysis was performed for all identified patients. Results Fifty-one patients were identified. Sample demographics showed that male lupus was more prevalent among Afro-Caribbeans (37%,n=19), followed by Asians (33%,n=17) and Caucasians (29%,n=15). The median age was 40.5 (IQR:32.5-52.7) years, with median age at SLE diagnosis 28 years (IQR:23-45).Family history of an AI condition was seen in 25%, whilst 14% had a family history specifically of SLE. Possible significant stressor prior to diagnosis reported in 45% (n = 23) patients. Serological evidence of previous infection with EBV, VZV or parvovirus was found in 76%. Although all patients were below the state pension age of 66, more than half were unemployed. The majority of males had multiorgan involvement including renal (67%,n=34), cutaneous (55%,n=28), hematological (45%,n=23), musculoskeletal (31%,n=16), cardiac (27%,n=14), pulmonary (20%,n=10), and neurologic (14%,n=7). Renal biopsy was done in 33/34 renal cases and the showed proliferative class-III/IV in 65%. Hypertension was a significant comorbidity in 39%, 47% had a concomitant AI condition. Juvenile-onset SLE was diagnosed in 6% of the patients with median age at disease onset 10 years (IQR:14-16,100% Caucasians). These males all had kidney nephropathy class-IV/V. Regarding serology, 94% were positive for antinuclear antibody, 40% speckled, 31% homogenous, and 8% for nucleolar and mixed pattern. Two patients ANA test was not recorded but they had confirmed renal/cutaneous biopsy findings.Three-quarters were positive for anti-double stranded DNA. Ro and La antigens were detected in 35% and 8%, while anti-Sm and anti-RNP antibodies were detected in 37% and 43%, respectively. Antiphospholipid antibodies were identified in less than a third, of which 40% presented with thrombotic events. Triple antiphospholipid antibodies was detected in 53%, 20% had LA, 15% had aCL, and 7% had either anti-B2GP1 or aCL/anti-B2GP. Conclusion Our dataset demonstrates a higher prevalence in Afro-Caribbean and Asians and a young age of onset (median 28 years) with presentation about 10 years earlier than most other reports. The majority were unemployed and reported significant life-stressors. Over three-quarters of patients had evidence of prior infection.Most of the lupus males had multiorgan involvement and over two-thirds had renal involvement, proliferative class-III/IV. There was a high prevalence of dsDNA, ENA (anti-Ro) and APL. Disclosure H. Aldeyarbi: None. S. George: None. G. Marchan: None. R. Rajakariar: None. A. Cove-Smith: None. A. Pakozdi: None. M. Cunningham: None. M. Lewis: None. B. Turner: None. D. Pyne: None.

Serological Evidence of Crimean-Congo Haemorrhagic Fever in Livestock in the Omaheke Region of Namibia.

This research examined the positivity ratio of Crimean-Congo haemorrhagic fever (CCHF) antibodies in cattle and sheep within Namibia's Omaheke region after a human disease outbreak in the same geographical area. A total of 200 samples (100 cattle and 100 sheep) were randomly collected from animals brought to two regional auction sites, and then tested using the ID Screen® CCHF Double Antigen Multi-Species Enzyme-Linked Immunosorbent Assay kit. Of the cattle samples, 36% tested positive, while 22% of the sheep samples were seropositive. The cattle had a significantly higher positivity ratio than sheep at the individual animal level (p = 0.0291). At the herd level, 62.5% of cattle herds and 45.5% of sheep flocks had at least one positive animal, but this difference was statistically insignificant (p = 0.2475). The fourteen cattle farms with at least one seropositive animal were dispersed across the Omaheke region. In contrast, the ten sheep farms with seropositive cases were predominantly situated in the southern half of the region. The study concluded that the CCHF is endemic in the Omaheke region and likely in most of Namibia, underscoring the importance of continued surveillance and preventive measures to mitigate the impact of CCHFV on animal health and potential spillover into human populations.

Molecular and Serological Detection of Bovine Coronaviruses in Marmots (Marmota marmota) in the Alpine Region.

In this study, virological surveillance focused on coronaviruses in marmots in the Alpine region in 2022, captured as part of a population control reduction program in the Livigno area. Seventy-six faecal samples were randomly collected from marmots at the time of capture and release and tested for genome detection of pan-coronavirus, pan-pestivirus, canine distemper virus, and influenza A and D virus. Nine faecal samples were positive in the Pan-CoV RT-PCR, while all were negative for the other viruses. Pan-coronavirus positives were further identified using Illumina's complete genome sequencing, which showed the highest homology with Bovine Coronavirus previously detected in roe deer in the Alps. Blood samples (n.35) were collected randomly from animals at release and tested for bovine coronavirus (BCoV) antibodies using competitive ELISA and VNT. Serological analyses revealed that 8/35 sera were positive for BCoV antibodies in both serological tests. This study provides molecular and serological evidence of the presence of BCoV in an alpine marmot population due to a likely spillover event. Marmots share areas and pastures with roe deer and other wild ruminants, and environmental transmission is a concrete possibility.

Molecular and serological evidence of chikungunya virus infection with high case fatality among pediatric population with acute encephalitis syndrome: first report from Eastern Uttar Pradesh, India.

Acute encephalitis syndrome (AES) outbreaks in children of Eastern Uttar Pradesh (E-UP) region of India have been a longstanding public health issue, with a significant case fatality rate of 20-25%. Since past decade, a rise in chikungunya (CHIK) cases has been occurring, which is a reported etiology of AES. However, the burden of chikungunya virus (CHIKV) among pediatric AES (pAES) is unknown from E-UP. We included 238 hospitalized pAES cases. The presence of IgM antibodies for CHIKV, and Dengue virus (DENV) was tested, and RT-PCR was performed for CHIKV and DENV in serologically confirmed CHIKV and DENV pAES cases. Positive samples were sequenced using Sangers sequencing. Further, to check for co-infection, IgM antibodies for other AES etiologies including Japanese encephalitis virus (JEV), Leptospira and Orientia tsutsugamushi (OT) in serum were also investigated. IgM ELISA demonstrated 5.04% (12) positivity for CHIKV. Among CHIKV IgM positive, 3 (25%, 3/12) pAES patients died. CHIKV genome was detected in 3 pAES specimens. Among which, 2 CHIKV cases were also positive for OT DNA. Partially sequenced CHIKV were genotyped as ECSA. The overall finding indicates evidence of CHIKV infection with high case fatality among pAES patients from E-UP. This study advocates constant serological and molecular surveillance of CHIKV in AES endemic regions of India.

SARS-CoV-2 infection and psychological distress : a prospective sero-survey in southern Switzerland

IntroductionThe COVID-19 pandemic has had an impact on the mental health of the population that, to some extent, may be due to the neurotropism of SARS-CoV-2. However, evidence is extremely sparse on the prospective association between serological evidence of COVID-19 infection and psychological distress.ObjectivesWe aimed to explore the prospective association between seropositivity and psychological distress – assessed by symptoms of depression, anxiety and stress – in the general adult population in southern Switzerland. Further, we investigated whether this association varied over time and between pandemic waves.MethodsWe used data from 305 adults who participated in the Corona Immunitas Ticino (CIT) prospective sero-survey cohort study. We tested the association between serologically confirmed SARS-COV-2 infection at baseline (June–December 2020) and depression, anxiety and stress scores as measured by the DASS-21 scale at three time points between December 2020 and March 2021, also taking into account for sociodemographic characteristics (age, gender, education level, presence of chronic diseases, smoking, obesity).ResultsIn our sample, 84.3% (mean age of 51.30, SD= ± .93) were never infected. Seropositive participants were significantly younger on average (M=46.90, SD= ±2.00, P= .04). At the first follow-up (see Table 1), seropositive participants had higher rates of mild conditions for depression (OR= .64; P= .014) and anxiety (OR= .50; P= .030), than seronegatives. Overall, after the 6-month follow-up, seropositive participants had significantly lower rates of mild conditions for DASS-21 subscales. In addition, prevalence of mild conditions for depression, anxiety and stress decreased more rapidly over time among infected vs. never infected (see Figure 1). Older age and the presence of chronic diseases were associated with mild anxiety (OR= .97; P= .013; OR=3.47; P= .001) and stress (OR= .96; P= .003; OR= 2.56; P= .010).Table 1.Associations (Odds Ratios) between seropositive immunological status and mental health between December 2020 and March 2021 in Ticino, southern Switzerland (N=305)DASS-21 defined mild conditionORP valueCI (95%)Depression0.6410.0140.449 – 0.914Anxiety0.5020.0300.270 – 0.936Stress0.7120.1130.468 – 1.083Note. Generalized estimating equation models results. Co-variates include time, age, gender, chronic diseases, obesity, smoking and education level.ConclusionsOur results provide new evidence on the association between COVID-19 seropositivity and poor mental health and underline the public health implications of the pandemic because the number of infected individuals largely exceed the 770 million of recorded COVID-19 (symptomatic) cases.Disclosure of InterestNone Declared

Evaluation of feline heartworm disease based on gross necropsy, serology, pulmonary histopathology, and radiographic evidence in adult shelter cats in northeastern Alabama

Background: Veterinary knowledge regarding feline heartworm has been increasing significantly over the past two decades. Necropsy surveys of shelter cats have shown feline adult heartworm infection prevalence to be 5–20% of the rate in unprotected dogs; however, other studies have shown feline heartworm antibody prevalence up to 33%, reflecting higher exposure rates and potential immature adult infections. Thus, the true prevalence of feline heartworm infection is likely underestimated due to the limitations of current diagnostic techniques, inadequate testing protocols, and the high likelihood of cats exhibiting transient clinical signs or dying without confirmation of infection. Diagnosing Feline Heartworm Disease (FHWD), also referred to as Heartworm Associated Respiratory Disease (HARD), is one of the conundrums of veterinary medicine. The purpose of this study was to evaluate and characterize the occurrence of Heartworm Associated Respiratory Disease [HARD] in shelter cats, naturally-infected with D.immitis.MethodsFifty shelter cats slated for euthanasia between December 2009 and June 2010 were investigated by gross necropsy, radiography, serology, and lung histopathology using techniques that have been established in experimental models of cat heartworm infection. The relationship between pulmonary vascular disease and serological markers for heartworm was also examined using correlations and statistical modeling. Serology included standard heartworm antigen test and a commonly used heartworm antibody test. Also included were heat-treated heartworm antigen test and two additional heartworm antibody tests previously evaluated on experimentally-infected cats.ResultsNone of the cats were heartworm antibody (HW Ab) positive on a commonly used HW Ab test used by many reference laboratories even though 20% of the study cats were heartworm antigen (HW Ag) positive on heat-treated samples. Two additional HW Ab test were positive on 26% and 22% of the study cats. The combination of heat-treated HW Ag, HW Ab tests, and histopathology indicated 34% of the study cats had HARD.ConclusionsUtilizing both, the above tests, and thoracic radiographs, enhanced the ability to predict vascular disease, possibly caused by infection with immature and adult heartworms and supported the premise that cats develop heartworm disease at the same rate as dogs.Graphical

Identification of a novel orthonairovirus from ticks and serological survey in animals near China-North korea border.

Emerging pathogenic tick-borne viruses (TBVs) have attracted a great deal of attention due to their significant impact on human and animal health. A novel orthonairovirus named Dadong virus (DDV) was isolated from Haemaphysalis concinna ticks in the Changbai Mountain region on the China-North Korea border. DDV can induce cytopathic effects in mammalian and human cell lines. Phylogenetic analysis showed that it belongs to the genus Orthonairovirus, family Nairoviridae, exhibiting 72.4%-81.3% nucleic acid identity to Tofla orthonairovirus, known to cause lethal infection in IFNAR KO mice. The first serological evidence of DDV circulating in cattle and mice was also obtained, with 4.0% (1/25) of cattle and 2.27% (1/44) of mice seropositive for DDV. Further investigations, including serological surveys using human samples, are required to assess the public health risk posed by DDV.