Serological Studies Research Articles

Kinetics of IgM, IgA, IgG to SARS-CoV-2 in children with COVID-19 in Lviv region in different periods of the infectious process depending on the severity of the course and age

Aim. The research aims at analyzing the kinetics of IgA, IgM, and IgG to SARS-CoV-2 in children based on the severity of COVID-19 and age.
 Materials and Methods. The conducted prospective study involved 88 children (mean age 9.4 years) with COVID-19, admitted to the "Lviv Regional Pediatric Clinical Hospital "OKHMATDYT" from 2020 to 2021. The participants included 36 males (40.90%), and 52 females (59.10%) in the observation group. Diagnosis verification relied on clinical manifestations of the disease, with the detection of SARS-CoV-2 RNA from nasal mucus using the PCR method. The values of IgA, IgM, and IgG to S and N proteins of SARS-CoV-2, determined by the ELISA method at different times of the infectious process in 380 blood serum samples, were analyzed.
 Results and Discussion.The research findings of IgM to SARS-CoV-2 in the first week of illness revealed a median value of 0.24 [0.14; 1.39], increasing to 0.49 [0.30; 2.87] in the second week. The highest median value of IgA to SARS-CoV-2 is 0.33 [0.24; 1.00] was found from 15 to 30 days, after 30 days it was 0.24 [0.20; 0.28].
 The increase in the median value of IgG-N to SARS-CoV-2 was observed from the second week of the illness, reaching 1.13 [0.52; 3.17], with its maximum value at 5.68 [2.39; 8.86] within the period up to three months. Severe COVID-19 was diagnosed in 27 children (30.68%), comprising 15 females (55.56%) and 12 males (44.44%). In the majority of hospitalized children, IgM values at different degrees of disease severity were positive from the first to the seventh day of illness. In children with a severe course of SARS-CoV-2, the median value of IgM in blood serum during this period was 1.39 [1.36; 4.07]. There was a statistically significant difference between the IgG levels for moderate and severe forms on days 15-30 of the illness: 0.54 [0.21; 1.89] compared to 5.55 [4.99; 5.80], respectively (p<0.05). In patients with both moderate and severe forms of the disease, median values of IgG to N SARS-CoV-2 were positive throughout the study period. A significant increase in the median value of IgG to N SARS-CoV-2 was observed in females from day 31 to day 90. In severe cases of the disease, the median value of IgG to SARS-CoV-2 from three to six months was 9.40 [7.80; 10.60], which was higher than in patients with a moderate form of the disease - 8.72 [8.64; 8.97] (p<0.05).
 Conclusions. Serological studies enable the investigation of the immune response to SARS-CoV-2, determination of seroconversion, and characterization of the course of COVID-19, being crucial for epidemiological research. The levels of IgM, IgA, and IgG to SARS-CoV-2 depend on the disease's severity and the patient's age.

SEROMONITORING OF CRIMEAN-CONGO HEMORRHAGIC FEVER IN FARM ANIMALS

The article presents data from serological studies of blood sera of farm animals for the presence of antibodies to the Crimean-Congo haemorrhagic fever virus (CCHF). In 2022, 590 small cattle blood sera collected in 4 regions were examined, and in 2023, 1004 small cattle sera and 1090 cattle sera from 15 regions of Kazakhstan. As a result of the studies, it was established that the seroprevalence of CCHF virus among cattle in 2023 was 5.32%. Seropositive cattle were detected in 6 (Atyrau (9.38%), Kyzylorda (57.5%), Zhambyl (40%), Turkestan (78.58%), Almaty (4.77%), West Kazakhstan (1, 93%) from 15 studied regions. Seropositive sheep were detected in 4 regions in 2022 and in 5 out of 15 studied regions in 2023. The presence of antibodies to the CCHF virus was detected in 2022 in West Kazakhstan (4.5%), Turkestan (11 .3%), Zhambyl (30.9%) and Kyzylorda (44.3%) regions, and 2023 in West Kazakhstan (6.9%), Turkestan (14.52%), Zhambyl (15%), Kyzylorda (70%) and North Kazakhstan (12.1%) regions. The results of our research show that the distribution area of CCHF has expanded significantly. Based on the data obtained, we can conclude that two endemic regions for CCHF have formed on the territory of Kazakhstan: the southern endemic region, including Kyzylorda, Turkestan, Zhambyl, and Almaty regions, as well as the western endemic region, including West Kazakhstan and Atyrau regions. Given the constant movement of wild and farm animals within the country, there is a high risk of CCHF spreading from endemic regions to free regions. To confirm these data, it is necessary to conduct constant monitoring of farm animals, ticks, and other blood-sucking carriers of this virus.

Seroprevalence and herd-level associated factors of pathogenic Leptospira spp. circulating locally in dairy cattle in Uruguay

Leptospirosis is a zoonotic disease of worldwide importance. In Uruguay, it is endemic in cattle and primarily affects people with occupational exposure to livestock. The aim of this study was to determine the national seroprevalence and associated factors of local pathogen Leptospires in dairy cattle. A cross-sectional study was carried out. Herds were stratified by size (1–50, 51–250, and > 250 cattle), and up to 60 dairy cows per herd were randomly selected. A total of 4269 serum samples from 101 dairy herds were analyzed by microscopic agglutination test (MAT). A two-stage sampling design was used to estimate population seroprevalence of Leptospira spp. In order to determine the factors associated with the disease, herds with at least 1 seropositive animal were considered as case herds. Seroprevalence of Leptospira was 27.80% with a 95% CI [21.06, 34.54] at the animal level and 86.92% with a 95% CI [80.00, 93.75] at the herd level. The serology confirms the predominance of serogroups Sejroe and Pomona in our herd with the presence of incidental leptospires infection, in smaller proportion, but with a wide distribution at farm level. The population size and purchasing replacement of cows on dairy farms were associated with infection at farm level. The serologic studies confirmed that exposure to Leptospira spp. is endemic in our herds, and the spreading over dairy herds. Although the movement of purchased females and the size of the herd were associated with the disease, more studies should be conducted, to better understand the epidemiology of the disease and to highlight the possible risks to public health, especially in rural workers, farmers and veterinarians.

The effectiveness of scientifically based monitoring programs and therapeutic and preventive measures for controlled infectious diseases of animals

The aim of the work was to assess the effectiveness of an improved monitoring program for controlled infectious animal diseases and individual vaccination programs for acute respiratory viral infection in cattle. To fulfill the tasks set, serological studies, PCR diagnostics, bacteriological and coprological methods of examining biological samples from animals were carried out. As a result of the work, the main factors influencing the effectiveness of vaccine prophylaxis of acute respiratory viral infection in cattle populations have been identified. It was found that in three administrative and administrative districts of the Sverdlovsk region, the main factors in 35.1% of cases are violations of the rules of vaccination of acute respiratory viral infection of cattle, in 13.5% of cases - violations of zoo-hygienic and veterinary–sanitary conditions of keeping farm animals. A comprehensive assessment of the effectiveness of individual vaccination programs for cattle against acute respiratory viral infection has been carried out, taking into account the epizootological situation in agricultural organizations. It was shown that vaccination of cattle against acute respiratory viral infection according to individual programs ensured the formation of specific immunity in 92.5-95.0% of animals. The number of immunotolerant individuals and animals with a low level of immunoreactivity in the physiological group of young cattle did not exceed 3.5%, in the physiological group of adult animals – 1.25%. The high efficiency of improved scientifically based programs for monitoring, diagnosis, therapeutic, preventive and health measures to protect animals from epizootically significant infectious diseases of cattle among the populations of farm animals of the Ural Federal District has been confirmed.

Challenges and advances in serological and molecular tests to aid leprosy diagnosis.

Leprosy is a neglected chronic infectious disease caused by obligate intracellular bacilli, Mycobacterium leprae and Mycobacterium lepromatosis. Despite multidrug therapy (MDT) success, leprosy accounts for more than 200,000 new cases yearly. Leprosy diagnosis remains based on the dermato-neurologic examination, but histopathology of skin biopsy and bacilloscopy of intradermal scraping are subsidiary diagnostic tests that require expertise and laboratory infrastructure. This minireview summarizes the state of the art of serologic tests to aid leprosy diagnosis, highlighting enzyme-linked immunosorbent assay (ELISA) and point-of-care tests (POCT) biotechnologies. Also, the impact of the postgenomic era on the description of new recombinantly expressed M. leprae-specific protein antigens, such as leprosy Infectious Disease Research Institute (IDRI) diagnostic (LID)-1 is summarized. Highly specific and sensitive molecular techniques to detect M. leprae DNA as the quantitative polymerase chain reaction (qPCR) and the loop-mediated isothermal amplification (LAMP) are briefly reviewed. Serology studies using phenolic glycolipid-I (PGL-I) semi-synthetic antigens, LID-1 fusion antigen, and the single fusion complex natural disaccharide-octyl (NDO)-LID show high sensitivity in multibacillary (MB) patients. However, serology is not applicable to paucibacillary patients, as they have weak humoral response and robust cell-mediated response, requiring tests for cellular biomarkers. Unlike ELISA-based tests, leprosy-specific POCT based on semi-synthetic PGL-I antigens and NDO-LID 1 antigen is easy to perform, cheaper, equipment-free, and can contribute to early diagnosis avoiding permanent incapacities and helping to interrupt M. leprae transmission. Besides its use to help diagnosis of household contacts or at-risk populations in endemic areas, potential applications of leprosy serology include monitoring MDT efficacy, identification of recent infection, especially in young children, as surrogate markers of disease progression to orient adult chemoprophylaxis and as a predictor of type 2 leprosy reactions. Advances in molecular biology techniques have reduced the complexity and execution time of qPCR confirming its utility to help diagnosis while leprosy-specific LAMP holds promise as an adjunct test to detect M. leprae DNA.

Equine influenza outbreak in Eastern of Algeria in 2021: The first introduction of Florida Clade 1 to Maghreb area

We have performed an equine influenza (EI) serological study of the equine population in Algeria by testing 298 serum samples collected between February and August 2021 from 5 provinces. The results were obtained performing an NP-ELISA. Our results revealed that 49.3% (147/298) samples positive for antibodies to EI (H3N8). During this study and after a gap of one decade an outbreak of EI was reported in Algeria in the first week of March 2021. The disease was confirmed by virus detection from the nasal swabs (n = 39) by qRT-PCR and by identifying 5 EI seroconversion. The virus sequences were identified as H3N8 by sequencing the haemagglutinin (HA) and neuraminidase (NA) genes. Alignment of HA1 amino acid sequence confirmed that viruses belong to Clade 1 of the Florida sublineage in the American lineage. This study indicate the first detection of FC1 strain of EIV in Maghreb area.

Study of features of influenza virus circulation in the southern region of Kazakhstan during the 2021 epidemic season

Influenza viruses are among the most prevalent infectious agents, leading to massive seasonal epidemics and pandemics with high mortality rates. The ability of influenza virus to antigenic variability determines the high population susceptibility, wide spread of infection, and short intervals between epidemics. In recent years, the co-circulation of influenza viruses that belong to A/H1N1pdm09 and A/ H3N2 subtypes and influenza type B virus has been observed. Here we summarize the data we explored to establish the features of the influenza virus circulation in the southern region of the Republic of Kazakhstan. To conduct virological and serological studies, 590 biosamples were collected from sick patients (419 swabs and 171 blood serums). Influenza type A virus RNA was found in 39 (9.31%) samples including that of A/H1N1pdm09 virus in 15 (3.58%), A/H3N2 virus in 23 (5.49%). It has also been noted that isolates A/Almaty/10/21 and A/Almaty/15/21 were profiled by the antigenic formula A/H3N2. The results of virological, serological, and molecular genetic studies confirm the simultaneous circulation of influenza A viruses (H1N1pdm09 and H3N2), and influenza type B virus. Some thoughts on the current scenario as well as implications for the future are presented as well.

АНАЛИЗ СПЕКТРА ПАТОГЕНОВ ПАРАЗИТАРНОЙ, БАКТЕРИАЛЬНОЙ И ВИРУСНОЙ ЭТИОЛОГИИ В ПРОМЫШЛЕННОМ ПТИЦЕВОДСТВЕ. ПРАКТИЧЕСКИЙ ОПЫТ

Practical experience in diagnosing infectious and parasitic diseases of poultry is presented using the example of an industrial flock of laying hens kept on the territory of a poultry farm. An assessment is made of the spectrum of pathogens of parasitic, bacterial and viral etiology circulating in a particular poultry farm. Clinical, pathological, parasitological and serological studies were carried out on samples of material taken from the poultry population. The immune status of the chicken population was monitored in relation to pathogens of infectious and parasitic diseases and the effectiveness of specific prevention against infectious and parasitic diseases in poultry was analyzed.

Divergent Genotype of Hepatitis A Virus in Alpacas, Bolivia, 2019.

Hepatitis A virus (HAV) is a common human pathogen found exclusively in primates. In a molecular and serologic study of 64 alpacas in Bolivia, we detected RNA of distinct HAV in ≈9% of animals and HAV antibodies in ≈64%. Complete-genome analysis suggests a long association of HAV with alpacas.

Seroprevalence and risk factors for Neospora spp. infection in equine in Egypt

Neospora infections in equine are associated with reproductive disorders and neurological diseases. Nevertheless, Egypt has no epidemiological information on this parasite in equine. This study determined the prevalence of Neospora spp. infection in 325 equines from three Egyptian governorates located at Northern Egypt using cELISA. The prevalence of antibodies against Neospora spp. was 19% (95% CI: 14.09–25.05) in horse, 34.1% (95%CI: 24.92–44.69) in donkey and 26.7% (95% CI: 15.97–41.04) in mule. In comparison to horse, donkey had a considerably higher chance of contracting Neospora spp. infection (OR = 1.80, 95% CI: 0.78–4.13; P = 0.016). The risk was also higher in freely grazing animals (OR = 3.49, 95% CI: 0.95–12.78; P = 0.059). Moreover, yearling animals (12–24 months) (OR = 5.03, 95% CI: 1.51–16.80; P = 0.009) and those with natural breeding (OR = 11.80, 95% CI: 3.24–42.99, P < 0.0001) and a history of early abortion (OR = 7.04, 95% CI: 3.01–16.47; P < 0.0001) also showed a greater risk of seropositivity. The risk of Neospora infection increased significantly in equines contacted with dogs (OR = 5.16, 95% CI: 1.76–15.10; P = 0.003). This the first serological study to determine the seroprevalence of Neospora spp. in equine in Egypt. Further studies are necessary to identify the species of Neospora and to understand the role of above-mentioned risk factors in spreading of infection.

Increased risk of chronic fatigue syndrome following infection: a 17-year population-based cohort study

BackgroundPrevious serological studies have indicated an association between viruses and atypical pathogens and Chronic Fatigue Syndrome (CFS). This study aims to investigate the correlation between infections from common pathogens, including typical bacteria, and the subsequent risk of developing CFS. The analysis is based on data from Taiwan’s National Health Insurance Research Database.MethodsFrom 2000 to 2017, we included a total of 395,811 cases aged 20 years or older newly diagnosed with infection. The cases were matched 1:1 with controls using a propensity score and were followed up until diagnoses of CFS were made.ResultsThe Cox proportional hazards regression analysis was used to estimate the relationship between infection and the subsequent risk of CFS. The incidence density rates among non-infection and infection population were 3.67 and 5.40 per 1000 person‐years, respectively (adjusted hazard ratio [HR] = 1.5, with a 95% confidence interval [CI] 1.47–1.54). Patients infected with Varicella-zoster virus, Mycobacterium tuberculosis, Escherichia coli, Candida, Salmonella, Staphylococcus aureus and influenza virus had a significantly higher risk of CFS than those without these pathogens (p < 0.05). Patients taking doxycycline, azithromycin, moxifloxacin, levofloxacin, or ciprofloxacin had a significantly lower risk of CFS than patients in the corresponding control group (p < 0.05).ConclusionOur population-based retrospective cohort study found that infection with common pathogens, including bacteria, viruses, is associated with an increased risk of developing CFS.

Assessment of the State of Antidiphtheria Immunity in Different Age Groups of the Population of the Russian Federation Based on Seromonitoring Data for 2015–2021

Relevance. Diphtheria is one of the dangerous diseases that threaten human life. Immunization is the only means of creating a favorable epidemiological situation. Ensuring the immunity of the population to this infection prevents the occurrence of the rise and spread of diphtheria among the population. One of the ways to assess the state of specific immunity to diphtheria is annual serological monitoring. Aims. Assessment of the state of antidiphtheria immunity in different age groups of the population of the Russian Federation based on seromonitoring data for 2015–2021. Materials and methods. The data of serological monitoring of diphtheria and the state of vaccination of the population by indicator groups from 85 subjects of the Russian Federation in 2015–2021 were analyzed. In just 7 years, in terms of seromonitoring in Russia, 439,874 people were examined for the presence of antibodies to diphtheria, including 73,559 children in the age group of 3–4 years, 74,424 adolescents aged 15–17 years, and 291,891 adults aged 18 and older. During the same period, 12,154 controlled blood sera from 20 subjects of the Russian Federation were examined. In the age group of 3–4 years – 1834 children, 15–17 years – 1366 teenagers, 18–29 years – 1711 adults, 30–39 years – 1724 adults, 40–49 years – 1918 adults, 50–59 years – 1798 adults, 60 years and older – 1803 adults. The presence of antibodies to diphtheria was determined in the course of passive hemagglutination. The protective titers of antibodies were taken to be dilution of sera with a titer of 1:20 or more, the intensity of anti-diphtheria immunity was assessed as follows: antibody titers in dilution of sera 1:20–1:40 – low titers, 1:80–1:160 – medium and 1:320 or more – high titers of antibodies of JSC «Biomed» im. I. I. Mechnikov. Results and discussion. In Russia, improving the surveillance system for diphtheria continues to be an urgent task of the private epidemiology of this infection. The data obtained during the study allowed us to characterize the population immunity of the population of the Russian Federation, as a whole across the country, as sufficient to prevent the occurrence and spread of diphtheria. The main factor contributing to this was the long-term high coverage of vaccinations against diphtheria of persons in the decreed age groups (more than 95% of those vaccinated from the number of persons to be vaccinated in each age group). When comparing the level of immunization of the population depending on age, it was found that the percentage of vaccinated persons in the age group of people 50 years and older was statistically significantly lower than in the group of people younger than 50 years. The data of serological studies in Russia as a whole showed a high proportion of people with protective titers of antibodies to diphtheria in each age group – 3–4 years – 96.7 ± 0.1%, 15–17 years – 98.3 ± 0.1%, 18–29 years – 96,0 ± 0,4% – 97,5 ± 0,3%, 30–39 – 95,9 ± 0,4% – 97,5 ± 0.3%, 40–49 years old – 95,7 ± 0,4% – 97,7 ± 0,3%. The largest proportion of seronegative individuals is detected among groups aged 50–59 years and 60 years and older. The analysis of the share of seronegative persons in certain subjects of the Russian Federation revealed that the number of territories with a share of seronegative persons of more than 10% in the age groups of 50–59 years and 60 years and older was significantly higher than in other age groups. Conclusion. Thus, when planning companies for «сatch-up» immunization, it is advisable to provide mandatory revaccination of seronegative persons over 50 years of age. Timely revaccination according to the National Vaccination Calendar, tracking the proportion of persons susceptible to diphtheria in all indicator groups, followed by revaccination of seronegative persons in older ages will allow maintaining a high level of population immunity (more than 95%) and ensuring a consistently low incidence of diphtheria in the country for many years.

Anti-HEV seroprevalence and rate of viremia in a German cohort of dogs, cats, and horses

Hepatitis E virus (HEV) genotype 3 infections in Germany are mainly transmitted zoonotically through the consumption of swine meat. Furthermore, there is evidence that pets might come into contact with HEV, but the relevance of companion animals as possible sources of HEV transmission in Germany still needs to be defined. A monitoring study was therefore carried out on dogs, cats, and horses from Germany. In total 365 serum samples from pets (124 dogs, 119 cats, and 122 horses) were tested for HEV by PCR and for anti-HEV antibodies by a commercial ELISA. The HEV seroprevalence determined by the sero-assay varied significantly between dogs (10%), cats (6%), and horses (2%). Liver injury-related enzymes, alanine transaminase (ALT), and aspartate transaminase (AST) showed no differences between HEV-positive or negative animals. None of the pet serum samples tested positive for PCR. This serological study suggests that dogs and cats are significantly exposed to HEV in Germany, while horses are of minor relevance.

The 2022 Banff Meeting Lung Report

The Lung Session of the 2022 16th Banff Foundation for Allograft Pathology Conference—held in Banff, Alberta—focused on non-rejection lung allograft pathology and novel technologies for the detection of allograft injury. A multidisciplinary panel reviewed the state-of-the-art of current histopathologic entities, serologic studies, and molecular practices, as well as novel applications of digital pathology with artificial intelligence, gene expression analysis, and quantitative image analysis of chest computerized tomography. Current states of need as well as prospective integration of the aforementioned tools and technologies for complete assessment of allograft injury and its impact on lung transplant outcomes were discussed. Key conclusions from the discussion were: (1) recognition of limitations in current standard of care assessment of lung allograft dysfunction; (2) agreement on the need for a consensus regarding the standardized approach to the collection and assessment of pathologic data, inclusive of all lesions associated with graft outcome (eg, non-rejection pathology); and (3) optimism regarding promising novel diagnostic modalities, especially minimally invasive, which should be integrated into large, prospective multicenter studies to further evaluate their utility in clinical practice for directing personalized therapies to improve graft outcomes.

Inhalation of Spray-Dried Extract of Salvia rosmarinus Spenn Alleviates Lung Inflammatory, Oxidative, and Remodeling Changes in Asthmatic Rats

Introduction: For centuries, Salvia rosmarinus Spenn has been applied as folk medicine to cure different diseases due to its anti-inflammatory, antibacterial, antioxidant, antifungal, and antitumor effects. To find bioactive medicinal herbs exerting a protective effect on airway inflammation and remodeling, we assessed the anti-oxidative and anti-inflammatory effects of an aqueous spray-dried extract of Salvia rosmarinus Spenn. (rosemary) in an ovalbumin-induced asthmatic rat model. Methods: Rats were randomly divided into normal control (control), asthma, asthma+rosemary extract (RE) (13 mg/kg), asthma+RE (50 mg/kg), and asthma+budesonide groups. After 50 days, animals were anesthetized, and then blood, bronchoalveolar lavage fluid (BALF), and lung tissues were collected for subsequent serological and pathological studies. Histopathology of lung tissues was evaluated by H&E staining. The oxidative stress parameters and airway inflammation factors in BALF and lung tissue were explored. Results: Using thin layer chromatography, the presence of rosmarinic acid was confirmed in aqueous extract of rosemary. Furthermore, RE markedly decreased immunoglobulin E levels (50 mg/kg; p < 0.001 vs. asthma group) and inflammatory cytokines (50 mg/kg; p < 0.001 vs. asthma group) and increased antioxidant enzymes (50 mg/kg, p < 0.001 vs. asthma group). Furthermore, RE at a concentration of 50 mg/kg obviously reduced the number of inflammatory cells, goblet cells, and pathological changes compared to the asthma group. Conclusion: The results showed that RE administration might prevent or alleviate allergic asthma-related pathological change, probably via antioxidant and anti-inflammatory mechanisms.

Seroprevalence of anti-SARS-CoV-2 antibodies before and after implementation of anti-COVID-19 vaccination among hospital staff in Bangui, Central African Republic.

Healthcare workers (HCWs) are at high to very high risk for SARS-CoV-2 infection. The persistence of this pandemic worldwide has instigated the need for an investigation of the level of prevention through immunization and vaccination against SARS-CoV-2 among HCWs. The objective of our study was to evaluate any changes in anti-COVID-19 serological status before and after the vaccination campaign of health personnel in the Central African Republic. We carried out a repeated cross-sectional serological study on HCWs at the university hospital centers of Bangui. Blood samples were collected and tested for anti-SARS-CoV-2 IgM and IgG using the ELISA technique on blood samples. A total of 179 and 141 HCWs were included in the first and second surveys, respectively. Of these staff, 31.8% of HCWs were positive for anti-SARS-CoV-2 IgG in the first survey, whereas 95.7% were positive for anti-SARS-CoV-2 IgG in the second survey. However, the proportion of HCWs positive for SARS-CoV-2 IgM antibodies was low (9.7% in the first survey and 3.6% in the second survey). These findings showed a sharp increase in seroprevalence over a one-year period. This increase is primarily due to the synergistic effect of the infection and the implementation of vaccines against COVID-19. Further studies to assess the persistence of anti-SARS-CoV-2 antibodies are needed.

Sero-epidemiology of bovine tuberculosis in dairy cattle in Chattogram, Bangladesh

Mycobacterium bovis-caused bovine tuberculosis (bTB) is a global public health concern and commercially significant zoonotic disease. Many wild and domesticated animals, including cattle, are susceptible to this fatal disease and play an important role in cross-species transmission. To gain a better understanding of bTB in dairy cattle, a bTB serological study is also necessary in order to identify efficient bTB control strategies in Bangladesh. In Bangladesh, however, seroepidemiological research is either non-existent or limited (particularly Chattogram). To determine the seroprevalence of bTB and related possible risk factors in dairy cattle, a serological cross-sectional study was conducted (both animal and farm level). We estimated the seroprevalence of bTB was 7.5%(N=442) in this investigation, which also identified one animal-level and two farm-level possible risk factors. Individual animal risk factors included cattle source (own stock: OR=3.4, 95% CI: 1.4-8.1, p=0.006), and farm risk factors included population size (Larger: OR= 26.2, 95% CI: 2.2-319.1, p=0.010) and stocking density (Low and moderate: OR=19.6, 95%CI: 1.5-261.5, p=0.024). In the face-in housing system, there was also a higher risk of bTB seropositivity (OR=4.5). The research's key findings are thoroughly explored, and the findings will aid in the prevention and control of bTB in Bangladesh. In addition, early detection of positive cases, as well as their prompt removal and good farm management practices, can assist in preventing the spread of bTB to new human or bovine hosts. In underdeveloped nations like Bangladesh, a coordinated effort with local public health officials is critical for implementing an efficient TB control program.

Assessing the post hoc effectiveness of tixagevimab-cilgavimab for prevention of SARS-CoV-2 infections in solid organ transplant recipients.

Tixagevimab-cilgavimab (Tix-Cil) was authorized for prophylaxis against COVID-19 in immunocompromised patients from December 2021 through January 2023. Real-world effectiveness for solid organ transplant (SOT) recipients has been unclear. We enrolled 911 SOT recipients into a longitudinal COVID-19 serology study, of whom 381 (42%) received ≥1 dose of Tix-Cil. We collected and analyzed data on incident SARS-CoV-2 infections and antibody kinetics for all patients from January 2022 to March 2023, including periods dominated by Omicron BA and BQ subvariants. Over 253 ± 131 days of follow-up, there were 324 new-onset SARS-CoV-2 infections: 117 (31%) in Tix-Cil treated and 207 (39%) in Tix-Cil untreated patients (p = .012). In analyses adjusting for demographic, clinical, and COVID-19 exposure factors, any Tix-Cil treatment was associated with lower infection risk (OR 0.52, 95% CI 0.27-0.96, p = .039) throughout the surveillance period including when more resistant BQ.1 and BQ.1.1 subvariants had emerged (12/1/2022 onwards). Among treated patients, receiving a Tix-Cil dose was associated with substantial and sustained increase in anti-spike IgG antibody and angiotensin-converting enzyme 2 binding inhibition levels (Abbott Architect assay) that together also demonstrated association with lower infection risk (p = .042). During the full surveillance period, the frequency of infections requiring hospitalization was low overall (N = 26, 2.9% of the total cohort) and not significantly different between Tix-Cil recipients (N = 12, 3.2% of treated patients) and non-Tix-Cil recipients (N = 14, 2.6% of untreated patients) with unadjusted p = .31 for between-group difference. In a large cohort of SOT recipients, we found that Tix-Cil reduced infection risk even amidst emergent Omicron subvariants. Additionally, the extent of measurable humoral response to Tix-Cil may indicate relative effectiveness. Pre-exposure monoclonal antibody therapy may represent a strategy that will continue to offer clinical benefit for immunocompromised persons who are known to derive limited protection from vaccinations.

Serological evidence for potential yellow fever virus infection in non-human primates, southeastern Mexico

BackgroundArthropod-borne flaviviruses like dengue virus (DENV) and yellow fever virus (YFV) are major human pathogens. In Latin America, YFV is maintained in sylvatic cycles involving non-human primates (NHP) and forest-dwelling mosquitos. YFV supposedly does not circulate north of Panama.MethodsWe conducted a serologic study for flaviviruses and other emerging viruses in NHP from southeastern Mexico. A total of thirty sera of black-handed spider monkeys (Ateles geoffroyi, n = 25), black howler monkeys (Alouatta pigra, n = 3), and mantled howler monkeys (Al. palliata, n = 2) sampled in 2012 and 2018 were screened by an indirect immunofluorescence assay (IFA) to detected IgG antibodies against DENV, YFV, Zika virus (ZIKV), West Nile virus (WNV), Rift Valley fever virus, Crimean-Congo hemorrhagic fever virus, Middle East respiratory syndrome coronavirus, and Zaire Ebola virus, and confirmed by plaque reduction neutralization tests (PRNT90) representing all mosquito-borne flavivirus serocomplexes circulating in the Americas.ResultsA total of 16 sera (53.3%; 95% CI, 34.3–71.7) showed IFA reactivity to at least one tested flavivirus with end-point titers ranging from 1:100 to 1:1000. No serum reacted with other viruses. Monotypic and high mean PRNT90 endpoint YFV titers of 1:246 were found in 3 black-handed spider monkey sera (10.0%; 95% CI, 2.1–26.5) sampled in 2018 in Tabasco, compared to all other flaviviruses tested. Monotypic endpoint PRNT90 titers of 1:28 for Ilheus virus and 1:22 for WNV in serum of black howler monkeys sampled in 2018 in Tabasco suggested additional flavivirus exposure.ConclusionsOur findings may suggest unnoticed YFV circulation. Intensification of YFV surveillance in NHP and vectors is warranted in Mexico and potentially other areas considered free of yellow fever.

Features of Local Bradyrhizobia Populations after Long-Term Period in the Soil without a Host Plant

In previous years, the serological and genetic diversities of soybean nodule bacteria in agrocenoses of Ukraine have been researched. Less attention was paid to the study of their survival in the soil. Taking into account the natural heterogeneity of bacteria of the genus Bradyrhizobium, the aim of this work was to evaluate the diversity of bradyrhizobia in local populations of different soils after a long-term period without leguminous plants, to obtain new isolates of nodule bacteria and to study their properties. Methods. Microbiological (isolation of bradyrhizobia from the nodules of trap plants, study of the properties of strains), serological (study of the diversity of rhizobia in nodule populations, study of the serological affiliation of strains), vegetation and field experiments (study of plant infecting with bradyrhizobia). Results. Local populations of bradyrhizobia in sod-podzolic soil and leached chornozem were studied using trap plants of the genera Glycine, Vigna, and Lupinus. It was established that after a 7 to 8-year period without leguminous plants, active nodule bacteria remained in both types of soil, which nodulated cultivated and wild soybeans, cowpeas, mung beans, adzuki beans, and lupine. The main microsymbionts of plants of the genera Glycine and Vigna on different types of soil were soybean bradyrhizobia belonging to 6 serological groups: 46, M8, КВ11, 634b, HR, and B1. The representatives of 4 serogroups corresponded to the inoculant strains of Bradyrhizobium japonicum 46, M8, 634b, and КВ11, which were periodically used in the studied areas. In addition to B. japonicum, cowpea plants trapped microsymbionts of B. lupini serogroup 367a (4.2%) from the soil. Bradyrhizobia of serogroup B1 were detected both in nodules of cowpea (6.3%) and wild soybean (12.5%). 45.8% of lupine nodules were formed by bacteria B. lupini of serogroup 367a. The appearance in populations of representatives of serogroups HR and B1 along with a group of unidentified microsymbionts requires further research. Cultivation of trap plants of wild soybeans and various types of cowpea made it possible to identify saprophytic strain B. japonicum M8 (formed 25.0% to 83.4% of nodules) in the sod-podzolic soil, which did not infect the roots of cultivated soybeans. 70 isolates of bradyrhizobia were obtained from nodules of trap plants, which were preliminarily identified as B. japonicum, B. lupini, and Bradyrhizobium sp. Conclusions. The results confirm the importance of using different leguminous trap plants for a more complete characterization of the local rhizobial community. Cultivation of plants of the genera Glycine, Vigna, and Lupinus, capable of cross-infection, made it possible to detect bacteria B. japonicum (serogroups 46, M8, КВ11, 634b, HR), B. lupini (serogroup 367a), and Bradyrhizobium sp. (serogroup B1), which exist for a long-term period as saprophytes in sod-podzolic soil and leached chornozem. 70 isolates of bradyrhizobia were obtained, 35 of which were serologically related to the inoculant strains of B. japonicum introduced into the agrocenosis at the beginning of the research.