Serological Reactions Research Articles

Risk factors and outcome of hepatitis C infection among patients in a secondary care hospital: A 5-year retrospective study.

Hepatitis C virus (HCV) infection, predominantly transmitted by exposure to infected blood, remains one of the major public health problems worldwide. This study aims to identify the risk factors of HCV transmission and its chronic complications among the study group. This retrospective study was approved by the Research and Ethical Review and Approve Committee (RERAC) of Oman and conducted at a secondary-care hospital situated in the North Batinah region of Oman. The study population included all HCV cases confirmed by positive serology and reverse-transcription polymerase chain reaction tests during their presence at the hospital between January 2017 and December 2022. The relevant data of the study population were retrieved from the hospital electronic health record system. The data were analyzed using the Statistical Package for the Social Sciences (SPSS), Version 26.0. A total of 177 HCV confirmed cases were included in the study. HCV infection was predominant among males (74%) and individuals of the age group of 21-60 years (74.6%). Genotyping was possible only in 107 cases. Among HCV genotypes, genotype 3 (58.9%) was the most frequently identified, followed by genotype 1 (34.6%). Hemodialysis (21.5%), history of blood transfusion (16.4%), and injection drug use (11.9%) were the major risk factors for HCV infection, while cirrhosis (7.3%) and fatty liver disease (4%) were the most frequently observed chronic HCV complications. HCV infection in the spouse/partner (21.5%), alcohol use (7.3%), and co-infection with hepatitis B virus (2.3%) and human immunodeficiency virus (1.7%) were the other significant factors detected in our study population. HCV is a multi-factorial disease leading to severe chronic complications, thus representing a public health threat. This clearly emphasizes the cruciality of HCV community awareness campaigns and enhancement of Omani national guidelines for early screening of high-risk groups as well as effective management of HCV-infected cases to reduce the substantial burden of the disease on patients as well as the healthcare system.

Outbreak of Mycoplasma pneumoniae pneumonia in hospitalized patients: Who is concerned? Nord Franche-Comté Hospital, France, 2023-2024.

We report an outbreak of confirmed Mycoplasma pneumoniae community-acquired pneumonia (CAP) in Nord Franche-Comté Hospital, France, from 14 November 2023 to 31 January 2024. All 13 inpatients (11 adults with a mean age of 45.5years and 2 children) were diagnosed with positive serology and/or positive reverse transcription polymerase chain reaction (RT-PCR) on respiratory specimens. All patients were immunocompetent and required oxygen support with a mean duration of oxygen support of 6.2days. Two patients were transferred to the intensive care unit (ICU) but were not mechanically ventilated. Patients were treated with macrolides (n=12, 92.3%) with recovery in all cases. No significant epidemiological link was reported in these patients.

Sars-cov-2 and denv co-infection: Diagnostic challenge and curse on overloaded health care system

Co-infection with dengue is posing a diagnostic challenge in dengue-endemic countries because of similar clinical symptoms & laboratory findings between COVID 19 and Dengue infection. This co-infection is a warning for dengue endemic regions to face the challenge of differentiating and managing two disease entities together as both show serological cross reactivity which can mislead the timely diagnosis and treatment and is associated with increased mortality. And if timely diagnosis is not made, it will spread the virus to other people as timely isolation will not be done.: Present study aimed to determine the prevalence of COVID-19 & dengue co-infection in a tertiary care centre and to compare the laboratory findings among patients of COVID-19, dengue and co-infection cases. : This cross-sectional study was conducted in the Department of Microbiology, SMSR, Sharda Hospital and University. : This cross-sectional study was done on COVID-19 positive patients and dengue positive patients over the period of four months. Nasopharyngeal/ oropharyngeal swabs were subjected to RT-PCR for COVID-19 infection and serum samples of the patients were used for performing rapid card test for dengue infection. : The statistical analysis was performed with SPSS Software (Statistical Package for Social Sciences) and presented in form of tables and graphs. P<0.05 was considered as statistically significant. Out of 45 cases with COVID-19 & DENV co-infection, age group 40-70yrs constitute 62.2% of cases. 24.4% (11 patients) out of 45 co-infection patients showed leucopenia. 62.2% (28 patients) out of 45 co-infection patients showed lymphopenia. 64.4% (29 patients) out of 45 co-infection patients showed increased levels of D-Dimer. 48.9% (22 patients) out of 45 co-infection cases developed thrombocytopenia. : In dengue-endemic regions like India overlapping out-breaks of dengue & COVID-19 infection, poses a challenge for accurate diagnosis & treatment because of similarities in clinical symptoms and laboratory findings.

A new genotype of hepatitis A virus causing transient liver enzyme elevations in Mauritius-origin laboratory-housed Macaca fascicularis.

Hepatitis A virus (HAV) infects humans and nonhuman primates, typically causing an acute self-limited illness. Three HAV genotypes have been described so far for humans, and three genotypes have been described for nonhuman primates. We observed transiently elevated liver enzymes in Mauritius-origin laboratory-housed macaques in Germany and were not able to demonstrate an etiology including HAV by serology and polymerase chain reaction (PCR). HAV is a rare pathogen in cynomolgus macaques, and since all employees were routinely vaccinated against HAV, it was not a part of the routine vaccination and screening program. A deep sequencing approach identified a new HAV genotype (referred to as Simian_HAV_Macaca/Germany/Mue-1/2022) in blood samples from affected animals. This HAV was demonstrated by reverse transcription PCR in blood and liver and by in situ hybridization in liver, gall bladder, and septal ducts. A commercial vaccine was used to protect animals from liver enzyme elevation. The newly identified simian HAV genotype demonstrates 80% nucleotide sequence identity to other simian and human HAV genotypes. There was deeper divergence between Simian_HAV_Macaca/Germany/Mue-1/2022 and other previously described HAVs, including both human and simian viruses. In situ hybridization indicated persistence in the biliary epithelium up to 3 months after liver enzymes were elevated. Vaccination using a commercial vaccine against human HAV prevented reoccurrence of liver enzyme elevations. Because available assays for HAV did not detect this new HAV genotype, knowledge of its existence may ameliorate potential significant epidemiological and research implications in laboratories globally.

New brucellosis erythrocyte diagnosticum for IHT in comparison with other serological methods (SAT, CFT, RBT and IDT)

Relevance. Brucellosis is registered in many countries of the world, including Russia. The most unfavorable situation in the Russian Federation has developed in the Southern and North Caucasus Federal Districts. In the first place among the number of identified sick animals is the Dagestan Republic, where, despite the efforts of veterinary specialists, it is not possible to reduce the number of oci of brucellosis. With the help of classical methods (SAT, CFT), only 70% of animals infected with brucellosis can be detected. In this regard, domestic and foreign researchers have done a lot of work to improve existing and develop new diagnostic tools and methods.Methods. One of the most sensitive methods for the diagnosis of brucellosis is the indirect hemagglutination reaction (IHT). In comparative tests in IHT, with an improved antigen, good results were obtained.Results. The possibility of obtaining a highly active erythrocyte diagnosticum has been established with the combined use of two new surfactants: Progress products manufactured by AMC Media LLC (LosinoPetrovsk, Moscow region) and sodium dodecyl sulfate. The most rational parameters of the use of detergents for the treatment of brucella suspension and their optimal concentrations have been determined. It was found that IHT with a new antigen is specific and highly sensitive, compared with other serological reactions.

Possible effect of mutations on serological detection of Borrelia burgdorferi sensu stricto ospC major groups: An in-silico study.

The outer surface protein C (OspC) of the agent of Lyme disease, Borrelia burgdorferi sensu stricto, is a major lipoprotein surface-expressed during early-phase human infections. Antibodies to OspC are used in serological diagnoses. This study explored the hypothesis that serological test sensitivity decreases as genetic similarity of ospC major groups (MGs) of infecting strains, and ospC A (the MG in the strain B31 used to prepare antigen for serodiagnosis assays) decreases. We used a previously published microarray dataset to compare serological reactivity to ospC A (measured as pixel intensity) versus reactivity to 22 other ospC MGs, within a population of 55 patients diagnosed by two-tier serological testing using B. burgdorferi s.s. strain B31 as antigen, in which the ospC MG is OspC A. The difference in reactivity of sera to ospC A and reactivity to each of the other 22 ospC MGs (termed 'reactivity difference') was the outcome variable in regression analysis in which genetic distance of the ospC MGs from ospC A was the explanatory variable. Genetic distance was computed for the whole ospC sequence, and 9 subsections, from Neighbour Joining phylogenetic trees of the 23 ospC MGs. Regression analysis was conducted using genetic distance for the full ospC sequence, and the subsections individually. There was a significant association between the reactivity difference and genetic distance of ospC MGs from ospC A: increased genetic distance reduced reactivity to OspC A. No single ospC subsection sequence fully explained the relationship between genetic distance and reactivity difference. An analysis of single nucleotide polymorphisms supported a biological explanation via specific amino acid modifications likely to change protein binding affinity. This adds support to the hypothesis that genetic diversity of B. burgdorferi s.s. (here specifically OspC) may impact serological diagnostic test performance. Further prospective studies are necessary to explore the clinical implications of these findings.

Serological Prevalence of Latent Epstein-Barr Virus Infection in Children and Adolescents

Background: Epstein-Barr Virus (EBV), first discovered in 1946, is one of the most common viruses, which found over the world causing latent infection or different undistinguishable symptoms ranged from mild to severe. This prevalence and age distribution of this latent infection varies significantly in different populations. Aim: Serological detection of anti-EBV IgG antibodies in children and adolescents using of the sandwich enzyme-linked immunosorbent assay (ELISA), and estimating the association of seropositivity to sex of study population. Materials and Methods: A total of 182 serum samples were obtained randomly from the study population that involved children (5-12 years old) and adolescents (13-17 years old) of both sexes in Sulaymaniyah province (Iraq) during January-February (2023). Results: Sera of an overall 29.12% study individuals were showed a serological positive reactivity to EBV-IgG antibodies. Significantly (P<0.0289), latent EBV was higher in adolescents (42.86%) than those observed in children (15.39%). Concerning the association of seropositivity to sex of study population, there was a significant increase (P<0.0224) in prevalence of anti-EBV-IgG antibodies among females (42.47%) than males (20.18%). Also, females were appeared significantly (P<0.0001) at higher risk of infection (2.104) than males (0.475). Conclusion: The seroprevalence of latent EBV infection in female adolescent was higher than male children; however, additional investigations using of serological as well as molecular assays are of great importance to demonstrate the extent of infection and to define the full spectrum of EBV-associated diseases.

Pulmonary coccidioidomycosis complicated by nontuberculous mycobacterial pulmonary diseases with a literature review.

Following endobronchial examination, a young mine supervisor was treated with antibiotics for a pulmonary nontuberculous mycobacterial infection for approximately 1 year. However, a review of the radiological findings, which had not been previously assessed, revealed a different possibility. Accordingly, pulmonary resection was performed, enabling histopathological analysis, which showed numerous yeast-like fungi. Given the history of a stay in the southwestern United States for 2 months in 2009, 8 years previously, coccidioidomycosis was strongly suspected and the diagnosis was subsequently confirmed by serology and polymerase chain reaction testing of the excised specimen. Here, we report an educational case emphasizing the importance of meticulous medical history-taking and awareness of endemic mycoses in other countries in the context of globalization.

Treatment Leptospira Infection In Dog At Pet Vet Clinic, Center of Jakarta

Leptospirosis is a disease caused by Leptospira spp., zoonotic Gram-negative bacteria. This study aimed to determine the handling of a leptospirosis case in a dog at the Pet Vet Clinic, Jakarta. Handling began with anamnesis and continued by examining the patient's physical condition, followed by serological, microscopic, and polymerase chain reaction examinations. An examination revealed that the dog had Leptospirosis. The therapy given was the administration of crystalline procaine and penicillin-G antibiotics. Supportive treatment was given with hepatoprotective, lipotropic, and diuretic supplements. Ringer's lactate was used as fluid therapy. The treatment administered showed positive, progressive results in the patient.

Ischemic strokes revealing neurosyphilis: Study of six (6) observations at the neurology Department of the University Hospital of Conakry.

In sub-Saharan Africa (SSA), stroke is a major public health problem and the etiological aspects are poorly studied and documented because of under-medicalization; the syphilitic etiology is rarely mentioned. We performed a retrospective study of 472 patients hospitalized for ischemic stroke between 2016 and 2021 in the Neurology Department of the University Hospital of Conakry, confirmed by neuroradiological explorations (brain CT, MRI-Angio) and a biological workup including VDRL-TPHA serological reactions in blood and CSF. Syphilitic etiology was retained for six (6) patients (4 men and 2 women) with a mean age of 43years (extremes 36 and 49years). The clinical picture was dominated by carotid syndromes: superficial and deep sylvian syndrome, anterior cerebral artery syndrome and vertebro-basilar syndromes and one case of lacunar syndrome.The diagnosis was based on the positivity of serological reactions (VDRL-TPHA) in blood and cerebrospinal fluid (CSF) and the presence of a predominantly lymphocytic hypercellularity and a hyperproteinorachy in the CSF in the absence of any other etiology. These neurological vascular syndromes consecutive to a cerebral treponematous attack are often the result of a still poorly conducted management of primary and secondary syphilis in our country.

Pathogenic Leptospira are widespread in the urban wildlife of southern California

Leptospirosis, the most widespread zoonotic disease in the world, is broadly understudied in multi-host wildlife systems. Knowledge gaps regarding Leptospira circulation in wildlife, particularly in densely populated areas, contribute to frequent misdiagnoses in humans and domestic animals. We assessed Leptospira prevalence levels and risk factors in five target wildlife species across the greater Los Angeles region: striped skunks (Mephitis mephitis), raccoons (Procyon lotor), coyotes (Canis latrans), Virginia opossums (Didelphis virginiana), and fox squirrels (Sciurus niger). We sampled more than 960 individual animals, including over 700 from target species in the greater Los Angeles region, and an additional 266 sampled opportunistically from other California regions and species. In the five target species seroprevalences ranged from 5 to 60%, and infection prevalences ranged from 0.8 to 15.2% in all except fox squirrels (0%). Leptospira phylogenomics and patterns of serologic reactivity suggest that mainland terrestrial wildlife, particularly mesocarnivores, could be the source of repeated observed introductions of Leptospira into local marine and island ecosystems. Overall, we found evidence of widespread Leptospira exposure in wildlife across Los Angeles and surrounding regions. This indicates exposure risk for humans and domestic animals and highlights that this pathogen can circulate endemically in many wildlife species even in densely populated urban areas.

Brucella abortus Strain RB51 Administered to Prepubescent Water Buffaloes, from Vaccination to Lactation: Kinetics of Antibody Response and Vaccine Safety.

Brucella RB51 is a live modified vaccine. Its use in water buffalo has been proposed using a vaccination protocol different to that used for cattle, but knowledge of the long-term effects of RB51 vaccination in this species remains incomplete. The aim of the study was to evaluate the safety and kinetics of antibody responses in water buffaloes vaccinated according to the protocol described for the bovine species in the WOAH Manual, modified with the use of a triple dose. Water buffaloes were vaccinated with the vaccine RB51. A booster vaccination was administered at 12 months of age. When turning 23-25 months old, female animals were induced to pregnancy. RB51-specific antibodies were detected and quantified using a CFT based on the RB51 antigen. Vaccinated animals showed a positive serological reaction following each vaccine injection, but titers and the duration of the antibody differed among animals. For 36 weeks after booster vaccination, the comparison of CFT values between vaccinated and control groups remained constantly significant. Afterwards, antibody titers decreased. No relevant changes in antibody response were recorded during pregnancy or lactation. In conclusion, results indicated that the vaccination schedule applied is safe and allows for vaccinated and unvaccinated controls to be discriminated between for up to 8 months after booster vaccination.

Confirmation of Groundnut ringspot orthotospovirus (GRSV) Infection in Eggplant Cultivars in Brazil.

Eggplant (Solanum melongena L.) is an economically important vegetable crop in Brazil, especially in family-based farming. Eggplant hybrids 'Ciça' and 'Napoli' (≈ 400 plants) were detected exhibiting virus-like symptoms (5-20% incidence) in field surveys (2015-2018) in Brasília-DF (Figure 1). Symptoms included chlorosis, mosaic and apical leaf deformation. Six symptomatic leaf samples were collected from fruit-bearing plants (around 100 days after planting) aiming at verifying the potential orthotospovirus infection. Double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) was carried out with polyclonal antibodies (produced at Centro Nacional de Pesquisa de Hortaliças - CNPH) against the N gene coat protein of the three major orthotospoviruses: tomato spotted wilt orthotospovirus (TSWV), groundnut ringspot orthotospovirus (GRSV) and, tomato chlorotic spot orthotospovirus (TCSV). Strong serological reactions were observed only against GRSV antibodies in the extracts from symptomatic samples, but not in the controls. To confirm the causal agent of those symptoms, total RNA was extracted from infected leaf samples via the standard Trizol® (Sigma) protocol and subsequently used in a two-step reverse transcriptase polymerase chain reaction (RT-PCR) approach. Synthesis of the cDNA was carried out with the J13 primer (5'-CCC GGA TCC AGA GCA AT-3') (Cortez et al., 2001) followed by PCR assays with the primer pair BR60 (5'-AGA GCA ATC GTG TCA-3`) and BR65 (5`-ATC AAG CCT TCT GAA AGT CAT-3') (Eiras et al., 2002). This primer set amplifies a fragment of 453 bp including the 3' untranslated region at the 3' terminus of the S RNA and the protein N-coding gene of at least five species: TSWV, GRSV, TCSV, chrysanthemum stem necrosis orthotospovirus (CSNV) and zucchini lethal chlorosis orthotospovirus (ZLCV). In addition, GRSV-specific primers (LNA Reis, unpublished) were used for amplification of all three segments: L segment: LF/LR (5'-AAC AGG ATT CAG CAA TAT GG-3'/ 5'-AAT TCC TTG AAG ACA ATT GTG T -3'); M segment: MF/MR (5'-TTT GTC CAA CCA TAC CAG ACC C- 3' / 5'-GGC TTC AAT AAA GGC TTG GG-3') and, S segment: SF/SR (5'-TTC AAA CTC AGT TGT ACT CTG A-3'/5'-TTA CTT TCG ATC TGG TTG AA- 3'). Amplicons with 509 bp (MT043204), 289 bp (MT043205), and 901 bp (MT043203) were obtained for L, M and S segments of the eggplant isolate DF-687. PCR amplicons corresponding to a segment of the N-coding gene (396 bp) of a second eggplant isolate (BJL02; MK176337) were obtained with the primer pair BR60/BR65 and subjected to Sanger dideoxy sequencing at CNPH. Alignments of nucleotide sequences of both isolates revealed identity levels varying around 99% to the corresponding genomic regions of a large set of GRSV isolates from GenBank database. PCR assays using total RNA as template yielded 494 bp amplicons solely with GRSV-specific primers (Webster et al., 2011), but no products were obtained with TSWV-specific primers (Adkins and Rosskopf, 2002), confirming the former as the sole causal agent of the field symptoms. Leaves of eggplant cv. 'Ciça' and indicator hosts, including Nicotiana rustica, Capsicum chinense 'PI 159236' (with the Tsw gene), and S. lycopersicum cv. Santa Clara were rub inoculated with extracts prepared from eggplant samples naturally infected with GRSV. Mosaic, necrotic ringspots and systemic leaf deformation symptoms were observed around ten days after inoculation on newly emerged leaves of all inoculated plants. GRSV infection was confirmed by DAS-ELISA and RT-PCR ten days after inoculation. Eggplant was erroneously listed as a host of GRSV in Brazil (Kitajima, 2020). Hence, this is the first report of eggplant infection by this virus in South America. No significant yield losses have been observed in eggplant due to GRSV infection since the overall symptoms are often mild. However, this natural host of GRSV might impact disease management strategies since eggplant is quite often cultivated under family-based farming conditions as a companion crop of highly susceptible tomato, sweet-pepper, and lettuce cultivars.

Prevalence of Hepatitis C Virus and Its Occult Infection in Hemodialysis Patients

Background: Hepatitis C virus (HCV) is one of the most common infections in hemodialysis patients, which has been associated with increased incidence of morbidity and mortality, particularly in low- and middle-income countries. Objectives: The current study aimed to evaluate the HCV antibody, occult HCV infection (OCI), and related risk factors among hemodialysis patients. Methods: In this cross-sectional study, 100 hemodialysis patients referred to a dialysis center in Kerman between December 2021 and March 2022 were assessed for HCV, OCI, and their related risk factors. The information related to risk factors was collected by questionnaire, while HCV and OCI were detected through serology and real-time polymerase chain reaction (PCR) methods, respectively. Results: Among the patients participating in the study, 61 were men, and 39 were women. The average age was 58.1 ± 14.9 years in men and 63.6 ± 11.4 years in women. Diabetes and hypertension history, old age, low education, self-employment, and urban living were more common in chronic kidney disease patients. The enzyme-linked immunosorbent assay (ELISA) revealed 3% positive seroprevalence HCV infection, but only 1% was positive for OCI. Although no statistically significant relationship was found between the presence of HCV (antibody and OCI) and other parameters, all positive HCV cases were identified in patients with low education and freelance employment. Conclusions: Hemodialysis patients had a low prevalence of HCV antibody and OCI. Improving various factors and conditions such as lifestyle, occupation, educational level, and dialysis ward and machine disinfection could be beneficial in managing and controlling hemodialysis complications such as HCV and OCI.

Serological relationships among strains of grapevine leafroll-associated virus 4 reflect the evolutive behavior of its coat protein gene

This research studied serological relationships and genetic diversity of Argentinean isolates of grapevine leafroll-associated virus-4 (GLRaV-4). Phylogenetic analysis of coat protein (CP) sequences from 19 local isolates revealed clustering with the previously described GLRaV-4 strain 5, strain 6, and strain 9 groups. Evolutionary sequence analysis of the obtained and database-available sequences showed evidence of recombination events. Additionally, both CP N- and C-terminal regions appeared to be under purifying selection, but the N-terminal region presented seven sites under positive selection, with a dN/dS ratio 5-fold greater than that of the C-terminal region. Serological reactivity against monoclonal antibodies supports a higher occurrence probability for linear epitopes in the N-terminal region, as inferred by the sequence analysis. The obtained results reflect an unusual evolutionary behavior of the CP that, together with protein serological reactivity, suggests biological significance of the observed variability. Highlights: The occurrence of GLRaV-4 strains -5, -6 and -9 was recorded in Argentina. The coat protein sequence showed a highly variable N-terminal region among the strains. An evolutionary analysis inferred the occurrence of sites under positive diversifying selection pressure. The most variable region of the coat protein presented the highest probability of occurrence of linear epitopes.

West Nile virus emergence in humans in Extremadura, Spain 2020.

In Spain, the largest human West Nile virus (WNV) outbreak among humans was reported in 2020, constituting the second most important outbreak in Europe that season. Extremadura (southwestern Spain) was one of the affected areas, reporting six human cases. The first autochthonous human case in Spain was reported in Extremadura in 2004, and no other human cases were reported until 2020. In this work, we describe the first WNV human outbreak registered in Extremadura, focusing on the most important clinical aspects, diagnostic results, and control actions which followed. In 2020, from September to October, human WNV infections were diagnosed using a combination of molecular and serological methods (an in-house specific qRT-PCR and a commercial ELISA for anti-WNV IgM and IgG antibodies) and by analysing serum, urine, and/or cerebrospinal fluid samples. Serological positive serum samples were further tested using commercial kits against related flaviviruses Usutu and Tick-borne encephalitis in order to analyse serological reactivity and to confirm the results by neutralisation assays. In total, six cases of WNV infection (five with neuroinvasive disease and one with fever) were identified. Clinical presentation and laboratory findings are described. No viral RNA was detected in any of the analysed samples, but serological cross-reactivity was detected against the other tested flaviviruses. Molecular and serological methods for WNV detection in various samples as well as differential diagnosis are recommended. The largest number of human cases of WNV infection ever registered in Extremadura, Spain, occurred in 2020 in areas where circulation of WNV and other flaviviruses has been previously reported in humans and animals. Therefore, it is necessary to enhance surveillance not only for the early detection and implementation of response measures for WNV but also for other emerging flaviviruses that could be endemic in this area.

Occurrence of serological reactions for Leptospira spp. in donkeys and mules from Minas Gerais, Brazil.

Research concerning leptospirosis in donkeys and mules has been neglected around the world. Therefore, the aim of this study was to investigate the epidemiological situation of the prevalence of anti-Leptospira spp. antibodies in donkeys and mules from the state of Minas Gerais, Brazil. Blood serum samples were collected from 180 animals (109 donkeys and 71 mules) in two rural properties from the state of Minas Gerais, Brazil, and then submitted to a microscopic agglutination test (MAT). Urea and creatinine values were also quantified. Epidemiological variables such as age, breeding system, contact with other animal species, source of water and food, vaccination against leptospirosis, presence of reproductive alterations, and rodent control were also investigated. From 180 samples collected, 39 (21.67%) showed positive results in the MAT, at a dilution ≥ 1:100. Some animals were reactive for more than one serovar. The serovar Tarassovi was the most frequent (14.07%), followed by Hardjo (11.85%) and Wolffi (11.11%). There was a statistically significant difference between animals from 0 to 3 years of age reactive in the MAT in comparison to the other age groups. Most of the animals had urea and creatinine concentrations within the acceptable reference limit; however, there was a significant increase in creatinine levels in some of the test animals. The studied properties showed differences in some epidemiological aspects such as vaccination of the animals, presence of reproductive problems in the herd, and rodent control. Such aspects pointed as risk factors that may influence the frequency of positive serological results in property 1. The present study demonstrated that the prevalence of leptospirosis in donkeys and mules is high and several serovars are being maintained by these animals, representing a potential public health risk.

Delayed positivity of serological reactions in secondary syphilis against the background of severe HIV-induced immunosuppression

In recent decades, there has been an increase in syphilis associated with HIV infection cases, especially among men who have sex with men. The global prevalence of syphilitic infection among people living with HIV exceeds population rates. Concomitant HIV infection can affect not just the clinical course of syphilis, but also the production of antibodies to Treponema pallidum. In the presence of severe immunodeficiency in patients with HIV infection associated with secondary syphilis, the results of non-treponemal and/or treponemal tests may be false-negative or may become positive at a later date. Such cases are known, they occur infrequently and cause some diagnostic difficulties. The article presents a clinical observation of delayed positivity of serological reactions in secondary syphilis in a 23-year-old HIV-positive man from the authors' practice. The tactic of managing HIV-infected patients with clinical symptoms of syphilis and negative results of serological tests is discussed.

Clinical investigation and management of Brucella suis seropositive dogs: A longitudinal case series.

Brucellosis in dogs caused by Brucella suis is an emerging zoonotic disease. To document clinical characteristics, serology, microbiology, and clinical response to treatment in B. suis-seropositive dogs. Longitudinal study of 27 privately-owned dogs. Dogs that tested positive by serology, culture, or real-time polymerase chain reaction (qPCR) were included in the study. Clinical (physical examination and imaging) and laboratory (serology, hematology, serum biochemistry, and qPCR or culture) assessments were made at baseline and after approximately 3, 6, 12, and 18 months. Dogs were followed for 10 895 dog days, with 17/27 dogs completing the 18-month follow-up. Ten dogs had signs consistent with brucellosis before enrollment (n=4), at baseline (n=2) or during follow-up (n=6), with 2 dogs experiencing relapse of historical signs. Antibody titers persisted for the duration of follow-up in 15/17 dogs (88%). Radiographic (n=5) and ultrasound (n=11) findings, of variable clinical relevance, were observed. Brucella DNA and organisms were detected in 3 dogs, all of which had clinical signs, including in the milk of a bitch around the time of whelping. Brucella DNA was not detected in blood (n=92 samples), urine (n=80), saliva (n=95) or preputial swabs (n=78) at any time during follow-up. Six dogs underwent treatment, all of which achieved clinical remission although remission was not reflected by decreasing antibody titers. Most dogs with B. suis infections have subclinical infections. Serology is poorly associated with clinical disease. Excretion of organisms appears rare except in whelping bitches. Clinical management using antibiotics with or without surgery is recommended.

Immunological reactivity of animals with tuberculosis under the influence of ionising radiation

Effective control of animal tuberculosis is possible only with a comprehensive examination of the biology of the pathogen, epizootiology, pathogenesis, prevention methods, economic and environmental factors that affect the course of the disease. It is known that radiation exposure leads to autosensitisation of the body by the breakdown products of its tissues and the development of non-specific (false) immunological reactions. Therefore, the purpose of the study was to examine the immunological (serological) reactivity of tuberculosis patients exposed to gamma radiation in laboratory animals. Radiological, bacteriological, allergic, serological, and pathoanatomical research methods were used in the study. Guinea pigs were consistently irradiated with various doses of gamma rays, infected with Mycobacterium tuberculosis of various types, and, for 90 days, were examined by clinical, allergic, pathoanatomical, and serological methods in the complement fixation reaction (CFR) and passive hemagglutination reaction (PHGR) according to Boyden to detect antitubercular complementbinding antibodies and tissue autoantibodies. 45 and 90 days after infection with M. bovis and M. tuberculosis antitubercular complement-binding antibodies were recorded in serum samples of irradiated and non-irradiated animals in diagnostic titres (1:20-1:80), which indicates the active development of the infectious process. In irradiated and intact guinea pigs infected with M. avium, no anti-tuberculosis antibodies were detected in since guinea pigs are not susceptible to infection with the causative agent of avian tuberculosis. In serum samples from uninfected guinea pigs, both irradiated and intact, antitubercular complement-binding antibodies were not detected during the entire follow-up period (90 days). The high content of tissue autoantibodies in blood serum samples of animals irradiated with a dose of 200 R (0.0516 C/kg) is a manifestation of autosensitisation of the body by the breakdown products of its tissues due to radiation damage. The presence of tissue autoantibodies in blood serum samples of irradiated and Mycobacterium-infected animals did not affect serological indicators for the indication of anti-tuberculosis antibodies, which should be considered when conducting diagnostic studies by veterinary medicine laboratories