STUDY OF HUMORAL IMMUNITY TO INFECTIONS IN MEDICAL WORKERS

Introduction. In the course of their work, medical workers are exposed to a biological factor, including bacterial, viral nature. Medical personnel come into contact with patients with measles, rubella, diphtheria, tuberculosis, hepatitis, coronavirus infection and other infectious diseases. The aim of the study is to assess the humoral immunity by the presence antibodies to the measles, rubella, hepatitis B viruses, to the causative agent COVID-19, tuberculosis and diphtheria bacteria in health care workers. Methods. Antibodies to measles, rubella, hepatitis B viruses, diphtheria and tetanus pathogens were measured in blood serum samples of 1221 MW; total antibodies to mycobacterium tuberculosis - in 120 MW; antibodies to the nucleocapsid protein of the SARS-CoV-2 virus – in 301 MW. The study was carried out by the method of enzyme immunoassay using commercial test systems; antibodies to diphtheria toxoid were detected in the passive hemagglutination reaction. The control group consisted of persons of engineering and technical personnel, comparable in age, gender and work experience. Results. Medical personnel were found to have significantly more frequent detection of seronegative reactions to the presence of antibodies to the hepatitis B virus (40.9% and 13.5%, p<0.001) of measles (28.8% and 3.9%, p<0.05); significantly high prevalence in the presence of total antibodies to mycobacterium tuberculosis (7.5% of cases in medical, 0% of cases of workers in the control group, p<0.05). In comparison with doctors, nurses had a significantly higher prevalence of antibodies to the nucleocapsid of the SARS-CoV-2 virus (38.9% and 23.7%, p<0.05). Conclusions. The study of post-vaccination immunity in medical workers showed the presence of a high proportion of seronegative individuals among vaccinated (viral hepatitis B, measles) medical workers and, accordingly, significant biological risks. A higher seroprevalence in total antibodies to Mycobacterium tuberculosis may also indicate insufficient immune protection among MW. The biological significance of seroprevalence to SARS-CoV-2 virus proteins (for nurses) requires further study.

Seroprevalence of mycoplasmosis in broiler, layer, and native chickens in Giza, Egypt

We aimed to investigate Mycoplasma infections among chicken flocks (Ross, Lohmann and native) in Giza, Egypt, using serological tests, including the slide plate agglutination (SPA) test, hemagglutination inhibition (HI) test, and enzyme-linked immunosorbent assay (ELISA). The slide plate agglutination examination, a serological test, indicated the prevalence of Mg and Ms infections of 10.9% and 13.2%, respectively. On 91 SPA test positive serum samples for either Mg or Ms, a passive hemagglutination/hemagglutination inhibition (HI) test was performed. The SPA and HI test findings were found to be comparable. On 90 SPA test positive samples, an ELISA was performed using commercial kits for Mg and Ms serodiagnosis. According to the ELISA data, only 83.33% and 18.88% of SPA test positive samples were confirmed as positive for Ms and Mg infections, respectively. The prevalence increased to 84.44% and 77.77%, respectively, when suspected samples were deemed positive.

State of the immune system in women using the “Provag” probiotic

Lactobacilli are widely used in clinical practice as probiotics, biologically active additives and probiotic products for functional nutrition. Some probiotics can be considered as bacterial vaccines due to induction of immune response, accompanied by production of specific antibodies. The aim of the present study was to evaluate the state of cellular and humoral immunity in women by using probiotic strains of lactobacilli. The study included 31 healthy women aged 25-45 years. As a source of probiotic lactobacterial complex, we used the “Provag” preparation (RU 77.99.11.003.E.003746.02.11 of 11.02.2011, 1 capsule contains 109 Lactobacillus gasseri 57C, Lactobacillus fermentum 57A и Lactobacillus plantarum 57B). The drug was used for 30 days, at a rate of one capsule per day. The immune system was examined twice: before administering the drug and after 30 days of treatment. The study of blood lymphocyte populations and subpopulations was performed by flow cytometry using direct immunofluorescence technique. The concentration of IgA, IgM, IgG in blood serum was determined using enzyme immunoassay. To determine specific antibodies, we used passive hemagglutination reaction with erythrocyte diagnosticum. The complex of probiotic lactobacilli Lactobacillus gasseri, Lactobacillus fermentum and Lactobacillus plantarum corresponding to the “Provag” preparation was used as a source of antigen. It has been revealed that the number of T and B lymphocytes in peripheral blood increased after 30 days of treatment with the probiotic preparation “Provag” in healthy women. Elevated contents of T cells was due to the T helper cell fraction. Increased levels of T helpers and B lymphocytes were associated with stimulation of humoral immunity, as evidenced by increasing concentration of IgA and IgG in blood serum. By means of passive hemagglutination reaction, we have found that 90% of healthy women showed increased concentrations of specific IgA in blood after 30 days of treatment with “Provag” preparation.

The Main Results of Activities to Improve the Environment and Protect the Population of the Tver Region from Measles Infection

Background. The Russian and international community is concerned about the growing incidence of measles. This is typical for highly developed and developing countries and has an impact on the epidemic situation in Russia. Purpose of research: to study the main results of the activities carried out by the Rospotrebnadzor administration in the Tver region to improve the state of the environment and protect the population of the Tver region from measles infection. Material and methods. The results of implementation of measures to reduce the impact of risk factors of measles on the health of the population of the Tver region in 2017-2019 were analyzed. Analyzed indicators are: the incidence of measles per 100 thousand population; coverage of preventive vaccinations to prevent the spread of measles among controlled individuals (%); results of serological monitoring of the state of collective immunity against measles in indicator population groups by a passive hemagglutination reaction method with a protective titer of 1:10 or more (absolute number, %); comparative assessment of changes in indicators of the number of measles seronegative persons in indicator groups of the population (%). Results and discussion. A set of measures aimed at preventing the incidence of measles is being implemented in the Tver region. To do this, the population is immunized against measles every year. In 2017 38,881 people were vaccinated, in 2018 – 35,476 and in 2019 – 42,347 people. This led to the fact that in 2017 in the Tver region there were no cases of measles. In 2018 the incidence of measles was 0.23 per 100 thousand population (3 cases) and in 2019 – 0.86 per 100 thousand population (11 cases). All cases of measles were imported from foreign countries and various regions of Russia. The situation in the incidence of measles in the Tver region is much better than in the Russian Federation and the Central Federal District of Russia. This is facilitated by a consistently high vaccination coverage of adults and children. Vaccination coverage of children aged two years in 2019 amounted to 98.2%, at the age of 6 years – 94.4% and adults 18-35 years old – 99.7%. If during seromonitoring an increase in the specific gravity of seronegative persons was detected, then their vaccination was carried out as planned. Conclusion. The implementation on a regular basis by the Office of Rospotrebnadzor in the Tver region of a set of effective measures aimed at combating measles helps prevent the incidence of measles infection in the population of the Tver region.

1648. Prevalence of Orientia tsutsugamushi, Anaplasma phagocytophilum, and Leptospira interrogans in Striped Field Mice in Gwangju, Republic of Korea

Background Scrub typhus, anaplasmosis, and leptospirosis are well-known diseases that are considered common, widespread rodent-borne infectious diseases Methods This study investigated the prevalence of Orientia tsutsugamushi, Anaplasma phagocytophilum, and Leptospira interrogans in wild rodents through molecular detection using organ samples and through serological assay using blood samples of mice collected from two distinct sites in Gwangju Metropolitan City, Republic of Korea (ROK). Results A total of 47 wild rodents, identified as Apodemus agrarius (A. agrarius), were captured from June to August 2016. The seroprevalence of antibodies against bacterial pathogens in A. agrarius sera was analyzed; 17.4% (8/46) were identified as O. tsutsugamushi through indirect immunofluorescence assay and 2.2% (1/46) were identified as Leptospira species through passive hemagglutination assay. Using polymerase chain reaction, the spleen, kidney and blood samples were investigated for the presence of O. tsutsugamushi, A. phagocytophilum, and L. interrogans. Out of the 47 A. agrarius, 19.1% (9/47) were positive for A. phagocytophilum and 6.4% (3/47) were positive for L. interrogans, while none were positive for O. tsutsugamushi. Four out of 46 (8.7%) blood samples, six out of 45 (13.3%) spleen samples, and one out of 47 (2.1%) kidney samples were positive for A. phagocytophilum. Three out of 47 (6.4%) kidney samples were positive for L. interrogans. The sequencing results of PCR positive samples demonstrated >99% similarity with A. phagocytophilum and L. interrogans sequences Conclusion A. phagocytophilum was mostly detected in the spleen, whereas L. interrogans was mostly detected in the kidneys. Notably, A. phagocytophilum and L. interrogans were detected in A. agrarius living in close proximity to humans in the metropolitan suburbans. The results of this study indicate that rodent-borne bacteria may be present in wild rodents in the metropolitan suburban areas of ROK Disclosures All authors: No reported disclosures.

DIAGNOSTIC IMMINOARRAY ASSAY FOR CHARACTERIZATION OF IMMUNOGLOBULIN IGG AND IGM LEVEL IN SYPHILIS PATIENTS SERUM TOWARDS 12 RECOMBINANT ANTIGENS OF T. PALLIDUM BEFORE AND AFTER THE THERAPY

The aim of the study was to characterize the dynamics of immunoglobulin IgG and IgM level in syphilis patients serum at different stages of the disease before and after the therapy towards 12 diagnostic antigens of T. pallidum in an microarray assay and to evaluate these data as possible prognostic markers. The dynamics of immunoglobulin IgG and IgM level was measured in the reaction of indirect immunofluorescence using microarray and compared to the results of non-treponemal RPR test and treponemal tests as EIA and reaction of passive hemagglutination. In microarray assay diagnostically high level of IgM in patients with primary, secondary and early latent and late latent syphilis decreased dramatically to zero after the successful therapy. Continuously high level of IgM after the therapy proposes the persistence of infection agents in the organism and points out the need of additional antimicrobial treatment. In most of the cases anti-treponemal IgG level also declined after the successful therapy and this confirms the appropriate treatment. The results of microarray assay coincide with the results of other mentioned laboratory tests for syphilis diagnostics. Microarray assay with the recombinant T. pallidum antigens gives the perspective for creating methods with wider spectrum of diagnostic and therapy control options using the IgM immunoglobulin level as a marker for successful syphilis treatment.

Evaluation of non specific body resistance of children with eye disorder and flatfoot

Aim. To study the correlation between the value of nonspecific resistance of the organism (NRO) and the rate of visual organ pathology as well as the prevalence of platypodia among pupils. Materials and methods. The study included 108 pupils aged 10–12 years, residents of Perm (46 boys and 62 girls). To realize the stated targets, there were used immunological, clinical and statistical methods. Nonspecific resistance of the organism was assessed by the antibody titer (AT) value in the saliva. From the total number of the examined patients, the visual organpathology was detected in 15 persons, platypodia – in 9. NRO value in children was evaluated using the developed by the authors express-method, based on the determination of humoral factors of immunity in the saliva – the antibody titer in passive hemagglutination reaction (PHGR) to Shigella sonnei by means of commercial antigen erythrocyte diagnosticum. Results. It was established that NRO influences the possibility of developing both: visual organ pathology and platypodia in the examined patients. Conclusion. The obtained results of the study permit to recommend the method of human adolescent NRO assessment, which was worked out by us.

STUDY RESULTS OF NATURAL FOCI OF TULAREMIA IN THE CRIMEA

We analyzed the observations’ results of natural foci of tularemia on the territory of Crimea during 2015–2018. Material from small mammals, ticks and pellets of predatory birds by means of polymerase chain reaction (PCR), enzyme-linked immunoassay (ELISA) and the reactions of indirect (passive) hemagglutination (RIHA) was investigated. Positive samples were detected in the zoological and entomological material. Synanthropic and hemisinanthropic species are found among infected small mammals, which indicates the existing risk of human diseases in human settlements. The activity of natural foci registered in 14 of the 26 municipal territories of the peninsula. To clarify the boundaries of natural foci and determine the degree of their activity, it is necessary to continue monitoring of natural ecosystems, conduct a comprehensive analysis of the populations’ status of small mammals and blood-sucking ectoparasites, epizootic and epidemic manifestations in various areas of Crimea for a longer period.

Certification of a New Batch of the Industry Reference Standard of Polysaccharide Content in Schigellvac Vaccine

The article summarises materials on the certification of the industry reference standard of Schigella sonnei polysaccharide dysentery vaccine (commercial name — Schigellvac). The industry reference standard is used to assess the consistency of the vaccine «Specific activity» testing by passive hemagglutination inhibition assay. A certification programme for the industry reference standard was developed. Samples of the candidate vaccine were tested in terms of the following quality characteristics: «Appearance», «Identification», «Extractable Volume». The test results confirmed that the samples comply with the current requirements of the manufacturer’s product specification file for Schigellvac vaccine. It was determined that the certification parameter — the polysaccharide dilution ratio which results in inhibition of passive hemagglutination in a homologous system — has to fall in the range from 1:128 to 1:512. The following set of standard documents accompanying a scientific/technological product was approved for the industry reference standard No. 42-28-386-2017: passport, patient information leaflet, mockup labels for primary and secondary packaging.

Clinical and epidemiological characteristic of chronic brucellosis

Aim. To study clinical epidemiological and laboratory features of chronic brucellosis in the Republic of Tatarstan in ten-year aspect. Methods. 59 patients infected with various forms of brucellosis in 2007-2017 were examined. Clinical laboratory and instrumental diagnosis of brucellosis was confirmed by the immunoassay (EIA) with determination of IgM and IgG antibodies, passive hemagglutination test with a brucellar diagnosticum, Coombs test, Wright and Hedelson agglutination test. Results. Clinically 91 % of patients had asthenic-vegetative syndrome, 55 % - mild intoxication symptoms, 89 % - articular syndrome, 49 % - fibrositis. EIA revealed in 91 % of patients IgG (38 %) and IgM (53 %) antibodies to causative agents of brucellosis, 25 % of patients had positive Wright agglutination test, and 30 % - positive Hedelson agglutination test. In 9 % of cases the diagnosis was confirmed by Coombs test and in 26 % by passive hemagglutination test with brucellar diagnosticum. The retrospective analysis with clinical cases of patients with chronic brucellosis indicates introduced cases in 19 % (from the republics of Central Asia and Transcaucasia), local cases in 81 % (from the Republic of Tatarstan), their occupational character (57 %), the mixed (contact and alimentary) route of infection (21 %), and 64 % with clinically primary involvement of the musculoskeletal system and peripheral nervous system, i.e. prevalence of the mixed form of chronic brucellosis. Conclusion. Chronic brucellosis in the Republic of Tatarstan is characterized by high risk of introduced cases, occupational history, prevalence of the mixed route of infection in females and working-age patients; with the features of systemic disease involving the musculoskeletal and peripheral nervous system against the background of mild syndrome of intoxication and moderate asthenic-vegetative syndrome. Divergence of the results of serological diagnostics requires careful studying of duration of infection, features of the immune response in each case on follow-up.