[Diagnostic efficacy of phosphorescent immunochips for serologic diagnostics of tick-borne encephalitis].

AIM: To assess sensitivity and specificity of phosphorescent immunochips developed by the authors on the basis of microplate phosphorescent assay (PHOSPHAN) for detection of IgM and IgG antibodies to tick-borne encephalitis virus (TBEV) in sera of patients and to compare results of PHOSPHAN assay with results obtained by lanthanide immunofluorescence assay (LIFA) and solid-phase enzyme immunoassay (SPEIA). MATERIALS AND METHODS: Two hundred sixty one serum samples were tested, including 155 samples from 74 patients with clinical diagnosis of TBE confirmed by serologic identification of IgM antibodies to TBEV. Sera were collected in 2003 in Perm region from persons, which fell ill during seasonal increased activity of ticks-vectors of TBEV, as well as from healthy blood donors. Phosphorescent immunochip corresponds 96-well plate with 4 active microzones formed on the bottom of each well, which are able to detect specific IgM and IgG antibodies to TBEV. Immune reaction was visualized by conjugate of streptavidin with Pt-coproporphyrin. Intensity of fluorescence was measured by scanning the bottom of previously dried microwell with scanner IFI-02. RESULTS: Comparable sensitivity and specificity of POSHPHAN assay, LIFA and SPEIA was demonstrated for detection of IgM and IgG antibodies to TBEV in samples. Immunoluminescence-based PHOSPHAN assay and LIFA were more sensitive for analysis of sera with low titer of specific IgM antibodies. CONCLUSION: PHOSPHAN assay could be used for early serologic diagnostics of TBE as well as for assessment of antibody level for control of efficacy of treatment in patients with prolonged illness or level of protective immunity in vaccinees.

[Isolation of tick-borne borreliosis agent from blood of patients].

During spring-autumn period of 2006 Borrelia were isolated for the first time in Russia from blood of 79 patients treated in Perm City Clinical Hospital for Infectious Diseases No. 1 with diagnosis "tickborne borreliosis, manifestive form with migrating erythema, localized stage". Ten primary isolates (12.7% of total seeded samples) were obtained by seeding plasma samples on the BSK medium. Their subsequent identification by polymerase chain reaction-restriction fragments length polymorphism revealed presence of Borrelia garinii NT29 in all patients. Length of sequenced fragment of rrfA-rrlB region was 253 b.p. Seven isolates had 100% and 3 - 99.6% similarity with typical strain NT29 (L30130). Nucleotide sequences of 4 obtained isolates were deposited in GenBank database (No. AM932199 - AM932202). It was proposed that B. garinii NT29 more frequently than other Borrelia species can be an etiologic agent of tick-borne borreliosis not only in Perm region but also in whole Russia.

[Testing for antibodies to tick-borne encephalitis virus using blood dried on filter paper].

Possibility to use blood dried on filter paper for serological testing on antibodies to tick-borne encephalitis (TBE). Sensitivity and specificity of specific IgM detection in dry stains of blood by lanthanide fluorescence immunoassay was 94.9% (86.9-100%) and 97.5% (94-100%) respectively, compared with results obtained in tests of sera. Agreement in positive and negative results of tests for IgM against TBE in 562 serum samples and dry blood stains was 95.3%. During analysis of both types of biomaterial high degree of correlation was observed between intensity of fluorescence when testing for both IgM (r=0.86700; p=0.05; n=562), and IgG (r=0.83883; p=0.05; n=337) toTBE virus. Use of this mildly invasive technique of blood draw is reasonable during conduction of large-scale population studies for seroepidemiologic monitoring, investigation of disease outbreaks, control of effectiveness of vaccination against TBE, assessing of level of specific immunity in population of endemic regions, control of treatment, and serologic diagnostics of acute TBE in hospitalized patients, in which blood draw is difficult to perform.

[Choosing the threshold level in the detecting of antibodies to the causative agents of Ixodes tick-borne borreliosis by lanthanide immonofluorescence assay].

The paper describes the algorithm of choice of the threshold level of fluorescence, which identifies the positive and negative results of lanthanide immunofluorescence assay when IgM and IgG antibodies to the causative agents of Ixodes tick-borne borreliosis are detected in the sera of patients. The diagnostic specificity index of the method in detecting antibodies of both types was 95.3% for the chosen value. According to the time of sampling, the diagnostic sensitivity indices for IgM and IgG antibodies were 10.4 to 40.9% and 3.3 to 18.2%, respectively.

Risk for human tick-borne encephalitis, borrelioses, and double infection in the pre-Ural region of Russia.

We assessed the risk for human tick-borne encephalitis (TBE), ixodid tick-borne borrelioses, and double infection from 1994 to 1998 in Perm, which has among the highest rates of reported cases in Russia. We studied 3,473 unfed adult Ixodes persulcatus ticks collected from vegetation in natural foci and 62,816 ticks removed from humans. TBE virus and Borrelia may coexist in ticks.

[Presence of HTLV-I antibodies in patients with sexually transmitted diseases]. / Nalichie antitel k HTLV-I u patsientov s zabolevaniiami, peredaiushchimisia polovym putem.

The prevalence of human T-lymphotropic type I virus (HTLV-I) among patients with sexually-transmitted diseases is studied in Russia. Primary screening of antibodies to HTLV-I in the sera was carried out by enzyme immunoassay with recombinant gag and env HTLV-I-specific antigens synthesized in Escherichia coli. For secondary screening, Serodia HTLV-I and Vironostika Microelisa System kits were used. None of the 1271 serum samples collected in the towns of Perm and Ekaterinburg was HTLV-I-positive. This indicates a lower, in comparison with other European countries, level of infection with this virus, at least in this region of Russia. Testing of sera from 79 HIV-infected patients revealed none infected with HTLV-I.

[Regularities in the spread of hepatitis C virus and its genotypes in Russian and countries within the former USSR]. / Zakonomernosti rasprostraneniia virusa gepatita C i ego genotipov v Rossii i stranakh SNG.

The incidence of markers of hepatitis C virus (HCV in the blood of 4216 normal subjects living in the European Russia (Northern, North-Western, Central, Central Chernozem, Volga-Vyatka, Volga, and North Caucasian regions), in the Urals, in Siberia (Eastern Siberian region), in the Far East, and in Monogolia is assessed. The incidence of antibodies to HCV varied from 0.7% in the Central region to 3.8% in the Central Chernozem and 10.7% in Mongolia. HCV genotyping (identification of 1a, 1b, 2a, 2b, and 3a genotypes) was performed using 469 RNA of HCV-positive sera of donors and patients collected in Russia, Moldova, Turkmenistan, and Mongolia. The 1b genotype predominated everywhere (68.9%), its incidence being the highest in Moldova (96%). Unclassifiable variants of HCV were found in 28 (6%) of sera. The regularities of HCV genotypes circulation in the European Russia were the same as in other European countries, whereas their prevalence in Eastern Russia was rather like that in China or Japan. The prevalence of genotypes did not depend on the clinical manifestations of diseases caused by HCV.

[Antibacterial therapy as a means of preventing ixodid tick-borne borreliosis]. / Antibakterial'naia terapiia kak sposob profilaktiki iksodovykh kleshchevykh borreliozov.

A special epidemiological experiment to prevent borreliosis in persons bitten by infected ticks was performed in 1992-1994 in the Russia's Perm region where Borrelia garinii and B.afzelii circulate, and Ixodes persulcatus tick is the sole vector transmitting these pathogens to human beings. Adult ticks were removed from the bodies of persons who had referred to health facilities for first aid. Vital preparations were made from the material obtained from the gut of each tick and examined microscopically (up to 250 microscopic fields per preparation). The patients bitten by infected ticks were divided into experimental and control groups and kept under special medical and serological control for 4-5 months. The patients of the experimental group received doxycycline (100 mg twice daily) for 3-5 days after ticks had bitten. Borreliosis was diagnosed by a combination of clinical and serological data. The control group consisted of 97 patients who took no antibiotics after ticks biting and 12 of them contracted borreliosis. In 823 cases Borrelia were not revealed while microscopically analyzing the ticks removed from the patients' bodies; in this group six patients contracted borreliosis. The morbidity rate (per 100 patients) in the experimental group was 1.1, i.e. 11 times lower than that in control group. Among the patients bitten by infected ticks and untreated with antibiotics, this index was 17.6 times higher than in the group bitten by ticks in which Borrelia were not found. There is no absolute probability of detecting the pathogen during a direct microscopic analysis of the preparation made from the tick removed from the body of a bitten patient. However, this rapid identification of Borrelia, followed by short-term antibiotic treatment for microbiological evidence is an effective tool for preventing patients from contracting borrelioses.

[An assessment of epidemic outbreaks of salmonellosis connected with poultry plant production]. / Otsenka épidemicheskikh vspyshek sal'monelleza, sviazannykh s produktsiei ptitsefabrik.

The causes of the simultaneous rise of salmonellosis morbidity induced by S. enteritidis among the population of three towns in the Perm region were studied. The study revealed the leading role of eggs and chicken meat as factors contributing to the transfer of this infection to the population of different territories, commonly supplied with the products of one poultry plant. The contamination of eggs and chickens with S. enteritidis occurred at the plant due to Salmonella infection of chickens, parallel with the use of nonbalanced mixed fodder, originally intended for feeding swine. Analysis of the epidemic and epizootic processes of Salmonella infection in this epidemic situation made it possible to reliably establish the factors contributing to the transfer of the infective agent and the site of contamination.

[Trends in the development of the epidemic process in salmonellosis caused by Salmonella typhimurium and Salmonella enteritidis]. / Tendentsii razvitiia épidemicheskogo protsessa sal'monellezov, obuslovlennykh Salmonella typhimurium i Salmonella enteritidis.

The dynamics and structure of the epidemic process of Salmonella infections among the population of Perm in 1983-1988 was studied and the results of evaluation of antibiotic resistance of the dominating Salmonella species analyzed. The study revealed that a decrease in salmonellosis morbidity caused by S. typhimurium was associated with a limited circulation of anthroponotic (antibiotic-resistant) variants of Salmonellae and a relative increase in the proportion of zoonotic (antibiotic-sensitive) strains. At the period of elevated morbidity this Salmonella infection affected mainly young children in cold months, whereas in recent years seasonal morbidity rises shifted to spring-summer and summer-autumn months, affecting older age groups of the population. The study also revealed that a rise in salmonellosis morbidity caused by S. enteritidis was due to increased circulation of zoonotic variants of Salmonellae. Changes in the epidemiological situation necessitate correction of the system of epidemiological surveillance on Salmonella infections with the emphasis on sanitation measures in stock-breeding farms with unfavorable epidemiological situation.

[Efficacy of a complex program for controlling influenza in a large industrial city]. / Effektivnost' kompleksnoi programmy bor'by s grippom v usloviiakh krupnogo promyshlennogo goroda.

The epidemiological and economic effectiveness of the realization of the complex three-year (1980-1982) program for the control of influenza in Perm is shown. The coverage of 46-51% of the city population, including working people, pensioners and children, with immunization carried out with the use of live and inactivated vaccines made it possible to decrease morbidity rate 2.12 times in comparison with the average data for many years. The greatest effect was achieved at large industrial enterprises where, simultaneously with vaccination covering 90% of the employees, urgent prophylaxis with remantadin and the early treatment of influenza patients were carried out. Due to these measures the morbidity rate and the number of disability days per 100 employees decreased 3-6 times.