[Use of RT-PCR and enzyme immunoassays for the specific diagnosis of Crimean hemorrhagic fever].

The objective of the investigation was to evaluate the efficiency of the RT-PCR kit "AmplySens CHF" produced by InterlabService of the Central Research Institute of Epidemiology and that of the ELISA kits made by the D. I. Ivanovsky Research Institute of Virology for the specific diagnosis of Crimean hemorrhagic fever (CHF). Examination of sera from CHF patients from the Astrakhan Region showed that positive RT-PCR results were observed in 95.2 and 37.5% on days 4-8 and 9-13 after disease onset, respectively; but they were absent on days 13-17. Positive ELISA-IgM results were found in 93% on disease days 6 to 16. A high percentage (78.9%) of positive IgG samples was seen only on days 9-16. Thus, RT-PCR has a marked efficiency in diagnosing CHF until day 8 of illness while ELISA-IgM has it on day 8 or later. ELISA-IgG can be considered to be a confirming rather than compulsory test. The findings suggest that the RT-PCR kit "AmplySens CHF" produced by InterlabService of the Central Research Institute of Epidemiology and that of the ELISA kits made by the D. I. Ivanovsky Research Institute of Virology have a pronounced sensitivity and specificity and a high efficiency when concurrently used to verify CHF in patients.

[Genotyping of West Nile fever virus strains circulating in southern Russia as an epidemiological investigation method: principles and results].

AIM: Characteristic of West Nile fever (WNF) virus strains circulating in southern Russia. MATERIALS AND METHODS: WNF RNA was amplified directly from clinical samples, mosquitoes and bird tissues by PCR, nucleotides were sequenced directly and analyzed comparatively. RESULTS: Related but different genovariants of WNF lineage 1a--"Volgograd" and "Astrakhan"--circulated during WNF outbreaks of 1999 and 2000-2003 in Volgograd and Astrakhan regions. In 2005 "Volgograd" WNF variant emerged in Astrakhan region and along with "Astrakhan" variant caused a new morbidity increase. In 2004 in sera of 2 WNF patients from Rostov region WNF lineage 2 RNA was detected, this was the first WNF clinical case caused by WNF lineage 2 outside of Africa. WNF outbreak in Volgograd region in 2007 was caused by this unique WNF lineage that may preliminary be called Russian. Finally, during a major WNF outbreak in 2010 in Volgograd and Rostov regions in clinical samples only russian genovariant WNF lineage 2 RNA was detected again. CONCLUSION: After emergence of a certain WNF genovariant the virus is capable of persisting in natural foci in southern Russia. A near disappearance of one of the WNF clones by substitution or displacement with another maybe possible. Determination of genetic characteristics of WNF strains circulating in Russia is an important element of WNF epidemiological surveillance and control of this disease.

[Hemostatic disorders and their implication in the pathogenesis of Astrakhan rickettsial fever].

AIM: to define a role of hemostatic disorders in the pathogenesis of Astrakhan rickettsial fever (ARL). SUBJECTS AND METHODS: Platelet functional activity and plasma hemostatic parameters were studied in 89 patients of moderate ARL. RESULTS: The clinical manifestations of hemostatic disorders at the height of ARL were characterized by the appearance of typhoid maculopapular rashes in 91.4% of the patients, solitary elements of which were transformed to petechiae in 20% of cases. At convalescence (on day 10.2 +/- 1.3 of the disease), all eruptions regressed via pigmentation. At the peak of the fever, there were nasal hemorrhages and bleedings from the sites of injections; lowered platelet aggregation was detectable in the presence of thrombocytopenia at the height. Coagulation hemostasis changes were characterized only by elevated fibrinogen levels. Increased platelet functional activity and decreased fibrinogen concentrations were observed at convalescence. CONCLUSION: The basis of the clinical manifestations of ARL is hemostatic disorders due to thrombocytopenia and diminished platelet functional activity. In early convalescence, there was improved platelet aggregatability; however, the increasing trend for the rate of aggregation and the radius of aggregates suggests a risk of thrombogenesis in convalescents, which requires their follow-up with obligatory hemostatic monitoring.

[Results of examination of healthy residents in the southern region of Russia and patients feverish to pappataci fever virus antibodies].

Sera from patients with acute seasonal fevers and apparently healthy individuals living in the Astrakhan Region, Krasnodar Territory, or Rostov Region were examined in two modifications of enzyme immunoassay for detection of IgM and IgG antibodies to Neapolitan and Sicilian pappataci fever viruses. IgM antibodies to Sicilian pappataci fever virus were detected in a patient from the Volodarsky District, Astrakhan Region, who had been admitted for the unverified diagnosis of Q fever. A donor residing in the Novorossiysk District, Krasnodar Territory, was found to have IgA antibodies to Neapolitan pappataci fever virus. The findings show it expedient to conduct further investigations of the serodiagnosis and seroepidemiology of pappataci fevers in the southern Russian region where mosquitoes of the genus Phlebotomus inhabit.

[ West Nile fever among residents of the Astrakhan region in 2002]. / Zabolevaemost' i zarazhaemost' naseleniia Astrakhanskoi oblasti likhoradkoi Zapadnogo Nila v 2002 g.

Thirty-three persons infected with West Nile fever were detected in 2002 in the Astrakhan Region; the diagnosis was confirmed serologically and the maximal number of the infected was registered in August, same year. The indices of the specific humoral immunity varied from 3.3% to 27.1%. A monitoring determined the highest infection risk among the residents of the Volga middle delta.

[Status of cellular immunity in patients with Astrakhan fever]. / Sostoianie kletochnogo immuniteta u bol'nykh astrakhanskoi likhoradkoi.

AIM: To ascertain regularities of development of cellular immunity in patients with Astrakhan fever (AF) with reference to AF severity, treatment and course. MATERIAL AND METHODS: Cellular factors of immunity--relative and absolute contents of T-lymphocytes (early and late), T-helpers and T-suppressors, B-lymphocytes, neutrophils (early and late)--were studied in 75 patients with AF (63 patients with moderate and 12 patients with severe disease) in the course of the disease progression (weeks 1-5). The patients received antibacterial treatment--doxicyclin, rifampicin and doxicycline in combination with alpha 2-realdiron and gamma-reaferon. RESULTS: Examination of immunocompetent cells has revealed suppression of T- and B-immunity for 2 weeks in moderate AF and 3 weeks in severe AF. The number of T-helpers was low for 3 weeks while of T-suppressors rose beginning from week 2. Immunoregulatory index Tx/Tc remains low till the end of the disease. The number of early and late neutrophils increased since weeks 2 of the disease in moderate and week 3 in severe AF. CONCLUSION: Doxicycline efficiency was higher than that of rifampicin. Interferon preparations decrease relative number of early and late T-lymphocytes, neutrocytes and T-helpers but their absolute number is at the control level. Relative content of T-suppressors and B-lymphocytes is as in controls but their absolute content is higher.

[The humoral immunity indices and complement functional activity in salmonellosis during the dynamics of the disease]. / Nekotorye pokazateli gumoral'nogo immuniteta i funktsional'naia aktivnost' komplementa pri sal'monelleze v dinamike zabolevaniia.

In 65 patients with bacteriologically confirmed gastrointestinal salmonellosis of moderate severity (41 males and 24 females) the disease in an acute phase was characterized by activation of complement system and specific antibody formation, by a growth in the levels of IgA, G and M. In early convalescence IgA and IgM remained high, IgG in females returned to normal, in males was still high. An inverse correlation was found between functional activity of complement components C3, C4 and C5 and levels of IgM, IgG.