The results of screening more than 23,000 serum samples from persons belonging to risk groups, as well as those not belonging to such groups, in Moscow, Vilnius and Klaipeda are presented. Screening was carried out with the use of an assay system manufactured by the Scientific and Industrial Amalgamation "Antigen" (USSR). In this screening 3 HIV carriers were detected; of these, 2 were foreign students from two African countries.
More than 80,000 blood samples are annually transported to the Lutsk diagnostic center for assessment of antibodies to HIV. A polystyrol container for 50 vials is used for transportation of the blood samples for these purpose. The advantages of this way of transportation are discussed.
Blood sera, originating four regions of Russia and Byelorussia and previously tested for the content of antibodies to HIV-1 proteins, were studied in the enzyme immunoassay on the basis of recombinant sequences gp160, as well as on the basis of oligopeptides corresponding to sequences V3 of six HIV-1 strains. The possibility of using sequences gp160, contained in fusion polypeptides synthesized in Escherichia coli cells, for the detection of antibodies in laboratory research was shown. Differences in the reactivity of the sera under study with respect to fragments gp160 correlated with the geographical origin of these sera: similarity between the serum samples from Elista and Rostov and their difference from serum samples collected in other regions were shown.
The data on the study of the spread of HIV infection among injecting drug users in St. Petersburg, carried out by the method of the random testing of blood remaining in used syringes, are presented. Injecting drug users visiting buses working in accordance with the program "Buses for Assistance to Drug Addicts" were chosen as a study group. The exchange of syringes was one of the elements of this program. The work was carried out in two areas with a high concentration of drug users. The eluates from syringes used by 300 persons were studied. The average rate of the spread of HIV in the cohort under study was 12%. The results were indicative of a high degree of the spread of HIV among injecting drug users in St. Petersburg. Epidemiological patrol surveillance proved to be an effective method for the evaluation of the epidemiological situation in a highly inaccessible group of the population.
For the first time a nosocomial focus of HIV infection was established. Out of 83,000 inhabitants of the Kalmyck ASSR who underwent planned examination in the course of epidemiological investigation, 65 cases of HIV infection were detected and all of them were traced to the focus of hospital infection (56 children and 9 adults: 1 man and 8 women; of these, 7 women contacted the infection from their infected children in the process of breast feeding). The children were infected during their stay in two hospitals of Elista where they received multiple intravenous and intramuscular injections. The infection spread from the infant department of the regional pediatric hospital to 4 more departments and to the infectious diseases hospital. Transmission of this infection was maintained for several months by the use of nonsterile syringes in parenteral manipulations.
In view of the fact that Russian immunoblot assay systems yield indefinite results, thus making it necessary to carry out prolonged dispensary observations of patients and their multiple examinations, the scheme of the expert diagnostics of HIV infection on the basis of EIA results is proposed. 51 sera which had yielded indefinite results in the immunoblot assay (antibodies to gagl, envl, poll) were handed over for verification to the Regional Center in 1996-1997. Patients from whom the sera had been taken were placed under dispensary observation in the Center for 6-12 months. After the retrospective analysis of these serum samples with the use of the EIA systems 40 samples proved to be negative and 11 samples gave the positive reaction.
Broad and potent cellular and humoral immune responses after a second late HIV-modified vaccinia virus ankara vaccination in HIV-DNA-primed and HIV-modified vaccinia virus Ankara-boosted Swedish vaccinees.
We have previously shown that an HIV vaccine regimen including three HIV-DNA immunizations and a single HIV-modified vaccinia virus Ankara (MVA) boost was safe and highly immunogenic in Swedish volunteers. A median 38 months after the first HIV-MVA vaccination, 24 volunteers received 10(8) plaque-forming units of HIV-MVA. The vaccine was well tolerated. Two weeks after this HIV-MVA vaccination, 18 (82%) of 22 evaluable vaccinees were interferon (IFN)-? enzyme-linked immunospot (ELISpot) reactive: 18 to Gag and 10 (45%) to Env. A median minimal epitope count of 4 to Gag or Env was found in a subset of 10 vaccinees. Intracellular cytokine staining revealed CD4(+) and/or CD8(+) T cell responses in 23 (95%) of 24 vaccinees, 19 to Gag and 19 to Env. The frequency of HIV-specific CD4(+) and CD8(+) T cell responses was equally high (75%). A high proportion of CD4(+) and CD8(+) T cell responses to Gag was polyfunctional with production of three or more cytokines (40% and 60%, respectively). Of the Env-specific CD4(+) T cells 40% were polyfunctional. Strong lymphoproliferative responses to Aldrithiol-2 (AT-2)-treated subtype A, B, C, and A_E virus were demonstrable in 21 (95%) of 22 vaccinees. All vaccinees developed binding antibodies to Env and Gag. Neutralizing antibodies were detected in a peripheral blood mononuclear cell (PBMC)-based assay against subtype B and CRF01_AE viruses. The neutralizing antibody response rates were influenced by the vaccine dose and/or mode of delivery used at the previous HIV-MVA vaccination. Thus, a second late HIV-MVA boost induced strong and broad cellular immune responses and improved antibody responses. The data support further exploration of this vaccine concept.
The sensitivity and specificity of the developed anti-HIV1/2 third generation enzyme immunoassay, the IEA-HIV1/2-III, was examined. The test system for the detection of anti-HIV antibodies included peroxidase-conjugated HIV-specific recombinant Gag protein fragments (epitopes of p24 and p17 proteins), Env-1 (epitopes of p41 and p120 proteins), and Env-2 (p36 epitopes). Sensitivity was evaluated with 346 sera from HIV1-seropositive subjects, Anti-HIV1 Low Titer panels no. 10 and PRB-106 and seropositive panel PRB-931 in comparison with other third- and second-generation assays. The IEA-HIV1/2-III assays are characterized with high sensitivity comparable to the other third generation assays and the better sensitivity with respect to the second generation test-kit to determine HIV-specific antibodies in human sera. The specificity was determined using three hundred sixty-seven potentially cross-reactive samples (but negative for anti-HIV1/2). Only one specimen among them was reactive by IEA-HIV1/2-III.
The Genie HIV-1/2 kit (Sanofi Diagnostics Pasteur, Montreal, Quebec), a synthetic-peptide solid-phase enzyme immunoassay, was evaluated as a confirmatory assay for HIV-1 antibodies in comparison with Western blot (BioRad, Hercules, CA, USA) on 50 stored HIV-1 antibody-positive sera and the 137 sera yielding repeated positive results in the conventional EIA screen out of 13405 fresh patient sera from Saskatchewan in 1993. The stored HIV-1-positive sera were uniformly positive in the Genie test. Of the 137 EIA screen-positive sera, 33 were uniformly positive and 64 were uniformly negative in Genie and Western blot; 36 were Genie-negative and indeterminate by Western blot; and four were Genie indeterminate, of which one was negative and three were indeterminate by Western blot. All HIV-1 Western blot-indeterminate and Genie-interdeterminate sera were negative in radio-immunoprecipitation assay (RIPA) and Western blot for HIV-1 and HIV-2 antibodies performed by a reference laboratory. Genie gave an accurate definitive result for 97% of EIA positive sera compared with 71% for Western blot. There was excellent correlation between Genie, Western blot and RIPA results. However, the Genie assay was faster, less costly and yielded fewer indeterminate results than Western blot in confirmatory testing for HIV-1 antibodies.