Investigation of the results obtained following repeated boosters with Di-Te vaccine in HIV positive children.

The paper is an attempt to study the effect of repeated boosters with Di-Te vaccine in positive children. The efficacy of their administration (vaccinal coverage degree, level of secreted antitoxins, the persistency of the immune response) and their influence upon the subsequent evolution of HIV infection are investigated.

Use of the presence of anti-protein gag antibodies as an evolution marker of HIV infection.

The paper studies the modifications occurring in the prevalence of anti-protein gag antibodies during the evolution of the infection in a paediatric population iatrogenically infected and not submitted to antiretroviral treatment. The study was performed by annual clinical examination of children and by laboratory determinations: western-blot, p24 Ag assay, determination of lymphocyte population by flowcytometry. The predictive capacity of p17 antibodies was revealed, their occurrence after seroconversion pointing to a favourable evolution, with a longer asymptomatic period; the disappearance of these antibodies during the disease indicates a more advanced stage of the disease. The disappearance of p24 and p55 antibodies during the evolution of the disease shows a more advanced stage of the disease, both clinically and as concerning the immunosuppression degree.

HIV-1 diversity in Romania.

OBJECTIVES: To evaluate the prevalence and the dynamics of HIV-1 subtypes in Romanian adults and children, and to investigate the origins of the nosocomial epidemic. DESIGN: A total of 1000 serum and plasma samples, from adults (n = 579) and children (n = 421) who were diagnosed as being HIV-1-infected during 1990-1997 in 39 of the 41 Romanian districts, were serotyped. Viral DNA was isolated from blood samples of 84 patients and the viruses were genotyped. METHODS: Serotyping was performed with a peptide subtype-specific enzyme immunoassay (SSEIA), based on in vitro competition for antibody binding between the representative V3 peptides of the different clades (A-F). Proviral HIV-1 DNA was genotyped by heteroduplex mobility assay or by sequence analysis of the C2-V3 env region. RESULTS: SSEIA showed that 93% of the samples from horizontally infected children were serotype F, 1% were serotype B, and the remaining 6% were uninterpretable. In vertically infected children, 74% of strains were serotype F, 10% were serotype A, 3% were serotype B, and 3% were serotype E. Serotype F was also the dominant subtype in adults (68%), but serotypes A, B, C, D and E were also detected. SSEIA gave indeterminate results in 7% of cases. A strong correlation (90%) between serotyping and genotyping for subtype F was found. Analysis of the relative incidence of the different serotypes over a 7-year period (1990-1997) showed a stable distribution. CONCLUSIONS: Subtype F largely dominates the epidemiology of HIV-1 infection in both children and adults in Romania, although other major subtypes are present. The predominance of subtype F in Romania may be a future potential source of HIV-1 variability in Europe.

Characterization of the epidemiological process of HIV infection using some immunological markers.

In an attempt to elucidate the causes which led to the high percentage of HIV infection in the infantile population in Romania, the paper deals with the study of the evolution of the infection process, in the 0-6 years age group; the process was separately studied in children from closed collectivities (5,318 sera) and children living with their families (2,462). The study of the various patterns obtained with sera analysed by western-blot allowed of concluding that the massive spreading of the infection in both types of infantile population occurred in 1991-1992, the most intense process being reported in the 0-2 years age group (children from closed collectivities). The differences between the evolution of HIV infection epidemic in the above mentioned infantile populations and that noticed in adults are shown.

Significance of the positivity of some ELISA tests different as concerning the antigenic source in interpreting the western blot indeterminate sera in monitoring the epidemiology of high risk populations.

The paper analyses 50 pairs of sera pre-elevated within the "sentinel" epidemiological surveillance in a population exposed to a high risk at a 2 months interval. At the first determination all these sera showed an indeterminate Western Blot pattern; after 2 months, 93.7% revealed the occurrence of a certainly positive pattern. The paper is an analysis of the way in which different ELISA kits diagnosed at the first determination the Western Blot indeterminate sera. The purpose of the paper is to adopt a methodology of accurately diagnosing HIV infections in a population exposed to a high risk within an epidemiological surveillance of the "sentinel" type where the receiving of a second serum sample is quite difficult.