RESUMEN
Countries of the former Soviet Union are experiencing an emerging HIV-1 epidemic due to a rapid expansion of HIV-1 among injecting drug users (IDUs). To study the molecular epidemiology of HIV-1 among IDUs in St. Petersburg, Russia, virus sequences were obtained from 22 individuals. Phylogenetic analysis of the env and gag regions revealed circulation of two major HIV-1 populations, one belonging to HIV-1 subtype A, and another being a recombinant of subtype A and B viruses (gagA/envB). Both virus populations were highly homogeneous, with a mean pairwise genetic distance of <2%, and similar to viruses obtained earlier from IDUs in other regions of the former Soviet Union. Distribution of the two major HIV-1 genotypes in St. Petersburg correlated with geographical origin of infections. In one individual, a virus type previously unseen among IDUs was found, which demonstrates the possibility that new viruses are entering this risk group.
Asunto(s)
Genes env/genética , Genes gag/genética , Infecciones por VIH/virología , VIH-1/genética , Abuso de Sustancias por Vía Intravenosa/virología , Adulto , Secuencia de Aminoácidos , Secuencia de Consenso , Femenino , Genotipo , Infecciones por VIH/epidemiología , Humanos , Masculino , Epidemiología Molecular , Datos de Secuencia Molecular , Filogenia , Federación de Rusia/epidemiología , Alineación de Secuencia , Abuso de Sustancias por Vía Intravenosa/epidemiologíaRESUMEN
A major diphtheria epidemic affecting the whole population of St. Petersburg started in 1990. During the period of 1991 to 1995, 4600 patients with clinical respiratory tract diphtheria were treated in Botkin's Hospital. From 112 (2.4%) of these patients only a nontoxigenic strain of Corynebacterium diphtheriae was isolated. Three patients with this strain who were suffering from clinical disease consistent with classical toxic diphtheria died. All had myocarditis, two had asphyxia due to membrane formation in the lower respiratory tract, and one had severe polyneuritis. In two patients the causative agent was of the biotype mitis and in the third intermedius, whereas the prevailing epidemic strain was of the biotype gravis. As the clinical presentation of the disease in the three patients who died was typical of toxic diphtheria, it is considered likely that the immunodiffusion test for toxin production in vitro may fail to detect strains of Corynebacterium diphtheriae producing toxin in vivo.
