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A resurgence of diphtheria spread throughout the Russian Federation in the early 1990s; diphtheria had been well controlled, but circulation of toxigenic strains of Corynebacterium diphtheriae had persisted since the implementation of universal childhood vaccination in the late 1950s. More than 115,000 cases and 3,000 deaths were reported from 1990 to 1997, and, in contrast to the situation in the prevaccine era, most of the cases and deaths occurred among adults. Contributing factors included the accumulation of susceptible individuals among both adults and children and probably the introduction of new strains of C. diphtheriae. Vaccine quality, vaccine supply, or access to vaccine providers did not significantly contribute to the epidemic. Mass vaccination of adults and improved childhood immunization controlled the epidemic. High levels of population immunity, especially among children, will be needed to prevent and control similar outbreaks in the future.

Prior to the completion of this and other studies, low effectiveness of diphtheria toxoid-containing vaccine was suspected to be a major contributing factor to the diphtheria epidemic that began in the Russian Federation in 1990. A vaccine effectiveness study was done in Moscow by enrolling physician-diagnosed cases and 10 control subjects per case. Controls were matched to cases by age (+/-3 months) and clinic registration. Vaccination history was abstracted from a standardized form for case-patients and from clinic vaccination records for control subjects. Two hundred seventeen case-patients and 2169 matched controls were included in the study. Most controls (92%) had received three or more doses of a diphtheria toxoid vaccine, compared with 72% of case-patients. The vaccine effectiveness for three or more doses was 97% (95% confidence interval: 94.3-98.4). Low vaccine effectiveness was not a contributing factor to the diphtheria epidemic in the Russian Federation. To control and prevent diphtheria epidemics, it is necessary to achieve and maintain high vaccination coverage with three or more doses of diphtheria toxoid among adults and children.

The specialized plague control facilities which began being founded as a system of institutions in Russia in 1897 have made a great contribution to epidemiological well-being against quarantine and particularly menacing diseases. The developmental stages of plague control service in different periods of the country's social life and its place in the general governmental preventive and antiepidemic measures are shown. The paper emphasizes that it is expedient to maintain the antiepidemic readiness of plaque control facilities due the fact that the epidemic situation is due menacing and zoonosis is expected to aggravate in the late 20th to the early 21st centuries.

The data on the epidemiological analysis of cholera cases in the epicenter of this infection in the Daghestan, viz. in the village of Gerga, Kaiakent District, are presented. The outbreak of cholera was due to the import of this infection by pilgrims from their hajj to Saudi Arabia. The causative agent of the outbreak was the epidemic variant of V. cholerae eltor Ogawa. Everyday contacts were the main route of the transmission and spread of this infection, the water factor playing an insignificant role. Two epidemic waves of cholera were registered in Gerga, each of them provoked the penetration of the infection to other regions of the Republic of Daghestan.