Vol 17, No 1 (2012)

The specific features of Legionella colonization of water supply systems were studied in the large healthcare facilities (HCF) of Moscow. Examination of 16 buildings of 5 Moscow multidisciplinary HCFs, including their risk-group units, revealed the high level (68%) of Legionella pneumophila contamination of hot water supply systems. Among the Legionella pneumophila strains circulating in the hot water supply systems of Moscow HCFs, there was a preponderance of its serogroup 6 (44%), 5 (26%), and 1 (13%) strains. The findings suggest that it is necessary to arrange a set of prophylactic measures for microbiological monitoring and protection of water systems in the HCFs, which are aimed at preventing nosocomial legionellosis.

Leptospirosis was studied in the natural and anthropurgic foci in the Volgograd Region. The etiological structure of Leptospira was established in wild and farm animals. Retrospective analysis of human morbidity identified three main periods associated with the change of Leptospira serogroups that cause the disease.

The paper considers topical problems in the scientific and methodological provision of epidemiological surveillance of rotavirus infection, such as the significance of different routes of pathogen transmission, a trend in the development of an epidemic process, and mechanisms of its self-regulation. The virological and epidemiological data suggest that the role of rotavirus transmission via water is insignificant (contact transmission is typified by the age-related structure of morbidity; water basins and drinking water show noninfectious viral markers, the resistance of which is much higher than that of the pathogen). A total of 8556patients aged 0 to 14 years with acute enteric infections, who were treated at the Children ’s Infectious Diseases Unit, City Hospital One, Rostov-on-Don, were examined for rotavirus in the period from February 2006 to January 2009. Group A rotaviruses were detected in 34% of the patients. Examination of variations in the trend of rotavirus incidence in children of different ages revealed a set of epidemiological parameters reflecting the dynamics of an epidemic process -phasic development and a change in epidemic infection cycles in the urban population. There was a continuous alternation of epidemic cycles every 2-2.5 months. The developed methods for monitoring the epidemic process make it possible to accurately assess the current epidemiological situation and to predict higher morbidity among infants.

The review deals with the properties of Vibrio cholerae (classical, El Tor, 0139, non-01/non-0139 strains) circulating worldwide during the seventh cholera pandemic. Particular attention is given to the variability in the cholera pathogen: the replacement of classical Vibrio cholerae by the El Tor biotype and subsequently the emergence of serogroup Vibrio cholerae 0139 and genetically altered El Tor Vibrio cholerae; the causes giving rise to these changes and spread of Vibrio cholera in the countries of the Asian continent. A large genetic variability found in Asian strains suggests that there is a real possibility of the emergence of new clones with new properties, including those with an epidemic potential. The Vibrio cholerae strains, that periodically appear in Asia and have an epidemic potential and new properties, spread over all continents, by causing cholera infection. The cholera pathogen adapts to new existence conditions in some cases, by altering some properties and, by having been rooted in a certain area, causes mainly sporadic cases of the disease. These Vibrio cholerae strains, unlike the Asian strains (the pathogens of the seventh pandemic), may be virulent, by preserving the virulence genes in the genome; however, they are, in most cases, non-endemic and unable to spread widely.

The paper provides a clinical and laboratory description of a case of dengue hemorrhagic fever imported by our countryman from Thailand to Omsk. It shows that the hemorrhagic fever of the disease may be developed in Russian citizens during multiple visits to endemic areas.

The paper deals with the history of controlling the outbreaks occurring in 1911-1914. It gives the chain of affairs of statesmen (including principal medical inspector L. N. Malinovsky) in controlling plague. The activities of the Tsaritsyno bacteriology station (its head was medical bacteriologist A. A. Churilina) and the Chita bacteriology station (its head was medical bacteriologist I. S. Dudchenko) are analyzed.