[Epidemiologic approaches to diagnosis of diseases dependent on ecologic factors]. / Epidemiologicheskie podkhody k diagnostike ékologozavisimykh boleznei.

The article deals with peculiarities in diagnosis of diseases caused by environmental hazards. The diagnosis covers population level and includes evaluation of environmental quality. Analysis of health for whole population and for risk groups enables to reveal "indicator" diseases. Social and hygienic monitoring, complex sanitary and ecologic examination recommend disclosure of facts and causes for any "nonspecific" diseases, definition of disorders caused by specific environmental hazards. The authors consider unity of hygienic and epidemiologic analysis for causative relationships in "human-environment" system in evaluation of noninfectious risk factors.

[Periodicity of chickenpox and epidemic parotitis]. / O periodichnosti vetrianoi ospy i épidemicheskogo parotita.

The pattern of the dynamics of incidence of chickenpox and epidemic mumps in Leningrad for many years was studied. The application of mathematical methods of treatment of the incidence data revealed the main trends of the processes and the occurrence of three rhythms in each infection. The average values of the periods of these rhythms differ for chickenpox and epidemic mumps and are 11.0, 6.2, and 4.1 years and 8.2, 4.0, and 2.8 years, respectively. The study of the age incidence in comparison with the dynamics of the epidemic process for many years showed that periodicity of these infections could not be explained completely by variations of the herd immunity of the population.