Acute intestinal infections were clinically and epidemiologically studied in children residing in the towns with different quantitative and qualitative composition of ambient air pollutants and in the districts of a town, which differ in the level of technogenic ambient air pollution. Six hundred and eighty patients with different types of shigellosis and 421 patients with salmonellosis admitted to the infection hospitals of the towns of Angarsk (an intensively polluted locality) and Irkutsk (a better ecological area) were examined in 1995 to 2000. The technogenic ambient air pollution was found to exert a noticeable impact on the incidence with S. sonnei dysentery. In poor environmental areas, all the infections under study are characterized by a great burden, duration, more severe clinical symptoms, and poor laboratory changes in the presence of a decreased responsiveness.
The causes of the simultaneous rise of salmonellosis morbidity induced by S. enteritidis among the population of three towns in the Perm region were studied. The study revealed the leading role of eggs and chicken meat as factors contributing to the transfer of this infection to the population of different territories, commonly supplied with the products of one poultry plant. The contamination of eggs and chickens with S. enteritidis occurred at the plant due to Salmonella infection of chickens, parallel with the use of nonbalanced mixed fodder, originally intended for feeding swine. Analysis of the epidemic and epizootic processes of Salmonella infection in this epidemic situation made it possible to reliably establish the factors contributing to the transfer of the infective agent and the site of contamination.
[An assessment of the connection between the annual population morbidity of salmonellosis due to Salmonella enteritidis and the dynamics of the epizootic process among chickens in commercial poultry plants].
The dynamics of annual morbidity in salmonellosis caused by S. enteritidis among the population of Perm during the period of 1987-1992 was analyzed. Blood sera taken from 4,689 practically healthy donors and from 6,997 hens at poultry breeding complexes were studied in the passive hemagglutination test with the use of complex Salmonella diagnosticum. The study revealed that seasonal rises in morbidity caused by S. enteritidis in winter and spring months, as well as in autumn months, were linked with the activation of the epizootic process of Salmonella infection among hens at poultry-breeding complexes during these periods of the year. A rise in the level of anti-Salmonella antibodies in poultry and human blood sera was found to be the precursor of the aggravation of the epidemic situation.
Serum samples from 641 workers of large poultry and meat-packing plants were studied in the passive hemagglutination test with the use of Salmonella complex and serogroup diagnostica. A specific increase in the level of anti-Salmonella antibodies in 60.7% of poultry plant workers and in 9.8% of meat-packing plant workers was established. Among the workers of the poultry plants the most pronounced immune shifts were detected in persons having contacts with sick poultry and pathological material and among the employees of the meat-packing plant, in those who ate raw sausage meat. A high level of antibodies in the professional groups under study was observed as early as in the first year of work at the plant and persisted over the whole period of this work. Under the conditions of constant contamination of the workers of poultry and meat-packing plants with small doses of salmonellae specific immunity to this infection was seemingly induced, which inhibited the development of the manifest forms of infection, but did not prevent the formation of chronic carrier state.