listerellosis, an acute infectious natural-focus zoonosis-type disease of man and animals caused by the microorganism Listeria monocytogenes.
Murine rodents are the natural reservoirs of listeriosis. The causative agent is also discharged by the tick Ixodes persulcatus. Persons are usually infected through animals upon ingesting Listeria-infested milk, meat, or eggs, from the bite of infected arthropods, or through the respiratory tract. The disease is found sporadically in various countries of Europe, Africa, America, and Australia and, occasionally, in the USSR. The disease appears after an incubation period that lasts a minimum of two weeks. The course takes a variety of clinical forms. Diagnosis is established on the basis of bacteriological investigations of the discharges of the tonsils, blood, cerebrospinal fluid, and amniotic fluid. In infants, meconium and mucus from the pharynx and nose are examined. Listeriosis is treated with antibiotics, and it is prevented by following veterinary sanitation and interrupting the paths of transmission of the infection.
REFERENCE
Tripolitova, A. A., and G. V. Borisova.
Listerioz. Tomsk, 1965. (Bibliography.)
N. D. MIKERINA
The majority of farm animals and many wild animals are subject to infection with listeriosis. Young and pregnant animals are especially sensitive. Infected animals are the source of the causative agent, releasing
Listeria along with nasal discharges, feces, urine, the genital discharges that accompany listeriotic abortions, and milk (with listeriotic mastitides). Sheep are most commonly affected; here the disease is seasonal (winter-spring), a consequence of the activation of the transmissive factor of the causative agent (the migration of infected rodents to fodder stores) and of a decrease in the animals’ resistance (connected with changes in the conditions of keeping and feeding and with pregnancy). One of the factors in transmitting
Listeria is silage, in which the organisms find favorable conditions for multiplying and accumulating.
Listeriosis in animals occurs sporadically (less often, epizootically). Confinement is usual, because of the presence of animal carriers, the prolonged viability of
Listeria in the environment, and the existence of natural foci. The disease may proceed acutely, subacutely, or, more rarely, chronically. Nervous, septicemic, mixed, erosive, and asymptomatic (carrier) forms are distinguished. The genital system can also be affected (abortions, placental retention, endometritides, and metritides), and there are listeriotic mastitides. Diagnosis is established on the basis of a complex of epizootological data, the clinical picture, and bacteriological investigations. Prevention entails supplying farms with animals from more favorable areas, conducting investigations to discover animals that may be carriers or are affected with the latent form of the disease, controlling rodents, and vaccinating the animals.
REFERENCE
Bakulov, I. A. Listerioz sel’skokhoziaistvennykh zhivotnykh. Moscow, 1967.