Российский паразитологический журнал (Oct 2019)
BRAIN DISORDERS (CEPHENOMIOSIS) IN ELKS CAUSED BY CEPHENOMYIA ULRICHII AND PREVENTION OF DISEASE
Abstract
Objective of research: The purpose of this research was to study the changes of histology picture and macroanatomic changes in cephenomiosis of elks and to estimate the efficacy of sodium azide against gadfly larvae. Materials and methods: Macroanatomic studies of nasal cavity, sinuses and Eustachian tubes were conducted. Furthermore, histological examinations of elk’s brain with gadfly larvae were carried out to investigate some aspects of pathogenesis of oestrosis. Hard cerebral shell was dissected and removed. After removing brain was dissected into small slices that were placed to the fixative solution. Brain was dissected by standard methods; brain slices were stained with hematoxylin and eosin. We used carbol-xilol in proportion 1: 4-1: 10 for clearing brain slices. When using this staining method, cell nuclei are purple or blue, cytoplasm is pink-red, connective tissue light pink. Effects of different disinfectants (sodium azide solution 0,1 %, chlorophos 0,1 %, formalin 1 %) on gadfly larvae were studied. extrosal encephalitis Results and discussion: Pathologic-anatomical studies enabled to detect the pronounced microscopic features of meningoencephalitis (hyperthermia, mild hemorrhage, brain swelling). The diagnosis of meningoencephalitis was confirmed after histological examination of several brain sections. More than 300 Cephenemyia ulrichii larvae were detected. When investigating histological slices we carried out differential diagnostics of prion-related encephalitis. Inflammatory infiltrates around the vessels, changes in the vessel wall, diffuse proliferative response of micro-and oligodendroglia were determined. Direct effects of causative agents on brain tissue are important for pathogenesis of extrosal encephalitis. Allergic reactions have also a definite value, especially in subacute encephalitis due to the large number of parasitizing larvae. Sodium azide and chlorophos solutions have proved to be the most effective against gadfly larvae. It was found that larvae died within several hours in sodium azide and chlorophos solution 0,1%. However, in comparison to chlorophos, sodium azide did not cause the death of soil microflora.
