Pathogenesis of Cell Injury by Rickettsia conorii.
Annual summary rept. no. 1, 11 Apr 83-10 Apr 84,
NORTH CAROLINA UNIV AT CHAPEL HILL
Pagination or Media Count:
This work was undertaken to determine the pathogenic mechanism by which Rickettsia conorii causes disease. R. Conorii, an organism that has been neglected in spite of its widespread distribution and pathogenic qualities, was studied in human subjects and in vitro. The purpose of the work is to elucidate the pathology of boutonneuse fever and the pathogenic mechanisms which might be blocked therapeutically or prophylactically. Human tissues were investigated by light microscopy, histochemistry, immunofluorescence, and electron microscopy. In vitro models of cell injury by R. conorii included parabiotic chambers and the plaque model. Biopsies of 17 taches noires and 4 liver biopsies from patients with boutonneuse fever and necropsy tissues from two fatal cases of South African tick bite fever and amputated, gangrenous fingers from another patient with severe Rickettsia conorii infection were examined. R. conorii were identified in 11 taches noires, none of the liver biopsies, the endothelium or macrophages of the kidneys, brain, meninges, liver, spleen, heart, lung, lumph node, skin, and pancreas of the autopsy cases, and the blood vessels of the partially necrotic tissue of the amputated fingers. These results lead us to conclude that a rapid diagnostic test has been achieved, that visceral lesions and rickettsial distribution occur in fatal cases, and that further studies of taches noires and protease and phospholipase inhibitors are important.
- *TICKBORNE DISEASES
- IN VITRO ANALYSIS
- ELECTRON MICROSCOPY
- WOUNDS AND INJURIES
- BLOOD VESSELS
- RETICULOENDOTHELIAL SYSTEM
- Medicine and Medical Research