Queensland tick typhus
Queensland tick typhus - the acute rickettsial illness characterised by a fever, primary affect, a regional lymphadenitis, a generalised lymphadenopathy and a maculo-papular exanthema.
Aetiology. The originator - Rickettsia australis concerns bunch of mite-borne spotted fevers. Possesses properties, characteristic for all Rickettsias (pl Rickettsiae). Parasitizes in a cytoplasma and kernels of cells of an endothelium of pots of the sick human. It is pathogenic for Guinea pigs and white mice. In the antigenic attitude differs from Rickettsias (pl Rickettsiae) of bunch of a spotted fever.
Epidemiology. Concerns zoonoses with connatural focus. It is extended in state of Queensland in Australia. Transmitting agents are pincers Ixodes holocyclus, L. tasmani. The infection contamination reservoir in the nature are donors of pincers - a red rat, an opossum, the kangaroo, etc. Transmissions of infection from the human to the human is not observed.
Pathogenesis. Infection atriums is the skin in a place of a puncture of the tick where the aboriginal inflammation of a skin (primary affect) educes, on lymphatic pathes of Rickettsias (pl Rickettsiae) reach regional lymph nodes, causing development of a regional lymphadenitis. Then Rickettsias (pl Rickettsiae) inpour into blood, causing signs of the general intoxication. Are localised in an endothelium of pots.
They usually do not cause the expressed anatomical changes. Diseases are not accompanied by development thrombus - a hemorrhagic syndrome and tromboembolic episodes, abandon durable immunity.
Symptoms and flow. The incubation interval proceeds 7-10 days. Disease begins acutely. The body temperature to 38-39C° raises, the fever of constant phylum lasts more often than 5-10 days. Patients note the general delicacy, a moderate headache, the depression of appetite moderately expressed to a pain in muscles. At survey almost at all patients tap primary affect and a regional lymphadenitis to it. The augmentation and other bunches of lymph nodes becomes perceptible, but it is expressed less, than regional, their morbidity is absent, whereas the regional lymphadenitis is accompanied by morbidity at a palpation. The exanthema appears for 4-6th day of illness, an eruption abundant enough polymorphic. Eruption elements consist of maculae to 10 mm in diameter, separate maculae can merge. Roseolas and papules are observed also. The eruption is extended on all body, eruption elements appear also on palms and soles. The eruption remains during all feverish season. Disease proceeds in easy or middleserious forms.
Complications it is not described.
The diagnosis and the differential diagnosis. For diagnostics great value epidemiological data (have stay in precinctive district, punctures of the tick and so forth), and also clinical semiology (primary affect, an abundant eruption, good-quality flow). To differentiate it is necessary with other rickettsioses (a sapropyra endemial, Scrub typhus, etc.).