Ospovidny rickettsiosis

Description:

Ospovidny rickettsiosis (synonyms: a gamazovy rickettsiosis, rickettsial smallpox) – a benign transmissible rickettsial infection. The disease is for the first time described in 1946-1947 in suburbs of New York and in view of similarity to chicken pox received the name of rickettsial smallpox (rickettsialpox). In the 50th of the XX century the disease was revealed in other regions of the USA, in the Central and South Africa, in Uzbekistan, Turkmenistan and Kazakhstan.

Symptoms of the Ospovidny rickettsiosis:

Incubation interval duration at an ospovidny rickettsiosis is definitely not established and makes, apparently, about 7-10 days.

In an incubation interval (in 5–7 days prior to development of a syndrome of intoxication) on skin in the place of a sting of a tick infiltrate of 1-2 cm in size inflammatory, dense to the touch in the form of a papule of red color appears. Then the papule turns into the bubble which is deeply getting into skin when which wrinkling and drying the black scab is formed. Primary affect is located usually on the closed parts of a body, but it can be noted on the back of brushes, a neck, a face and is combined with regional lymphadenitis. Primary affect remains 3–3 1/2 weeks; after its healing there is a gentle scar.

In 5–7 days after emergence of primary affect in patients the intoksikatsionny syndrome sharply develops, high fever (39–4 °C), a fever, sharp headaches, sleeplessness, muscle and spin pains are noted. Fever of remittiruyushchy character remains on high figures within 6–7 days and comes to an end with critical or krizolitichesky decrease in temperature. About 2–3 days of the feverish period makulezno-papular or erythematic rash develops.

1–2 days later rash passes in vesicular with a diameter of elements up to 2-10 mm and more. Rash extends on all body, including the person, and sometimes also palmar and bottom surfaces. Rash elements not plentiful, easily give in to calculation. In rare instances elements of rash can not turn into vesicles or simulate a nodose erythema. Further vesicles dry up, and on their place the crusts of black color disappearing for the 4-10th day of a disease without formation of hems are formed.
Signs of defeat of cardiovascular system and internals are usually insignificant.
In a gemogramma it is possible to reveal an insignificant leukopenia, a neutropenia with a deviation to the left, thrombocytopenia. SOE is moderately raised.

The disease proceeds without complications and comes to an end with recovery.

Reasons of the Ospovidny rickettsiosis:

The activator of an ospovidny rickettsiosis is Rickettsia akariHuebneretal, 1946, Dermacentroxenus relating to a subgenus. On the properties the activator is close to other rickettsiae from group of tick-borne spotty fevers.
Ospovidny rickettsiosis – an endemic disease. An infection tank under natural conditions are house rodents – mice and, perhaps, rats. Circulation of rickettsiae is carried out by means of the gamazovy ticks of Allogermanys sussanguineus parasitizing on mice.
The person catches an ospovidny rickettsiosis in the epizootic centers as a result of attack and suction of the infected gamazovy ticks.
Diseases in the form of sporadic cases are noted in the city and rural centers during the whole year with increase in incidence in the period of activity of mites (May-August). More often men are ill.
The Ospovidny rickettsiosis is known in North America, the Central and South Africa, in the southern areas of Ukraine.

Treatment of the Ospovidny rickettsiosis:

The etiotropic means including derivatives of tetracycline or chloramphenicol in usual dosages during all feverish period and the first week of an apireksiya are used. Hold also events for the prevention of consecutive infection.