Clinical manifestations. Endemic typhus epidemic like fever, but usually easier to start with less severe and less pronounced common symptoms. Fever may be accompanied by a non-permanent pain and blood mialgiey. Spotty rash tends to remain scattered, neobilnoy and without hemorrhage. The disease is rarely lasts longer than two weeks and is not usually accompanied by lesions of internal organs.
Ethology. Endemic typhus is caused by Rickettsia t have phi (old name – Rickettsia mooseri), which resembles R. prowazekii.
Epidemiology. Natural hosts are rats (Rattus rattus often and R. norvegicus), whose disease is often asymptomatic. Vector that infects rats, and sometimes inadvertently rights, is rat flea (usually Xenopsilla cheopis). The disease is widespread in the world, affects all races. There is a trend towards more frequent contamination of adult males. Typically there in summer and autumn. In the United States are rare, mostly in the south-east coast of the Gulf, in the border southern states and Hawaii. The main risk factor is contact with rats and their blohami.
The incubation period lasts from 6 to 14 days.
Diagnostic tests. Used agglutination test reaction to a culture of Proteus OH-19, which reaches a maximum in 2-3 weeks from the beginning of the disease, although this test is not enough sensitive and specific. Indirect immunofluorescence or DNC reaches a peak at the same time or slightly later. Diagnostic significance is fourfold or more increase in titer antibodies in serum made in the midst of sickness and in recovery. Reactions may give a positive result and with the epidemic typhus tife. Serology differentiation of these diseases is possible through cross-absorption serum patient. Perhaps the selection cause, with crops, but it requires special equipment, experienced personnel and the risk of laboratory infection.
Treatment. Drug of choice is tetracycline (which should not give children under 9 years old) or Chloramphenicol. In the early appointment of the effect of drugs usually occurs within 2-3 days. Therapy should be to continue until the 2-3rd day of normal temperature.
The isolation of hospitalized patients. Precautions are not recommended.
The control measures. It is necessary to kill rat fleas appropriate insecticide, it is preferable to rodenticides (drugs, destroyed rodents), as well as after the death of rats blohi will look for another host. Rat population must be destroyed by appropriate means. A vaccine against endemic typhus currently does not apply. The treatment of persons who were in contact, not recommended.