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At least 181 records · Page 10Linked to original sources
PubMed1991

[Serological demonstration of the detection of tick-borne rickettsial disease in Astrakhan Province].

Starting from 1978, noncontagious febrile diseases of unclear etiology, accompanied by pronounced headache, roseolous-papular eruptions, prolonged convalescence period, are registered in May-September in Astrakhan Province. These diseases can be effectively treated with chrolamphenicol. In 11 out of 12 sera obtained from such patients the complement fixation test with the antigens of rickettsiae causing tick-borne spotted fever, epidemic typhus, as well as Coxiella burnetii antigen, revealed the presence of antibodies (in 8 sera) only to the antigens of rickettsiae causing tick-borne spotted fever (R. akari, R. conorii, R. sibirica), or the titers of antibodies to these antigens were greater (1 serum), equal and lower (2 sera) in comparison with those of the antigens of rickettsiae causing epidemic typhus. The dynamics and values of antibody titers in 7 patients with the antigens of three rickettsial species of the tick-transmitted biotype indicated that the disease was related to tick-borne spotted fever.

Antibodies, Bacterial↗
PubMed1992

The laboratory diagnosis of rickettsial diseases in Hong Kong.

Indirect immunoperoxidase (IP) tests against antigens of Rickettsia typhi, R. sibirica and R. tsutsugamushi were carried out on serum samples from 10 patients known to have high titres against one or more Proteus OX antigens in the Weil-Felix (WF) test. The IP test confirmed rickettsial infection in nine of the 10 patients, giving unequivocal indications of the grouping of the infecting Rickettsia species and, in one instance, showing a diagnostic IgM titre in a specimen taken on day 3 of the patient's illness. IP tests confirmed four cases of spotted fever group rickettsial infection, three cases of urban or murine typhus and two of scrub typhus.

Adolescent↗
PubMed1991

A ten years experience on diagnosis of rickettsial diseases using the indirect immunoperoxidase methods.

An accurate diagnosis of Tsutsugamushi disease (TD) can be made within a few hours after receiving serum specimens by detecting the specific IgG and IgM antibodies in the patient's serum. Using the indirect immunoperoxidase test we found a total of 730 cases of TD in 32 out of 47 prefectures when serum samples from 2,224 cases of suspected disease or fever of unknown origin or from patients with febrile exanthema of unknown cause were examined during a 10 years period (from May 1980 till December 1989). In addition, 27 cases of spotted fever group rickettsial infection were confirmed and one case of African spotted fever group infection was also detected in 1988. Furthermore, possibly the first case of TD was found in People's Republic of Congo (Africa) in 1989.

Adolescent↗
PubMed2002

The past and present threat of rickettsial diseases to military medicine and international public health.

Morbidity and mortality caused by rickettsioses have had a major influence on military activities and public health for >2000 years. The threat posed by the rickettsioses is reviewed, focusing on the impact and epidemiology of those that have adversely influenced wartime operations and the current challenges posed by these diseases. With their uneven worldwide distribution, the discovery of drug-refractory strains of Orientia tsutsugamushi, the increased threat of their use in acts of bioterrorism, frequent deployment of troops to regions of endemicity, and exposures due to increased humanitarian missions, these diseases continue to be a threat to military personnel in the field. Effective strategies to reduce the impact of these diseases include development of effective vaccines, enhanced surveillance, and development of new safe, effective, and odorless repellants. The continuation of a proven, highly productive military infectious disease research program is essential for providing solutions to these daunting tasks.

Animals↗
PubMed1994

Depletion of gamma interferon and tumor necrosis factor alpha in mice with Rickettsia conorii-infected endothelium: impairment of rickettsicidal nitric oxide production resulting in fatal, overwhelming rickettsial disease.

C3H/HeN mice infected intravenously with a dose of Rickettsia conorii (Malish 7 strain) that is sublethal for immunocompetent animals (1.1 x 10(3) PFU) developed disseminated infection of endothelial cells of the brain, lungs, heart, liver, kidney, testis, and testicular adnexa. In R. conorii-infected mice depleted of gamma interferon (IFN-gamma) and/or tumor necrosis factor alpha (TNF-alpha) by intravenous administration of neutralizing monoclonal antibodies on days 0, 2, and 4, the mortality rate was 100%. Death of the cytokine-depleted animals on days 5 and 6 was associated with overwhelming rickettsial infection documented by titration of rickettsial content in the brain and liver and by immunohistologic demonstration of massive quantities of R. conorii in endothelial cells of all organs examined, in macrophages of the liver and spleen, and in hepatocytes. Nondepleted, immunocompetent animals showed markedly reduced rickettsial content in the tissues on day 6, with rickettsial destruction in phagolysosomes not only in macrophages but also in endothelial cells and hepatocytes. All nondepleted, infected mice recovered and appeared completely healthy by day 9. Assay of liver infiltrated by lymphocytes and macrophages revealed mRNA of IFN-gamma and TNF-alpha, indicating that the host defenses were activated at the site of infection. Treatment of mice with an analog of L-arginine reduced the synthesis of nitric oxide and impaired rickettsial killing. Nitric oxide production was also impaired in cytokine-depleted infected mice. These observations support the hypothesis that IFN-gamma secreted by T lymphocytes and natural killer cells and TNF-alpha secreted by macrophages act in a synergistic, paracrine fashion on adjacent rickettsia-infected endothelial cells, hepatocytes, and macrophages to stimulate synthesis of nitric oxide, which kills intracellular R. conorii.

Animals↗
PubMed1989

Acute febrile cerebrovasculitis. A non-spotted fever group rickettsial disease.

In December 1985, a patient was seen with an illness that was clinically compatible with the recently described clinical syndrome of acute febrile cerebrovasculitis, including fever, headache, altered mentation, multifocal neurologic signs, and cerebrospinal fluid pleocytosis. An extensive medical evaluation failed to reveal a cause, until, retrospectively, she was shown to have antibodies to Rickettsia typhi. Detailed serologic analysis with enzyme immunoassays and protein immunoblots indicated that she was infected with a non-spotted fever group Rickettsia, most likely either R typhi or Rickettsia canada. Serum samples from a mouse trapped at her home contained antibody only to R canada. Evaluation of patients with acute febrile cerebrovasculitis in the future should include rickettsial blood cultures to attempt specific identification of the species involved.

Adult↗