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At least 1,081 records · Page 60Linked to original sources
PubMed1975

Pathophysiologic features of Q fever-infected guinea pigs.

Guinea pigs infected with 9-mile phase I strain of Coxiella burnetii had increased blood glucose concentrations; alkaline phosphatase (ALP), glutamic-oxalacetic transaminase (GOT), alpha-hydroxybutyrate dehydrogenase (alpha-HBDH), and creatine phosphokinase (CPK) activities; and bilirubin value. Hypocalcemia and hypophosphatemia were evident in the latter days of infection. At necropsy of the guinea pigs, necrotic foci were in liver, spleen, and heart. Seemingly, the major pathophysiologic changes in infected guinea pigs were the direct result of lesions in liver, spleen, and heart in which rickettsial bodies were readily observable with histologic staining procedures. The guinea pig may serve as an animal disease model for Q fever.

Alkaline Phosphatase↗
PubMed1986

Acute febrile cerebrovasculitis: a syndrome of unknown, perhaps rickettsial, cause.

In late 1983, five patients living near Charlottesville, Virginia, were treated for an unusual syndrome of fever, headache, altered mentation, multifocal neurologic signs, and cerebrospinal fluid pleocytosis. Clinical signs of brainstem disease developed in four patients. All five had had recent exposure to forests or wood and contact with flea-infested dogs. Two patients died; one survivor has had recurrent seizures. Brain biopsy samples in two patients and autopsy findings in another showed cerebral vasculitis and perivasculitis involving mostly venules and capillaries. In the autopsy, the severest vascular lesions involved the brainstem and thalami, where they were accompanied by acute fibrinoid necrosis, but discrete vascular lesions of lesser intensity were randomly distributed in the white matter and cortex. Serologic studies on paired specimens in four patients showed significant cross-reacting antibody responses to rickettsial (typhus-group) antigens in the indirect hemagglutination, latex agglutination, and IgM microimmunofluorescence tests, but no agent was visualized or isolated. The cause of this serious inflammatory disorder is unknown.

Acute Disease↗
PubMed1986

Q fever pneumonia associated with exposure to wild rabbits.

4 patients with atypical pneumonia and a history of exposure to wild rabbits were found to have antibodies to Coxiella burnetii but not to the other organisms also commonly associated with atypical pneumonia. 10 (45%) of 22 snowshoe hares caught in the area where 1 of the patients snared his rabbits had antibodies to Coxiella burnetii. Q fever ought to be included in the differential diagnosis of pneumonia acquired following exposure to wild rabbits.

Animal Population Groups↗
PubMed1997

Adenosine deaminase activity in the aetiological diagnosis of community-acquired pneumonia.

A prospective study was undertaken to assess the usefulness of serum adenosine deaminase (ADA) activity in the aetiological diagnosis of 75 patients (mean age 58 years) with community-acquired pneumonia who required hospitalization. Measurements of ADA were also carried out in 35 healthy subjects (mean age 52 years). The serum ADA activity in patients with typical bacterial pneumonia (TBP) was 21 +/- 7 IU/l and in controls 22 +/- 9 IU/l. In 43 patients with atypical pneumonia (AP), ADA levels (43 +/- 23 IU/l) were significantly higher than in the previously related groups (p < 0.001). Analysis within the group of atypical pneumonia showed significant differences for infections caused by Coxiella burnetii (61 +/- 19 IU/l, p < 0.001), Mycoplasma pneumoniae (44 +/- 26 IU/l, p < 0.001) and Legionella pneumophila (39 +/- 15 IU/l, p < 0.05), as compared with patients with bacterial pneumonia and normal control subjects. We conclude that serum ADA in patients with community-acquired pneumonia requiring hospitalization may provide useful additional diagnostic information on the aetiology of pulmonary infection.

Adenosine Deaminase↗
PubMed1991

Evaluation of Rhipicephalus sanguineus as a potential biologic vector of Ehrlichia platys.

The brown dog tick, Rhipicephalus sanguineus (Acari: Ixodidae), transmits several diseases among dogs including Ehrlichia canis infection. The role of Rhipicephalus sanguineus as a biologic vector for E platys, the rickettsial agent of infectious canine cyclic thrombocytopenia, was studied in dogs. Laboratory-cultured, pathogen-free nymph ticks were fed to repletion on dogs acutely infected with E platys. Tick engorgement coincided with the development of initial parasitemia and thrombocytopenia in the infected dogs. Following repletion, nymph ticks were allowed to molt under controlled conditions. One-month-old E platys-exposed adult ticks failed to infect naive dogs in animal transmission studies. The presence of E platys was not detected in midguts or salivary glands of similarly exposed adult ticks by use of light and transmission electron microscopy. These studies indicate that R sanguineus may not transmit E platys infection.

Animals↗
PubMed1993

Preliminary evaluation of the INDX DIP-S-TICKS with positive rickettsial samples in Malaysia.

Forty-four serum samples of various reactivities to rickettsial antigens demonstrated by the indirect immunoperoxidase technique were tested with INDX Dip-S-Ticks (INDX Integrated Diagnostics Inc., USA) Kit for the detection of tick borne diseases. The kit utilised Rickettsia rickettsii the causative agent of Rocky Mountain spotted fever (RMSF) as antigens. The samples positive for endemic typhus were also tested against R. typhi, the agent for endemic typhus by the same method. The aim of this study was to determine the extent of cross-reactivity of R. rickettsii with rickettsial infections in Malaysia. Nine out of 12 tick typhus, 4 out of 10 scrub typhus and 4 out of 12 endemic typhus samples cross reacted with R. rickettsii. Ten out of 12 endemic samples were positive with R. typhi by the same method. From the study, we concluded that the INDX Dip-S-Ticks Kit can be used as a rapid screening test to detect endemic and tick-borne rickettsial infections in Malaysia but a second serological test is strongly recommended on all weakly reactive cases.

Animals↗
PubMed2001

Endemic typhus in Singapore--a re-emerging infectious disease?

UNLABELLED: Singapore is a modern urban city and endemic typhus is thought to be a disease of the past. This may be due to lack of specific serological testing as indirect immunoperoxidase testing using specific rickettsial antigens (U.S. Army Medical Research Unit, Institute of Medical Research, Kuala Lumpur, Malaysia) has only recently become available. In the last fourteen months, twenty-one cases of endemic typhus were diagnosed in patients hospitalised for acute febrile illnesses at the National University Hospital. We conducted a case control study to define the clinical and laboratory features of endemic typhus in Singapore. METHOD: Demographic, clinical and laboratory data were reviewed for cases and twenty-one age and sex matched controls who had negative serologic tests as part of a work-up for fever of unknown origin. RESULTS: Apart from a higher initial temperature (39 degrees C vs 37.9 degrees C (p < 0.001)) and ALT(p = 0.002), cases and controls had similar presentations of fever, myalgia, headache, cough, normal WBC and platelet counts. Singapore residents and migrant workers were represented in both groups (p = ns). CONCLUSION: Endemic typhus remains an important cause of acute febrile illness in Singaporein both the local and migrant worker populations. The presentation is similar to other causes of acute febrile illnesses and the diagnosis will be missed unless it is specifically sought.

Adult↗
PubMedDate not supplied

[A case of Kawasaki disease. Case report].

The Authors describe the case of a little girl from Buenos Aires that presents, as regards the clinical picture and the course, the features of Kawasaki illness. It is the first case described in Calabria. The Authors come to the hypothesis that Kawasaki illness, could be a benign variant of periarteritis nodosa, caused from an infections noxa (Rickettsie?).

Anti-Bacterial Agents↗
PubMed1989

Detection and quantitation of Anaplasma marginale in carrier cattle by using a nucleic acid probe.

Cattle which have recovered from acute infection with Anaplasma marginale, a rickettsial hemoparasite of cattle, frequently remain persistently infected with a low-level parasitemia and serve as reservoirs for disease transmission. To fully understand the role of these carriers in disease prevalence and transmission, it is essential that low levels of parasitemia can be accurately detected and quantitated. We have developed a nucleic acid probe, derived from a portion of a gene encoding a 105,000-molecular-weight surface protein, that can detect A. marginale-infected erythrocytes. The probe is specific for A. marginale and can detect 0.01 ng of genomic DNA and 500 to 1,000 infected erythrocytes in 0.5 ml of blood, which is equivalent to a parasitemia of 0.000025%. This makes the probe at least 4,000 times more sensitive than light microscopy. Hybridization of the probe with treated blood from animals proven to be carriers of anaplasmosis showed that parasitemia levels were highly variable among carriers, ranging from greater than 0.0025 to less than 0.000025%. Parasitemia levels of individual animals on different dates were also variable. These results imply that, at any given time, individuals within a group of cattle may differ significantly in their abilities to transmit disease.

Anaplasma↗
PubMed1978

Chlamydiae, rickettsiae, and their cell wall defective variants.

Inapparent chlamydial and rickettsial infections are an important source of the dissemination of the parasites and may cause explosive outbreaks of severe diseases in man and animal. However, it is engimatic how these obligate intracellular microbes induce latency and why or how inapparent infections convert into active disease. Currently, microbiologists believe that chlamydiae and rickettsiae are gram-negative bacteria unique in their intracellular habitat. This review presents evidence that these organisms have another peculiarity; namely, defective cell walls present throughout much of their life cycle. In this survey, the properties of the small and large forms of chlamydiae and rickettsiae are reexamined with regard to the current knowledge of cell wall defective variants of free-living bacteria. Data are presented in support of the concept that chlamydiae and rickettsiae are cell wall defective microbes whose small 'bacterial' forms have lost the ability to reproduce as bacteria during evolution; the large forms including ultrafilterable phases of the life cycle of these parasites are responsible for inapparent infections of healthy carriers, whereas conversion into small 'bacterial forms may cause, under appropriate conditions manifest diseases. This concept may provide challenging and profitable directions in the search to explain puzzling phenomena associated with chlamydiae and rickettsiae.

Biological Evolution↗
PubMed1987

[Current status of the Q-rickettsial endocarditis problem and the 1st case reported in Bulgaria].

A vast literary review on Q-rickettsial endocarditis is presented--spread, frequency, predilection, clinical course, laboratory findings, diagnosis, treatment, prognosis. The first case of Q-rickettsial endocarditis in Bulgaria is reported. The case was proved by the high titre of the specific antibodies while the patient was still alive and post mortem by visualizing the causative agent in the aortic valve and by its isolation through inoculation of material from the aortic valve. The infection was not influenced by high doses of penicillin, gentamycin and brulamycin but was suppressed by vibramycin in combination with lincomycin and biseptol. The lethal outcome was due to severe heart failure. It is suggested that other cases of Q-rickettsial endocarditis should be expected since Q-fever is widely spread in Bulgaria and the characteristics of the disease, its diagnosis and treatment ought to be well known.

Aortic Valve↗
PubMed1987

Identification of drugs effective against Cowdria ruminantium using a mouse screening system.

Heartwater is a tick-transmitted rickettsial infection of ruminants, caused by Cowdria ruminantium. The tetracyclines are the only compounds available for therapy of the disease. A screen, using mice infected with C. ruminantium, was developed and used to identify new compounds with potential for the control of heartwater. A series of di-4-methyl-thiosemicarbazones was shown to be highly active in the mouse model and their efficacy was confirmed in further trials in sheep infected with C. ruminantium. The mouse screen was shown to be simple to operate and reliably predictive of activity against heartwater. Ways in which the screen may be improved are suggested.

Animals↗
PubMed1992

[Tsutsugamushi disease found in Haruna District, Gunma Prefecture--evaluations of the clinical features and the outbreak pattern].

From November to December in 1990, 7 cases of tsutsugamushi disease were found first in the southern foot of Mt. Haruna of Gunma Pref., Japan. The present study was conducted to clarify the clinical features and the outbreak pattern of rickettsial infection in this area. All the patients consisting of 6 males and 1 female farmers were admitted to our hospital, complaining of high fever, chills and skin rash on 5-12 days after working in the field. Based on laboratory examinations and one (or two) typical eschar, a tentative diagnosis of tsutsugamushi disease was made and all patients became better soon after the therapy with intravenous administration of minocyclin (200 mg/day). The high titer of serum antibody to Karp type Rickettsia (Orientia?) tsustugamushi was detected by an immunoperoxidase test (IP) in most of the patients, and also a Karp-like strain was isolated from only one patient, probably due to low virulence to mice. The agricultural areas along the Agatuma and Nakuta rivers in the northern foot of Mt. Haruna have been well known as the most endemic foci of the disease in Gunma Pref. Nevertheless, it was suggested that outbreaks of the disease might be potentially wide-spread throughout this Pref., when the prevalences of the disease were evaluated as incidences to a hundred thousand inhabitants or adjusted by the density of agricultural populations of each administrative divisions. As most of the patients in Gunma Pref. have been officially reported in autumn, a statistical trial indicates that there is a significant correlation between the levels of temperature and outbreaks of the disease in autumn.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗