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At least 1,297 records · Page 72Linked to original sources
PubMed1990

Vaccine prophylaxis of abattoir-associated Q fever: eight years' experience in Australian abattoirs.

During the period 1981-8 a clinical trial of a Q fever vaccine (Q-vax; Commonwealth Serum Laboratories, Melbourne) has been conducted in abattoir workers and other at-risk groups in South Australia. Volunteers in four abattoirs and visitors to the abattoirs were given one subcutaneous dose of 30 micrograms of a formalin-inactivated, highly-purified Coxiella burnetii cells, Henzerling strain, Phase 1 antigenic state, in a volume of 0.5 ml. During the period, over 4000 subjects have been vaccinated and the programme continues in the abattoirs and related groups. 'Common' reactions to the vaccine comprised tenderness and erythema, rarely oedema at the inoculation site and sometimes transient headache. Two more serious 'uncommon' reactions, immune abscess at the inoculation site, were observed in two subjects, and two others developed small subcutaneous lumps which gradually dispersed without intervention. Protective efficacy of the vaccine appeared to be absolute and to last for 5 years at least. Eight Q fever cases were observed in vaccinees, but all were in persons vaccinated during the incubation period of a natural attack of Q fever before vaccine-induced immunity had had time (greater than or equal to 13 days after vaccination) to develop. On the other hand, 97 Q fever cases were detected in persons working in, or visiting the same abattoir environments. Assays for antibody and cellular immunity showed an 80-82% seroconversion after vaccination, mostly IgM antibody to Phase 2 antigen, in the 3 months after vaccination. This fell to about 60%, mostly IgG antibody to Phase 1 antigen, after 20 months. On the other hand, 85-95% of vaccinees developed markers of cell mediated immunity as judged by lymphoproliferative responses with C. burnetii antigens; these rates remained elevated for at least 5 years. The Q fever vaccine, unlike other killed rickettsial vaccines, has the property of stimulating long-lasting T lymphocyte memory and this may account for its unusual protective efficacy as a killed vaccine.

Abattoirs↗
PubMed1998

Detection of a spotted fever group rickettsia in Amblyomma cajennense (Acari: Ixodidae) in south Texas.

Thai tick typhus rickettsia (strain TT-118), a spotted fever group rickettsia of indeterminant pathogenicity, was isolated from a mixed pool of larval Ixodes and Rhipicephalus ticks collected from Thailand in 1962. Here we report the surprising finding of a spotted fever group rickettsia with closest sequence homology to the Thai tick typhus rickettsia in Amblyomma cajennense (F.) ticks from south Texas. Sequence analysis was performed on segments of 3 genes that differentiate rickettsial species; all 3 genes sequenced, the 17-kDa, glta, and rompA, when compared with those of other rickettsiae, showed the highest degree of similarity to the Thai tick typhus rickettsia with 99.5, 99.5, and 100% homology, respectively. This is the 1st finding of a rickettsial species in A. cajennense ticks in Texas and the United States. If this rickettsia is pathogenic, exposure to infected A. cajennense ticks may pose a previously unrecognized health risk to people who have been fed upon by these ticks.

Animals↗
PubMedDate not supplied

Prevalence of antiviral antibodies in workers handling wastewater and sludge.

Serological investigations were performed between 1977-1978 with 972 serum samples from 243 subjects having either direct (group A) or sporadic (group B) occupational contact with wastewater or sludge. the control group (C) was represented by 100 persons having no contact with such material. The sera were tested against influenza, parainfluenza, adeno-, herpes, coronavirus, rickettsial and chlamydial antigens, as well as for the presence of HBsAg and anti-HBs. Statistically significant differences between group A and groups B and C were found as regards the prevalence of antibodies to adenovirus and parainfluenza virus type 1 antigens.

Antibodies, Viral↗
PubMedDate not supplied

Report on ticks collected in the Southeast and Mid-West regions of Brazil: analyzing the potential transmission of tick-borne pathogens to man.

Specimens of ticks were collected in 1993, 1996, 1997, and 1998, mostly from wild and domestic animals in the Southeast and Mid-West regions of Brazil. Nine species of Amblyommidae were identified: Anocentor nitens, Amblyomma cajennense, Amblyomma ovale, Amblyomma fulvum, Amblyomma striatum, Amblyomma rotundatum, Boophilus microplus, Boophilus annulatus, and Rhipicephalus sanguineus. The potential of these tick species as transmitters of pathogens to man was analyzed. A Flaviviridade Flavivirus was isolated from Amblyomma cajennense specimens collected from a sick capybara (Hydrochaeris hydrochaeris). Amblyomma cajennense is the main transmitter of Rickettsia rickettsii (=R. rickettsi), the causative agent of spotted fever in Brazil. Wild mammals, mainly capybaras and deer, infested by ticks and living in close contact with cattle, horses and dogs, offer the risk of transmission of wild zoonosis to these domestic animals and to man.

Animals↗
PubMed1984

[Severe Chlamydia psittaci pneumopathy in an adult].

A previously well 56 year-old woman presented with an adult respiratory distress syndrome which worsened under penicillin treatment, responding only to erythromycin and rifampicin, as well as CPAP ventilation. Diagnostic serology was positive to Chlamydia psittaci. Psittacosis is not a frequent cause of primary extensive pneumonia in intensive care units; other diseases should be looked for in the presence of these non-specific clinical and biological pictures (Legionella pneumophila, Mycoplasma pneumoniae, Streptococcus pneumoniae). Pneumocystis should also be looked for in a typical pneumonia; erythromycin is the antibiotic of first choice in the treatment of primary extensive pneumonia.

Critical Care↗
PubMed1972

Serological diagnosis of tropical canine pancytopenia by indirect immunofluorescence.

An indirect fluorescent-antibody test for detection and titration of antibodies to Ehrlichia canis, the causative agent of tropical canine pancytopenia, has been described. The organism propagated by an in vitro technique in canine blood monocytes served as an antigen in the test. The specificity of the test was revealed by absence of cross-reactivity between the antigen and sera from dogs infected with various common pathogens and specific sera against eight rickettsial species. The accuracy of the test was ascertained by isolation of the organism from reactor dogs located in and outside the United States. Histopathological examination of nine reactor dogs revealed plasmacytosis of meninges and kidneys in eight of them.

Animals↗
PubMed1991

Use of monoclonal antibodies against Rickettsia tsutsugamushi Kawasaki for serodiagnosis by enzyme-linked immunosorbent assay.

Monoclonal antibodies (MAbs) against Rickettsia tsutsugamushi Kawasaki were prepared. The crossreactivity tests of the MAbs performed by using antigenically distinct strains of R. tsutsugamushi in immunofluorescence and immunoblotting analyses indicated that the Kawasaki strain contains a strain-specific epitope and also contains a common epitope on the 56-kDa polypeptide cross-reactive with the Gilliam strain, group- and subgroup-specific epitopes on the 46-kDa polypeptide, and a subgroup-specific epitope on the 25-kDa polypeptide. By using the strain-specific MAb for serodiagnosis of tsutsugamushi disease (or scrub typhus fever), we have established a method which was designated the inhibition enzyme-linked immunosorbent assay. The principle of the method is to measure the percentage of inhibition of antigen absorption on a MAb-coated plate by antibody-positive sample sera which were mixed with the antigen suspension. The advantages of this test for practical use are that (i) crude antigen can be used, i.e., purification of the antigen is not required; (ii) the test is more sensitive than immunofluorescence; (iii) the final judgment of plus or minus is clear-cut; and (iv) rickettsial antigenic types in the patients can be distinguished by this test.

Antibodies, Bacterial↗
PubMed1987

[Electron microscopic methods for the rapid diagnosis of Q fever in animals].

Methods have been worked out for the electron-microscopic diagnosis of Q-fever. A characteristic feature with them is the use of clinical, pathological, and experimental material that is investigated through negative contrast and ultra thin sections for the detection of rickettsial cells and inclusions. It is underlined that the methods referred to are readily applicable, economic, highly effective, and hazardless. They are described for the first time and could be adopted into the diagnostic and epizootiologic practice as well as in experimental investigations.

Abortion, Veterinary↗
PubMed2001

[New and emerging rickettsial and bartonella infections].

There have been recently reports on over 10 new and resurgent rickettsioses and bartonelloses in different countries, which reflects both socioeconomic processes in society and a higher methodological level of indication and identification of causative agents. In 1991, the author' laboratory, N. F. Gamaleya Research Institute of Experimental Medicine, Russian Academy of Medical Sciences, established the etiology of the new rickettsiosis Astrakhan spotted fever. It separated and studied 2 strains of Rickettsia sp. nov. from patients and 8 ones from the carrier the Ixodes tick Rhipicephalus pumilio. It is suggested that the natural focus has transformed to the anthropurgic one due to technogenic environmental pollution. The annual increase in morbidity rates (2000 cases in 1983 to 2000) and its area are a challenge to public health care and medical science. The paper presents data on the new bartonellosis cat-scratch disease (caused by Bartonella henselae) detected not only in Russia. There is also information on tick-borne rickettsiosis, epidemic typhus, and trench fever as resurgent infections.

Bartonella↗
PubMed2005

Detection of Brazilian spotted fever infection by polymerase chain reaction in a patient from the state of São Paulo.

Brazilian spotted fever (BSF) cases have been increasing in the state of São Paulo but no genomic information about local rickettsia isolated from humans has been well documented. We recovered spotted-fever group rickettsiae from a sample of patient blood cultured in Vero cells using the shell vial technique. Rickettsial DNA fragments (gltA, ompA, and, ompB genes) were detected, and analysis of the ompB gene base sequences showed identity with the Rickettsia rickettsii ompB sequence available in the GenBank.

Animals↗
PubMed2002

Isolation and PCR detection of rickettsiae from clinical and rodent samples in Malaysia.

Isolation of rickettsiae from patients' blood samples and organ samples of wild rodents from areas with high seroprevalence of rickettsial infections was attempted using cell culture assay and animal passages. L929 mouse fibroblast cells grown in 24 well tissue culture plate were inoculated with buffy coat of febrile patients and examined for the growth of rickettsiae by Giemsa, Gimenez staining and direct immunofluorescence assay. No rickettsiae were isolated from 48 patients' blood samples. No symptomatic infections were noted in mice or guinea pigs infected with 50 organ samples of wild rodents. There was no rickettsial DNA amplified from these samples using various PCR detection systems for Orientia tsutsugamushi, typhus and spotted fever group rickettsiae.

Adolescent↗
PubMed1991

Histopathology and immunopathology of skin biopsy specimens in Mediterranean spotted fever.

Histology of skin lesions and demonstration in them of Rickettsia conorii by direct immunofluorescence test (DIF) are presented in 13 patients with Mediterranean spotted fever (MSF). The lymphohistiocytic vasculitis which dominated the picture is not specific, however, it could be suggestive for the diagnosis of rickettsiosis. By DIF we demonstrated rickettsial coccobacillary forms in all the patients: in 12 macular lesions and in one "tache noire". The diagnosis was also confirmed by indirect immunofluorescence test in each case. DIF test was shown to be sensitive, specific and reliable in early diagnosis of MSF.

Adult↗
PubMed1975

Electron microscopy of Cowdria ruminantium infected reticulo-endothelial cells of the mammalian host.

An electron microscopic study of structures suspected to represent a possible developmental cycle of Cowdria ruminantium in reticulo-endothelial cells of mice and ruminants is reported. After infection dense bodies increase in size and undergo division to form fragmented dense bodies. These in turn apparently sub-divide and become organized to give rise to mature "organisms". In none of these structures do limiting membranes separate the parasitic inclusions from the host cell cytoplasm. Present observations suggest that growth of the organism in reticulo-endothelial cells differs from that of chlamydial and rickettsial agents and somewhat resembles the replication of some viruses. Developmental stages observed after infection of ruminants with the Ball 3 strain of the heartwater agent are indistinguishable from those seen with the mouse adapted strain. These observations support the hypothesis that C. ruminantium released from reticulo-endothelial cells subsequently penetrates endothelial cells where further multiplication by binary fission occurs.

Animals↗
PubMed1976

Functional and morphologic changes during experimental Rocky Mountain spotted fever in guinea pigs.

Experimental Rocky Mountain spotted fever was studied in guinea pigs following intraperitoneal inoculation of 10(7) Rickettsia rickettsii. After a 2-day incubation period, animals developed fever, progressive emaciation, and scrotal swelling with necrosis. Vasculitis, with increased small vessel permeability for colloidal carbon, was evident in cremaster muscles as early as 1 day after inoculation. Inflammatory changes in vessels became progressively more severe as numbers of circulating rickettsiae increased. Thrombosis and vascular occlusion were first evident on day 4. Mild thrombocytopenia developed, coinciding with the development of vasculitis, and preceding the appearance of either fibrin-split products in blood or thrombi in vessels. Rickettsiae were first detected in blood on day 2; peak rickettsemia occurred on days 5 to 8. Rickettsiae were demonstrated in inflamed vessels on day 5 and later, but not at earlier stages. Serum lysozyme concentration was moderately elevated and hemolytic complement was moderately depressed throughout the illness. Agglutinating antibody was present in low titers on days 3 to 10. Antibody titers increased on days 12 to 16 after the rickettsiae were cleared from blood. These studies indicate that vasculitis seen early in the course of Rocky Mountain spotted fever is the result of rickettsial infection, but is not dependent on the presence of rickettsiae in endothelial cells or other blood vessel components.

Agglutination Tests↗
PubMed1979

The occurence of coxiellosis among rodents and shrews in the Tarai area of Uttar Praedesh.

Rodents and shrews were screened for serologic evidence of Coxiella burnetii. Attempts were made to isolate the organism from the spleen and liver. Seroreactors: total positive/total tested (% positive), in rats (Rattus rattus, R. norvegicus), ground shrews (Suncus murinus), bandicoots (Bandicota indica, B. bengalensis) and the house mouse (Mus musculus), respectively, were 13/105 (12.38), 6/42 (14.3), 2/15 (13.3) and 1/7 (14.3). Of the eight rickettsial isolants recovered including four from field and household rats, three from ground shrew and one from bandicoots, only three comprising one each from rat, shrew and bandicoot, could be typed as C. burnetii. This appears to be the first record of rodents and an insectivore as reservoirs of C. burnetii in India.

Animals↗
PubMed1999

Serological evidence of Ehrlichia infection in Swedish Lyme borreliosis patients.

We studied sera from patients who had participated in a prospective study of borreliosis in Sweden and had acquired tick bites in areas of the country with a high prevalence of granulocytic ehrlichial infections in animals. The sera were examined for IgG anti Ehrlichia antibodies by an indirect immunofluorescence assay using a locally isolated bovine Ehrlichia antigen. Confirmation of the serological results was done at the Unité des Rickettsies, Marseille, France. Three out of 37 of the investigated patients and 1 out of 100 investigated healthy blood donors had significant antibody titres to granulocytotropic Ehrlichiae. No patient or blood donor had specific antibody titres to Ehrlichia chaffeensis. These data suggest that Scandinavian Ehrlichia species can infect and evoke immunological response in tick-exposed humans.

Acute Disease↗
PubMed1967

Pneumonia in Indian and Eskimo infants and children. I. A clinical study.

Ninety-seven Indian and Eskimo infants and children who suffered 112 episodes of pneumonia were the subjects of a prospective study carried out at the Charles Camsell Hospital, Edmonton, Alberta, from August 1963 until August 1964. Investigation included viral studies and an evaluation 10 days after admission. The patients were divided into four diagnostic categories and a comparison was made between cases of bacterial and viral origin. The frequency of right-sided disease, particularly of the upper lobe and/or dependent segment involvement, is described. An evaluation of physical signs is attempted. The problem of recurrent pneumonia and the differential diagnosis of tuberculosis in Indian and Eskimo children with pneumonia is discussed.

Adolescent↗
PubMed1985

Canine Rocky Mountain spotted fever: a kennel epizootic.

Within a period of 5 consecutive days after the initial observation of illness was made, 7 of 12 Siberian Husky dogs developed clinical signs of Rickettsia rickettsii infection. One dog died and was necropsied. Clinical signs of infection consisted of lethargy, anorexia, ocular and nasal discharges, and neurologic disorder (incoordination and rolling). Scleral blood vessel injection, fever, lymphadenomegaly, splenomegaly, and increased bronchovesicular lung sounds were prominent findings. Clinical laboratory test results identified decreased platelet numbers, variable neutrophil counts, increased serum alkaline phosphatase activity, hyponatremia, hypokalemia, and bilirubinuria. Diagnosis of Rocky Mountain spotted fever was confirmed by serologic evaluation of acute and convalescent sera, using the micro-immunofluorescence technique, and R rickettsii antigen was determined by demonstration of intracellular rickettsial organisms in vascular endothelial cells of brain and lung (stained with carbol-basic fuchsin and aqueous malachite green) and by demonstration of spotted fever-group rickettsiae in tissues by direct fluorescent antibody technique. Near-simultaneous naturally occurring tick-borne infection of 7 dogs with R rickettsii documents an unreported occurrence.

Animals↗