Seroepidemiological investigation of Brucella canis antibodies in different human population groups. (49/532)

A study was conducted to determine the prevalence of Brucella canis antibodies in specified groups based on their exposure to dogs. The method used was a microtiter technique, and the presence of antibodies at a 1:12 or greater dilution of serum was considered a positive test. Eleven (5.7%) of the newborn infants had evidence of maternal antibodies, and 67.8% of the persons with an average exposure to dogs had B. canis antibodies, with a 62.1% prevalence in males and a 72.4% prevalence in females (P less than or equal to 0.001). Veterinarians had a much higher rate of infection (72.6%) than male blood donors (56.9%) (P less than or equal to 0.01). Patients with fevers of undetermined origin had significantly higher antibody titers to B. canis than all other patients (P less than or equal to 0.001). This study presents evidence that the prevalence of B. canis antibodies in humans is high, and that the incidence of brucellosis may increase when physicians consider B. canis as a possible etiological agent in febrile illnesses.  (+info)

Musculoskeletal involvement of brucellosis in different age groups: a study of 195 cases. (50/532)

OBJECTIVE: The aim of the present study was to determine the distribution and characteristics of arthritis in 195 patients with musculoskeletal involvement due to brucellosis in different age groups in the southeastern region of Turkey. PATIENTS AND METHODS: We carried out a retrospective analysis of 283 patients with brucellosis records and identified 195 with musculoskeletal involvement. Patients were classified into acutesubacute (<12 months) and chronic (>12 months) brucellosis. Patients were also classified into three age groups: <15 years old (group A), 15-45 years (group B), and over 45 years (group C). In addition, patients were classified into five subgroups according to type of arthritis: peripheral arthritis, polyarthritis, spondylitis, sacroiliitis, and spondylitis/sacroiliitis. RESULTS: 195 (69%) of the 283 patients [138 female (49%), 145 male (51%)] had musculoskeletal involvement. Of the patients with musculoskeletal involvement 113 (58%) were female and 82 (42%) were male, ranging in age from 3 to 71 years (mean age 33.14 +/- 15.03). Of 195 patients studied, 39 (14%) were <15 years old (group A), 122 (43%) were aged 15-45 (group B), and 34 (12%) were over 45 (group C). The most commonly affected joints were the sacroiliac joint in 108 patients (55%), peripheral joints in 106 (54%), and spondylitis in 60 (31%). Of 108 patients with sacroiliitis, 19 were in group A, 76 in group B, and 13 in group C. Bilateral sacroiliitis was less common in group B (23 patients) than in groups A (3) and C (3) (p <0.05). Spondylitis was more common in group B (18%). Sacroiliitis and polyarthritis were more common than other types of musculoskeletal involvement in females, whereas in males the distribution of all types was similar. In patients aged under 15 and 15-45, sacroiliitis and polyarthritis were common compared with other types of arthritis, but the distribution was similar in patients over 45. CONCLUSION: In southeastern Anatolia musculoskeletal involvement in brucellosis is frequent. The series presented suggests that musculoskeletal involvement in group A is higher than groups A and C. The prevalence of musculoskeletal involvement appears to differ according to age, sex and clinical type.  (+info)

Time-space clustering of human brucellosis, California, 1973-1992. (51/532)

Infection with Brucella spp. continues to pose a human health risk in California despite great strides in eradicating the disease from domestic animals. Clustering of human cases in time and space has important public health implications for understanding risk factors and sources of infection. Temporal-spatial clustering of human brucellosis in California for the 20-year period 1973-1992 was evaluated by the Ederer-Myers-Mantel, Moran's I, and population-adjusted Moran's I procedures. Cases were clustered in concentrated agricultural regions in the first 5-year interval (1973-1977). Time-space clustering of human brucellosis cases in California late in the 20-year study period may reflect the distribution of Hispanic populations. Public health programs in California should focus on educating Hispanic populations about the risk of consuming dairy products, such as soft cheeses, made from unpasteurized milk.  (+info)

Comparison of Brucella abortus and Brucella melitensis infections of mice and their effect on acquired cellular resistance. (52/532)

By using mice infected with strains of Brucella abortus and Brucella melitensis we examined the histological responses to infection, the relationship of histology to persistence of organisms, and the relation of persistence of organisms to the acquisition of acquired cellular resistance (ACR). Infection with B. abortus resulted in well-formed granulomas in the livers, which persisted for more than 30 days. In contrast, infection with B. melitensis produced microabscesses in the livers which resolved before 30 days. The clearance of organisms from the tissues was also different. A total of 30 days after infection, large numbers of viable bacteria were recovered from the tissues of B. abortus-infected mice whereas bacteria were no longer recoverable from B. melitensis-infected animals. ACR to Listeria monocytogenes, another intracellular pathogen, persisted for more than 30 days in B. abortus-infected mice but waned rapidly in B. melitensis-infected animals. This disappearance of ACR due to B. melitensis paralleled the clearance of bacteria from the tissues.  (+info)

Diverse bacteria are pathogens of Caenorhabditis elegans. (53/532)

Practically and ethically attractive as model systems, invertebrate organisms are increasingly recognized as relevant for the study of bacterial pathogenesis. We show here that the nematode Caenorhabditis elegans is susceptible to a surprisingly broad range of bacteria and may constitute a useful model for the study of both pathogens and symbionts.  (+info)

Diminished production of T helper 1 cytokines correlates with T cell unresponsiveness to Brucella cytoplasmic proteins in chronic human brucellosis. (54/532)

This study evaluated the cellular immune response against Brucella species cytoplasmic protein (CP) in peripheral blood mononuclear cells (PBMC) of 25 patients with brucellosis. In vitro proliferation and cytokine gene expression and production were investigated. PBMC from 14 patients proliferated in response to CP (responder patients [RPs]) and cells from 11 patients did not (nonresponder patients [NRPs]). CP-specific interleukin (IL)-2 and interferon-gamma were significantly induced in PBMC from RPs, compared with cells from NRPs. No significant differences were found in the production of IL-10 between the 2 groups. CP did not induce IL-4 production. A close relationship was observed between the clinical status of the patients and the T cell response against CP. Patient with acute infections responded to CP and induced production of T helper 1 (Th1) cytokines, whereas chronically infected patients did not. Diminished production of Th1 cytokines may contribute to T cell unresponsiveness in chronic human brucellosis.  (+info)

Sensitivity and specificity of an indirect enzyme-linked immunoassay for the diagnosis of Brucella canis infection in dogs. (55/532)

The diagnosis of B. canis infection in dogs is based on bacteriological examination and serological methods including agglutination and gel diffusion tests. Bacteriological studies are the only methods that have been considered specific but, as intermittent periods of abacteraemia may occur, a negative blood culture cannot be used as a criterion for excluding canine brucellosis. Close contact between people and infected dogs increases the risk of transmission; however, its impact on public health is probably underestimated due to lack of reporting and inadequate diagnostic services. This paper describes an indirect enzyme-linked immunoassay (IELISA) procedure for the diagnosis of brucellosis caused by B. canis in a population of normal and infected dogs previously screened by the buffered plate antigen test (BPAT) and rapid slide agglutination test (RSAT). The serological survey was performed with 446 field sera. The 270 sera from the asymptomatic group found negative by BPA, RSAT and blood culture showed IELISA specificities of 96.7% and 100%, respectively, when cut-off values of OD 0.237 and 0.281 were selected. For 52 sera from culture-positive dogs, IELISA sensitivity was 100% with cut-off values of OD414 0.237 and 0.281. OD414 0.281 was selected because this value provided the highest accuracy with minimal false-negative and false-positive results. This cut-off value was used to study 124 blood culture-negative but RSAT positive sera. IELISA produced 107 positive results; the 17 sera that were negative by IELISA presented a wide range of reactivities by RSAT (2 were RSAT positive at 1 in 2 dilution and 15 were weakly positive with pure serum). These samples were probably from animals at an early stage of the infection or were false-positive results. The IELISA described here detects IgG and IgA antibodies that are useful for evaluating the clinical status of dogs. Although RSAT is a practical screening test, a supplementary technique such as IELISA should be used on all positive RSAT samples to ensure diagnostic specificity. Furthermore, people in contact with infected dogs could be investigated for possible transmission. The procedure described in this study was relatively simple and could have widespread applications.  (+info)

Evaluation of dipstick serologic tests for diagnosis of brucellosis and typhoid Fever in egypt. (56/532)

Two dipstick assays for the detection of Brucella- and typhoid-specific immunoglobulin M, recently developed by the Royal Tropical Institute of The Netherlands, were evaluated by use of 85 plasma samples from Egyptian patients. Both dipsticks were simple and accurate rapid diagnostic assays, and they can be useful adjuncts for the diagnosis of typhoid fever and brucellosis.  (+info)