Evaluation of the presence of Rickettsia slovaca infection in domestic ruminants in Catalonia, Northeastern Spain.

Rickettsia slovaca is the etiological agent of the human disease tick-borne lymphadenopathy (TIBOLA) transmitted by Dermacentor spp. ticks. In our area, Dermacentor marginatus is the most important tick vector; adult ticks feed on mammals, especially ungulates such as wild boars and domestic ruminants. The epidemiology of tick-transmitted diseases describes a wild cycle and a domestic cycle and both are connected by ticks. To identify the role of domestic ruminants in the transmission and maintenance of R. slovaca infection, blood samples from sheep (n=95), goats (n=91), and bullfighting cattle (n=100) were collected during a herd health program, and livestock grazing was selected to ensure tick contact. Samples were analyzed by serology using an indirect immunofluorescent assay (IFA) and molecular techniques (real-time PCR). Seroprevalence was 15.7% in sheep, 20.8% in goats, and 65.0% in bullfighting cattle. On the basis of molecular methods, R. slovaca infection was demonstrated in a goat blood sample with an antibody titer of 1:160. This is the first time that R. slovaca has been identified in a goat blood sample. These results suggest that domestic ruminants are exposed to R. slovaca infection and, because the domestic cycle is close to the human environment, this could increase the risk of transmitting the pathogen to human beings.

Accuracy of monoclonal stool tests for determining cure of Helicobacter pylori infection after treatment.

BACKGROUND: Studies comparing new monoclonal fecal tests for evaluating cure of Helicobacter pylori infection after treatment are scarce. The objective was to compare the diagnostic accuracy of three monoclonal stool tests: two rapid in-office tools -RAPID Hp StAR and ImmunoCard STAT! HpSA - and an EIA test - Amplified IDEIA Hp StAR. MATERIALS AND METHODS: Diagnostic reliability of the three tests was evaluated in 88 patients at least 8 weeks after H. pylori treatment. Readings of immunochromatographic tests were performed by two different observers. Sensitivity, specificity, positive and negative predictive values and 95% confidence intervals were calculated. RESULTS: All tests presented similar performance for post-eradication testing. Sensitivity for detecting persistent infection was 100% for both Amplified IDEIA and RAPID Hp StAR and 90% for ImmunoCard STAT! HpSA. Respective specificities were 94.9%, 92.3-93.6% and 94.9%. Negative predictive values were very high (100%, 100% and 98.7% respectively). But positive predictive values were lower, ranging from 62.5 to 71.4%. CONCLUSION: All monoclonal fecal tests in this series presented similar performance in the post-treatment setting. A negative test after treatment adequately predicted cure of the infection. However, nearly a third of tests were false positive, showing a poor predictive yield for persistent infection.

Comparative accuracy of 3 monoclonal stool tests for diagnosis of Helicobacter pylori infection among patients with dyspepsia.

BACKGROUND: Well-devised studies comparing new but different monoclonal fecal tests for diagnosing Helicobacter pylori infection are scarce. The objective of this study was to compare the diagnostic accuracy of 3 monoclonal stool tests: 2 rapid in-office tools-RAPID Hp StAR and ImmunoCard STAT! HpSA-and an enzyme immunoassay test-Amplified IDEIA Hp StAR-for diagnosing H. pylori infection prior to eradication treatment. METHODS: Diagnostic reliability was evaluated in 199 untreated consecutive patients with dyspeptic symptoms. The gold standard for diagnosing H. pylori infection was defined as the concordance of the rapid urease test, histopathology, and urea breath test. Readings of immunochromatographic tests were performed by 2 different observers. Sensitivity, specificity, positive and negative predictive values, and 95% confidence intervals were calculated. Sensitivity and specificity were compared using the McNemar test. RESULTS: The sensitivity and specificity of Amplified IDEIA Hp StAR were 90% and 89%, respectively. This enzyme immunoassay test was significantly more sensitive than ImmunoCard STAT! HpSA and more specific than RAPID Hp StAR. The sensitivity and specificity of RAPID Hp StAR were 91% and 80%, respectively, according to observer 1, and 92% and 76%, respectively, according to observer 2. It was significantly more sensitive and less specific than ImmunoCard STAT! HpSA. The sensitivity and specificity of ImmunoCard STAT! HpSA were 69% and 90%, respectively, according to observer 1, and 74% and 89%, respectively, according to observer 2. CONCLUSIONS: Amplified IDEIA Hp StAR seems to be the most accurate stool test for diagnosing H. pylori for patients with dyspeptic symptoms. The currently available in-office tests obtain slightly less reliable results.

Accuracy of diagnostic tests for Helicobacter pylori: a reappraisal.

BACKGROUND: Despite many changes, no large studies comparing the different diagnostic tests for Helicobacter pylori have been performed in the past 10 years. In this time, monoclonal stool antigen immunoassays and in-office 13C-urea breath tests (UBTs) have appeared. The aim of this study was to evaluate the accuracy of invasive and noninvasive tests in a large series of dyspeptic patients. METHODS: A total of 199 dyspeptic patients who had not previously been treated for H. pylori infection were prospectively enrolled. Noninvasive analyses included a commercial infrared-based UBT and a commercially available stool test. Biopsy-based tests included histological examination and a rapid urease test. A patient was considered to be infected when at least 2 test results were positive. Sensitivity, specificity, positive and negative predictive values, and 95% confidence intervals were calculated. The test results were compared using the McNemar test. RESULTS: Rates of positive test results were similar (54%) for the rapid urease test, histopathological examination, and the stool test. By contrast, 75% of UBT results were positive, and the UBT was associated with a very low specificity (60%). For this reason, the delta cutoff value for the UBT was recalculated as 8.5%. Sensitivities and specificities with this new cutoff value were 95% and 100%, respectively, for the rapid urease test; 94% and 99%, respectively, for histopathological examination; 90% and 93%, respectively, for the stool test; and 90% and 90%, respectively, for the UBT. CONCLUSIONS: Histological examination and rapid urease testing showed excellent diagnostic reliability. The stool test seems to be a good, noninvasive alternative to endoscopy-based tests. By contrast, the infrared-based UBT evaluated in our study showed a lower than expected performance, which was partially corrected when the cutoff value for the test was recalculated.

Is the vaccination coverage established enough to control pertussis, or it is a re-emerging disease?

Although vaccination coverage is high in Catalonia, Spain, pertussis is still a significant cause of morbidity and mortality among infants, overall due to adolescent and adult contacts. An epidemiological study from voluntary health care centres to detect confirmed pertussis cases was carried out in Catalonia. From 465 pertussis-suspect-cases, we identified 126 confirmed events, 73 of them confirmed by laboratory tests. Most of cases were infants less than 4 months old 23 (18.3%), adolescents 22 (17.4%) and adults 46 (36.5%). Sixty-one cases (49.6%) presented paroxysmal cough, 33 (26.8%) post-tussive vomiting and inspiratory whoop, and 27 (22%) apnoea. The vaccination status was not known for 46 (36.5%) patients. Of the total vaccine status documented, 59 (73.8%) patients had received at least one dose. Sixty patients (47.6%) were considered index cases, 32 of them (53.3%) were children under 1-year old. Among contacts identified as pertussis cases, 63.6% (42/66) were older than 14 years of age. These contacts were parents (30), siblings (19), grandmother (4), and others (13). These results confirm protective efficacy of pertussis vaccine only during few time. Regular pertussis boosters in teenagers, and/or in adults who take care of young children, could decrease the incidence of the infection.

A comparison of the reproductive ability of Varroa destructor (Mesostigmata:Varroidae) in worker and drone brood of Africanized honey bees (Apis mellifera).

Colony infestation by the parasitic mite, Varroa destructor is one of the most serious problems for beekeeping worldwide. In order to reproduce varroa females, enter worker or drone brood shortly before the cell is sealed. To test the hypothesis that, due to the preference of mites to invade drone brood to reproduce, a high proportion of the mite reproduction should occur in drone cells, a comparative study of mite reproductive rate in worker and drone brood of Africanized honey bees (AHB) was done for 370 mites. After determining the number, developmental stage and sex of the offspring in worker cells, the foundress female mite was immediately transferred into an uninfested drone cell. Mite fertility in single infested worker and drone brood cells was 76.5 and 79.3%, respectively. There was no difference between the groups (X(2)= 0.78, P = 0.37). However, one of the most significant differences in mite reproduction was the higher percentage of mites producing viable offspring (cells that contain one live adult male and at least one adult female mite) in drone cells (38.1%) compared to worker cells (13.8%) (X(2)= 55.4, P < 0.01). Furthermore, a high level of immature offspring occurred in worker cells and not in drone cells (X(2)= 69, P < 0.01). Although no differences were found in the percentage of non-reproducing mites, more than 74% (n = 85) of the mites that did not reproduce in worker brood, produced offspring when they were transferred to drone brood.

Ten years' experience of isolation of Rickettsia spp. from blood samples using the shell-vial cell culture assay.

Two strategies to improve the efficacy of the shell-vial method for Rickettsia were analyzed. Blood samples from 59 patients with Mediterranean spotted fever (MSF) were examined using the shell-vial technique. (i) DNA from positive lenses was obtained when they were contaminated. (ii) Blood sample from one patient was cultured in 17 shell-vials. R. conorii was identified in four cases by polymerase chain reaction (PCR)-RFLP. Three of these were obtained from cells adherent to lenses and the fourth one by using total patient blood sample. Rickettsia isolation using all blood samples as well as DNA from shell-vial lenses could be useful in the study of rickettsial infections.

Evaluation of four different fecal tests for determination of cure after Helicobacter pylori treatment.

BACKGROUND: Data evaluating the monoclonal tests for determination of cure after Helicobacter pylori treatment are scarce. GOALS: This study was aimed to evaluate the usefulness of 4 stool tests-2 new RAPID monoclonal immunochromatographic tests (RAPID Hp StAR, DakoCytomation, Cambridge, UK and ImmunoCard STAT! HpSA, Meridian Diagnostics, Cincinnati, OH) a monoclonal EIA test (Amplified IDEIA Hp StAR, DakoCytomation, Cambridge, UK), and a polyclonal EIA test (Premier Platinum HpSA, Meridian Diagnostics, Cincinnati, OH)-to confirm cure of H. pylori infection after eradication treatment. STUDY: Ninety-seven patients who underwent eradication treatment were included. Cure of H. pylori infection was determined using 2 consecutive reference tests. Fecal tests were performed according to the specifications of the manufacturer. Sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS: After H. pylori eradication, the RAPID Hp StAR test has a sensitivity of 73% for detecting persistent infection, a specificity of 96% to 98%, a positive predictive value of 73% to 80% and a negative predictive value of 96%. For ImmunoCard STAT! HpSA the corresponding values were 91%, 97%, 77%, and 99%, for Amplified IDEIA Hp StAR 73%, 97%, 73%, and 97%, and for Premier Platinum HpSA 91%, 79%, 35%, and 98%. CONCLUSIONS: All tests except Premier Platinum HpSA were highly accurate confirming eradication after treatment.

Prevalence of Bartonella henselae in cats in Catalonia, Spain.

Bartonella henselae, an emerging pathogen bacterium, is the main causative agent of the cat scratch disease. While the first clinical descriptions were associated with immunosupressed patients, it is now more frequently observed in patients with normal immune status (endocarditis and bacteremia). Cats were found to be the only known reservoir of B. henselae. In this paper, we report the results obtained in the first study made to investigate the prevalence of B. henselae bacteremia and antibodies in domestic cats in Catalonia, Spain. Serum samples from 115 cats were tested for antibodies to B. henselae by immunofluorescent antibody testing, and 29.6% had a titer >or= 1:64. Seven B. henselae strains were isolated using standard culture techniques and amplification by a polymerase chain reaction and subsequent sequencing was performed on the intergenic spacer region between the 16 and 23S ribosomal RNA genes. Of all factors concerning the studied bacteremia rate (age, sex, habitat, presence of antibodies, contact with animals, parasites), only the presence of antibodies to B. henselae was statistically significant.

Bacillary angiomatosis caused by Bartonella quintana.

Bacillary angiomatosis is a disorder of neovascular proliferation involving skin and lymph nodes of immunosuppressed patients. Bartonella henselae or Bartonella quintana have been inculpated as causative by direct culture or PCR amplification of DNA sequences. Here, we report the clinical evolution of a patient infected with human immunodeficiency virus (HIV) whose B. quintana infection was diagnosed by PCR.

Usefulness of non-invasive tests for diagnosing Helicobacter pylori infection in patients undergoing dialysis for chronic renal failure.

BACKGROUND: Helicobacter pylori infection in chronic renal failure patients has been linked to peptic ulcer and gastric neoplasia after kidney transplantation. It may also contribute to the accelerated arteriosclerosis that is usual in this population. Few data are available on the usefulness of noninvasive diagnostic tests for H. pylori infection in dialyzed patients, especially regarding the new fecal antigen detection tests. The objective of this study was to determine the efficacy of a noninvasive test for H. pylori infection in patients with chronic renal failure. METHODS: Eighty-six patients were included in a cross-sectional study. Urea breath test, serology and three fecal tests--FemtoLab H. pylori (Connex, Germany), Premier Platinum HpSA (Meridian, USA) and Simple H. pylori (Operon SA, Spain) were performed. Helicobacter pylori status was determined by concordance of the tests. Sensitivity, specificity and positive and negative predictive values were calculated for each test. RESULTS: Sensitivity, specificity, positive and negative predictive values were 94%, 96%, 94% and 96% for the urea breath test; 97%, 64%, 66% and 97% for serology; 86%, 100%, 100% and 91%, for FemtoLab H. pylori; 58%, 96%, 91% and 76% for Premier Platinum HpSA and 61%, 78%, 74% and 67% for Simple H. pylori. CONCLUSIONS: The urea breath test seems to be the most reliable diagnostic method for H. pylori infection in patients with chronic renal failure. Serology has a low specificity, and the results of the fecal tests vary widely.