Ferran Segura - Academia.edu (original) (raw)

Papers by Ferran Segura

Research paper thumbnail of Prevalence of antibodies to spotted fever group rickettsiae in the region of Split (southern Croatia)

European Journal of Epidemiology, 2002

The prevalence of IgG antibodies to spotted fever group rickettsiae (SFG) was investigated by the... more The prevalence of IgG antibodies to spotted fever group rickettsiae (SFG) was investigated by the indirect immunofluorescence assay in a sample of 1207 healthy residents of the central part of southern Croatia (eastern coast of Adriatic Sea). Sera obtained from subjects living in three different places of residency (urban, suburban and rural environs of the region) were tested. Overall 528

Research paper thumbnail of Tobramycin nephrotoxicity. A prospective clinical study

Postgraduate Medical Journal, 1979

The nephrotoxicity of tobramycin given at a dose of 4.5 mg/kg/day for a period of 12 days to a gr... more The nephrotoxicity of tobramycin given at a dose of 4.5 mg/kg/day for a period of 12 days to a group of 90 patients with a mean age of 62.9 years was studied. Toxicity was determined on the basis of 3 main criteria (oliguria <400 ml/24 hr, serum creatinine 0.4 mg increase over a minimum basal level of 1.2 mg/100 ml, BUN 5 mg increase over a minimum of 25 mg/100 ml); and 3 minor criteria (proteinuria, microhaematuria and cylindruria). These parameters were determined before treatment at 7, 10, 14, 17, 21, and 30 days afterwards. The age and coexistence of factors such as hypertension, diabetes, anaemia, cardiac insufficiency, shock and dehydration were considered. Nephrotoxicity level ranges from 3.3 to 38'8 % depending on the criterion used, and is related to hypertension (P<0.001), age (P<0.005) and association with ampicillin (P<0-005). Nephrotoxicity was reversible spontaneously in 96.7% of the cases and no differences have been observed between patients with moderate renal insufficiency and those with normal renal function on the initiation of treatment.

Research paper thumbnail of Occult H. pylori infection partially explains ‘false‐positive’ results of 13 C‐urea breath test

United European Gastroenterology Journal, 2015

Background: In a previous study, UBiT-100 mg, (Otsuka, Spain), a commercial 13 C-urea breath test... more Background: In a previous study, UBiT-100 mg, (Otsuka, Spain), a commercial 13 C-urea breath test omitting citric acid pretreatment, had a high rate of false-positive results; however, it is possible that UBiT detected low-density 'occult' infection missed by other routine reference tests. We aimed to validate previous results in a new cohort and to rule out the possibility that false-positive UBiT were due to an 'occult' infection missed by reference tests. Methods: Dyspeptic patients (n ¼ 272) were prospectively enrolled and UBiT was performed, according to the manufacturer's recommendations. Helicobacter pylori infection was determined by combining culture, histology and rapid urease test results. We calculated UBiT sensitivity, specificity, positive and negative predictive values (with 95% CI). In addition, we evaluated 'occult' H. pylori infection using two previously-validated polymerase chain reaction (PCR) methods for urease A (UreA) and 16 S sequences in gastric biopsies. We included 44 patients with a false-positive UBiT, and two control groups of 25 patients each, that were positive and negative for all H. pylori tests. Results: UBiT showed a false-positive rate of 17%, with a specificity of 83%. All the positive controls and 12 of 44 patients (27%) with false-positive UBiT were positive for all two PCR tests; by contrast, none of our negative controls had two positive PCR tests. Conclusions: UBiT suffers from a high rate of false-positive results and sub-optimal specificity, and the protocol skipping citric acid pre-treatment should be revised; however, low-density 'occult' H. pylori infection that was undetectable by conventional tests accounted for around 25% of the 'false-positive' results.

Research paper thumbnail of First Molecular Detection, by Quantitative Real-Time PCR, of Rickettsia typhi and Rickettsia felis in Fleas from Northeastern Spain

Background: Rickettsia typhi is the etiological agent of Murine typhus (MT). Rickettsia felis pro... more Background: Rickettsia typhi is the etiological agent of Murine typhus (MT). Rickettsia felis produces Flea-borne spotted fever, a syndrome indistinguishable from MT. Both are transmitted to humans by fleas. Serologic evidence of both infections in humans; cats and dogs have been observed in Spain. Recognition of routes of transmission is of great importance to prevent human infection. The aim of this study was to determine the presence of R typhi and R felis in fleas from Northeast of Spain. Methods: Between May 2006 and July 2006, 64 fleas were recovered from kennels. Most of them were collected from cages and a few of them from dogs. Fleas were rinsed with ethanol, dried, identified and stored at 4ºC. Fleas were individually triturated in 100 µl BHI. 50µl were used DNA extraction. Rickettsial DNA was determined by an adaptation of quantitative real-time PCR previously described by Henry et al. OmpB-specific primers and molecular beacon probes targeting specifically each Rickettsi...

Research paper thumbnail of Seroprevalencia de la infección por Borrelia burgdorferi en el área del Vallès Occidental (Barcelona)

Research paper thumbnail of Overall and cause-specific mortality in HIV-positive subjects compared to the general population

Journal of the International AIDS Society, 2014

Emerging non-AIDS related causes of death have been observed in HIV-positive subjects in industri... more Emerging non-AIDS related causes of death have been observed in HIV-positive subjects in industrialized countries. We aimed to analyze overall and cause-specific excess of mortality of HIV-positive patients compared to the general population and to assess the effect of prognostic factors. We used generalized linear models with Poisson error structure to estimate overall and cause-specific excess of mortality in HIV-positive patients from 2004 to 2012 in the cohort of the Spanish Network of HIV Research (CoRIS), compared to Spanish general population and to assess the impact of multiple risk factors. We investigated differences between short-term and long-term risk factors effects on excess of mortality. Multiple Imputation by Chained Equations was used to deal with missing data. In 9162 patients there were 363 deaths, 16.0% were non-AIDS malignancies, 10.5% liver and 0.3% cardiovascular related. Excess mortality was 1.20 deaths per 100 person years (py) for all-cause mortality, 0.16...

Research paper thumbnail of Real-Time PCR Improves Helicobacter pylori Detection in Patients with Peptic Ulcer Bleeding

PLoS ONE, 2011

Background and Aims: Histological and rapid urease tests to detect H. pylori in biopsy specimens ... more Background and Aims: Histological and rapid urease tests to detect H. pylori in biopsy specimens obtained during peptic ulcer bleeding episodes (PUB) often produce false-negative results. We aimed to examine whether immunohistochemistry and real-time PCR can improve the sensitivity of these biopsies. Patients and Methods: We selected 52 histology-negative formalin-fixed paraffin-embedded biopsy specimens obtained during PUB episodes. Additional tests showed 10 were true negatives and 42 were false negatives. We also selected 17 histology-positive biopsy specimens obtained during PUB to use as controls. We performed immunohistochemistry staining and real-time PCR for 16S rRNA, ureA, and 23S rRNA for H. pylori genes on all specimens. Results: All controls were positive for H. pylori on all PCR assays and immunohistochemical staining. Regarding the 52 initially negative biopsies, all PCR tests were significantly more sensitive than immunohistochemical staining (p,0.01). Sensitivity and specificity were 55% and 80% for 16S rRNA PCR, 43% and 90% for ureA PCR, 41% and 80% for 23S rRNA PCR, and 7% and 100% for immunohistochemical staining, respectively. Combined analysis of PCR assays for two genes were significantly more sensitive than ureA or 23S rRNA PCR tests alone (p,0.05) and marginally better than 16S rRNA PCR alone. The best combination was 16S rRNA+ureA, with a sensitivity of 64% and a specificity of 80%. Conclusions: Real-time PCR improves the detection of H. pylori infection in histology-negative formalin-fixed paraffinembedded biopsy samples obtained during PUB episodes. The low reported prevalence of H. pylori in PUB may be due to the failure of conventional tests to detect infection.

Research paper thumbnail of The role of dogs in the eco-epidemiology of Rickettsia typhi, etiological agent of Murine typhus

Veterinary Microbiology, 2013

Rickettsia typhi is the causative agent of Murine typhus (MT). This disease is one of the most pr... more Rickettsia typhi is the causative agent of Murine typhus (MT). This disease is one of the most prevalent rickettsial infections, widely distributed through the world, and it is endemic in many coastal areas (Civen and Ngo, 2008, pp. 913-918). However, its prevalence in many countries is unknown, partly because MT could be misdiagnosed and underreported. Clinical symptoms are not specific and MT may be mistaken for other diseases (

Research paper thumbnail of A Simplification Trial Switching From Nucleoside Reverse Transcriptase Inhibitors to Once-Daily Fixed-Dose Abacavir/Lamivudine or Tenofovir/Emtricitabine in HIV-1-Infected Patients With Virological Suppression

JAIDS Journal of Acquired Immune Deficiency Syndromes, 2009

Data comparing abacavir/lamivudine versus tenofovir/emtricitabine in antiretroviral-naive patient... more Data comparing abacavir/lamivudine versus tenofovir/emtricitabine in antiretroviral-naive patients are controversial. We compared 48-week efficacy and safety of these combinations as substitutes of nucleosides in patients with virological suppression. We randomly assigned 333 HIV-1-infected patients on lamivudine-containing triple regimens with &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;200 copies per milliliter for at least 6 months to switch their nucleosides to either abacavir/lamivudine (n = 167) or tenofovir/emtricitabine (n = 166). The primary outcome was treatment failure…

Research paper thumbnail of An Outbreak of Norovirus Infection in a Long-Term-Care Unit in Spain

Infection Control & Hospital Epidemiology, 2005

Background:Norovirus belongs to the Caliciviridae family and causes outbreaks of infectious enter... more Background:Norovirus belongs to the Caliciviridae family and causes outbreaks of infectious enteritis by fecal-oral transmission. In Spain, there have been few outbreaks reported due to this virus. We describe an outbreak on a long-term-care hospital ward.Methods:Cases were classified as probable, confirmed, and secondary. Stool cultures were performed. Polymerase chain reaction detection of norovirus was also performed.Results:The outbreak occurred from December 7 to 28, 2001, involving 60 cases (32 patients, 19 staff members, 8 patients' relatives, and 1 relative of a staff member). Most (82%) of the cases were female. The most frequently involved ages were 20 to 39 years for staff members and 70 to 89 years for patients. The incubation period of secondary cases in patients' families had a median of 48 hours (range, 1 to 7 days). Clinical symptoms included diarrhea (85%), vomiting (75%), fever (37%), nausea (23%), and abdominal pain (12%). Median duration of the disease wa...

Research paper thumbnail of M1054 Real-Time PCR Analysis of H. pylori-Negative Paraffin-Embedded Biopsies Reveal Infection in Most Patients with Bleeding Ulcer

Gastroenterology, 2009

Gastroenterology, Volume 136, Issue 5, Pages A-340, May 2009, Authors:Xavier Calvet; María José R... more Gastroenterology, Volume 136, Issue 5, Pages A-340, May 2009, Authors:Xavier Calvet; María José Ramírez-Lázaro; Sergio Lario; Pilar García-Iglesias; Alex Casalots; Jordi Sánchez-Delgado; Valentí Puig; Félix Junquera; Ferran Segura.

Research paper thumbnail of Clinical significance of methicillin-resistantStaphylococcus aureuscolonization in residents in community long-term-care facilities in Spain

Epidemiology and Infection, 2011

SUMMARYMethicillin-resistantStaphylococcus aureus(MRSA) is highly prevalent in Spanish hospitals ... more SUMMARYMethicillin-resistantStaphylococcus aureus(MRSA) is highly prevalent in Spanish hospitals and community long-term-care facilities (LTCFs). This longitudinal study was performed in community LTCFs to determine whether MRSA colonization is associated with MRSA infections and overall mortality. Nasal and decubitus ulcer cultures were performed every 6 months for an 18-month period on 178 MRSA-colonized residents (86 490 patient-days) and 196 non-MRSA carriers (97 470 patient-days). Fourteen residents developed MRSA infections and 10 of these were skin and soft tissue infections. Two patients with respiratory infections required hospitalization. The incidence rate of MRSA infection was 0·12/1000 patient-days in MRSA carriers and 0·05/1000 patient-days in non-carriers (P=0·46). No difference in MRSA infection rate was found according to the duration of MRSA colonization (P=0·69). The mortality rate was 20·8% in colonized residents and 16·8% in non-carriers; four residents with MRS...

Research paper thumbnail of Prudent use of antimicrobials: Have we done the best we can? The SEIMC and REIPI statement

Enfermedades Infecciosas y Microbiología Clínica, 2010

Research paper thumbnail of Diagnóstico precoz de la infección por VIH

Enfermedades Infecciosas y Microbiología Clínica, 2012

Cartas científicas Diagnóstico precoz de la infección por VIH Early diagnosis of HIV infection * ... more Cartas científicas Diagnóstico precoz de la infección por VIH Early diagnosis of HIV infection * Autor para correspondencia.

Research paper thumbnail of Adherencia al tratamiento antirretroviral. Estudio de prevalencia en un hospital general

Enfermedades Infecciosas y Microbiología Clínica, 2003

Research paper thumbnail of Cohorte RIS de pacientes con infección por VIH sin tratamiento antirretroviral previo (CoRIS): metodología y primeros resultados

Enfermedades Infecciosas y Microbiología Clínica, 2007

Spanish cohort of naïve HIV-infected patients (CoRIS): Rationale, organization and initial result... more Spanish cohort of naïve HIV-infected patients (CoRIS): Rationale, organization and initial results OBJECTIVE. To describe the methodology and baseline results of the Spanish cohort of naïve HIV-infected patients included in the Research Network on HIV/AIDS (CoRIS). METHODS. CoRIS is a multicenter, hospital-based prospective cohort of HIV sero-prevalent, retroviral-naïve subjects, over 13 years old, and seen at 17 hospitals in 8 of the 17 Autonomous Regions in Spain from January 2004 to October 2005. The socio-demographic characteristics, as well as epidemiological, clinical, laboratory and treatment data were recorded, and biological samples were collected at baseline and during follow-up. RESULTS. A total of 1,591 subjects have been included in CoRIS; 24% are women, median age at cohort entry is 36 years, and 74% were diagnosed during 2004 or 2005. Twenty-seven percent came from countries other than Spain, mainly Latin-America (16%) and sub-Saharan Africa (5%). Thirty-two percent had completed secondary education and 16% university studies. The most frequent categories of transmission were men having sex with men (37%) and heterosexual sex (36%); only 21% were injection drug users. At cohort entry, median CD4 count was 317 cells/mm 3 and median viral load was 52,300 copies/mL; 18% were diagnosed with AIDS. Main AIDS-defining illnesses were Pneumocystis jiroveci pneumonia (6.1%), esophageal candidiasis (3.3%) and tuberculosis (extrapulmonary, 3.0% and pulmonary 2.7%). There were 35 deaths (2.2%). Thirty-three percent of patients gave a baseline sample to the BioBank. CONCLUSIONS. CoRIS offers relevant information about the current epidemiological profile of HIV infection in Spain, where sexual transmission has become predominant. The type and amount of information obtained from clinical and epidemiological data collection together with biological samples demonstrate the viability of the project, which offers many possibilities for future research.

Research paper thumbnail of Enfermedades producidas por Rickettsia

Enfermedades Infecciosas y Microbiología Clínica, 2005

vessel vasculitis, which may affect lungs (interstitial pneumonitis), heart (miopericarditis), sk... more vessel vasculitis, which may affect lungs (interstitial pneumonitis), heart (miopericarditis), skin (rash), central nervous system (meningoencephalitis), as well as liver, and kidneys. They are classified in two groups: spotted-fever group, and typhus group rickettsia. In Spain the most prevalent rickettsioses of both groups are mediterranean spotted fever (caused by R. conorii), and murine typhus (caused by R. typhi), respectively. This review focuses mainly in these two diseases, and also in other rickettsioses of interest due to their recently emergence or reemergence (R. slovaca, R. africae, R. prowazekii, R. felis), or to their high incidence in other areas (R. rickettsii, Orientia tsutsugamushi).

Research paper thumbnail of The dog as an epidemiological marker of Rickettsia conorii infection

Clinical Microbiology and Infection, 2009

Research paper thumbnail of Comparative Accuracy of 3 Monoclonal Stool Tests for Diagnosis ofHelicobacter pyloriInfection among Patients with Dyspepsia

Clinical Infectious Diseases, 2010

Background. Well-devised studies comparing new but different monoclonal fecal tests for diagnosin... more 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. Fecal tests, biopsy-based analyses (eg, histopathology and the rapid urease test), and the urea breath test are the main tools used for diagnosis of Helicobacter pylori infection [1]. Fecal immunoassays perform far more irregularly than other methods do, and indeed the diagnostic accuracy of the different stool tests varies widely [2, 3]. One of the reasons for this variation in

Research paper thumbnail of Clarithromycin for the Treatment of Mediterranean Spotted Fever

Clinical Infectious Diseases, 2002

Research paper thumbnail of Prevalence of antibodies to spotted fever group rickettsiae in the region of Split (southern Croatia)

European Journal of Epidemiology, 2002

The prevalence of IgG antibodies to spotted fever group rickettsiae (SFG) was investigated by the... more The prevalence of IgG antibodies to spotted fever group rickettsiae (SFG) was investigated by the indirect immunofluorescence assay in a sample of 1207 healthy residents of the central part of southern Croatia (eastern coast of Adriatic Sea). Sera obtained from subjects living in three different places of residency (urban, suburban and rural environs of the region) were tested. Overall 528

Research paper thumbnail of Tobramycin nephrotoxicity. A prospective clinical study

Postgraduate Medical Journal, 1979

The nephrotoxicity of tobramycin given at a dose of 4.5 mg/kg/day for a period of 12 days to a gr... more The nephrotoxicity of tobramycin given at a dose of 4.5 mg/kg/day for a period of 12 days to a group of 90 patients with a mean age of 62.9 years was studied. Toxicity was determined on the basis of 3 main criteria (oliguria <400 ml/24 hr, serum creatinine 0.4 mg increase over a minimum basal level of 1.2 mg/100 ml, BUN 5 mg increase over a minimum of 25 mg/100 ml); and 3 minor criteria (proteinuria, microhaematuria and cylindruria). These parameters were determined before treatment at 7, 10, 14, 17, 21, and 30 days afterwards. The age and coexistence of factors such as hypertension, diabetes, anaemia, cardiac insufficiency, shock and dehydration were considered. Nephrotoxicity level ranges from 3.3 to 38'8 % depending on the criterion used, and is related to hypertension (P<0.001), age (P<0.005) and association with ampicillin (P<0-005). Nephrotoxicity was reversible spontaneously in 96.7% of the cases and no differences have been observed between patients with moderate renal insufficiency and those with normal renal function on the initiation of treatment.

Research paper thumbnail of Occult H. pylori infection partially explains ‘false‐positive’ results of 13 C‐urea breath test

United European Gastroenterology Journal, 2015

Background: In a previous study, UBiT-100 mg, (Otsuka, Spain), a commercial 13 C-urea breath test... more Background: In a previous study, UBiT-100 mg, (Otsuka, Spain), a commercial 13 C-urea breath test omitting citric acid pretreatment, had a high rate of false-positive results; however, it is possible that UBiT detected low-density 'occult' infection missed by other routine reference tests. We aimed to validate previous results in a new cohort and to rule out the possibility that false-positive UBiT were due to an 'occult' infection missed by reference tests. Methods: Dyspeptic patients (n ¼ 272) were prospectively enrolled and UBiT was performed, according to the manufacturer's recommendations. Helicobacter pylori infection was determined by combining culture, histology and rapid urease test results. We calculated UBiT sensitivity, specificity, positive and negative predictive values (with 95% CI). In addition, we evaluated 'occult' H. pylori infection using two previously-validated polymerase chain reaction (PCR) methods for urease A (UreA) and 16 S sequences in gastric biopsies. We included 44 patients with a false-positive UBiT, and two control groups of 25 patients each, that were positive and negative for all H. pylori tests. Results: UBiT showed a false-positive rate of 17%, with a specificity of 83%. All the positive controls and 12 of 44 patients (27%) with false-positive UBiT were positive for all two PCR tests; by contrast, none of our negative controls had two positive PCR tests. Conclusions: UBiT suffers from a high rate of false-positive results and sub-optimal specificity, and the protocol skipping citric acid pre-treatment should be revised; however, low-density 'occult' H. pylori infection that was undetectable by conventional tests accounted for around 25% of the 'false-positive' results.

Research paper thumbnail of First Molecular Detection, by Quantitative Real-Time PCR, of Rickettsia typhi and Rickettsia felis in Fleas from Northeastern Spain

Background: Rickettsia typhi is the etiological agent of Murine typhus (MT). Rickettsia felis pro... more Background: Rickettsia typhi is the etiological agent of Murine typhus (MT). Rickettsia felis produces Flea-borne spotted fever, a syndrome indistinguishable from MT. Both are transmitted to humans by fleas. Serologic evidence of both infections in humans; cats and dogs have been observed in Spain. Recognition of routes of transmission is of great importance to prevent human infection. The aim of this study was to determine the presence of R typhi and R felis in fleas from Northeast of Spain. Methods: Between May 2006 and July 2006, 64 fleas were recovered from kennels. Most of them were collected from cages and a few of them from dogs. Fleas were rinsed with ethanol, dried, identified and stored at 4ºC. Fleas were individually triturated in 100 µl BHI. 50µl were used DNA extraction. Rickettsial DNA was determined by an adaptation of quantitative real-time PCR previously described by Henry et al. OmpB-specific primers and molecular beacon probes targeting specifically each Rickettsi...

Research paper thumbnail of Seroprevalencia de la infección por Borrelia burgdorferi en el área del Vallès Occidental (Barcelona)

Research paper thumbnail of Overall and cause-specific mortality in HIV-positive subjects compared to the general population

Journal of the International AIDS Society, 2014

Emerging non-AIDS related causes of death have been observed in HIV-positive subjects in industri... more Emerging non-AIDS related causes of death have been observed in HIV-positive subjects in industrialized countries. We aimed to analyze overall and cause-specific excess of mortality of HIV-positive patients compared to the general population and to assess the effect of prognostic factors. We used generalized linear models with Poisson error structure to estimate overall and cause-specific excess of mortality in HIV-positive patients from 2004 to 2012 in the cohort of the Spanish Network of HIV Research (CoRIS), compared to Spanish general population and to assess the impact of multiple risk factors. We investigated differences between short-term and long-term risk factors effects on excess of mortality. Multiple Imputation by Chained Equations was used to deal with missing data. In 9162 patients there were 363 deaths, 16.0% were non-AIDS malignancies, 10.5% liver and 0.3% cardiovascular related. Excess mortality was 1.20 deaths per 100 person years (py) for all-cause mortality, 0.16...

Research paper thumbnail of Real-Time PCR Improves Helicobacter pylori Detection in Patients with Peptic Ulcer Bleeding

PLoS ONE, 2011

Background and Aims: Histological and rapid urease tests to detect H. pylori in biopsy specimens ... more Background and Aims: Histological and rapid urease tests to detect H. pylori in biopsy specimens obtained during peptic ulcer bleeding episodes (PUB) often produce false-negative results. We aimed to examine whether immunohistochemistry and real-time PCR can improve the sensitivity of these biopsies. Patients and Methods: We selected 52 histology-negative formalin-fixed paraffin-embedded biopsy specimens obtained during PUB episodes. Additional tests showed 10 were true negatives and 42 were false negatives. We also selected 17 histology-positive biopsy specimens obtained during PUB to use as controls. We performed immunohistochemistry staining and real-time PCR for 16S rRNA, ureA, and 23S rRNA for H. pylori genes on all specimens. Results: All controls were positive for H. pylori on all PCR assays and immunohistochemical staining. Regarding the 52 initially negative biopsies, all PCR tests were significantly more sensitive than immunohistochemical staining (p,0.01). Sensitivity and specificity were 55% and 80% for 16S rRNA PCR, 43% and 90% for ureA PCR, 41% and 80% for 23S rRNA PCR, and 7% and 100% for immunohistochemical staining, respectively. Combined analysis of PCR assays for two genes were significantly more sensitive than ureA or 23S rRNA PCR tests alone (p,0.05) and marginally better than 16S rRNA PCR alone. The best combination was 16S rRNA+ureA, with a sensitivity of 64% and a specificity of 80%. Conclusions: Real-time PCR improves the detection of H. pylori infection in histology-negative formalin-fixed paraffinembedded biopsy samples obtained during PUB episodes. The low reported prevalence of H. pylori in PUB may be due to the failure of conventional tests to detect infection.

Research paper thumbnail of The role of dogs in the eco-epidemiology of Rickettsia typhi, etiological agent of Murine typhus

Veterinary Microbiology, 2013

Rickettsia typhi is the causative agent of Murine typhus (MT). This disease is one of the most pr... more Rickettsia typhi is the causative agent of Murine typhus (MT). This disease is one of the most prevalent rickettsial infections, widely distributed through the world, and it is endemic in many coastal areas (Civen and Ngo, 2008, pp. 913-918). However, its prevalence in many countries is unknown, partly because MT could be misdiagnosed and underreported. Clinical symptoms are not specific and MT may be mistaken for other diseases (

Research paper thumbnail of A Simplification Trial Switching From Nucleoside Reverse Transcriptase Inhibitors to Once-Daily Fixed-Dose Abacavir/Lamivudine or Tenofovir/Emtricitabine in HIV-1-Infected Patients With Virological Suppression

JAIDS Journal of Acquired Immune Deficiency Syndromes, 2009

Data comparing abacavir/lamivudine versus tenofovir/emtricitabine in antiretroviral-naive patient... more Data comparing abacavir/lamivudine versus tenofovir/emtricitabine in antiretroviral-naive patients are controversial. We compared 48-week efficacy and safety of these combinations as substitutes of nucleosides in patients with virological suppression. We randomly assigned 333 HIV-1-infected patients on lamivudine-containing triple regimens with &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;200 copies per milliliter for at least 6 months to switch their nucleosides to either abacavir/lamivudine (n = 167) or tenofovir/emtricitabine (n = 166). The primary outcome was treatment failure…

Research paper thumbnail of An Outbreak of Norovirus Infection in a Long-Term-Care Unit in Spain

Infection Control & Hospital Epidemiology, 2005

Background:Norovirus belongs to the Caliciviridae family and causes outbreaks of infectious enter... more Background:Norovirus belongs to the Caliciviridae family and causes outbreaks of infectious enteritis by fecal-oral transmission. In Spain, there have been few outbreaks reported due to this virus. We describe an outbreak on a long-term-care hospital ward.Methods:Cases were classified as probable, confirmed, and secondary. Stool cultures were performed. Polymerase chain reaction detection of norovirus was also performed.Results:The outbreak occurred from December 7 to 28, 2001, involving 60 cases (32 patients, 19 staff members, 8 patients' relatives, and 1 relative of a staff member). Most (82%) of the cases were female. The most frequently involved ages were 20 to 39 years for staff members and 70 to 89 years for patients. The incubation period of secondary cases in patients' families had a median of 48 hours (range, 1 to 7 days). Clinical symptoms included diarrhea (85%), vomiting (75%), fever (37%), nausea (23%), and abdominal pain (12%). Median duration of the disease wa...

Research paper thumbnail of M1054 Real-Time PCR Analysis of H. pylori-Negative Paraffin-Embedded Biopsies Reveal Infection in Most Patients with Bleeding Ulcer

Gastroenterology, 2009

Gastroenterology, Volume 136, Issue 5, Pages A-340, May 2009, Authors:Xavier Calvet; María José R... more Gastroenterology, Volume 136, Issue 5, Pages A-340, May 2009, Authors:Xavier Calvet; María José Ramírez-Lázaro; Sergio Lario; Pilar García-Iglesias; Alex Casalots; Jordi Sánchez-Delgado; Valentí Puig; Félix Junquera; Ferran Segura.

Research paper thumbnail of Clinical significance of methicillin-resistantStaphylococcus aureuscolonization in residents in community long-term-care facilities in Spain

Epidemiology and Infection, 2011

SUMMARYMethicillin-resistantStaphylococcus aureus(MRSA) is highly prevalent in Spanish hospitals ... more SUMMARYMethicillin-resistantStaphylococcus aureus(MRSA) is highly prevalent in Spanish hospitals and community long-term-care facilities (LTCFs). This longitudinal study was performed in community LTCFs to determine whether MRSA colonization is associated with MRSA infections and overall mortality. Nasal and decubitus ulcer cultures were performed every 6 months for an 18-month period on 178 MRSA-colonized residents (86 490 patient-days) and 196 non-MRSA carriers (97 470 patient-days). Fourteen residents developed MRSA infections and 10 of these were skin and soft tissue infections. Two patients with respiratory infections required hospitalization. The incidence rate of MRSA infection was 0·12/1000 patient-days in MRSA carriers and 0·05/1000 patient-days in non-carriers (P=0·46). No difference in MRSA infection rate was found according to the duration of MRSA colonization (P=0·69). The mortality rate was 20·8% in colonized residents and 16·8% in non-carriers; four residents with MRS...

Research paper thumbnail of Prudent use of antimicrobials: Have we done the best we can? The SEIMC and REIPI statement

Enfermedades Infecciosas y Microbiología Clínica, 2010

Research paper thumbnail of Diagnóstico precoz de la infección por VIH

Enfermedades Infecciosas y Microbiología Clínica, 2012

Cartas científicas Diagnóstico precoz de la infección por VIH Early diagnosis of HIV infection * ... more Cartas científicas Diagnóstico precoz de la infección por VIH Early diagnosis of HIV infection * Autor para correspondencia.

Research paper thumbnail of Adherencia al tratamiento antirretroviral. Estudio de prevalencia en un hospital general

Enfermedades Infecciosas y Microbiología Clínica, 2003

Research paper thumbnail of Cohorte RIS de pacientes con infección por VIH sin tratamiento antirretroviral previo (CoRIS): metodología y primeros resultados

Enfermedades Infecciosas y Microbiología Clínica, 2007

Spanish cohort of naïve HIV-infected patients (CoRIS): Rationale, organization and initial result... more Spanish cohort of naïve HIV-infected patients (CoRIS): Rationale, organization and initial results OBJECTIVE. To describe the methodology and baseline results of the Spanish cohort of naïve HIV-infected patients included in the Research Network on HIV/AIDS (CoRIS). METHODS. CoRIS is a multicenter, hospital-based prospective cohort of HIV sero-prevalent, retroviral-naïve subjects, over 13 years old, and seen at 17 hospitals in 8 of the 17 Autonomous Regions in Spain from January 2004 to October 2005. The socio-demographic characteristics, as well as epidemiological, clinical, laboratory and treatment data were recorded, and biological samples were collected at baseline and during follow-up. RESULTS. A total of 1,591 subjects have been included in CoRIS; 24% are women, median age at cohort entry is 36 years, and 74% were diagnosed during 2004 or 2005. Twenty-seven percent came from countries other than Spain, mainly Latin-America (16%) and sub-Saharan Africa (5%). Thirty-two percent had completed secondary education and 16% university studies. The most frequent categories of transmission were men having sex with men (37%) and heterosexual sex (36%); only 21% were injection drug users. At cohort entry, median CD4 count was 317 cells/mm 3 and median viral load was 52,300 copies/mL; 18% were diagnosed with AIDS. Main AIDS-defining illnesses were Pneumocystis jiroveci pneumonia (6.1%), esophageal candidiasis (3.3%) and tuberculosis (extrapulmonary, 3.0% and pulmonary 2.7%). There were 35 deaths (2.2%). Thirty-three percent of patients gave a baseline sample to the BioBank. CONCLUSIONS. CoRIS offers relevant information about the current epidemiological profile of HIV infection in Spain, where sexual transmission has become predominant. The type and amount of information obtained from clinical and epidemiological data collection together with biological samples demonstrate the viability of the project, which offers many possibilities for future research.

Research paper thumbnail of Enfermedades producidas por Rickettsia

Enfermedades Infecciosas y Microbiología Clínica, 2005

vessel vasculitis, which may affect lungs (interstitial pneumonitis), heart (miopericarditis), sk... more vessel vasculitis, which may affect lungs (interstitial pneumonitis), heart (miopericarditis), skin (rash), central nervous system (meningoencephalitis), as well as liver, and kidneys. They are classified in two groups: spotted-fever group, and typhus group rickettsia. In Spain the most prevalent rickettsioses of both groups are mediterranean spotted fever (caused by R. conorii), and murine typhus (caused by R. typhi), respectively. This review focuses mainly in these two diseases, and also in other rickettsioses of interest due to their recently emergence or reemergence (R. slovaca, R. africae, R. prowazekii, R. felis), or to their high incidence in other areas (R. rickettsii, Orientia tsutsugamushi).

Research paper thumbnail of The dog as an epidemiological marker of Rickettsia conorii infection

Clinical Microbiology and Infection, 2009

Research paper thumbnail of Comparative Accuracy of 3 Monoclonal Stool Tests for Diagnosis ofHelicobacter pyloriInfection among Patients with Dyspepsia

Clinical Infectious Diseases, 2010

Background. Well-devised studies comparing new but different monoclonal fecal tests for diagnosin... more 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. Fecal tests, biopsy-based analyses (eg, histopathology and the rapid urease test), and the urea breath test are the main tools used for diagnosis of Helicobacter pylori infection [1]. Fecal immunoassays perform far more irregularly than other methods do, and indeed the diagnostic accuracy of the different stool tests varies widely [2, 3]. One of the reasons for this variation in

Research paper thumbnail of Clarithromycin for the Treatment of Mediterranean Spotted Fever

Clinical Infectious Diseases, 2002