Diagnostic yield of bacteriological tests and predictors of severe outcome in adult patients with COVID-19 presenting to the emergency department.

BACKGROUND: Guidelines recommend maximal efforts to obtain blood and sputum cultures in patients with COVID-19, as bacterial coinfection is associated with worse outcomes. The aim of this study was to evaluate the yield of bacteriological tests, including blood and sputum cultures, and the association of multiple biomarkers and the Pneumonia Severity Index (PSI) with clinical and microbiological outcomes in patients with COVID-19 presenting to the emergency department (ED). METHODS: This is a substudy of a large observational cohort study (PredictED study). The PredictED included adult patients from whom a blood culture was drawn at the ED of Haga Teaching Hospital, The Netherlands. For this substudy, all patients who tested positive for SARS-CoV-2 by PCR in March and April 2020 were included. The primary outcome was the incidence of bacterial coinfection. We used logistic regression analysis for associations of procalcitonin, C reactive protein (CRP), ferritin, lymphocyte count and PSI score with a severe disease course, defined as intensive care unit admission and/or 30-day mortality. The area under the receiver operating characteristics curve (AUC) quantified the discriminatory performance. RESULTS: We included 142 SARS-CoV-2 positive patients. On presentation, the median duration of symptoms was 8 days. 41 (29%) patients had a severe disease course and 24 (17%) died within 30 days. The incidence of bacterial coinfection was 2/142 (1.4%). None of the blood cultures showed pathogen growth while 6.3% was contaminated. The AUCs for predicting severe disease were 0.76 (95% CI 0.68 to 0.84), 0.70 (0.61 to 0.79), 0.62 (0.51 to 0.74), 0.62 (0.51 to 0.72) and 0.72 (0.63 to 0.81) for procalcitonin, CRP, ferritin, lymphocyte count and PSI score, respectively. CONCLUSION: Blood cultures appear to have limited value while procalcitonin and the PSI appear to be promising tools in helping physicians identify patients at risk for severe disease course in COVID-19 at presentation to the ED.

Intraoperative bile duct cultures in patients undergoing pancreatic head resection: Prospective comparison of bile duct swab versus bile duct aspiration.

BACKGROUND: Postoperative surgical site infection is a major source of morbidity after pancreatic head resections, and data suggest bacterobilia as a leading cause. Some centers use intraoperative bile duct cultures to guide postoperative antimicrobial prophylaxis. This prospective study evaluates culture differences between traditional bile duct swab versus bile duct aspiration intraoperative samples. METHODS: Prospective patients undergoing pancreatic head resection with both bile duct swab and bile duct aspiration were included. Cultures were reviewed for organism characteristics. Any growth of organisms was considered a positive culture. Bile duct swab yield and characteristics were compared with bile duct aspiration. Postoperative surgical site infection complications were compared to bile duct culture results. RESULTS: Fifty patients were included. Bile duct aspiration resulted in a significantly higher median number of organisms compared to bile duct swab (6 vs 3; P < .001). There were no differences in the number of patients (37 vs 33) having positive bile duct aspiration and bile duct swab cultures (P = .385). Anaerobic cultures (not possible with bile duct swab) were positive in 21 patients with bile duct aspiration. A total of 37 (74%) patients had preoperative biliary stenting, which highly associated (P < .001) with positive cultures. Bile duct culture organisms correlated with postoperative surgical site infection in 12/17 (71%) patients. CONCLUSION: Use of bile duct aspiration improves intraoperative bile duct culture organism yield over bile duct swab and may improve tailoring of antibiotics in patients undergoing pancreatic head resection.

Day-of-Free Tissue Transfer Qualitative Cultures Do Not Predict Limb Salvage Outcomes.

BACKGROUND: Successful free tissue transfer is critical for lower extremity salvage in the chronic wound population. The rates of lower extremity free tissue transfer success lag behind those for other anatomical sites. The aim of this study was to evaluate whether positive qualitative day-of-free tissue transfer cultures or pathogen virulence negatively impacts short- and long-term outcomes of lower extremity free tissue transfer. METHODS: Between April of 2011 and January of 2018, 105 lower extremity free tissue transfer procedures were performed. Growth level and speciation were identified from qualitative cultures taken during free tissue transfer. The relationship between demographics, comorbidities, culture data, postoperative infection, free tissue transfer survival, and long-term limb salvage was examined using logistic regression. RESULTS: The median Charlson Comorbidity Index was 3. Intraoperative free tissue transfer cultures were positive in 39.1 percent. Flap survival was 93.3 percent. Postoperative infection developed in 12.4 percent. The limb salvage rate was 81.0 percent. Positive culture was not significant for flap survival, postoperative infection, or amputation. Cultures positive for Enterococcus species had a significant relationship with flap success (OR, 0.08; p = 0.01) and amputation (OR, 7.32; p = 0.04). Insufficient antimicrobial coverage had a significant relationship with postoperative infection (OR, 6.56; p = 0.01) despite the lack of pathogen concordance. On multivariate analysis, postoperative infection (OR, 12.85; p < 0.01) and Charlson Comorbidity Index were predictive of eventual amputation (OR, 1.44; p = 0.01). CONCLUSIONS: Positive day-of-free tissue transfer cultures, regardless of pathogen, had limited predictive value for short- and long-term outcomes of free tissue transfer in the authors' cohort. These findings call for a broader multicenter prospective analysis and consideration of health care-associated infections and their impact on limb salvage outcomes. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Current Status of Helicobacter pylori Diagnosis and Eradication Therapy in Japan Using a Nationwide Database.

BACKGROUND: Helicobacter pylori infection increases the risk of stomach cancer; therefore, eradication therapy is recommended for infected individuals. Although several methods are recommended for the diagnosis and therapy of H. pylori infection, their frequency and effectiveness have not been fully investigated in Japan. METHODS: A nationwide claims database including >1.6 million patients (April 2008 - -October 2016) in Japan was utilized. We analyzed the distribution of methods for H. pylori diagnosis and therapy, waiting period between eradication and diagnostic test, and success rate of primary therapy. RESULTS: Data for 481,041 patients were extracted. After primary eradication therapy, urea breath test was used for >80% of diagnoses, and antibody measurement for 0.7%. The success rate of primary eradication was >80% for most diagnostic methods and 69.0% for antibody measurement; inappropriately-timed antibody measurement may have contributed to this disparity. The overall success rate of eradication therapy decreased from 2011 to 2014, but increased from 2015, coinciding with launch of the potassium-competitive acid blocker vonoprazan, which showed a higher success rate of eradication than proton-pump inhibitors. CONCLUSIONS: Diagnostic tests of H. pylori infection mostly followed Japanese Society for Helicobacter Research guidance, although some antibody measurements were timed inappropriately. Vonoprazan appears to increase the success rate of primary therapy.

Fatores associados à cura e ao abandono do tratamento da tuberculose na população privada de liberdade / Factors associated with recovery and the abandonment of tuberculosis treatment in the incarcerated population

RESUMO: Objetivo: Este estudo objetivou investigar os fatores associados aos desfechos de cura e abandono na população privada de liberdade com tuberculose. Métodos: Estudo quantitativo, observacional e analítico. Realizado com dados oriundos do Sistema de Informação de Agravos de Notificação (Sinan), de tuberculose da população privada de liberdade nos anos de 2007 a 2016 no estado da Paraíba. Foram incluídas as notificações de indivíduos maiores de 18 anos notificados como "casos novos" e como encerramento por "cura" ou "abandono". Excluíram-se aqueles que até dezembro de 2016 não tinham a situação de encerramento. Realizaram-se estatísticas bivariada e multivariada, por meio de regressão de Poisson. Resultados: Com 614 notificações, a maioria foi do sexo masculino (93,8%). Na análise bivariada, houve associação estaticamente relevante dos desfechos com síndrome da imunodeficiência adquirida (p = 0,044), sorologia para vírus da imunodeficiência humana (p = 0,048) e não realização de baciloscopia de acompanhamento (p = 0,001). Na análise multivariada ajustada, a síndrome da imunodeficiência adquirida (risco relativo - RR = 1,998; intervalo de confiança de 95% - IC95% 1,078 - 3,704; p = 0,028) e a não realização de baciloscopia de acompanhamento (RR = 5,211; IC95% 2,158 - 12,583; p < 0,001*) permaneceram significativamente associadas ao desfecho de abandono. Conclusão: Os desfechos de cura e abandono estão associados principalmente com a realização ou não da baciloscopia de acompanhamento e com a síndrome da imunodeficiência adquirida.

ABSTRACT: Objective: This study aimed to investigate the factors associated with the outcomes of recovery and abandonment in the incarcerated population with tuberculosis. Methods: A quantitative and observational analytical study was performed with data from the Notification Disease Information System (Sinan), tuberculosis data from the incarcerated population in the state of Paraiba from 2007 to 2016; Notifications of individuals over the age of 18, reported as "new cases" and the outcome, "recovery" or "abandonment" status were included. Those people who until December 2016 had no outcome information were excluded. Analyses were performed using bivariate and multivariate statistics from the Poisson regression. Results: Of the 614 notifications, most were male (93.8%). In the bivariate analysis, there was a statistically relevant association of outcomes with Acquired Immunodeficiency Syndrome (p = 0.044), Human Immunodeficiency Virus (HIV) serology (p = 0.048) and lack of completion of follow-up bacilloscopy (p = 0.001). In the adjusted multivariate analysis, Acquired Immunodeficiency Syndrome (RR = 1.998; 95%CI 1.078 - 3.704; p = 0.028) and lack of completion of follow-up bacilloscopy (RR = 5.251; 95%CI 2.158 - 12.583; p <0.001*) remained significantly associated with the dropout outcome. Conclusion: Recovery and abandonment outcomes were mainly associated with whether the follow-up bacilloscopy was performed or not and Acquired Immunodeficiency Syndrome.

Perianal Tuberculosis: Lessons Learned in 57 Patients From 743 Samples of Histopathology and Polymerase Chain Reaction and a Systematic Review of Literature.

BACKGROUND: Few data are published on perianal tuberculosis. OBJECTIVE: This study aimed to determine the best method to diagnose tuberculosis in patients with fistula-in-ano and to conduct a systematic review to determine the incidence and characteristics of tuberculosis fistula-in-ano. DATA SOURCES: The prospective study data and existing literature were derived from PubMed, Google scholar, and Scopus STUDY SELECTION:: Prospective analysis of patients with tuberculous fistula-in-ano treated between 2014 and 2018 was conducted, and a systematic review of studies describing ≥3 patients with tuberculosis fistula-in-ano was completed. INTERVENTION: Testing of tuberculosis was performed by histopathology or polymerase chain reaction of tissue or pus from the fistula tract. MAIN OUTCOME MEASURES: The primary outcomes measured were the detection rate of various tests to detect tuberculosis in fistula-in-ano and the prevalence rate of tuberculosis in simple versus complex fistulas. RESULTS: In 637 samples (410 patients) tested, tuberculosis was detected in 49 samples (43 patients). Additional samples (n = 106) sent in patients with a high index of suspicion tested positive in 14 more patients. Thus, overall, 63 samples tested positive in 57 patients (total: 743 samples in 410 patients were tested). Tuberculosis was detected in 2 of 181 patients (1.1%) in tissue (histopathology), in 28 of 341 patients (8.2%) in tissue (polymerase chain reaction), and in 19 of 115 patients (16.5%) in pus (polymerase chain reaction) samples. To detect tuberculosis, tissue (polymerase chain reaction) was significantly better than tissue (histopathology) (28/341 vs 2/181, p < 0.00001) and pus (polymerase chain reaction) was significantly better than tissue (polymerase chain reaction) (19/115 vs 28/341, p < 0.0009). Tuberculosis was significantly more common in complex fistulas than in simple fistulas (20.3% vs 7.2%, p = 0.0002). The systematic review (n = 199) highlighted that tubercular fistulas are more common in recurrent and complex fistulas and in tuberculosis endemic regions. LIMITATIONS: The true sensitivity and specificity of each testing modality could not be determined because not all patients with tuberculosis fistula-in-ano were tested by every diagnostic modality studied. CONCLUSIONS: The tuberculosis detection rate of polymerase chain reaction was significantly higher than histopathology. Among polymerase chain reaction, pus had higher detection rate than tissue. Tuberculosis was associated with more complex and recurrent fistulas.

Nationwide observational study of mortality from complicated intra-abdominal infections and the role of bacterial cultures.

BACKGROUND: The benefit of taking intra-abdominal cultures during source control procedures in patients with complicated intra-abdominal infection (CIAI) is unknown. The aim of this study was to evaluate whether intra-abdominal cultures reduce the mortality rate of CIAI. METHODS: The Japanese Diagnosis Procedure Combination database was used to identify adult patients with CIAI who had undergone source control procedures on the first day of admission to hospital between April 2014 and March 2016. In-hospital mortality was compared between patients who did and those who did not have intra-abdominal cultures taken. A generalized linear mixed-effect logistic regression model and a random intercept per hospital were used to adjust for baseline confounders and institutional differences. Subgroup analyses were also performed according to disease cause, site of onset and severity of CIAI. RESULTS: Intra-abdominal cultures were taken from 16 303 of 41 495 included patients. Multivariable logistic regression analysis showed that patients with intra-abdominal cultures had a significantly lower mortality than those without (odds ratio 0·85, 95 per cent c.i. 0·77 to 0·95). Subgroup analyses revealed statistically significant differences in mortality between patients with and without cultures among those with lower intestinal perforation, biliary tract infection/perforation, healthcare-associated CIAI and high-risk community-acquired CIAI. CONCLUSIONS: Intra-abdominal cultures obtained during source control procedures may reduce in-hospital mortality, especially in patients with lower intestinal perforation, biliary tract infection/perforation, or healthcare-associated or high-risk community-acquired CIAI.

The 3-day rule for stool cultures: should all patients with haematological malignancies be excluded?

OBJECTIVES: The '3-day rule' for stool culture ordering suggests that only selected inpatients with nosocomial diarrhoea should have stool cultures for enteropathogenic bacteria (EPBs). Patients with haematological malignancies are not included in this group. We have analysed the ordering of stool cultures at Laikon Hospital to investigate whether all patients with haematological malignancies should be excluded from the 3-day rule. METHODS: We have retrospectively analysed all inpatient stool specimens sent to the microbiology laboratory for enteropathogenic bacteria culture at Laikon Hospital, Athens, Greece, between January 1, 2014 and December 31, 2014. We classified stool cultures sent after the third day as 'appropriate', 'excluded' with standard rule, 'excluded' with haematological malignancies, and 'inappropriate'. RESULTS: During the study period, 1101/1593 inpatient stool cultures (69.1%) had been ordered after the third day of hospitalization. The total yield for inpatient EPB stool cultures was 0.7% (11/1593). The yield for 'appropriate' cultures was significantly higher than the yield of all 'excluded' specimens (3.7% (3/81) versus 0.3% (2/585), p 0.018) and to 'inappropriate' orders (3.7% (3/81) versus 0.0% (0/485), p 0.0028). There was no difference in the yield between specimens 'excluded' with the standard rule and 'excluded' with haematological malignancies. CONCLUSIONS: In our hospital, the yield of stool cultures from patients with haematological malignancies is similar to that of patients 'excluded' from the standard 3-day rule. If patients with haematological malignancies were not excluded from the rule, we would reduce the inpatient stool cultures by 13.6% (217/1593) at the cost of missing one positive stool culture.

Candidaemia: Risk factors and validity of tools to predict risk of Candidaemia in Intensive care unit patients in Teaching Hospital Karapitiya

Introduction: The ability to predict candidaemia gives a significant advantage to the clinician by enabling pre-emptive treatment to reduce mortality. Objectives: To identify the prevalence, risk factors, and to validate candida colonization index (CI), candida score (CS) to reliably predict the development of candidaemia in the identified study sample. Methods: Cross sectional analytical study of consecutive admissions fulfilling inclusion criteria to intensive care units (ICUs) of Teaching Hospital Karapitiya from 1st December 2015 to 30th March 2016. Candida colonization of non-blood body sites was measured by culture on admission and repeated every 3rd day until discharge from ICU, death or development of candidaemia. CI, corrected CI (CCI), and CS were calculated for the study patients. Results: Candida colonization was found in 100 (65.7%) patients out of 152 patients screened. The presence of sepsis, gastro-intestinal infection or surgery, central venous line colonization, higher density of rectal, oral and urine colonization was significantly different among the infected and non-infected groups. Change of species of colonizing candida was also a significant new risk factor found in the study. All the indices and scores had excellent sensitivity and negative predictive values. However none of the scores had good specificity except for CCI, which was 94%. Conclusions: A combination of CI, CCI and CS formulated for the study sample could reliably predict candidaemia.

Cost-effectiveness analysis of universal screening for carbapenemase-producing Enterobacteriaceae in hospital inpatients.

The purpose of this study was to assess the cost-effectiveness of screening all hospital inpatients for carbapenemase-producing Enterobacteriaceae (CPE) at the time of hospital admission, compared to not screening, from a US hospital perspective. We used a linked transmission/Markov model to compare outcomes for a typical hospitalized medical patient, from a community with a colonization prevalence of 0.05%. Outcomes were number of colonized patients, CPE-related clinical infections and deaths, expected quality-adjusted life years (QALYs), cost, and the incremental cost-effectiveness ratio (ICER). Sensitivity analyses were performed to assess the effect of parameter uncertainty, using a willingness-to-pay threshold of $100,000 per QALY gained. Screening prevented six CPE colonization cases per 1000 patients (1/1000 colonized with screening, 7/1000 without screening), over half of all symptomatic CPE infections (2/10,000 symptomatic with screening, 5/10,000 symptomatic without screening), and nearly half of all CPE-related deaths (8/100,000 deaths with screening, 15/100,000 deaths without screening). Screening accrued 0.0009 additional QALYs and cost an additional $24.68, compared to not screening, and was cost-effective (ICER $26,283 per QALY gained). Our results were sensitive to uncertainty in prevalence and the number of secondary colonizations per colonized patient. Screening was not cost-effective at a prevalence below 0.015% or if transmission to fewer than 0.9 new patients occurred for each colonized patient. At prevalence levels above 0.3%, screening was cost-saving compared to not screening. Screening inpatients for CPE carriage is likely cost-effective, and may be cost-saving, depending on the local prevalence of carriage.

Clinical value of antistreptolysin O levels in adult patients with tonsillitis: report I.

To assess the clinical value of antistreptolysin O (ASO) level in adult patients with acute tonsillitis of group A beta-hemolytic streptococcus (GABHS) etiology and its interaction with the Centor score and throat cultures data. ASO antibody titers and throat cultures were obtained from 260 adult patients with acute tonsillitis of GABHS etiology initially proven by the Centor score. The results were compared with the group of 100 adult patients with recurrent tonsillitis who underwent tonsillectomy and with the group of 100 healthy adults. Throat cultures revealed GABHS-positive results in 69 acute cases (26.5%) and in 24 recurrent cases (24%), i.e., with no significant differences between the groups (p = 0.845). There was no significant difference between cases with GABHS-positive and with GABHS-negative throat culture in ASO titers results (mean 250 and 280, respectively, p = 0.44) but these titers were significantly higher than established normative data (p < 0.01). For the group of recurrent tonsillitis cases, the mean ASO titer was 363 being significantly higher in comparison with acute cases (p = 0.015). The ASO antibody titers are significantly higher than normative ranges in cases of acute tonsillitis in adults. The detection of the elevated titers may lead to early antibiotherapy to tonsillitis. The Centor score is supported by the ASO data and less supported by throat cultures data. Further research should reveal if these titers might have predictive value for possible further recurrence or serve as an indicator for tonsillectomy in cases of recurrent tonsillitis.

Mycobacterium bovis en fauna silvestre de la cuenca lechera de Santa Fe, Argentina / Mycobacterium bovis in wildlife of the dairy regions of Santa Fe (Argentina)

El control y la erradicación de la tuberculosis bovina basados en la detección de los animales infectados y su inmediata faena permitió lograr progresos satisfactorios en varios países y regiones, pero no todos pudieron lograrlo debido principalmente a la presencia de fauna silvestre infectada con Mycobacterium bovis. La Argentina aplica desde 1999 estas mismas premisas y ha logrado avances en los rodeos lecheros, aunque no se ha evaluado el factor ambiental como la fauna silvestre. El objetivo de este trabajo fue determinar si la fauna silvestre de la cuenca lechera de Santa Fe está infectada con M. bovis. Se realizó la captura/sacrificio de fauna silvestre presente en 5 rodeos lecheros con altos niveles de reaccionantes positivos a la prueba de tuberculina. Sobre 95 mamíferos silvestres examinados, se aisló M. bovis de 7 individuos de comadreja overa (Didelphis albiventris), de uno de zorro gris (Lycolapex gimnocercus) y de uno de rata (Rattus norvegicus). Los sitios anatómicos que produjeron estos aislamientos variaron de acuerdo con las especies; en ninguno de los ejemplares evaluados se observaron lesiones macroscópicas de tuberculosis. Los espoligotipos de M. bovis aislados con mayor frecuencia de los animales silvestres correspondieron a los tipos 34 (4 aislamientos) y 12 (3 aislamientos); el primero es el más corrientemente aislado del ganado en Argentina. Se discute en este estudio el papel de la comadreja overa (D. albiventris) como hospedador circunstancial de M. bovis

Control eradication campaigns of bovine tuberculosis based on the «test and slaughter¼ approach were successful in many countries and regions; however, in some areas the infection persists and one of the main reasons is Mycobacterium bovis infection in wild life species. Argentina has applied the same approach since 1999, achieving progress in dairy cattle herds. Nonetheless, the wildlife role has never been investigated. The objective of this study was to determine if wildlife from the Santa Fe dairy area is infected with M. bovis. Wildlife species having a positive tuberculin skin test were captured in five dairy farms. Ninety five wildlife mammals were captured; M. bovis was recovered from 7 possums (Didelphys albiventris), from one fox (Lycolapex gimnocercus) and from one rat (Rattus norvegicus). None of the animals exhibited macroscopic lesions. The most frequently isolated M. bovis spoligotypes were types 34 (4 isolates) and 12 (3 isolates). Spoligotype 34 is the most frequently isolated type in Argentine cattle. The role of D. albiventris as spillover host of M. bovis is discussed in this study

Blood cultures in acute surgical admissions.

INTRODUCTION: Obtaining blood cultures prior to the administration of antimicrobial therapy was a key recommendation of the 2012 UK Surviving Sepsis Campaign. Few studies have examined the effect blood cultures have on clinical management and there have been none on acute surgical admissions. This retrospective study sought to evaluate the effect of blood cultures on clinical management in acute surgical admissions. METHODS: Data on acute surgical patients admitted between 1 January and 31 December 2012 were extracted from hospital records. Patients given intravenous antibiotics within 24 hours of admission were identified. Data collected included antibiotics administered, blood culture results, admission observations and white blood cell count. Case notes were reviewed for patients with positive cultures to establish whether the result led to a change in management. RESULTS: Of 5,887 acute surgical admissions, 1,346 received intravenous antibiotics within 24 hours and 978 sets of blood cultures were taken in 690 patients. The recommended two sets of cultures were obtained in 246 patients (18%). Patients who had blood cultures taken had the same in-hospital mortality as those who had none taken (3.6% vs 3.5%, p=0.97). Blood cultures were positive in 80 cases (11.6%). The presence of systemic inflammatory response syndrome did not increase positivity rates (12.9% vs 10.3%, p=0.28). Overall, cultures altered management in two patients (0.3%). CONCLUSIONS: Blood cultures rarely affect clinical management. In order to assess the additional value that blood cultures bring to sepsis management in acute surgical admissions, a prospective randomised trial focusing on outcome is needed.

Evaluation of urinalyses ordered for diagnosis of urinary tract infections at an inpatient psychiatric hospital.

OBJECTIVE: A retrospective study was conducted to assess the diagnosis and treatment of urinary tract infections (UTIs) using urinalyses (UA)s at a psychiatric hospital. METHOD: Patients admitted between July 2010 and June 2011 receiving at least one UA during inpatient psychiatric hospitalization were included. Pregnant patients and those with a UA receiving antibiotic treatment in the emergency department were excluded. The primary objective of the study was to characterize and assess the appropriateness of UAs ordered for the diagnosis of UTIs. Secondary objectives included analyzing frequency of cultures obtained, appropriateness of empiric antibiotics, and de-escalation of therapy if warranted. RESULTS: Thirty-nine percent (n = 891/2292) of patients admitted received a UA at least once during their hospitalization. Of 203 patients further evaluated, 78% were asymptomatic, 11% were older than 65 years of age with altered mental status (AMS) or dementia, and 11% had typical UTI symptoms. Thirty-one patients were given antibiotics for a UTI during their stay, with a majority of those being asymptomatic (n = 19/31). CONCLUSIONS: A significant proportion of UAs ordered at a psychiatric hospital were inappropriate. When patients were treated, empiric antibiotic selection and length of treatment were appropriate in most instances.

Recovery and time to growth of isolates in blood culture bottles: comparison of BD Bactec Plus Aerobic/F and BD Bactec Plus Anaerobic/F bottles.

BACKGROUND: This study was done to compare the growth of pathogens in paired aerobic/anaerobic blood culture bottles versus the use of only aerobic bottles, and to analyze the time to growth in both atmospheres. METHODS: We retrospectively evaluated the results of all blood cultures collected over a 2-y period for the diagnosis of central venous catheter-related bloodstream infections or other severe infections in oncology patients. RESULTS: Among the 487 isolates, 174 (35.7%), all aerobic, grew only in the aerobic bottle; 250 (51.3%), all aerobic, grew in both bottles; and 63 (12.9%) grew only in the anaerobic bottle, of which 24 were anaerobic and 39 were aerobic microorganisms (8% of positive blood cultures). Of these 39 aerobic microorganisms, 12 were Gram-negative, 17 staphylococci (4 were Staphylococcus aureus), 5 streptococci, 2 Gram-positive bacilli, and 3 mixed growth. Though the mean time to positivity of pathogens grown in both atmospheres was significantly lower in the aerobic bottle than in the anaerobic bottle, in 71 cases (28.4%) the pathogens developed earlier in the anaerobic bottle than in the aerobic bottle - in 36 of these cases at least 1 h earlier, which is significant for starting targeted therapy. CONCLUSIONS: The use of paired aerobic/anaerobic blood culture bottles allowed the diagnosis of a percentage of bacteraemia due to either anaerobic or aerobic pathogens that would have been missed, as they grew only in the anaerobic atmosphere. Moreover in 8% of bacteraemia we identified a significant decrease in the time to detection, resulting in the opportunity to better manage the infections without an increase in costs.

Repeat genital Chlamydia trachomatis testing rates in young adults in England, 2010.

OBJECTIVES: To explore patterns of repeat chlamydia testing among young people in England and factors associated with testing positive at repeat test. METHODS: We analysed chlamydia testing among 15 to 24-year-olds in England in a single calendar year (2010) using data from the genitourinary medicine clinic activity dataset (GUMCAD) and tests reported through the National Chlamydia Screening Programme (NCSP). Case records were linked using patient clinic numbers (GUMCAD), or by matching date of birth, gender and postcode (NCSP). Individuals could not be linked between datasets. The incidence of repeat testing was estimated using survival analysis. Risk factors for testing positive at repeat test were explored using multivariable logistic regression. RESULTS: 1 235 058 tests in the NCSP dataset and 502 095 in GUMCAD were included. The incidence of repeat testing was 18.4 and 26.1 per 100 person years in the NCSP dataset and GUMCAD respectively. Among NCSP repeat tests, the proportion testing positive was higher in those reporting recent change of sexual partner (adjusted OR males 1.44; females 1.52), and among those with a positive compared to a negative baseline test (adjusted OR males 2.57; females 1.95). CONCLUSIONS: We observed moderate levels of repeat testing within a year. Considering the frequency of partner change among young people, more could be done to encourage re-testing upon change of sexual partner. Increasing re-testing following a positive test could probably identify unresolved or repeat infections that may otherwise go untreated. Work to establish the optimum approach to repeat testing in England is now warranted.

Impact of the type of diagnostic assay on Clostridium difficile infection and complication rates in a mandatory reporting program.

BACKGROUND: Most Clostridium difficile infection (CDI) surveillance programs neither specify the diagnostic method to be used nor stratify rates accordingly. We assessed the difference in healthcare-associated CDI (HA-CDI) incidence and complication rates obtained by 2 validated diagnostic methods. METHODS: This was a prospective cohort study of patients for whom a C. difficile test was ordered between 1 August 2010 and 31 July 2011. All specimens were tested in parallel by a commercial polymerase chain reaction (PCR) assay targeting toxin B gene tcdB, and a 3-step algorithm detecting glutamate dehydrogenase and toxins A and B by enzyme immunoassay and cell culture cytotoxicity assay (EIA/CCA). CDI incidence rate ratios were calculated using univariate Poisson regression. RESULTS: A total of 1321 stool samples were tested during a period totaling 95 750 patient-days. Eighty-five HA-CDI cases were detected by PCR and 56 cases by EIA/CCA (P = .01). The overall incidence rate was 8.9 per 10 000 patient-days (95% confidence interval [CI], 7.1-10.9) by PCR and 5.8 per 10 000 patient-days (95% CI, 4.4-7.4) by EIA/CCA (P = .01). The incidence rate ratio comparing PCR and EIA/CCA was 1.52 (95% CI, 1.08-2.13; P = .015). Overall complication rate was 27% (23/85) when CDI was diagnosed by PCR and 39% (22/56) by EIA/CCA (P = .16). Cases detected by PCR only were less likely to develop a complication of CDI compared with cases detected by both PCR and EIA/CCA (3% vs 39%, respectively; P < .001). CONCLUSIONS: Performing PCR instead of EIA/CCA is associated with a >50% increase in the CDI incidence rate. Standardization of diagnostic methods may be indicated to improve interhospital comparison.

Repeat chlamydia testing across a New Zealand district: 3 years of laboratory data.

OBJECTIVES: To investigate the impact of repeat chlamydia testing on annual population coverage estimates and to examine repeat testing patterns in a New Zealand district with high chlamydia testing rates. METHODS: Chlamydia testing data for 15-44-year-old men and women in a single New Zealand district during February 2008 to January 2011 were analysed. Annual coverage of testing was estimated in two ways, using the number of tests and the number of individuals as the numerator. Rates of repeat testing were calculated using survival analysis. RESULTS: There were 73 879 tests (12 251 men, 61 628 women) from 41 342 individuals (8437 men, 32 905 women) during 3 years. Coverage estimates in 2010 using the number of individuals as the numerator were 17% lower for men and 26% lower for women than when the number of tests was used (5.9% vs 4.9% for men and 28.7% vs 21.2% for women). The rate of repeat testing was 16.9 per 100 person-years among men (95% CI 16.2 to 17.7) and 31.6 among women (95% CI 31.1 to 32.2). Rates of repeat testing were higher among women, in younger age groups and following a positive rather than a negative baseline test (p<0.001). CONCLUSION: Relatively high rates of repeat testing were observed among young women in Waikato district during 2008 to 2010. Estimates of population coverage by test for this group therefore considerably overestimate individual coverage. The findings will inform discussions about improving surveillance to capture more accurate chlamydia testing coverage rates in New Zealand.

Irradiated allograft bone in spine surgery: to culture or not? A single center retrospective study.

STUDY DESIGN: Retrospective chart review. OBJECTIVE: We aimed to document the rate of infection in our institution after the use of irradiated cancellous allograft or iliac crest bone autograft in vertebral fusion procedures. We also reviewed the pertinence of microbiological culture of cadaveric allograft bone prior to its implantation. SUMMARY OF BACKGROUND DATA: Recent studies have shown similar postoperative infection rates between allograft and autograft. The pertinence of microbiological culture of allograft bone prior to its implantation is currently controversial. METHODS: Retrospectively, we identified 338 patients who underwent spine fusion procedures for which there was a minimum of a 1-year follow-up. Files from both the neurosurgery and orthopedics divisions of the Centre hospitalier universitaire de Sherbrooke were reviewed during 1999 to 2009. Irradiated allografts were used in 164 patients and autografts were used in 174 patients. Of the 164 allografts implanted, 53 were cultured peroperatively. Postoperative spinal infection was based on documented positive spine cultures at the time of re-exploration for presumed infection. Infection rates were compared using Fisher exact test. RESULTS: From the 53 peroperative cultures, 5 were positive (9.4%) and none of them led to antibiotherapy or surgical revision at 1 year. No significant difference was observed in the rate of surgical site infection at 1 year, after the use of irradiated allografts (1.8%) or autografts (1.7%), P = 1.0. CONCLUSION: Perceived association with infection should not influence the surgeon in bone graft choice for spinal fusion. There is a lack of scientific evidence to recommend for or against routine cultures on allograft implantation in the literature. Our results strongly underline the pertinence of larger multicenter clinical trials to assess the pertinence of peroperative allograft bone culture.

Chlamydia screening, retesting and repeat diagnoses in Cornwall, UK 2003-2009.

OBJECTIVES: This study aims to describe the patterns of testing and retesting for chlamydia in Cornwall during the first 5 years of the National Chlamydia Screening Programme. We evaluate the factors associated with retesting and estimate the incidence of chlamydia diagnosis and repeat diagnosis. STUDY DESIGN: Secondary database analysis. SELECTION CRITERIA: men and women tested for chlamydia between March 2003 and January 2009 in Cornwall, aged ≥12 years and ≤25 years at the first test. The factors associated with retesting in those with at least one known test result and at least 14 days follow-up time were analysed using Cox regression and the incidence of diagnosis and repeat diagnosis were calculated. RESULTS: The final dataset consisted of 71 066 records from 49 941 individuals; of whom 59.0% were female and 75.4% were only tested once. There were 48 375 individuals with at least one known test result (negative or positive) and at least 14 days follow-up, included in the Cox regression analysis. Factors associated with testing more than once were (adjusted HR, 95% CI): being female (2.24; 2.14 to 2.34) and initially testing positive (1.43; 1.35 to 1.51). The positivity at first episode declined from 13.2% (1077 cases) in 2003/2004 to 5.8% (843 cases) in 2008/2009. The incidence of diagnosis at the second test was 5.9 per 100 person years in those testing negative at the first test compared with 18.1 per 100 person years in those initially positive. DISCUSSION: Most individuals in this analysis were tested only once, but the testing volume and proportion of repeat tests were highest at the end of the study period. As the testing rate stabilises to 30% coverage, maintaining retesting rates in those previously tested and especially in those previously diagnosed with chlamydia will be necessary for the sustainability of the screening programme. CONCLUSIONS: A key feature of the next 5 years of the screening programme will be to maintain screening and rescreening.