Infection In Cohort Research Articles

Respiratory tract infections and risk factors for infection in a cohort of 330 patients with axial spondyloarthritis or psoriatic arthritis.

Respiratory tract infections (RTIs) are the most common infections in patients with rheumatic diseases under immunosuppressive treatment and may contribute to morbidity and mortality as well as increased healthcare costs. However, to date only limited data on infection risk in spondyloarthritis (SpA) patients are available. In this study we assessed the occurrence of respiratory tract infections in a monocentric real-world cohort consisting of 330 patients (168 psoriatic arthritis and 162 axial spondyloarthritis patients) and determined factors associated with increased infection risk. Out of 330 SpA patients, 89.3% had suffered from ≥ 1 upper respiratory tract infection (URTI) and 31.1% from ≥ 1 lower respiratory tract infection (LRTI) within the last two years. The most common URTIs were rhinitis and laryngitis/pharyngitis with 87.3% and 36.1%, respectively. Bronchitis constituted the most common LRTI, reported in 29.7% of patients. In a multivariate binomial logistic regression model occurrence of LRTI was associated with chronic lung disease (OR 17.44, p=0.006), glucocorticoid therapy (OR 9.24, p=0.012), previous history of severe airway infections (OR 6.82, p=0.013), and number of previous biological therapies (OR 1.72, p=0.017), whereas HLA B27 positivity was negatively associated (OR 0.29, p=0.025). Female patients reported significantly more LRTIs than male patients (p=0.006) and had a higher rate of antibiotic therapy (p=0.009). There were no significant differences between axSpA and PsA patients regarding infection frequency or antibiotic use. 45.4% of patients had required antibiotics for respiratory tract infections. Antibiotic therapy was associated with smoking (OR 3.40, p=0.008), biological therapy (OR 3.38, p=0.004), sleep quality (OR 1.13, p<0.001) and age (OR 0.96, p=0.030). Hypogammaglobulinemia (IgG<7g/l) was rare (3.4%) in this SpA cohort despite continuous immunomodulatory treatment. Awareness of these risk factors will assist physicians to identify patients with an increased infection risk, who will benefit from additional preventive measures, such as vaccination and smoking cessation or adjustment of DMARD therapy.

Prevalence and covid 19 vaccination rate in a population of patients with schizophrenia and a substance use disorder

IntroductionAs of August 27th, 2021, the diagnosed cases of COVID 19 in Spain are 4 758 003 with a prevalence of 10.03%. 68.4% of the Spanish population is fully vaccinatedObjectivesPrimary: To compare the prevalence of COVID infection in a cohort of patients with schizophrenia to patients with a dual diagnosis of schizophrenia and substance use disorder Secondary: To compare the rate of fully vaccinated patients diagnosed with schizophrenia with and without a coexisting substance use disorder.MethodsRetrospective descriptive study. The population in study is made up of patients with schizophrenia (46) and dual diagnosis schizophrenia (28) (following DSM 5 criteria) Confirmed cases were those cases with positive PCRResultsThere was not a stadistically significant difference in the prevalence of COVID 19 infection between both groups of patients. The prevalence of COVID infection among the dual diagnosis schizophrenia was 3.57% compared to 6.5% in those without coexisting substance abuse disorder. Relative to vaccination rate, we didn’t find a stadistically significant difference between both groups. However, there was a higher vaccination rate in the dual diagnosis schizophrenia group (82.12%) compared to the non-dual diagnosis schizophrenia group (69.56%)ConclusionsThe prevalence of COVID 19 infection in the dual diagnosis schizophrenia cohort is 3.57% and in the group of patients with schizophrenia without substance abuse disorder is 6,5%. In those with dual diagnosis schizophrenia the vaccination rate was un 82.12%. It was 69.56% in those without coexisting substance abuse disorder.DisclosureNo significant relationships.

Prospective Assessment of Symptoms to Evaluate Asymptomatic SARS-CoV-2 Infections in a Cohort of Health Care Workers.

BackgroundThe frequency of asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections is unclear and may be influenced by how symptoms are evaluated. In this study, we sought to determine the frequency of asymptomatic SARS-CoV-2 infections in a prospective cohort of health care workers (HCWs).MethodsA prospective cohort of HCWs, confirmed negative for SARS-CoV-2 exposure upon enrollment, were evaluated for SARS-CoV-2 infection by monthly analysis of SARS-CoV-2 antibodies as well as referral for polymerase chain reaction testing whenever they exhibited symptoms of coronavirus disease 2019 (COVID-19). Participants completed the standardized and validated FLU-PRO Plus symptom questionnaire scoring viral respiratory disease symptom intensity and frequency at least twice monthly during baseline periods of health and each day they had any symptoms that were different from their baseline.ResultsTwo hundred sixty-three participants were enrolled between August 25 and December 31, 2020. Through February 28, 2021, 12 participants were diagnosed with SARS-CoV-2 infection. Symptom analysis demonstrated that all 12 had at least mild symptoms of COVID-19, compared with baseline health, near or at time of infection.ConclusionsThese results suggest that asymptomatic SARS-CoV-2 infection in unvaccinated, immunocompetent adults is less common than previously reported. While infectious inoculum doses and patient factors may have played a role in the clinical manifestations of SARS-CoV-2 infections in this cohort, we suspect that the high rate of symptomatic disease was due primarily to participant attentiveness to symptoms and collection of symptoms in a standardized, prospective fashion. These results have implications for studies that estimate SARS-CoV-2 infection prevalence and for public health measures to control the spread of this virus.

Comparing Infection Rates from Using Different Surgical Preparation Solutions and Techniques in Foot &amp; Ankle Elective Surgery

Category:OtherIntroduction/Purpose:Surgical site infection (SSI) after Foot & Ankle surgery ranges from 1.2% to 13.2%, higher than any other elective orthopaedic procedure. Infection is of concern for the patient and expensive for the healthcare system. SSI is multifactorial and can be divided into host-related and perioperative factors. Skin preparation is one of the key peri-operative factors in reducing SSI. The current literature supports a combined chlorhexidine and alcohol preparation technique, although there is some conflicting evidence. Most studies to date have used proxy outcomes such as growth from swabs shortly after skin preparation. There are no large scale studies which have looked at definitive clinical outcomes such as the rate of postoperative SSI.Methods:A retrospective review of data was undertaken for two longitudinal cohorts which were using two different skin preparation solutions and techniques due to a change in hospital protocol. Each cohort was continuous and derived from the same overall populationIn cohort 1, Povidine-Iodine (Betadinetm) followed by Alcoholic Chlorhexidine was used on swabs (Double prep group). In cohort 2, 2 Alcoholic Chlorhexidine was used in a prep stick applicator. Standard criteria for diagnosing surgical site infection were used. All open injuries, procedures for ongoing infection, amputations for osteomyelitis /diabetic foot and COVID- 19 positive cases were excluded.Results:After applying standard exclusion criteria, 919 elective F&A procedures in the Double prep group and 491 procedures were included for the Single prep groupAs these were continuous longitudinal cohorts of large scale from the same population, there is a justifiable presumption of group matchingIn cohort 1 there were 15 superficial infections (1.6%) and 3 deep (0.3%). In cohort 2 there were 18 superfical infections (3.6%) and 1 deep (0.3%). The total infections in cohort 1 were 18 (2%) and 19 in cohort 2 (3.9%)There was an increase in superficial, and therefore total infection rates, in the single prep group compared to the double prep group. These increases were statistically significant; p <0.05 with regards to superficial infection and total infection rates in the single prep group.Conclusion:Double skin preparation, with Povidone-Iodine followed by alcoholic Chlorhexadine, statistically significantly decreases foot and ankle surgical infection rates as compared to a single alcoholic chlorhexidine skin preparation

Performance of the point-of-care circulating cathodic antigen test in the diagnosis of schistosomiasis japonica in a human cohort from Northern Samar, the Philippines

BackgroundZoonotic schistosomiasis, caused by Schistosoma japonicum, remains a major public health problem in the Philippines. This study aimed to evaluate the commercially available rapid diagnostic point-of-care circulating cathodic antigen (POC-CCA) test in detecting individuals infected with S. japonicum in a human cohort from an endemic area for schistosomiasis japonica in the Philippines.MethodsClinical samples were collectedin 18 barangays endemic for S. japonicum infection in Laoang and Palapag municipalities, Northern Samar, the Philippines, in 2015. The presence of CCA in filter-concentrated urine samples (n = 412) was evaluated using the commercial kits and the results were converted to images, which were further analyzed by ImageJ software to calculate R values. The diagnostic performance of the immunochromatographic POC-CCA test was compared using the Kato-Katz (KK) procedure, in-house enzyme-linked immunosorbent assays (ELISAs) and droplet digital (dd) PCR assays as reference.ResultsThe POC-CCA test was able to detect S. japonicum-infected individuals in the cohort with an eggs per gram of faeces (EPG) more than or equal to 10 with sensitivity/specificity values of 63.3%/93.3%. However, the assay showed an inability to diagnose schistosomiasis japonica infections in all cohort KK-positive individuals, of which the majority had an extremely low egg burden (EPG: 1–9). The prevalence of S. japonicum infection in the total cohort determined by the POC-CCA test was 12.4%, only half of that determined by the KK method (26.2%). When compared with the ELISAs and ddPCR assays as a reference, the POC-CCA assay was further shown to be a test with low sensitivity. Nevertheless, the assay exhibited significant positive correlations with egg burden determined by the KK technique and the target gene copy number index values determined by the ddPCR assays within the entire cohort.ConclusionsBy using in silico image analysis, the POC-CCA cassette test could be converted to a quantitative assay to avoid reader-variability. Because of its low sensitivity, the commercially available POC-CCA assay had limited potential for determining the status of a S. japonicum infection in the target cohort. The assay should be applied with caution in populations where schistosome parasites (especially S. japonicum) are present at low infection intensity.Graphic abstract

Association between oral contraceptives and serious infections: A population-based cohort study.

Oral contraceptives (OC)s are commonly used worldwide. In a recent study, we showed that the use of OCs is associated with an increased risk for neutropenia. We aimed to investigate the clinical implications of this finding by examining the infection rates of 4 serious infections before, during and after OCs. A retrospective cohort study using the electronic medical records of a large health organization. We selected 2 retrospective cohorts of women aged 16-40 between years 2005 and 2019. The first cohort examined infection rates during 2 years before OC use and 2 consecutive years of adherent OC use. The second cohort included women who consumed OCs adherently for 2 years and then discontinued their use for 2 consecutive years. Women's infection rates were compared by χ2 test, results were stratified by OC type and age. Overall, 21 595 and 20 728 women were included in Cohorts 1 and 2 respectively. We found a statistically significant higher relative risk for infection while using OCs; the overall risk ratios (95% confidence intervals) for infection in Cohorts 1 and 2 were 1.35 (1.32-1.38) and 1.27 (1.24-1.31), respectively. The overall infection risk remained statistically significant when stratified by age. This study demonstrates a high statistically and clinically significant risk for all infections followed during OC consumption, which is likely to have major clinical and economic implications. These findings may have implications to millions of women worldwide and should lead to more research on the safety of the pill.

Dynamic linkage of COVID-19 test results between Public Health England's Second Generation Surveillance System and UK Biobank.

UK Biobank (UKB) is an international health resource enabling research into the genetic and lifestyle determinants of common diseases of middle and older age. It comprises 500 000 participants. Public Health England’s Second Generation Surveillance System is a centralized microbiology database covering English clinical diagnostics laboratories that provides national surveillance of legally notifiable infections, bacterial isolations and antimicrobial resistance. We previously developed secure, pseudonymized, individual-level linkage of these systems. In this study, we implemented rapid dynamic linkage, which allows us to provide a regular feed of new COVID-19 (SARS-CoV-2) test results to UKB to facilitate rapid and urgent research into the epidemiological and human genetic risk factors for severe infection in the cohort. Here, we have characterized the first 1352 cases of COVID-19 in UKB participants, of whom 895 met our working definition of severe COVID-19 as inpatients hospitalized on or after 16 March 2020. We found that the incidence of severe COVID-19 among UKB cases was 27.4 % lower than the general population in England, although this difference varied significantly by age and sex. The total number of UKB cases could be estimated as 0.6 % of the publicly announced number of cases in England. We considered how increasing case numbers will affect the power of genome-wide association studies. This new dynamic linkage system has further potential to facilitate the investigation of other infections and the prospective collection of microbiological cultures to create a microbiological biobank (bugbank) for studying the interaction of environment, human and microbial genetics on infection in the UKB cohort.

Prevalence of Hepatitis C Virus Infection in a Surgical Population of Southeast China: A Large-Scale Multicenter Study.

Background Chronic HCV infection affects 80 million people globally and may progress to advanced liver disease. The present study aims to investigate the present epidemiology of HCV infection in a southeastern Chinese surgical patient cohort. Methods Blood samples obtained from 78,484 surgical patients from 18 different city and county hospitals were enrolled. The incidence of serum HCV antibody positivity, HCV RNA load, and HCV genotyping, as well as demographics and relevant clinical history, were investigated. Data were stratified using the multistage cluster random sampling method and further analyzed using the SPSS-20 package. Results HCV antibody positivity was detected in 0.15% of the population (95% confidence interval (CI): 0.12%–0.18%). Genotype 1b (55.74%) was the dominant type. The HCV infection peaked in the age groups of 16–20, 41–50, and 61–65 years, and it was higher in males than in females (0.19% vs. 0.13%, P < 0.05). The geographical distribution of infection rates differed: 0.19% (95% CI: 0.14%–0.24%), 0.18% (95% CI: 0.13%–0.23%), and 0.06% (95% CI: 0.03–0.09%) in plain areas, islands, and valley regions, respectively. Patients with transfusion history and urban residence were associated with high HCV RNA levels (adjusted odds ratio = 11.24 and 6.20, P < 0.05). Conclusion The prevalence of HCV infection in this cohort from southeast China was 0.17%, which is lower than the reported 0.43% infection rate in China in 2006. This result can be (partially) explained by the improvement of blood donor screening and the successful campaign for the use of disposable syringes and needles.

Comparison of Hickman Versus Proline Central Venous Catheters in Pediatric Patients Undergoing Hematopoietic Stem Cell Transplant

Introduction Central venous catheter (CVC) access is an essential component of pediatric hematopoietic stem cell transplant (HSCT). Long-term CVC access is associated with an increased risk of infection and device dysfunction. Studies have shown that one in four CVC devices in the pediatric population require removal prior to completion of treatment due to infectious or mechanical complications. A retrospective analysis evaluated CVC-related complications in Hickman versus Proline catheters among pediatric HSCT recipients. Methods We performed a detailed retrospective chart review of CVC related complications among pediatric patients who underwent HSCT between June 2016 and October 2019. During the study period there was a change in the standard CVC access device from Hickman to Proline catheter. We compared the complications related to Hickman Catheter (Cohort 1) to Proline line (Cohort 2). All patients received antibacterial prophylaxis with cefepime. Results Thirty- two patients with a median age 7 years (range 0.75-19) underwent HSCT for malignant (N=16) or nonmalignant (N=16) disease. The majority underwent allogeneic HSCT (N=29). CVC complications requiring line removal occurred in 3 out of 15 (20%) HSCTs in Cohort 1 in comparison to 2 out of 18 (11%) in Cohort 2. Of the 3 complications in Cohort 1, 2 (66%) were related to infection and 1 (33%) due to device malfunction. Both line removals in Cohort 2 were due to device malfunction. There was one documented central line infection in Cohort 2 that did not require line removal. Conclusion Results of this small pilot study suggests that Proline catheters for long-term access in pediatric HSCT recipients may lead to a decrease incidence of complications requiring line removal in comparison Hickman catheters. Further research is indicated in order to provide recommendations for the optimal CVC for long-term access in pediatric HSCT.

Long-term impact of infant immunization on hepatitis B prevalence: a systematic review and meta-analysis.

ObjectiveTo conduct a systematic review and meta-analysis of the long-term impact of infant vaccination on the prevalence of hepatitis B virus (HBV) infection at the population level.MethodsWe searched online databases for articles reporting comparisons between population cohorts aged ≥ 15 years who were exposed or unexposed to infant HBV immunization programmes. We categorized programmes as universal or targeted to infants whose mothers were positive for hepatitis B surface antigen (HBsAg). We included studies reporting prevalence of hepatitis B core antibody (HBcAb), HBsAg, or both. We evaluated the quality of the study methods and estimated the relative reduction in the prevalence of infection.FindingsOf 26 studies that met the inclusion criteria, most were from China (20 studies). The prevalence of HBV infection in unvaccinated and universally vaccinated cohorts ranged from 0.6% (116 of 20 305 people) to 16.3% (60/367) and from 0.3% (1/300) to 8.5% (73/857), respectively. Comparing cohorts with universal vaccination to those without vaccination, relative prevalences were 0.24 (95% confidence interval, CI: 0.16–0.35) for HBsAg and 0.23 (95% CI: 0.17–0.32) for HBcAb. For populations with targeted vaccination, relative prevalences were 0.32 (95% CI: 0.24–0.43) and 0.33 (95% CI: 0.23–0.45), respectively.ConclusionThe residual burden of infection in cohorts offered vaccination suggests that longer-term evaluations of vaccination coverage, timeliness and other aspects of programme quality are needed. As HBV-vaccinated infant cohorts reach adulthood, ongoing analysis of prevalence in adolescents and young adults will ensure that elimination efforts are on track.

An experience with mesh versus darn repair in inguinal hernias.

Background & Objective:The inguinal hernia accounts for 50 percent in old age males. A Lichtenstein type of operation has now become the method of choice in most developed countries but in the developing world traditional simple suture repair is still in common practice in resource limited hospitals due to the scarcity and expensive nature of the commercial prosthetic mesh. Our objective was to compare the rates of complications in Lichtenstein repair to tension free Darn repair.Methods:Ninety two male patients from 20-60 years of age reported for direct or indirect inguinal hernia with open Mesh/Lichtenstein or darn repair in emergency or electively from January 2014 to December 2015 were enrolled in this prospective randomized control trial (RCT). The primary end point was to compare the surgical site infection, length of hospital stay and hernia recurrence with different techniques.Results:The hospital stay was higher in patients who had Lichtenstein repair, Superficial surgical site infections in cohort A (6.5%) and cohort B (4.36%)were noted. Complications of recurrence in Group-A were (1.5%) as compared to Group-B which had a recurrence of 6.52%.Conclusion:Lichtenstein is more promising in comparison to Darn repair in terms of recurrence in inguinal hernia.

Interleukin-6 Levels Act as a Diagnostic Marker for Infection and a Prognostic Marker in Patients with Organ Dysfunction in Intensive Care Units.

There are significant unmet requirements for rapid differential diagnosis of infection in patients admitted to intensive care units. Serum levels of interleukin-6 (IL-6), procalcitonin (PCT), presepsin, and C-reactive protein (CRP) are measured in clinical practice; however, their clinical utility in patients with organ dysfunction has not been tested adequately. Thus, we investigated the diagnostic and prognostic value of IL-6, PCT, presepsin, and CRP in critically ill patients who had organ dysfunction with suspicion of infection. In 100 consecutive critically ill patients with organ dysfunction and suspected infection, serum levels of IL-6, PCT, presepsin, and CRP were measured upon suspicion of infection and serially every other day up to 7 days (cohort 1). The primary outcome variable was the presence of infections. The diagnostic value of IL-6 was further tested in cohort 2 (n = 72, case-control matched). The secondary outcome variables were the sequential organ failure assessment (SOFA) score, serum creatinine levels, and 28-day mortality. Among the four biomarkers, serum IL-6 levels had the highest area under the curve (AUC) value of 0.824 (95% confidence interval [CI] 0.735-0.913) for diagnosing infection in critically ill patients with organ dysfunction and suspected infection in cohort 1 (AUC [95% CI] for the other biomarkers: PCT, 0.813 [0.714-0.911]; CRP, 0.764 [0.645-0.883]; presepsin, 0.681 [0.513-0.849]). In cohort 2, the sensitivity and specificity of IL-6 for diagnosing infection were 0.861 and 0.806, respectively. The presepsin levels were significantly correlated with the SOFA score and serum creatinine levels upon suspicion of infection (r > 0.5), especially serum creatinine levels in the patients without infection (r = 0.789). Serum IL-6 levels were significant predictors of 28-day mortality. The AUC value of serum IL-6 levels for 28-day mortality increased over time; the serum IL-6 levels on Day 7 had the highest AUC value of 0.883 (95% CI, 0.788-0.978) for 28-day mortality. Among serum IL-6, PCT, presepsin, and CRP levels, serum IL-6 levels had the highest diagnostic value for infection. They were also significant predictors of 28-day mortality. Hence, they may improve diagnosis of infection and prediction of 28-day mortality in critically ill patients with organ dysfunction.

Interactions of Aspergillus fumigatus Conidia with Airway Epithelial Cells: A Critical Review.

Aspergillus fumigatus is an environmental filamentous fungus that also acts as an opportunistic pathogen able to cause a variety of symptoms, from an allergic response to a life-threatening disseminated fungal infection. The infectious agents are inhaled conidia whose first point of contact is most likely to be an airway epithelial cell (AEC). The interaction between epithelial cells and conidia is multifaceted and complex, and has implications for later steps in pathogenesis. Increasing evidence has demonstrated a key role for the airway epithelium in the response to respiratory pathogens, particularly at early stages of infection; therefore, elucidating the early stages of interaction of conidia with AECs is essential to understand the establishment of infection in cohorts of at-risk patients. Here, we present a comprehensive review of the early interactions between A. fumigatus and AECs, including bronchial and alveolar epithelial cells. We describe mechanisms of adhesion, internalization of conidia by AECs, the immune response of AECs, as well as the role of fungal virulence factors, and patterns of fungal gene expression characteristic of early infection. A clear understanding of the mechanisms involved in the early establishment of infection by A. fumigatus could point to novel targets for therapy and prophylaxis.

The Incidence and Predictors of Infection in Psoriasis and Psoriatic Arthritis: Results from Longitudinal Observational Cohorts.

To investigate the rate, type, characteristics, and predictors of infection in a cohort of patients with psoriatic arthritis (PsA) and a cohort of patients with psoriasis without arthritis (PsC). A cohort of patients with PsA and a cohort of patients with PsC were followed according to a standard protocol and information on the occurrence of infections was recorded. The rate of infection was estimated by fitting an exponential model. A Weibull regression model was fitted to estimate the relative risk of first infection associated with a number of covariates. Risk factors for recurrent infections were investigated using generalized estimating equations. There were 498 and 74 infections reported among 695 and 509 patients with PsA and PsC, respectively, with an incidence rate of 19.6 per 100 person-years in the PsA cohort compared with 12.2 in the PsC cohort. The HR of the time to the first infection in PsA versus PsC was 1.6 (p = 0.002), and higher in patients treated with biologics versus nonbiologics at 1.56 (95% CI 1.22-2.00) in PsA and 1.50 (95% CI 0.64-3.54) in the PsC cohorts. Female sex and treatment with biologics were associated with infection in the PsA cohort, whereas a lower Psoriasis Area and Severity Index score and a higher Functional Comorbidity Index were associated with infection in the PsC cohort. Ultraviolet treatment was protective against infection in both cohorts. No difference in rates of hospitalization was found (p = 0.66). There were no infection-related deaths in either cohort. The incidence rate of infection was higher in the PsA than the PsC cohort and higher among patients treated with biologics. The data confirm the association between infection and biologic treatment in psoriatic disease.

Determining the prevalence of cytomegalovirus infection in a cohort of preterm infants

Preterm birth is a global public health problem that is a significant cause of infant morbidity and mortality. Congenital cytomegalovirus (CMV) infection has been proposed as a risk factor for preterm birth, but the rate of CMV in infants born preterm is unclear. CMV is the leading infectious cause of sensorineural hearing loss, which will affect 15% - 20% of congenitally infected infants later in their childhood. 90% of infected infants are asymptomatic at birth and are not recognized as at risk for CMV-associated deficits. To determine the prevalence of CMV infection in a large cohort of preterm infants. DNA was extracted from cord blood, peripheral blood, saliva, and buccal swab samples collected from preterm infants. A total of 1200 unique DNA samples were tested for CMV using a nested PCR protocol. The proportions of preterm infants with CMV was compared by sample collection type, race, gender, and gestational age. A total of 37 infants tested positive for CMV (3.08%). After excluding twins, siblings, and infants older than two weeks at the time of sample collection, two out of 589 infants were CMV positive (0.3%), which was lower than the proportion of CMV observed in the general population. All positive samples came from buccal swabs. Our work suggests that while CMV infection may not be greater in preterm infants than in the general population, given the neurologic consequences of CMV in preterm infants, screening of this population may still be warranted. If so, our results suggest buccal swabs, collected at pregnancy or at birth, may be an ideal method for such a program.

Large scale modelling of salmon lice (Lepeophtheirus salmonis) infection pressure based on lice monitoring data from Norwegian salmonid farms

Infection by parasitic sea lice is a substantial problem in industrial scale salmon farming. To control the problem, Norwegian salmonid farms are not permitted to exceed a threshold level of infection on their fish, and farms are required to monitor and report lice levels on a weekly basis to ensure compliance with the regulation. In the present study, we combine the monitoring data with a deterministic model for salmon lice population dynamics to estimate farm production of infectious lice stages. Furthermore, we use an empirical estimate of the relative risk of salmon lice transmission between farms, that depend on inter-farm distances, to estimate the external infection pressure at a farm site, i.e. the infection pressure from infective salmon lice of neighbouring farm origin. Finally, we test whether our estimates of infection pressure from neighbouring farms as well as internal within farm infection pressure, predicts subsequent development of infection in cohorts of farmed salmonids in their initial phase of marine production. We find that estimated external infection pressure is a main predictor of salmon lice population dynamics in newly stocked cohorts of salmonids. Our results emphasize the importance of keeping the production of infectious lice stages at low levels within local networks of salmon farms. Our model can easily be implemented for real time estimation of infection pressure at the national scale, utilizing the masses of data generated through the compulsory lice monitoring in salmon farms. The implementation of such a system should give the salmon industry greater predictability with respect to salmon lice infection levels, and aid the decision making process when the development of new farm sites are planned.

Incidence and correlates of hepatitis C virus infection in a large cohort of prisoners who have injected drugs.

BackgroundHepatitis C virus (HCV) infection is common among prisoners, particularly those with a history of injecting drug use (IDU). Incarcerated people who inject drugs frequently report high-risk injecting practices both in prison and in the community. In spite of rising morbidity and mortality, utilisation of HCV-related services in Australia has been persistently low. This study aimed to describe the incidence, prevalence and correlates of HCV seropositivity in a large cohort of prisoners who have injected drugs, and to identify correlates of receiving confirmation of active infection.MethodsData-linkage to a State-wide statutory notifiable diseases surveillance system was used to investigate the incidence of notified HCV seropositivity, seroconversion and confirmed HCV infection in a cohort of 735 prisoners with a history of IDU, over 14 years of follow up. Hepatitis C test results from prison medical records were used to identify correlates of testing positive in prison.ResultsThe crude incidence of HCV notification was 5.1 cases per 100 person-years. By the end of follow up, 55.1% of the cohort had been the subject of a HCV-related notification, and 47.4% of those tested in prison were HCV seropositive. In multivariable analyses, injecting in prison was strongly associated with HCV seropositivity, as was opioid use compared to injection of other drugs. The rate of reported diagnostic confirmation among those with notified infections was very low, at 6.6 confirmations per 100 seropositive participants per year.ConclusionsInjecting drugs in prison was strongly associated with HCV seropositivity, highlighting the need for increased provision of services to mitigate the risk of transmission within prisons. Once identified as seropositive through screening, people with a history of IDU and incarceration may not be promptly receiving diagnostic services, which are necessary if they are to access treatment. Improving access to HCV-related services will be of particular importance in the coming years, as HCV-related morbidity and mortality is increasing, and next generation therapies are becoming more widely available.

Surgical site infections and other healthcare related infections in cohort of urological patients, 2010-2013

Background: Surgical site infections (SSIs) and other healthcare related infections continues to be significant problem in surgical patients across the globe. Aim: To analyze and compare the surveillance data from large cohort of patients operated in Clinic for Urology, Military Medical Academy Methods: A prospective cohort study was performed to identify incidence rate and risk factors for surgical site infections (SSI) from 2010 to 2013. Infection control personal collected general and healthcare related data about patients. The microbiologic testing was performed at the Institute of Medical Microbiology by routine methods. Results: A total of 3823 surgical procedures (3288 patients) were included in the study. The lowest incidence rate was observed in kidney surgery (total nephrectomy - 2.4% and partial nephrectomy - 3.6%), and highest during bladder surgery (total cystectomy - 21.6% and partial cystectomy - 23.5%). The postoperative infections (RR: 2.018; 95%:1.111 -3.666; SE: 0.305; p: 0.021), dra inage (RR:10.417; 95%CI:4.339 - 25.011; SE: 0.447; p: 0.000), preoperative length of hospital stay (RR:0.909; 95%CI: 0.880 - 0.939; SE: 0.017; p: 0.000) and total length of hospitalization (RR:1.140; 95%CI:1.117-1.164; SE: 0.010; p:0.000), as well as contamination class (RR:1.633; CI95%:1.215 - 2.194; SE:0.151; p:0.001) are independent risk factors for SSI in this cohort of patients. Incidence rate of diarrhea caused by Clostridium difficile was 5.01 to 10 000 patient days. The most common cause of SSI and urinary tract infections was Klebsiella spp. Conclusion: The greater attention has been given to adherence to recommendations for the prevention and control of SSIs as well as management of multidrug resistant organisms in urology department.

HIV-1 Superinfection Occurs Less Frequently Than Initial Infection in a Cohort of High-Risk Kenyan Women

HIV superinfection (reinfection) has been reported in several settings, but no study has been designed and powered to rigorously compare its incidence to that of initial infection. Determining whether HIV infection reduces the risk of superinfection is critical to understanding whether an immune response to natural HIV infection is protective. This study compares the incidence of initial infection and superinfection in a prospective seroincident cohort of high-risk women in Mombasa, Kenya. A next-generation sequencing-based pipeline was developed to screen 129 women for superinfection. Longitudinal plasma samples at <6 months, >2 years and one intervening time after initial HIV infection were analyzed. Amplicons in three genome regions were sequenced and a median of 901 sequences obtained per gene per timepoint. Phylogenetic evidence of polyphyly, confirmed by pairwise distance analysis, defined superinfection. Superinfection timing was determined by sequencing virus from intervening timepoints. These data were combined with published data from 17 additional women in the same cohort, totaling 146 women screened. Twenty-one cases of superinfection were identified for an estimated incidence rate of 2.61 per 100 person-years (pys). The incidence rate of initial infection among 1910 women in the same cohort was 5.75 per 100pys. Andersen-Gill proportional hazards models were used to compare incidences, adjusting for covariates known to influence HIV susceptibility in this cohort. Superinfection incidence was significantly lower than initial infection incidence, with a hazard ratio of 0.47 (CI 0.29–0.75, p = 0.0019). This lower incidence of superinfection was only observed >6 months after initial infection. This is the first adequately powered study to report that HIV infection reduces the risk of reinfection, raising the possibility that immune responses to natural infection are partially protective. The observation that superinfection risk changes with time implies a window of protection that coincides with the maturation of HIV-specific immunity.

Central line associated bloodstream infections in cohort of abdominal surgical patients

INTRODUCTION: Central venous catheter (CVC) placement is an unavoidable part of the everyday medical practice. At the same time CVC application is associated with high risk of development of central line-associated bloodstream infections (CLABSIs). These infections are cause of icreased morbidity and mortality rates as well as higer costs of the inpatient treatment2. Risk factors for onset of CLABSIs include duration of catheterization, length of hospital stay before catheterization, anatomic site of placement, CVC placement at the intensive care units (ICU), parenteral nutrition (PN) and ommisions diring CVC placement, use and care. CLABSI incidence rates vary depending on distribution of different risk factors associated with CVC and patient him/herself. The most significant causative organisms of CLABSIs are coagulase-negative Staphylococcocae, Staphylococcus aureus (S.aures), Enterococcus spp. i Candida spp. CLABSIs prevention measures include compliance with the rules of the aseptic technique upon placement, use and care of CVCs, which, based on the study results, may enable prevention of 65% to 70% of cases of CLABSIs. METHODS: A prospective cohort study included 200 patients hospitalized at the intensive care and therapy units of the CCS Clinic of Digestive Surgery in the period November 30th, 2006-November 31st, 2007 in whom CVC was placed for more than 48 hours. All the data necessary for the study were obtained based on the review of the case histories and they were recorded into the individual questionnaires for each patient. The questionnarire included patient information (age, gender, underlying disease, presence of other infections), information related to diagnostic and therapeutic procedures to which the patient was exposed. The incidence of CRBSIs in ICU patients, Institute of Digestive Diseases, CCS over the study period was 10.08 per 1,000 catheter-days. During the study CLABSI more often present in the females. Additionally, application of albumin and amino acids, ICU stay longer that 7 days and CVC application longer than 15 days, significantly more often present in patients with CRBSIs than in the group of patients without CRBSIs. Independent factors for development of CRBSI are gender, administration of albumin and amino acids. The most common microorganisms isolated from hemocultures and CVC were S. aureus and Klebsiella spp., with 31,8% of isolates each. Statistically significant difference was evidenced in frequency of resistance of S. aureus isolates to methicillin in the group of patients with CRBSI in comparison to the group of patients without CLABSIs. CLABSIs prevention measurs include compliance with the rules of the aseptic technique upon placement, use and care of CVCs.