Scandinavian Journal of Infectious Diseases最新文献

Background: Bloodstream infections (BSIs) are a well-recognized complication of parenteral nutrition (PN). However, their epidemiology and clinical consequences are incompletely described.

Methods: A retrospective cohort study was performed, from 2002 to 2009, of all hospital inpatients who were administered PN, outside the intensive care setting, at a major tertiary hospital in Queensland, Australia.

Results: In 780 episodes of PN administration, 120 BSIs occurred, giving an incidence of 10.0/1000 PN-days. The majority of PN-associated BSIs were classified as central line-associated (n = 98, 81.7%). Candida spp. were the most frequent pathogens. Observed BSI management revealed that over 8% of intravascular devices were inappropriately retained, over 30% of empirical antibiotic therapy was inappropriate, and 62% of antifungal therapy was delayed ≥ 48 h. All-cause hospital mortality was over 2-fold greater in patients with a PN-associated BSI compared to those without (17.9% vs 8.3%, crude odds ratio (OR) 2.4, 95% confidence interval (CI) 1.29-4.35, p = 0.002). BSI was identified as an independent risk factor for mortality (adjusted OR 3.54, 95% CI 1.76-7.12, p < 0.001). Low baseline albumin levels and a requirement for intravenous insulin infusion (a marker of sustained hyperglycaemia) were independent risk factors for the development of PN-associated BSIs.

Conclusions: PN-associated BSI in hospital inpatients is common and is associated with mortality. The implementation of standardized evidence-based infection prevention strategies, particularly targeting IVD maintenance, is a priority. PN-associated BSI management pathways require optimization, with timely IVD removal and appropriate antimicrobial therapy. Depending on local epidemiology patterns, empirical antifungal therapy should be considered.

Background: The treatment of patients co-infected with human immunodeficiency virus (HIV) and tuberculosis (TB) is challenging. The aim of this study was to compare socio-demographic and clinical characteristics among HIV-infected patients before and after the introduction of combined antiretroviral therapy (cART) in a Swedish cohort, and to identify factors associated with anti-TB treatment success as well as adverse reactions.

Methods: This was a retrospective observational study of HIV/TB co-infected patients in Stockholm County from 1987 to 2010. The study population was stratified into an early and a late cohort (before and after the introduction of cART in 1996). Data were analyzed using descriptive statistics and multiple logistic regression analysis.

Results: The study population comprised 127 patients; the majority were foreign-born (87%). The proportion of female patients more than doubled from the early to the late cohort, and anti-TB treatment success increased from 65% to 91%. The median duration of successful treatment was 8 months in both cohorts. Predictors of treatment success in the late cohort were cART (odds ratio (OR) 13.3, 95% confidence interval (CI) 1.5-114.8) and a CD4 cell count at TB diagnosis > 200 cells/μl (OR 17.2, 95% CI 1.2-236.6). Severe adverse reactions in the late cohort occurred in 23% and were associated with the initiation of cART after TB diagnosis (OR 13.3, 95% CI 1.6-112.4).

Conclusion: The introduction of cART was favourable for the treatment outcome of HIV-infected patients with concomitant TB. However, adverse reactions increased in patients who initiated cART during anti-TB treatment and these patients require careful attention.

Background: The Centor criteria and the streptococcal rapid antigen detection test (RADT) are commonly used to differentiate sore throat patients with group A streptococci (GAS) from patients with other pathogens. We aimed to investigate if procalcitonin (PCT), C-reactive protein (CRP), white blood cell count (WBC), and absolute neutrophil count (ANC) could increase the diagnostic accuracy when added to the Centor score and RADT, or be used instead of the RADT, in the differential diagnosis.

Methods: A 6-month prospective study was carried out in a Danish general practice with 8 physicians. One hundred acute tonsillitis patients aged 15 to 40 y were included.

Results: The prevalence of GAS was 26%. The sensitivity (90%) and specificity (97%) of the RADT were high. Mean values of CRP, WBC, and ANC were significantly higher in patients with GAS compared to non-GAS patients (p < 0.001). However, the sensitivities (66-90%) and specificities (45-75%) were low. No difference in PCT levels was found (p = 0.334). CRP was the most reliable infection marker (sensitivity 90% and specificity 45%) for GAS aetiology.

Conclusions: The sensitivity, specificity, and area under the curve of the RADT were higher than those of the 4 measured infection markers in the differentiation between GAS and non-GAS acute tonsillitis patients. The infection markers did not increase the diagnostic accuracy when added to the Centor score and RADT. When RADT is not available, measurement of CRP or ANC may increase the diagnostic accuracy in the detection of GAS-positive patients.

Background: The morphology of red blood cells (RBCs) is altered significantly during the maturation stages of malaria parasites, which include ring, trophozoite, and schizont. There is dissimilarity in terms of the morphological characteristics of parasitized RBCs infected by the 4 species of Plasmodium, including falciparum, vivax, malariae, and ovale. This makes the process of diagnosis very difficult, which may lead to a wrong treatment method and substantial damage to the health of the patient. An innovative technique in introduced that accurately defines the shape of parasitized RBCs at each stage of infection as a potential method of diagnosis.

Methods: Giemsa-stained thin blood films were prepared using blood samples collected from healthy donors as well as patients infected with P. malariae and P. ovale. The diameter and thickness of healthy and infected RBCs at each stage of infection were measured from their optical images using Olysia and Scanning Probe Image Processor (SPIP) software, respectively. A shape equation was fitted based on the morphological characteristics of RBCs, and their relative 2-dimensional shapes were plotted using Wolfram Mathematica.

Results: At the ring stage, the thicknesses of RBCs parasitized by P. malariae (Pm-RBCs) and P. ovale (Po-RBCs) increased by 42% and 51%, respectively. Both Pm-RBCs and Po-RBCs remained nearly biconcave throughout parasite development even though their volumes increased.

Conclusions: It is proposed that the morphology-based characterization technique introduced here could be used to intensify the accuracy of the Giemsa staining diagnosis method for the detection of the Plasmodium genus and infection stage. Based on the significant morphological alterations induced by different Plasmodium species, the results may also find practical use for faster prediction and treatment of human malaria.

Background: Opiate substitution therapy (OST) reduces the risk of death from directly drug-related causes in heroin users, allowing other chronic health problems to emerge. People who inject drugs (PWID) are exposed to hepatitis C virus (HCV), with an associated risk of chronic liver disease. We investigated HCV prevalence and liver-related morbidity in a cohort of OST recipients, and analyzed factors associated with significant hepatic fibrosis.

Methods: All patients registered on 1 April 2008 in 4 clinics providing OST in the 3 largest cities in Sweden were eligible for inclusion. HCV viremic subjects were evaluated for fibrosis stage by liver biopsy, transient elastometry (TE), and/or a biochemical fibrosis index (Göteborg University Cirrhosis Index; GUCI). Factors associated with severity of fibrosis were determined by logistic regression analysis.

Results: Out of 524 eligible patients, 277 consented to enrolment. Two hundred and thirty-six subjects (88%) were anti-HCV-positive, and 162 of these were viremic (69%). Significant liver fibrosis (defined as Ishak stages F3-F6, TE value ≥ 8.85 kPa, or GUCI > 0.33) was found in 69 out of 103 (67%) tested viremic patients, and was associated with alcohol intake (p = 0.03), higher body mass index (BMI; p = 0.04), and the presence of anti-HBc antibodies (indicating exposure to hepatitis B virus (HBV); p = 0.02).

Conclusions: Significant liver fibrosis was detected in two-thirds of HCV viremic OST recipients in this cohort, and was associated with alcohol use, high BMI, and exposure to HBV. These findings indicate that the management of HCV and associated risk factors should be emphasized in Swedish OST programs.

The distribution of Chlamydia trachomatis serotypes in the sexually active population may change over time. Serum from C. trachomatis seropositive women representing the 1980s, 1990s, and 2000s were available from a stratified random sample (11,067) of the Finnish Maternity Cohort for microimmunofluorescence-based classification. The C. trachomatis serotype distributions in the 1980s and 2000s were comparable, with serotypes G, E, and J being the most prevalent. In the 1990s the numbers of women seropositive for ≥ 2 serotypes peaked, and serotypes G/J were replaced by serotypes E/D. The temporary C. trachomatis serotype replacement parallels changes in the sexually active population in the 1990s in Finland.

Background: Diabetes is increasingly common in TB endemic regions and plays a role as a possible risk factor for increased progression from latent TB infection (LTBI) to active TB disease. Although the pathophysiological mechanisms are not fully understood, the immune system is weakened in diabetes patients and therefore the validity of interferon gamma release assays (IGRA) may be compromised. The aim of the present study was to assess the association between diabetes and Mycobacterium tuberculosis (Mtb) antigen-specific interferon gamma (IFN-γ) release in a TB endemic area among culture-confirmed TB patients and non-TB controls.

Methods: Culture-confirmed pulmonary TB patients (n = 187) and healthy non-TB neighbourhood controls (n = 190) from Mwanza, Tanzania were tested for the presence of circulating T cells recognizing Mtb antigens using an IGRA. The diabetes status of all participants was assessed using a standard oral glucose tolerance test. The impact of diabetes on the performance of the IGRA was estimated using robust linear and logistic regression.

Results: Compared to normal glucose tolerance, diabetes was associated with reduced levels of Mtb-specific IFN-γ. Increasing levels of fasting blood glucose (B - 0.3, 95% confidence interval - 0.6 to - 0.03, p = 0.033) was negatively associated with IFN-γ. Although TB patients had higher specific and lower unspecific mitogen IFN-γ responses compared to non-TB controls, the association between diabetes and IFN-γ did not depend on TB status.

Conclusion: Diabetes is associated with lower levels of Mtb antigen-specific IFN-γ, and the validity of IFN- γ tests for LTBI may be questionable in individuals with diabetes.

Background: We evaluated the distribution and vertical transmission of bacterial vaginal infections in asymptomatic pregnant women.

Methods: We performed multiplex PCR on secretions collected on cervical swabs from pregnant women at over 36 weeks of gestation and on oral secretions collected from their neonates immediately after delivery. We detected sexually transmitted infections (STIs) with the following 6 species: Trichomonas vaginalis, Mycoplasma hominis, Mycoplasma genitalium, Chlamydia trachomatis, Neisseria gonorrhoeae, and Ureaplasma urealyticum.

Results: Infectious agents were detected in 64 of 455 pregnant women (14.1%) and in 11 neonates (2.4%). The rate of vertical transmission was 17.2% and all the infectious agents detected in neonates were concordant with those found in their mothers. U. urealyticum was the most frequently detected in the maternal genitalia, followed by M. hominis. Women who were in labor for a longer period of time had a higher risk of vertically transmitting STI agents to their neonates.

Conclusions: Vertical transmission of bacterial STIs from mothers to their infants is possible at delivery and influenced by the duration of labor. STIs should be diagnosed in pregnant women to prevent vertical transmission from the mother to the infant at the time of delivery.

Introduction: Bacterial meningitis is a serious disease with a mortality rate of 15-20% in adults. We conducted a population-based study of bacterial meningitis in adults (≥ 16 y) in Iceland, 1995-2010.

Methods: Cases were identified based on positive bacterial cultures from cerebrospinal fluid (CSF) and/or the ICD codes for bacterial meningitis. Medical charts were reviewed and outcomes were assessed using the national population registry. The study period was divided into 2 equal parts, 1995-2002 and 2003-2010, before and after implementation of routine childhood vaccination against serogroup C meningococci, respectively.

Results: In total, 111 episodes occurred in 110 individuals. The most common causative organisms were Neisseria meningitidis (41%) and Streptococcus pneumoniae (30%). Only 30% of the patients presented with the classical symptom triad of fever, neck stiffness, and an altered mental status. The overall incidence was 3.2/100,000 inhabitants/y, and dropped significantly between the first and second halves of the study (p = 0.03). This drop was due to a reduced incidence of N. meningitidis meningitis: 34 and 12 cases in the first and second periods, respectively (p = 0.006). The incidence of meningitis caused by S. pneumoniae remained unchanged. The case fatality rates were 18% and 13% in the first and second halves of the study, respectively (difference not significant).

Conclusions: The incidence of bacterial meningitis has decreased since the implementation of meningococcal C vaccination in 2002. However, the case fatality rate has remained unchanged.

Background: In recent years, the clinical use of interferon gamma release assays (IGRAs) has increased exponentially, while their indications remain controversial given difficulties in interpretation. Four indications were recommended by the French National Authority for Health (HAS) in 2006. We evaluated the utilization of the QuantiFERON-TB Gold In-Tube (QFT-IT) test over a 1-y period in a French university hospital and the impact of IGRA results in particular.

Methods: The QFT-IT tests requested in 2009 were analysed retrospectively, excluding those from the Occupational Health Department, the Regional Tuberculosis Centre, and rheumatology consultations for which the indications were clearly defined.

Results: Three hundred and sixty QFT-IT tests were analysed. The interpretation was frequently problematic given the inclusion of a significant proportion of patients over 80 y of age (11%), immunocompromised patients (43%), and patients with a known history of tuberculosis (6%). The indications failed to comply with HAS recommendations in 42% of cases (151/360), i.e. 14% of all QFT-IT tests in 2009. Thirty-seven percent of request forms were related to suspected pulmonary tuberculosis. In the case of a positive QFT-IT test, the clinical decision-making was changed in 58% of cases when the indications met the HAS recommendations, compared with only 16% if they did not (p < 0.005).

Conclusion: When the indications do not meet the health authority recommendations, the diagnostic value of the IGRA remains limited.