Risk factors,clinical course and outcomes of pregnancy-related group A streptococcal infections: retrospective 13-year cohort study

Objectives

To investigate the incidence, risk factors, clinical course and outcomes of pregnancy-related group A streptococcus (GAS) infection.

脊柱内固定术后感染的危险因素分析及对策

目的探讨脊柱内固定术后感染的危险因素及对策。方法回顾性分析2012年1月至12月我科472例行脊柱内固定手术患者的病例资料,均为脊柱后路手术,其中9例术后伤口感染,接受伤口清创引流手术,未取出内固定及植骨,术后使用敏感抗生素,随访8~19个月(平均11个月),本文回顾性分析术后伤口感染相关危险因素及对策。结果手术时间100~325min;术中失血量200~1 500 mL;术后引流量65~1 350 mL,大多比同期同类手术明显增加。472例患者术后感染共9例,发生率1.91%(9/472)。伤口感染初始征象出现时间为术后10 d(6~16 d)。白细胞总数、血沉及CRP在术后4~7 d明显升高,且维持在高位水平14 d以上。细菌培养显示致病菌主要为常见皮肤菌群。除1例复发(再次使用敏感抗生素治愈)外,其余无临床感染复发征象。结论脊柱术后伤口感染主要发生于后路开放性手术,均为深部感染;术中、术后出血总量大、手术时间长是造成围手术期营养状况差及感染的危险因素。及时清创引流、一期缝合伤口及应用敏感抗生素,可取得良好效果;清创手术不必常规取出内固定物及植骨。     

Risk factors in the pathogenesis of invasive group A streptococcal infections: role of protective humoral immunity

An impressive change in the epidemiology and severity of invasive group A streptococcal infections occurred in the 1980s, and the incidence of streptococcal toxic shock syndrome cases continues to rise. The reason for the resurgence of severe invasive cases remains a mystery-has there been a change in the pathogen or in host protective immunity? To address these questions, we have studied 33 patients with invasive infection caused by genotypically indistinguishable M1T1 strains of Streptococcus pyogenes who had different disease outcomes. Patients were classified as having severe (n = 21) and nonsevere (n = 12) invasive infections based on the presence or absence of shock and organ failure. Levels of anti-M1 bactericidal antibodies and of anti-streptococcal superantigen neutralizing antibodies in plasma were significantly lower in both groups than in age- and geographically matched healthy controls (P < 0.01). Importantly, the levels of these protective antibodies in plasma samples from severe and nonsevere invasive cases were not different. Together the data suggest that low levels of protective antibodies may contribute to host susceptibility to invasive streptococcal infection but do not modulate disease outcome. Other immunogenetic factors that regulate superantigen responses may influence the severity of systemic manifestations associated with invasive streptococcal infection.     

Incidence and clinical variables associated with streptococcal throat infections: a prospective diagnostic cohort study

Background

Management of pharyngitis is commonly based on features which are thought to be associated with Lancefield group A beta-haemolytic streptococci (GABHS) but it is debatable which features best predict GABHS. Non-group A strains share major virulence factors with group A, but it is unclear how commonly they present and whether their presentation differs.

Aim

To assess the incidence and clinical variables associated with streptococcal infections.

Design and setting

Prospective diagnostic cohort study in UK primary care.

Method

The presence of pathogenic streptococci from throat swabs was assessed among patients aged ≥5 years presenting with acute sore throat.

Results

Pathogenic streptococci were found in 204/597 patients (34%, 95% CI = 31 to 38%): 33% (68/204) were non-group A streptococci, mostly C (n = 29), G (n = 18) and B (n = 17); rarely D (n = 3) and Streptococcus pneumoniae (n = 1). Patients presented with similar features whether the streptococci were group A or non-group A. The features best predicting A, C or G beta-haemolytic streptococci were patient’s assessment of severity (odds ratio [OR] for a bad sore throat 3.31, 95% CI = 1.24 to 8.83); doctors’ assessment of severity (severely inflamed tonsils OR 2.28, 95% CI = 1.39 to 3.74); absence of a bad cough (OR 2.73, 95% CI = 1.56 to 4.76), absence of a coryza (OR 1.54, 95% CI = 0.99 to 2.41); and moderately bad or worse muscle aches (OR 2.20, 95% CI = 1.41 to 3.42).

Conclusion

Non-group A strains commonly cause streptococcal sore throats, and present with similar symptomatic clinical features to group A streptococci. The best features to predict streptococcal sore throat presenting in primary care deserve revisiting.     

肝部分切除患者术后并发感染的相关影响因素分析

目的探讨肝部分切除患者术后感染的影响因素,为预防肝切除术后感染的发生提供理论依据。方法回顾性分析2007年12月至2012年12月210例诊断为肝癌行肝部分切除患者的临床资料,将其分为感染组和非感染组,比较2组相关临床资料,采用logistic逐步回归法进行统计学分析,筛选影响术后感染的关键性变量。结果肝部分切除术后有30例感染,感染率为14.3%。患者的年龄、手术时间、失血量、有无输血及有无肝硬化,2组比较差异均有统计学意义(P0.05)。logistic回归分析显示,患者的年龄、手术时间、失血量、有输血及肝硬化是肝部分切除术后感染的关键危险因素。结论年龄大于等于60岁、手术时间大于等于5 h、失血量大于等于3 000 mL、有输血及合并肝硬化是肝部分切除术后感染并发症的关键危险因素。     

Risk factors for and clinical implications of mixed Candida/bacterial bloodstream infections

Mixed Candida/bacterial bloodstream infections (BSIs) have been reported to occur in more than 23% of all episodes of candidaemia. However, the clinical implications of mixed Candida/bacterial BSIs are not well known. We performed a retrospective case-control study of all consecutive patients with candidaemia over a 5-year period to determine the risk factors for and clinical outcomes of mixed Candida/bacterial BSIs (cases) compared with monomicrobial candidaemia (controls). Thirty-seven (29%) out of 126 patients with candidaemia met the criteria for cases. Coagulase-negative staphylococci were the predominant bacteria (23%) in cases. In multivariate analysis, duration of previous hospital stay >7 weeks (odds ratio (OR), 2.86; 95% confidence interval (CI), 1.09–7.53), prior antibiotic therapy ≥7 days (OR, 0.33; 95% CI, 0.14–0.82) and septic shock at the time of candidaemia (OR, 2.60; 95% CI, 1.14–5.93) were significantly associated with cases. Documented clearance of candidaemia within 3 days after initiation of antifungal therapy was less frequent in cases (63% vs. 84%; p = 0.035). The difference in the rate of treatment failure at 2 weeks was not significant between cases (68%) and controls (62%; p = 0.55). The crude mortality at 6 weeks and survival through 100 days did not differ between the two patient groups (p = 0.56 and p = 0.80, respectively). Mixed Candida/bacterial BSIs showed a lower clearance rate of candidaemia during the early period of antifungal therapy, although the treatment response and survival rate were similar regardless of concurrent bacteraemia. Further studies on the clinical relevance of species-specific Candida-bacterial interactions are needed.     

外周中心静脉置管导管相关感染的相关因素与预防

由外周中心静脉置管（peripherally inserted central catheters,PICC）技术是从头静脉、贵要静脉或肘正中静脉插管到达上腔静脉（深静脉）,是需长时间肠外营养或肿瘤患者化疗常采用的静脉输注途径.但由于PICC置管的时间较长,可导致置管后相关感染的发生,导管相关感染（catheter-related infection,CRI）是长期置管的常见并发症,PICC置管并发症以机械性静脉炎、感染和导管阻塞等较为常见[1].     

Serotypes and clinical manifestations of group B streptococcal infections in western Sweden

Objectives   To study the serotype distributions of group B streptococci (GBS) isolated from blood and cerebrospinal fluid and from the genital tract of pregnant women and to investigate any possible relation between serotype, age and clinical manifestation.
Methods   Invasive strains were collected from 1988 to 1997 and genital strains from 1995 to 1996. Strains of GBS were serotyped with coagglutination. Clinical data were obtained from hospital notes.
Results   A total of 144 invasive strains, 78 from neonates and infants and 66 from adults, were serotyped. The most common isolates from neonates and infants were types III (62%), Ia (18%), and V (9%). The most common isolates from adults were types III (29%), Ib (23%), V (21%) and II (15%). A majority of the adults (94%) had an underlying medical condition. The most common serotypes of the 114 strains isolated from the genital tract of pregnant women were types III (32%), V (22%), Ia (13%), Ib (13%) and II (11%).
Conclusions   Serotype III was the single most frequent GBS isolate from infants and adults. Serotype V, which appeared first in 1992, was the third most frequent isolate. A vaccine containing five GBS capsular polysaccharides appears to be appropriate for the Swedish population.     

Risk factors for sporadic Campylobacter infections: results of a case-control study in southeastern Norway.

In 1989 and 1990, a case-control study designed to identify risk factors for sporadic infections with thermotolerant Campylobacter bacteria was conducted in three counties in southeastern Norway. The investigation was confined to infections which were acquired in Norway. A total of 52 bacteriologically confirmed cases and 103 controls matched by age, sex, and geographic region were interviewed. The following risk factors were found to be independently associated with illness in conditional logistic regression analysis: consumption of sausages at a barbecue (odds ratio [OR] = 7.64; P = 0.005), daily contact with a dog (OR = 4.26; P = 0.024), and eating of poultry which was brought into the house raw (frozen or refrigerated) (OR = 3.20; P = 0.024). The risk associated with consumption of sausages at a barbecue could not be attributed to cross-contamination from poultry products. By univariate analysis, consumption of poultry which was brought raw and frozen was associated with illness (OR = 2.42; P = 0.042), even though freezing substantially reduces the number of viable campylobacters. When poultry consumption was examined by country of origin, eating of poultry produced in Denmark or Sweden was strongly associated with illness (OR = 13.66; P = 0.014), whereas consumption of poultry produced in Norway was not (OR = 1.33; P = 0.41).     

Risk factors for late infections after allogeneic hematopoietic stem cell transplantation from a matched related donor.

After allogeneic hematopoietic stem cell transplantation (HSCT), early infections represent a major cause of morbidity and mortality but little information has been previously reported on late infections. Late infection incidence and risk factors were retrospectively determined in 196 long-term survivors after HLA matched related HSCT. Patients transplanted for aplastic anemia, chronic myelogenous leukemia (CML), and acute myelogenous leukemia (AML) were included. Median follow-up was 8 years. Thirty patients died beyond the first year, causes of death were relapse (n = 10) and infections (n = 19, associated with graft-versus-host disease [GVHD] in 16 patients). Late severe bacterial (LSB) and fungal infections occurred in 30 and 8 patients, yielding to an 8-year cumulative incidence of 15 (95%CI: 10-20) and 4% (95%CI: 1-6), respectively. The majority of viral infections were hepatitis C (HCV) and VZV (8-year cumulative incidence: 10 (95%CI: 5-14) and 27% (95%CI: 20-34), respectively. Three risk factors for LSB have been identified in multiple Cox analysis: CMV status (positive recipient and negative donor) (hazard ratio [HR]: 2.5, 95%CI: 1.1-5.9, P = .033), irradiation-based conditioning regimen (HR: 3.1, 95%CI: 1.2-7.8, P = .016), and extensive chronic GVHD (cGVHD; HR: 2.9, 95%CI: 1.3-6.9, P = .013). Extensive cGVHD was the only risk factor for non-HCV viral infections in patients transplanted for AML or CML (HR: 2.7, 95%CI: 1.4-5.1, P = .002). After HSCT, patients remain at high risk of infections even late after transplantation, in particular, with the above risk factors, and required a prolonged follow-up.     

Risk factors for central venous catheter-related infections in general surgery.

BACKGROUND AND PURPOSE: Central venous catheter (CVC) infection is a common problem during hospitalization and nosocomial bloodstream infection in these patients is associated with increased morbidity, mortality, and health care cost. This prospective study examined the risk factors of CVC-related infections. METHODS: During a 6-month period, a total of 281 patients who underwent central venous catheterization after general surgery were enrolled. RESULTS: The mean duration from CVC insertion to the development of infection was 7.12 days. The rate of bloodstream infection without isolation of the same organism from the catheter was 1.4% (4/281). The rate of catheter-related bloodstream infection was 6.0% (17/281). The rate of catheter bacteremia, defined as positive culture from a catheter blood sample in a patient without signs of infection, was 8.5% (24/281). The incidence of catheter-related bloodstream infection was 7.5/1000 catheter-days. Risk factors for catheter-related infection on univariate analysis included place of insertion (operating room or surgical ward), total parenteral nutrition (TPN), more than 3 tubings, and duration of catheterization. TPN was a significant risk factor in the logistic regression analysis. CONCLUSIONS: Established infection control guidelines should be rigorously observed with regard to catheter use and various risk factors controlled to prevent the occurrence of CVC-related infection, especially in patients receiving TPN.     

ICU院内病毒感染危险因素探讨

目的 分析ICU病房并发院内病毒感染的危险因素,以指导临床治疗.方法 对200例于ICU病房接受治疗的患者的临床资料进行回顾性分析,并将患者分为住院期间未发生院内病毒感染的未感染组(患者92例)和住院期间发生院内病毒感染的感染组(患者108例),统计两组患者临床资料,对导致院内感染的危险因素进行分析.结果 经单因素及logistic多因素分析显示,年龄＞ 60岁、住院时间＞14d、插管时间＞7d、糖尿病及低蛋白血症均为导致患者发生院内感染的危险因素(P＜0.05).而在发生院内感染的患者中,以呼吸系统感染者居多.结论 导致ICU院内感染的危险因素较多,临床应注意以上危险因素的防范.     

Pathogenesis of group A streptococcal infections

Group A streptococci are model extracellular gram-positive pathogens responsible for pharyngitis, impetigo, rheumatic fever, and acute glomerulonephritis. A resurgence of invasive streptococcal diseases and rheumatic fever has appeared in outbreaks over the past 10 years, with a predominant M1 serotype as well as others identified with the outbreaks. emm (M protein) gene sequencing has changed serotyping, and new virulence genes and new virulence regulatory networks have been defined. The emm gene superfamily has expanded to include antiphagocytic molecules and immunoglobulin-binding proteins with common structural features. At least nine superantigens have been characterized, all of which may contribute to toxic streptococcal syndrome. An emerging theme is the dichotomy between skin and throat strains in their epidemiology and genetic makeup. Eleven adhesins have been reported, and surface plasmin-binding proteins have been defined. The strong resistance of the group A streptococcus to phagocytosis is related to factor H and fibrinogen binding by M protein and to disarming complement component C5a by the C5a peptidase. Molecular mimicry appears to play a role in autoimmune mechanisms involved in rheumatic fever, while nephritis strain-associated proteins may lead to immune-mediated acute glomerulonephritis. Vaccine strategies have focused on recombinant M protein and C5a peptidase vaccines, and mucosal vaccine delivery systems are under investigation.     

Risk factors for recurrence and death after bacteraemia: a population-based study

Although most bacteraemic outcome studies have focused on mortality, a repeated episode(s) is another important outcome of bacteraemia. We sought to characterize patient factors and microbial species associated with recurrence and death from bacteraemia. Population-based surveillance for bacteraemia was conducted in a Canadian health region during 2000–2008. Episodes of bacteraemia were extracted and characterized. Transition intensities of both recurrence and death were estimated by separate multivariate Cox proportional hazards models. We identified 9713 patients with incident episodes of bacteraemia. Within 1 year: 892 (9.2%) had recurrent bacteraemia, 2401 (24.7%) had died without a recurrent episode and 330 (3.4%) had died after a recurrent episode. Independent risk factors for recurrence within 1 year (hazard ratio; 95% confidence interval) were: increasing Charlson comorbidity scores (score 1–2: 2.2; 1.8–2.7 and score 3+: 3.4; 2.8–4.2), origin of infection (nosocomial: 2.1; 1.8–2.6 and healthcare-associated: 2.4; 2.0–2.8), microorganism (polymicrobial: 1.5; 1.2–2.0 and fungal: 2.8; 1.9–4.2) and focus of infection (verified urogenital: 0.4; 0.3–0.6). Independent risk factors for death within 1 year included: a recurrent bacteraemic episode 3.6 (3.1–4.0), increasing age and different foci of infection. This study identifies patient groups at risk of having a recurrent episode and dying from these infections. It adds recurrent bacteraemia as an independent risk factor of death within 1 year and may help to target patients for prevention or changes in management.