Nonbacterial Causes Research Articles

Procalcitonin level as an aid for the diagnosis of bacterial infections following pediatric cardiac surgery

PurposeThe aim of the present study was to determine if blood procalcitonin can serve as an aid to differentiate between bacterial and nonbacterial cause of fever in children after cardiac surgery. Materials and MethodsA nested case-control study of children who underwent open cardiac surgery in critical care units of fourth-level pediatric hospital was performed. Blood samples for procalcitonin level were collected 1 day before operation; 1 hour postoperation; on postoperative days 1, 2, and 5; and on the day of fever, when it occurred. ResultsOf 665 children who underwent cardiac bypass surgery, 126 had a febrile episode postoperatively, 47 children with a proven bacterial infection and 79 without bacterial infection. Among the 68 children in whom fever developed within the first 5 postoperative days, procalcitonin level at fever day was significantly higher in those with bacterial infection (n = 16) than in those without infection (n = 52). Similarly, among the 58 children in whom fever developed after day 5 postoperation, a significant difference was found in procalcitonin level at fever day between those with (n = 31) and without (n = 27) bacterial infection. ConclusionDuring the critical early and late periods after cardiac surgery in children, procalcitonin level may help to differentiate patients with bacterial infection from patients in whom the fever is secondary to nonbacterial infectious causes.

A systematic review on the diagnosis of pediatric bacterial pneumonia: when gold is bronze.

BackgroundIn developing countries, pneumonia is one of the leading causes of death in children under five years of age and hence timely and accurate diagnosis is critical. In North America, pneumonia is also a common source of childhood morbidity and occasionally mortality. Clinicians traditionally have used the chest radiograph as the gold standard in the diagnosis of pneumonia, but they are becoming increasingly aware that it is not ideal. Numerous studies have shown that chest radiography findings lack precision in defining the etiology of childhood pneumonia. There is no single test that reliably distinguishes bacterial from non-bacterial causes. These factors have resulted in clinicians historically using a combination of physical signs and chest radiographs as a ‘gold standard’, though this combination of tests has been shown to be imperfect for diagnosis and assigning treatment. The objectives of this systematic review are to: 1) identify and categorize studies that have used single or multiple tests as a gold standard for assessing accuracy of other tests, and 2) given the ‘gold standard’ used, determine the accuracy of these other tests for diagnosing childhood bacterial pneumonia.Methods and FindingsSearch strategies were developed using a combination of subject headings and keywords adapted for 18 electronic bibliographic databases from inception to May 2008. Published studies were included if they: 1) included children one month to 18 years of age, 2) provided sufficient data regarding diagnostic accuracy to construct a 2×2 table, and 3) assessed the accuracy of one or more index tests as compared with other test(s) used as a ‘gold standard’. The literature search revealed 5,989 references of which 256 were screened for inclusion, resulting in 25 studies that satisfied all inclusion criteria. The studies examined a range of bacterium types and assessed the accuracy of several combinations of diagnostic tests. Eleven different gold standards were studied in the 25 included studies. Criterion validity was calculated for fourteen different index tests using eleven different gold standards. The most common gold standard utilized was blood culture tests used in six studies. Fourteen different tests were measured as index tests. PCT was the most common measured in five studies each with a different gold standard.ConclusionsWe have found that studies assessing the diagnostic accuracy of clinical, radiological, and laboratory tests for bacterial childhood pneumonia have used a heterogeneous group of gold standards, and found, at least in part because of this, that index tests have widely different accuracies. These findings highlight the need for identifying a widely accepted gold standard for diagnosis of bacterial pneumonia in children.

Diet and acne: a review of the evidence

Pharmaceutical acne treatments are costly and have potentially severe side-effects. Adolescent acne is typically the result of clogged, infected, pilosebaceous follicles. Adults may experience fewer comedones and more inflammatory lesions. 1 Normally, sebum travels up the follicle to the skin surface. Hormones may increase sebum production and cause follicular cells to hyperproliferate and block the follicular opening, forming a comedo. 4 Complete follicle blockage results in closed comedones (i.e. “whiteheads”), whereas incomplete blockage results in open comedones (“blackheads”). Comedo formation typically occurs over the course of 2–3 weeks. Acne may manifest in the form of noninflammatory comedones, superficial inflammatory lesions (papules, pustules), and/or deeper inflammatory lesions (nodules, cysts). Inflammatory lesion formation occurs most commonly when Propionibacterium acnes colonizes the pilosebaceous unit, triggering follicular rupture and a neutrophil cascade. 5

Ecthyma-gangrenosum-like lesions associated with methicillin-resistant Staphylococcus aureus infection

Ecthyma gangrenosum (EG) manifests as a skin lesion and is commonly associated with Pseudomonas aeruginosa septicemia in immunocompromised patients. Other viral, fungal and bacterial agents can also cause EG. The first clinical observation is grouped vesicles with surrounding erythema. Within a few days, they evolve into a gangrenous ulcer with a black/gray eschar surrounded by an erythematous halo. Herein, we present a patient with chronic obstructive pulmonary disease who developed EG-like lesions due to methicillin-resistant Staphylococcus aureus infection while he was in the intensive care unit.

Use of plasma C-reactive protein, procalcitonin, neutrophils, macrophage migration inhibitory factor, soluble urokinase-type plasminogen activator receptor, and soluble triggering receptor expressed on myeloid cells-1 in combination to diagnose infections: a prospective study

IntroductionAccurate and timely diagnosis of community-acquired bacterial infections in patients with systemic inflammation remains challenging both for clinician and laboratory. Combinations of markers, as opposed to single ones, may improve diagnosis and thereby survival. We therefore compared the diagnostic characteristics of novel and routinely used biomarkers of sepsis alone and in combination.MethodsThis prospective cohort study included patients with systemic inflammatory response syndrome who were suspected of having community-acquired infections. It was conducted in a medical emergency department and department of infectious diseases at a university hospital. A multiplex immunoassay measuring soluble urokinase-type plasminogen activator (suPAR) and soluble triggering receptor expressed on myeloid cells (sTREM)-1 and macrophage migration inhibitory factor (MIF) was used in parallel with standard measurements of C-reactive protein (CRP), procalcitonin (PCT), and neutrophils. Two composite markers were constructed – one including a linear combination of the three best performing markers and another including all six – and the area under the receiver operating characteristic curve (AUC) was used to compare their performance and those of the individual markers.ResultsA total of 151 patients were eligible for analysis. Of these, 96 had bacterial infections. The AUCs for detection of a bacterial cause of inflammation were 0.50 (95% confidence interval [CI] 0.40 to 0.60) for suPAR, 0.61 (95% CI 0.52 to 0.71) for sTREM-1, 0.63 (95% CI 0.53 to 0.72) for MIF, 0.72 (95% CI 0.63 to 0.79) for PCT, 0.74 (95% CI 0.66 to 0.81) for neutrophil count, 0.81 (95% CI 0.73 to 0.86) for CRP, 0.84 (95% CI 0.71 to 0.91) for the composite three-marker test, and 0.88 (95% CI 0.81 to 0.92) for the composite six-marker test. The AUC of the six-marker test was significantly greater than that of the single markers.ConclusionCombining information from several markers improves diagnostic accuracy in detecting bacterial versus nonbacterial causes of inflammation. Measurements of suPAR, sTREM-1 and MIF had limited value as single markers, whereas PCT and CRP exhibited acceptable diagnostic characteristics.Trial registrationNCT 00389337

Role of antimicrobial therapy in acute exacerbations of chronic obstructive pulmonary disease.

To define the role of antimicrobial therapy in the treatment of acute bronchitic exacerbations of chronic obstructive pulmonary disease (COPD) through review of placebo-controlled clinical trials. Specificalty, to determine the benefit of antimicrobial therapy on patient outcome. Placebo-controlled dinical trials identified by MEDLINE search (1957-December 1999). All placebo-controlled clinical trials that included COPD patients with no evidence of pneumonia or underlying asthma were included in the evaluation. The role of antimicrobial agents in the treatment of acute exacerbations of COPD is controversial. Patients with COPD are often chronically colonized with bacteria, and many exacerbations are due to nonbacterial causes. Four placebo-controlled clinical trials and a meta-analysis have demonstrated significant improvements in outcome for patients treated with an antibiotic versus placebo. In contrast, six studies failed to demonstrate statistical differences, possibly due to the small sample size and the subjectivity of outcome measures. Overall, the data suggest that the benefit of antimicrobial therapy in acute exacerbations of COPD may be related to exacerbation severity. Antimicrobial agents may have a beneficial effect in the treatment of acute exacerbations of COPD in certain patients. Pending further research in this area, we recommend antimicrobial therapy only for COPD patients with acute bronchitic exacerbations characterized by increased dyspnea, sputum volume, and purulence.

Role of Antimicrobial Therapy in Acute Exacerbations of Chronic Obstructive Pulmonary Disease

OBJECTIVE:To define the role of antimicrobial therapy in the treatment of acute bronchitic exacerbations of chronic obstructive pulmonary disease (COPD) through review of placebo-controlled clinical trials. Specifically, to determine the benefit of antimicrobial therapy on patient outcome.DATA SOURCES:Placebo-controlled clinical trials identified by MEDLINE search (1957–December 1999).STUDY SELECTION AND DATA EXTRACTION:All placebo-controlled clinical trials that included COPD patients with no evidence of pneumonia or underlying asthma were included in the evaluation.DATA SYNTHESIS:The role of antimicrobial agents in the treatment of acute exacerbations of COPD is controversial. Patients with COPD are often chronically colonized with bacteria, and many exacerbations are due to nonbacterial causes. Four placebo-controlled clinical trials and a meta-analysis have demonstrated significant improvements in outcome for patients treated with an antibiotic versus placebo. In contrast, six studies failed to demonstrate statistical differences, possibly due to the small sample size and the subjectivity of outcome measures. Overall, the data suggest that the benefit of antimicrobial therapy in acute exacerbations of COPD may be related to exacerbation severity.CONCLUSIONS:Antimicrobial agents may have a beneficial effect in the treatment of acute exacerbations of COPD in certain patients. Pending further research in this area, we recommend antimicrobial therapy only for COPD patients with acute bronchitic exacerbations characterized by increased dyspnea, sputum volume, and purulence.

C-reactive protein, Il-6 and procalcitonin as infection parameters in children with oncologic diseases

Due to anti-neoplastic therapy, there is a high incidence of infections and fever in pediatric patients with malignant disease. We have searched for parameters that may be of value in the early diagnosis of infection, in discriminating between bacterial and non-bacterial causes and for monitoring the response to antimicrobiotic therapy. 46 febrile episodes in 33 children with malignant diseases under anti-neoplastic therapy, aged 0.5 to 17 years, were included. Each patient was supplied with a central venous catheter (Hickman catheter). Blood was taken for the evaluation of C-reactive-protein (CRP), Interleukin-6 (IL-6) and Procalcitonin (PCT). Laboratory data included WBC, blood cultures, as well as microbiologic and serologic tests for important infectious agents. Patients were grouped as follows: 1. Patients with febrile diseases and positive blood cultures, 2. Patients with localized bacterial or mycotic infections and negative blood cultures, 3. Patients with fever of unknown origin, 4. Patients with viral infections, 5. Control group. CRP and IL-6 were more sensitive than PCT in detecting bacterial and mycotic diseases in leukopenic children, because of low PCT-levels in patients with localized infections. IL-6 values were high shortly after onset of fever and decreased under sufficient antimicrobiotic therapy until day three. Because of the quick response, IL-6 may be helpful in monitoring antimicrobiotic therapy. Using Procalcitonin-levels, we were not able to distinguish between localized bacterial and viral infection in leukocytopenic patients.

Causes of Fever in Patients Infected with Human Immunodeficiency Virus Who Were Admitted to Boston City Hospital

We prospectively studied causes of fever in patients with human immunodeficiency virus (HIV) infection that required admission to a municipal hospital. A total of 168 HIV-infected persons were admitted for 220 episodes of fever: 72% were male, 80% were nonwhite, 65% reported prior injection drug use, and 74% had a baseline CD4 lymphocyte count of < 200/mm3. Bacterial infections, principally pneumonia, accounted for > 60% of the episodes; Streptococcus pneumoniae and Staphylococcus aureus were most commonly isolated. Pneumocystis carinii pneumonia (PCP) and disseminated infection with Mycobacterium avium complex (MAC) comprised 53% of the remaining sources of fever. In comparison with episodes of fever due to nonbacterial causes, those associated with common bacterial infections were significantly more likely to involve patients with a history of injection drug use (P = .02), higher admission leukocyte count (P < .004), shorter duration of fever (P = .003), shorter hospital stays (P = .0001), and a CD4 count of > 100/mm3 (P = .002). We conclude that bacterial infection, especially pneumonia, is a common cause of fever in HIV-infected patients admitted to our hospital. Patients with bacterial infections are more likely to report a history of injection drug use and have CD4 counts of > 100/mm3, shorter duration of fever, decreased length of hospitalization, and lower mortality than patients with fever due to PCP, disseminated MAC infection, or other causes.

MODS/SIRS: result of an overwhelming inflammatory response?

Multiple organ dysfunction syndrome and the systemic inflammatory response syndrome are expressions of an inappropriate, generalized inflammatory response to severe inflammatory stimuli, which may be bacterial or nonbacterial in nature. The clinical signs and symptoms, morphologic alterations, and changes in oxygen transport seem to be the direct effect of phagocyte activation. So far, identifying the microorganisms and neutralizing their toxins has not been helpful in improving prognosis. As an essential adjunct to treating the bacterial or nonbacterial causes, finding safe ways of modulating the phagocyte response should be considered.

A foodborne outbreak causing a cholinergic syndrome

We report a foodborne outbreak causing a cholinergic syndrome in three members of a family. The clinical presentation was characterized by nausea, vomiting, abdominal pain, and weakness. Physical examination revealed evidence of peripheral motor weakness and decreased level of consciousness in all three patients. Bradycardia, hypotension, and seizures occurred in two patients. Although initial therapy included administration of antitoxin for possible botulism, subsequent investigation revealed evidence of accidental organophosphate (fensulfothion) poisoning. The ubiquitous use of organophosphates as agricultural and household insecticides has ensured their continuing importance as causes of foodborne poisoning in both developed and developing countries. Physicians must remain alert to the possibility of non-bacterial causes of foodborne outbreaks in order to initiate prompt and appropriate investigations and specific therapy.

Lung infections in children.

Airway infections in children is a considerably broad topic. This discussion focuses on several common nonbacterial causes of lower respiratory tract infection in children, including respiratory syncytial virus, Mycoplasma pneumoniae, and Chlamydia pneumoniae. In addition, the occurrence of two important bacterial causes of lower respiratory illness (Bordetella pertussis and Mycobacterium tuberculosis) is increasing. This review focuses on current information on the prophylaxis, treatment, and diagnosis of these agents. Finally, consideration is given to infections in immunocompromised children: the effects of respiratory syncytial virus infections in immunosuppressed transplant patients, and prevention and diagnosis of opportunistic infections (including Pneumocystis carinii) in children with human immunodeficiency virus.

Results of a questionnaire among Dutch urologists and general practitioners concerning diagnostics and treatment of patients with prostatitis syndromes.

By means of a questionnaire, all Dutch urologists (n = 250, 136 responded) and regional general practitioners (GPs; n = 400, 176 responded) were contacted concerning current diagnostics and treatment modalities applied in patients with prostatitis syndromes. The patients seen by urologists seem to be younger (30-40 years) and they mostly complain of pain in the perineum, penis or scrotum, while GPs see older patients (> 40 years) mainly presenting with micturition complaints. Urologists think nonbacterial causes (40%) most important, while GPs mention bacterial infections (63%) as the most important cause. The first choice of therapy is antibiotics, mostly co-trimoxazole Sulfatrim for 3 weeks, but patients seen by urologists are more resistant to this therapy. If not successful, urologists frequently prescribe a second course with antibiotics. However, many urologists think psychosomatic causes are an important factor in the etiology of prostatitis.

Noninfluenza respiratory virus infection in long-term care facilities.

Acute respiratory infections are a common problem in the general population, particularly during the winter months. Nonbacterial causes such as viruses, mycoplasma, and Chlamydia predominate,’ but with the exception of influenza virus, comprehensive studies are lacking that define the impact of these agents on the elderly. The institutionalized elderly represent a special subgroup of older persons who are prone to excess morbidity and mortality with respiratory infections. Each year, many residents of long-term care facilities become ill with respiratory illnesses not proven to be influenza, either by culture or serology. Recent studies have demonstrated the importance of a variety of viruses, including respiratory syncytial virus and parainfluenza, which can cause significant disease in this high-risk population. This article will review several of these epidemiologic studies and discuss in detail a number of viruses that are emerging as significant pathogens in the long-term care facility, with attention to modes of transmission and infection control.

Measurement of lactic acid in cerebrospinal fluid of patients with infections of the central nervous system.

The concentration of lactic acid in cerebrospinal fluid (CSF) was determined by gas-liquid chromatography in 205 samples of CSF from 97 patients with or without infections of the central nervous system. Patients without infection or those with nonbacterial (presumably viral) meningitis consistently had low concentrations of lactic acid in CSF (i.e., less than or equal to 35 mg/100 ml), whereas patients with bacterial or tuberculosis meningitis consistently had concentrations of lactic acid in CSF of greater than 35 mg/100 ml. There was no overlap in concentrations of lactic acid between these two groups. Further, lactic acid concentrations in CSF from patients partially treated for meningitis were generally greater than 35 mg/100 ml through the third day of therapy and, thereafter, progressively declined to less than 20 mg/100 ml by the seventh to 10th day of therapy. Relapse of bacterial infection was consistently documented by a recurrence of an increased concentration of lactic acid in CSF. Preliminary experience with determination of the concentration of lactic acid in CSF suggests that it may be useful in distinguishing bacterial (with or without positive cultures) and tuberculous meningitis from meningitis due to nonbacterial causes.

Viral and mycoplasma pneumonias.

Influenza and infection with Mycoplasma pneumoniae are common nonbacterial causes of pneumonia. Pneumonia also sometimes occurs as a complication of a viral infection such as varicella. This article describes the clinical picture seen with each type of infection and gives current recommendations for prophylaxis and therapy.

Resistance of the Fowl (Gallns domesticus) to Invasion by its Intestinal Flora: I. The Effect of Hormonal Bursectomy on the Invasiveness of the Intestinal Microflora of the Fowl

Attempts have been made to induce a lethal bacteraemia in fowls by suppressing with hormones the development of the bursa of Fabricius. Except for some mortality from non-bacterial causes, the bursectomized birds grew well and, with one exception, showed no obvious ill effects from an intravenous injection of large numbers of intestinal bacteria. Impaired antibody production was shown to result from bursectomy but in spite of this the intestinal flora did not become invasive.

Post-traumatic crepitation falsely suggesting gas gangrene.

The appearance of extensive soft-tissue gas after trauma is often interpreted as a sign of gas gangrene. Three patients with minor finger wounds were referred for treatment of gas gangrene because widespread subcutaneous crepitus developed in each. None, however, had clostridial myositis or any other apparent infection. Thus, posttraumatic soft-tissue gas does not necessarily indicate gas gangrene. Other possible causes of crepitation include dissemination of trapped environmental air by muscular activity, accumulation of gas generated by the chemical reaction between a metallic foreign body and tissue fluid and spread of compressed air accidentally injected into the wound. Knowledge of the various bacterial and nonbacterial causes of soft-tissue gas permits proper treatment and prevents unwarranted extensive debridement, amputation or hyperbaric oxygenation.