Apparent Source Of Infection Research Articles

Streptococcus agalactiae infective endocarditis in Canada: a multicenter retrospective nested case control analysis

BackgroundInfective endocarditis (IE) caused by Streptococcus agalactiae (GBS) is increasingly reported and associated with an aggressive course and high mortality rate. Existing literature on GBS IE is limited to case series; we compared the characteristics of patients with GBS IE to patients with GBS bacteremia without IE to identify risk factors for development of IE.MethodsA nested case–control study in a cohort of adult patients with GBS bacteremia over a 18-year period was conducted across seven centres in three Canadian cities. A chart review identified patients with possible or definite IE (per Modified Duke Criteria) and patients with IE were matched to those without endocarditis in a 1:3 fashion. Multivariate analyses were completed using logistic regression.ResultsOf 520 patients with GBS bacteremia, 28 cases of possible or definite IE were identified (5.4%). 68% (19/28) met criteria for definite IE, surgery was performed in 29% (8/28), and the overall in-hospital mortality rate was 29% (8/28). Multivariate analysis demonstrated that IE was associated with injection drug use (OR = 19.6, 95% CI = 3.39–111.11, p = 0.001), prosthetic valve (OR = 11.5, 95% CI = 1.73–76.92, p = 0.011) and lack of identified source of bacteremia (OR = 3.81, 95% CI = 1.24–11.65, p = 0.019).ConclusionsGBS bacteremia, especially amongst people who inject drugs, those with prosthetic valves, and those with no apparent source of infection, should increase clinical suspicion for IE.

Septic Arthritis of the Temporomandibular Joint without an Apparent Source of Infection: A Case Report

Septic arthritis of the temporomandibular joint (TMJ) is a rare disease that is characterized by preauricular pain, edema, malocclusion, trismus and abscess formation in the TMJ region. An 85-year-old male visited our hospital with the complaint of left-sided TMJ swelling, pain and trismus. Septic arthritis of the left TMJ was diagnosed on the basis of considerable elevation of CRP (Creactive proteins) and CT imaging findings. The patient was treated with oral Faropenem at 450 mg daily, but CRP increased three days after the initial visit. He was hospitalized and treated with intravenous administration of cefazolin at 2 g and clindamycin at 1.2 g daily for six days. Propionibacterium species and Veillonella species grew in a culture of the joint aspirate, but there was no apparent source of infection. After acute infectious symptoms had passed, the patient was treated with oral amoxicillin at 750 mg daily for eight weeks and was instructed to do jaw opening exercise. The patient was discharged on the 11th hospital day. After three weeks of the hospital discharge, the patient healed completely. To avoid serious complications, clinicians should include septic arthritis of the TMJ in the differential diagnosis of preauricular pain, trismus and swelling.

Molecular Epidemiology of Respiratory Viruses in Febrile Infants Under 90 Days Attending Pediatric Emergency Department

Fever is one of the most common presenting complaints in paediatric emergency departments (ED). Acute viral respiratory infection is the most common findings. The aim of this study is to define types of respiratory viruses among febrile infants under 90 days attending to emergency department. Methods: In addition to sepsis workup, nasopharyngeal aspirates were collected from 265 febrile infants without an apparent source of infection. A multiplex PCR assay was used to detect 15 human viral species and subtypes. Results: Overall, 154/265 (58.1%) NPA specimens from febrile infants were positive for at least one human virus. Viral types detected were as follows: (60/265,22.6%) rhinovirus, (50/265,18.9%) respiratory syncytial virus, (28/265,10.6%) parainfluenza virus, (11/265,4.2%) influenza virus, (12/265,4.5%) coronavirus, (10/265,3.8%) metapneumo, (8/265,3%) adenovirus, (2/265,0.75%) enterovirus, and (2/265,0.75%) bocavirus. Co-detection of two viruses or more was also observed. Positive bacterial cultures were reported in 16.5%, 3.5%, and 2.8% of urine, blood and CSF samples respectively. Conclusion: Viral infections are frequent in febrile infants without an apparent source. Testing NPA for molecular identification of viruses in addition to the routine sepsis workup may help more accurate management of febrile infants. This could also limit the unnecessary use of antibiotics, and nosocomial spread of viruses, however, this needs to be further investigated.

Complete and partly unexpected diagnostic findings at 18F-FDG-PET/CT scanning in patients with suspected prosthetic valve endocarditis

A 76-year-old male with previous aortic valve replacement presented with intermittent fever. No apparent source of infection was found at clinical inspection. Blood cultures were positive for Streptococcus anginosus . Infective endocarditis was suspected and transoesophageal echocardiography (TOE) was performed. The exam showed a mildly degenerated bioprosthesis with thickened leaflets; there was an increased gradient (mean gradient 22 mmHg); neither valvular nor perivalvular regurgitation was identified. These findings were suspect for …

Community acquired methicillin sensitive Staphylococcus aureus bacteremia, meningitis and brain abscess: A unique presentation

Introduction: ＂Staphylococcus aureus＂ causing isolate central nervous system (CNS) infection is rare. It is mostly related to either neurosurgical intervention or previous local or systemic infection rather than spontaneous isolated infection in adults. Case Report: We report a case of a previously healthy 19-year-old male with no risk factors of ＂Staphylococcus aureus＂ infection, who was found to have methicillin sensitive ＂Staphylococcus aureus＂ (MSSA) bacteremia, meningitis and cerebral abscess, without an apparent source of infection. Conclusion: Our case is a unique presentation of a young male presenting with isolated CNS infection by MSSA. This case highlights the challenge of early diagnosis of brain abscess, an entity that presents very often with non-specific signs, the diagnosis of which can be easily missed, with repercussions on long-term disability and mortality.

Management of fever without source in infants and children

Twenty percent of febrile children have fever without an apparent source of infection after history and physical examination. Of these, a small proportion may have an occult bacterial infection, including bacteremia, urinary tract infection (UTI), occult pneumonia, or, rarely, early bacterial meningitis. Febrile infants and young children have, by tradition, been arbitrarily assigned to different management strategies by age group: neonates (birth to 28 days), young infants (29 to 90 days), and older infants and young children (3 to 36 months). Infants younger than 3 months are often managed by using low-risk criteria, such as the Rochester Criteria or Philadelphia Criteria. The purpose of these criteria is to reduce the number of infants hospitalized unnecessarily and to identify infants who may be managed as outpatients by using clinical and laboratory criteria. In children with fever without source (FWS), occult UTIs occur in 3% to 4% of boys younger than 1 year and 8% to 9% of girls younger than 2 years of age. Most UTIs in boys occur in those who are uncircumcised. Occult pneumococcal bacteremia occurs in approximately 3% of children younger than 3 years with FWS with a temperature of 39.0°C (102.2°F) or greater and in approximately 10% of children with FWS with a temperature of 39.5°C (103.1°F) or greater and a WBC count of 15,000/mm3 or greater. The risk of a child with occult pneumococcal bacteremia later having meningitis is approximately 3%. The new conjugate pneumococcal vaccine (7 serogroups) has an efficacy of 90% for reducing invasive infections of Streptococcus pneumoniae. The widespread use of this vaccine will make the use of WBC counts and blood cultures and empiric antibiotic treatment of children with FWS who have received this vaccine obsolete. [Baraff LJ. Management of fever without source in infants and children. Ann Emerg Med. December 2000;36:602-614.]

The occult bacteremia controversy

A young child with a high fever and no source for infection is a common situation confronting pediatricians and pediatric emergency medicine physicians alike. Although most febrile children with no apparent source of infection are suffering from viral illnesses, a percentage will he harboring occult bacterial infection. Whereas most cases of occult bacteremia resolve spontaneously, a small number of cases progress to serious bacterial illness, This article reviews the approach to children 3 to 36 months of age with fever mid no apparent source and reflects on practice guidelines developed to guide clinicians managing this situation, The rationale for a variety of management approaches is reviewed and data from ongoing studies which might influence care in the future are presented.

Central venous catheter-related infections

Central venous catheter-related infections

Excess Mortality in Critically III Patients with Nosocomial Bloodstream Infections

To determine the excess mortality attributable to hospital-acquired bloodstream infections, we applied the acute physiology and chronic health evaluation (APACHE) II classification to 34 critically ill patients with this complication. The study included primary bloodstream infections, defined by a positive blood culture at least three days after hospitalization, in the absence of any other apparent source of infection. The most frequent blood isolates included Staphylococcus aureus (39 percent), Gram-negative rods (24 percent), and Candida albicans (15 percent); the spectrum of blood isolates suggested that most infections were related to intravascular catheters. In a control group of intensive care unit patients (n = 384), the death rate predicted by APACHE II was similar to the observed death rate (35.3 vs 37.8 percent). In a subgroup of control patients (n = 34), chosen for APACHE II scores that matched the patients with bloodstream infections, predicted and observed death rates were also similar (53.1 vs 52.9 percent). For patients with bloodstream infections, however, observed mortality (82.4 percent) significantly exceeded the predicted value (54.1 percent, p = 0.025). We conclude that critically ill patients who develop nosocomial bloodstream infections are at greater risk of death than patients with comparable severity of illness without this complication. The difference between the observed and predicted death rates, 28 percent, represents the excess mortality associated with bloodstream infection in critically ill patients.

Pyomyoma Associated with Polymicrobial Bacteremia and Fatal Septic Shock: Case Report and Review of the Literature

case of fatal septic shock due to pyomyoma (suppurative leiomyoma of the uterus) is reported. This unusual cause of sepsis and polymicrobial bacteremia should be rapidly identified because surgical therapy is essential for cure. Nine additional cases reported since 1945 are reviewed. Pyomyoma develops in association with either recent pregnancy or in postmenopausal patients who frequently have underlying vascular disease. The triad of: 1) bacteremia or sepsis; 2) leiomyoma uteri; and 3) no other apparent source of infection should suggest the diagnosis of pyomyoma.

Enterically transmitted non-A, non-B hepatitis: Recovery of virus-like particles from an epidemic in south delhi and transmission studies in rhesus monkeys

An epidemic of viral hepatitis, serologically characterized as due to non-A, non-B hepatitis, occurred in a village of South Delhi, India, in December, 1986, through January, 1987. Water contaminated with fecal matter was the apparent source of infection. Disease-associated virus-like particles were detected by immune electron microscopy in the feces of three patients within 5 days of illness. The virus-like particles were agglutinated by autologous acute-phase serum but not by convalescent serum. Rhesus monkeys inoculated with particle-containing fecal suspensions developed biochemical and morphologic features of acute, self-limited hepatitis. The findings in the present study and in earlier investigations of sporadic non-A, non-B hepatitis suggest that (i) the epidemic form and a proportion of sporadic cases of this infection in India may be related, both being enterically transmitted and associated with infection by a 27- to 32-nm virus-like particle, (ii) antibody responses to this virus occur early in disease and are transient and (iii) the rhesus monkey may prove to be a suitable model for studies of epidemic non-A, non-B hepatitis.

The incubation period necessary for detection of bacteremia in immunocompetent children with fever. Implications for the clinician.

The authors determined the time required for blood cultures to be detected as positive for the common bacterial pathogens in immunocompetent infants and children with fever who had no apparent source of infection. Records of the bacteriology laboratory were reviewed retrospectively from 1981 to 1984 for blood cultures that were positive for Haemophilus influenzae type b, Streptococcus pneumoniae, Neisseria meningitidis, Salmonella species, and group B streptococcus. Blood culturing by a conventional technique and a radiometric method were compared sequentially. Only four (1.5%) of 268 specimens were detected as positive after the second day of incubation; in each case that detection of bacteremia was delayed there was an identified source of infection. For H. influenzae, but not S. pneumoniae, significantly more bacteremias were detected earlier by the radiometric method. Discontinuation of empiric antibiotic therapy in immunocompetent children with suspected bacteremia and without focal infection appears warranted when blood cultures have been sterile for at least 48 hours.

Cardiopulmonary monitoring of critically ill patients (2).

Arterial LinesArterial lines are indicated for continuous monitoring of blood pressure and for very frequent sampling of arterial blood. Inserting arterial lines is a relatively safe and inexpensive procedure. Major complications include infection and thrombosis. The rate of catheter-associated sepsis (demonstrated by positive cultures of blood and the catheter tip that yield the same organism, with no other apparent source of infection) is about 4 per cent.16 Sepsis is more likely with surgical cutdowns if the catheter is left in place for more than four days or if evidence of local inflammation is present. The pressure transducer or flushing . . .

Leptospirosis associated with serovarshardjoandpomonain red deer calves (Census elaphus)

Four red deer calves (Cervus elaphus) died with severe nephritis apparently associated with infection by Leptospira interrogans serovar pomona. The sera of 12 in-contact red deer calves were examined for leptospiral agglutinins and nine showed titres to pomona consistent with recent infection. Two also showed titres of 1:100 to serovar hardjo. The urine of five of these in-contact calves was examined periodically over a period of nine months. All were initially leptospiruric, four being infected with pomona and one with hardjo. In four animals leptospiruria could only be detected for up to six months, but one animal infected with pomona was leptospiruric for at least eight months. The apparent source of infection was from infected cattle, and it is suggested that deer are unlikely to act as maintenance hosts for serovar pomona.

REVERSAL OF SIGNS AND SYMPTOMS OF ACQUIRED IMMUNODEFICIENCY SYNDROME (AIDS) WITH PREDNISONE

We describe in detail the case of a male infant of a prostitute and IV drug abuser. The child presented at 9 mo of age with severely delayed growth (6.6 kg) and development, recurrent bacterial infections, lymphadenopathy, hepatosplenomegaly (8 cm), persistent oral candidiasis, and chronic pulmonary infiltrates. Immunologic studies showed polyclonal hypergammaglobulinemia and inverted T-cell T4/T8 ratios. Skin tests to Candida and phytohemagglutinin were positive. Lung biopsy showed peribronchiolar lymphocytic infiltrates. Axillary lymph nodes contained obliterated margins with increased plasmacytes centrally. Liver biopsy demonstrated mild ballooning of hepatocytes. Bone marrow biopsy revealed hypercellularity with increased plasmacytes. EB virus was repeatedly isolated from lymph node, bone marrow, and blood lymphocytes, although antibodies to EBV did not appear for another 4 mo. Sera from both mother and child did contain antibody to human T-cell leukemia virus. Multiple sera were negative for antibody to cytomegalovirus and herpes virus. These viruses failed repeatedly to grow from tissue specimens. Initially, the child's course was observed off all treatment. After 8 wks of slow deterioration, he became lethargic, tachypneic, and febrile without apparent source of infection. At that point, he was begun on oral prednisone (PDR), 2 mg/kg/day. After 1 wk, he became afebrile with normal respirations. His adenopathy dissolved along with resolution of interstitial infiltrates. After 4 wks of PDR therapy, weight was 8.7 kg, serum immunoglobulins were normal, and spleen tip was just palpable. After tapering of PDR, all indicators of disease reverted toward pre-PDR values. Reinstitution of PDR again changed all parameters in a beneficial manner. We conclude that PDR may be effective in treatment of the AIDS prodrome.

Gastric ulceration associated with larval nematodes (Anisakis sp. type I) in pen reared green turtles (Chelonia mydas) from Torres Strait.

During turtle farming operations in Torres Strait, green turtles (Chelonia mydas) penned on Murray Island became infected with a larval nematode (Anisakis sp. Type I). The larvae were found associated with haemorrhagic ulcers in the pyloroduodenal junction of the alimentary tract. The apparent source of infection was a locally abundant sardine (Harengula ovalis), on which the Murray Island turtles were fed. Turtles held on other islands in the region were not fed sardines and remained uninfected. Recommendations were made to prevent further infection.

Haemophilus influenzae infections in adults: characterization of strains by serotypes, biotypes, and beta-lactamase production.

One hundred three cases of bacteremia or meningitis due to Haemophilus influenzae in adults were evaluated. Among 96 episodes of bacteremia, 60% were due to pneumonia and 15% to genital-related infections; 10% had no apparent source of infection. Of 42 isolates serotyped in routine fashion by slide agglutination, 79% were reported as type b. In contrast, of 45 isolates from the same interval with confirmed serotyping (usually by counterimmunoelectrophoresis), only 29% were type b and 64% were nontypable; 26% had been misidentified by routine slide agglutination. The majority (85%) of confirmed typable strains were biotype I. Four (40%) of 10 nontypable obstetrical isolates belonged to the relatively rare biotype IV. Only 2% of isolates were ampicillin-resistant, despite a high resistance rate among pediatric isolates in the same communities. When serotyping is carefully performed, nontypable organisms appear to be the major cause of invasive H. influenzae disease in adults.

Pathogenesis of the sporadic case of tuberculosis.

PROBABLY every physician has been surprised by the sporadic appearance of pulmonary and other forms of tuberculosis in a previously healthy older person in whom recent exposure to an open case of the infection appeared highly unlikely. Occasionally, active tuberculosis is discovered at autopsy as the cause of an unexplained illness in a person with no apparent source of infection in the environment. When the disease is extrapulmonary (kidney, spine and so forth) it is usually explained as a late progression of a dormant infection. But when it lies within the lung, it is common to invoke reinfection (or superinfection) . . .

PSEUDOMONAS AERUGINOSA BACTEREMIA

WITHIN recent months a case of Pseudomonas aeruginosa septicemia, with fatal termination, in a 6 month old infant has aroused interest in the subject. Reviews of the literature on this disease have appeared from time to time, but none has been found which assembles all the reported cases of Ps. aeruginosa bacteremia. The present article attempts to bring together all the published reports to date, with a table summarizing the data on the apparent source of infection, i.e., the most likely underlying condition affording a portal of entry to Ps. aeruginosa, with subsequent bacteremia. In some instances the organism was undoubtedly present as a secondary invader in an already damaged site. In other instances it seems probable that Ps. aeruginosa was the initial offending agent. Discussion will be directed principally toward the pediatric aspects of the problem of Ps. aeruginosa bacteremia. The first 57 reports 1 include only those