Impact of Rapid Molecular Multiplex Gastrointestinal Pathogen Testing in Management of Children during a Shigella Outbreak.

Fecal culture for isolation and identification of Shigella may take days. The BioFire FilmArray Gastrointestinal (GI) panel (bioMérieux, France) is a PCR-based assay that detects enteric pathogens including Shigella/enteroinvasive Escherichia coli (EIEC) in about an hour. The aim of this study was to evaluate the impact of GI panel detection of Shigella in a pediatric emergency department (ED) during an outbreak. Stool samples from children with acute gastroenteritis were tested by the GI panel. Test results were either withheld in preintervention (PRE) or reported to clinicians/families in the postintervention (POST) period. The impact of the GI panel testing on patient management and outcomes was measured. Shigella/EIEC was identified by the GI panel in the PRE (n = 30) and POST (n = 21) phase. The GI panel detected more Shigella infections than did culture; six of 31 (19.4%) Shigella GI panel-positive patients who also had stool cultures were missed by culture. Azithromycin therapy was prescribed for 20% of subjects in the PRE phase and 71.4% of subjects in the POST phase (P < 0.001). Time from the clinical encounter until starting azithromycin therapy was shorter in the POST phase (n = 9), 8.25 h (range, 6.37 to 52.37 h), than in the PRE phase (n = 1), 72 h. Six subjects in the PRE phase visited additional providers compared with one in the POST phase. Prompt diagnosis of shigellosis with the GI panel may provide the opportunity for prompt antimicrobial therapy and avoid additional visits to providers due to early definitive diagnosis. Prompt diagnosis of Shigella at an ED visit may optimize patient management and reduce transmission.

How well does physician selection of microbiologic tests identify Clostridium difficile and other pathogens in paediatric diarrhoea? Insights using multiplex PCR-based detection.

The objective of this study was to compare the aetiologic yield of standard-of-care microbiologic testing ordered by physicians with that of a multiplex PCR platform. Stool specimens obtained from children and young adults with gastrointestinal illness were evaluated by standard laboratory methods and a developmental version of the FilmArray Gastrointestinal (GI) Diagnostic System (FilmArray GI Panel), a rapid multiplex PCR platform that detects 23 bacterial, viral and protozoal agents. Results were classified according to the microbiologic tests requested by the treating physician. A median of three (range 1-10) microbiologic tests were performed by the clinical laboratory during 378 unique diarrhoeal episodes. A potential aetiologic agent was identified in 46% of stool specimens by standard laboratory methods and in 65% of specimens tested using the FilmArray GI Panel (p < 0.001). For those patients who only had Clostridium difficile testing requested, an alternative pathogen was identified in 29% of cases with the FilmArray GI Panel. Notably, 11 (12%) cases of norovirus were identified among children who only had testing for Clostridium difficile ordered. Among those who had C. difficile testing ordered in combination with other tests, an additional pathogen was identified in 57% of stool specimens with the FilmArray GI Panel. For patients who had no C. difficile testing performed, the FilmArray GI Panel identified a pathogen in 63% of cases, including C. difficile in 8%. Physician-specified laboratory testing may miss important diarrhoeal pathogens. Additionally, standard laboratory testing is likely to underestimate co-infections with multiple infectious diarrhoeagenic agents.

Clustering of post-diarrheal (Shiga toxin-mediated) hemolytic uremic syndrome in families.

AIMS: 1. To study the epidemiological and clinical features of Shiga toxin (Stx)-mediated (post-diarrheal) hemolytic uremic syndrome (HUS) occurring in more than 1 family member. 2. To compare familial with non-familial episodes, and concurrent familial with non-concurrent familial cases. 3. To determine the likelihood of Stx HUS occurring in a second family member. METHODS: A retrospective review from January 1970 through September 2001 of families in whom Stx HUS occurred in more than 1 family member was conducted using a computerized HUS registry. It contains information on 373 episodes that occurred in 356 families from Utah and neighboring states. Cases were categorized as being either concurrent (i.e., occurring within a month of one another) or non-concurrent, and the study was limited to those with typical (post-diarrheal) episodes. RESULTS: HUS occurred in 2 or more family members in 17 (4.8%) of the families in our registry. In 12 (3.4%) of these families episodes occurred with days to weeks of each other; in 5 families (1.4%) episodes were separated by intervals of several years. There were no statistically significant differences in demographic, seasonal, laboratory, clinical, or outcome variables between familial subsets (concurrent versus non-concurrent) or between familial and non-familial cases. CONCLUSIONS: When a child is diagnosed with D+ HUS, there is an increased risk that a second family member will also develop HUS; most often within days to weeks (i.e., within a month), but in some cases episodes may be separated by intervals of years. Non-concurrent cases suggest common environmental risk factors, or perhaps a genetic predisposition. Concurrent cases suggest a common source of infection or person-to-person transmission; a genetic predisposition cannot be excluded. These observations suggest that siblings of an index case who develop diarrhea should be kept under close surveillance.

Discriminators between hantavirus-infected and -uninfected persons enrolled in a trial of intravenous ribavirin for presumptive hantavirus pulmonary syndrome.

To provide a potentially therapeutic intervention and to collect clinical and laboratory data during an outbreak of hantavirus pulmonary syndrome (HPS), 140 patients from the United States with suspected HPS were enrolled for investigational intravenous ribavirin treatment. HPS was subsequently laboratory confirmed in 30 persons and not confirmed in 105 persons with adequate specimens. Patients with HPS were significantly more likely than were hantavirus-negative patients to report myalgias from onset of symptoms through hospitalization, nausea at outpatient presentation, and diarrhea and nausea at the time of hospitalization; they were significantly less likely to report respiratory symptoms early in the illness. The groups did not differ with regard to time from the onset of illness to the point at which they sought care; time from onset, hospitalization, or enrollment to death was significantly shorter for patients with HPS. At the time of hospitalization, patients with HPS more commonly had myelocytes, metamyelocytes, or promyelocytes on a peripheral blood smear, and significantly more of them had thrombocytopenia, hemoconcentration, and hypocapnia. Patterns of clinical symptoms, the pace of clinical evolution, and specific clinical laboratory parameters discriminated between these 2 groups.

Invasive serotype a Haemophilus influenzae infections with a virulence genotype resembling Haemophilus influenzae type b: emerging pathogen in the vaccine era?

OBJECTIVE: Haemophilus influenzae type b causes severe disease in nonimmune infants and young children; other serotypes are uncommon pathogens and thought to have low virulence. Some have hypothesized that with the virtual elimination of H influenzae type b, other serotypes might acquire virulence traits and emerge as important pathogens of children. We describe the clinical, epidemiologic, and molecular biologic features of 5 cases of severe disease attributable to Haemophilus influenzae type a. METHODS: After observing 4 cases of invasive disease caused by H influenzae type a, we reviewed microbiology records at 3 reference laboratories that perform all serotyping in Utah and surveillance databases. Strains of H influenzae type a and control strains were examined by Southern blotting with the use of the cap probe pUO38 and by pulsed-field gel electrophoresis. The putative virulence mutation, the IS1016-bexA deletion, was detected by polymerase chain reaction amplification and sequencing. RESULTS: During a 10-month period, we observed 5 children with severe invasive disease caused by H influenzae type a. No isolates of H influenzae type a had been submitted to the reference laboratories between 1992 and 1998. The median age of patients was 12 months (range: 6-48 months). Four of 5 had meningitis and bacteremia; 1 had purpura fulminans. Three isolates, representing 1 of 2 pulsed-field gel electrophoresis patterns, contained the IS1016-bexA deletion and were associated with particularly severe disease. CONCLUSIONS: We describe an unusual cluster of severe disease caused by H influenzae type a that resembles the clinical and epidemiologic features of H influenzae type b disease. Our data support the hypothesis that the IS1016-bexA deletion may identify more virulent strains of H influenzae. Haemophilus influenzae, epidemiology, virulence, serotyping, pathogenicity.

Contribution of the anomeric effect to the solution and crystal structure of [1S,2S,6S,7s]-1,6-diaza-4,9-dioxa-2,7-dimethoxycarbonylbicyclo[4.4.1]undecane, a condensation product of L-serine methyl ester with formaldehyde.

The reaction of L-serine methyl ester hydrochloride (1) with paraformaldehyde (2) in dichloromethane in the presence of triethylamine afforded a novel compound: [lS,2S,6S,7S]-1,6-diaza-4,9-dioxa-2,7-dimethoxycarbonylbicyclo[4.4.1]undecane (4) as a 2:3 adduct of 1 with 2. 1H and 13C NMR spectroscopy were unable to discriminate between two possible symmetrical structures. The latter was unambiguously proved by X-ray crystallography. The crystal structure established: (i) the existence of two identical seven-membered rings each containing a N-C-O grouping; (ii) the existence of a long C-O-C-N-C-N-C-O-C sequence in which each nitrogen belongs simultaneously to a N-C-O (oxazolidine) and to a N-C-N (aminal) motifs; (iii) the existence of a chair-like conformation for both seven-membered rings; (iv) the antiperiplanar geometry of pN-C-O and consequently the manifestation of a strong anomeric effect in both N-C-O groupings, whereas anomeric effect was virtually absent in the N-C-N sequence, as corroborated by bond distances and bond angles. Chemical shifts, coupling constants and NOE effects confirm that the conformational features of 4 are preserved in solution.

Sources of infection among persons with acute hepatitis A and no identified risk factors during a sustained community-wide outbreak.

CONTEXT: Hepatitis A is a common vaccine-preventable disease in the United States. Most cases occur during community-wide outbreaks, which can be difficult to control. Many case-patients have no identified source. OBJECTIVE: To identify foodborne and household sources of hepatitis A during a community-wide outbreak. DESIGN: Serologic and descriptive survey. SETTING: Salt Lake County, Utah. PARTICIPANTS: A total of 355 household contacts of 170 persons reported with hepatitis A during May 1996 to December 1996, who had no identified source of infection; and 730 food handlers working in establishments where case-patients had eaten. MAIN OUTCOME MEASURE: Prevalence of immunoglobulin M antibodies to hepatitis A virus (IgM anti-HAV) among household and food service contacts. RESULTS: Overall, 70 household contacts (20%) were IgM anti-HAV-positive, including 52% of children 3 to 5 years old and 30% of children <3 years old. In multivariate analysis, the presence of a child <3 years old (odds ratio [OR]: 8.8; 95% confidence limit [CL]: 2.1,36) and a delay of >/=14 days between illness onset and reporting (OR: 7. 9; 95% CL: 1.7,38) were associated with household transmission. Of 18 clusters of infections linked by transmission between households, 13 (72%) involved unrecognized infection among children <6 years old. No food handlers were IgM anti-HAV-positive. CONCLUSION: During a community-wide outbreak, HAV infection among children was common, was frequently unrecognized, and may have been an important source of transmission within and between households. Transmission from commercial food establishments was uncommon. Ongoing vaccination of children may prevent future outbreaks.

Anomeric effects in non-carbohydrate compounds: conformational differences between the oxazolidine rings of a cis-fused bicyclic system.

Tris(hydroxymethyl)aminomethane (Tris) can react with benzaldehyde (1:2 molar ratio) to produce cis-2,8-diphenyl-5-hydroxymethyl-1-aza-3,7-dioxabicyclo[3.3.0]octa ne, the structure of which has been confirmed by nuclear magnetic resonance spectroscopy and X-ray crystallography. The crystal structure showed that both oxazolidine rings A and B are puckered in opposite directions. Ring A exists in an E3 envelope form with 0-3 noticeably down (0.65 A) the plane of the remaining atoms, whereas ring B adopts the 7E envelope conformation with the 0-7 atom displaced up from the mean reference plane by 0.70 A. Comparison of bond angles and bond distances showed that both oxazolidine rings A and B exhibit cross endo-anomeric effects resulting from electron delocalization over the bond sequence O-3-C-2-N-1-C-8-O-7.

Immunologic and virologic effects of subcutaneous interleukin 2 in combination with antiretroviral therapy: A randomized controlled trial.

CONTEXT: While interleukin 2 (IL-2) is capable of inducing a marked expansion of the CD4 T-lymphocyte pool, limited data exist on whether IL-2 treatment can add significantly to the immunologic and virologic effects of potent antiretroviral therapy (ART). OBJECTIVE: To determine the rate and magnitude of CD4 cell recovery and viral suppression when using a combination therapy of IL-2 and ART compared with ART alone. DESIGN AND SETTING: Randomized, controlled multicenter trial conducted from April 1996 through April 1998 at 8 clinical sites in the United States. PATIENTS: Eighty-two adult outpatients who were infected with human immunodeficiency virus (HIV) and had baseline CD4 cell counts of 200 x 10(6)/L to 500 x 10(6)/L and baseline RNA levels of fewer than 10,000 copies/mL were randomized; 78 completed the study. INTERVENTIONS: Thirty-nine patients were randomly assigned to receive a combination therapy of subcutaneous IL-2 (administered in 5-day courses every 8 weeks at a starting dosage of 7.5 mIU twice per day) and ART; 43 were to receive ART therapy alone. MAIN OUTCOME MEASURES: Interleukin 2 safety and differential effects on CD4 cell counts, CD4 cell percentages, and plasma HIV RNA levels. RESULTS: The mean (SD) percentage increase in CD4 cell counts at 1 year for patients who received IL-2 was 112% (113%) compared with 18% (35%) in recipients of ART alone (P<.001). Both groups had mean (SD) increases in CD4 cell percentage: from 20.4% (6.3%) to 32.3% (12.4%) for the combination therapy group compared with 20.4% (5.1%) to 23.0% (7.2%) for recipients of ART alone (P<.001). Using a sensitive viral RNA assay, mean viral load changes were -0.28 and 0.09 log(10) copies for IL-2 recipients and control patients, respectively (P=.03). Twenty (67%) of 30 evaluable patients receiving IL-2 achieved final viral loads of fewer than 50 copies/mL compared with 13 (36%) of 36 control patients (P=.02). Toxic effects were common among patients who received IL-2 and were managed with antipyretics, hydration, rest, and dosage reduction as needed. CONCLUSIONS: Intermittent therapy with IL-2 and ART produced a substantially greater increase in CD4 cells and was associated with a larger decrease in viral load than ART alone. Clinical end-point trials will be necessary to determine whether the enhanced viral suppression and CD4 cell increases associated with IL-2 therapy will translate into improved clinical outcomes. JAMA. 2000;284:183-189

A community pseudo-outbreak of invasive Staphylococcus aureus infection.

Outbreaks of invasive infection caused by methicillin-susceptible and methicillin-resistant Staphylococcus aureus occur in hospitals, long term care institutions, and in patients discharged from these settings. In contrast, epidemic S. aureus infection has not been reported in well persons in the community. Here, we describe a group of healthy young adults who resided in the same neighborhood and participated together in school sports, and who developed serious S. aureus infections within 3 weeks of each other, suggesting a true community outbreak. Timely use of molecular epidemiological tools, however, demonstrated that their illnesses were caused by unrelated bacterial strains.

[Arthroplasty in congenital aortic coarctation in adults with balloon and endovascular prosthesis: immediate results and 6-month follow-up]. / Aortoplastía en coartación aórtica congénita del adulto con balón y protesis endovascular: resultados inmediatos y seguimiento a 6 meses.

Up to 1982, surgery was the treatment of aortic coarctation, with postsurgical recoarctation in 39% of cases. Since 1984 balloon aortoplasty has been performed successfully in adolescents and adult patients. We present the immediate results, and more than six months follow up of 6 patients with congenital aortic coarctation, who underwent this procedure. Five of the six patients were male, with an average age of 28.6 years (15-46), and in 4 of them a stent was placed. Systolic pressure of ascending aorta decreased from 187.1 mm of Hg (+/- 41.8) to 128 (+/- 25.4), and transaortic gradient from 66 mm of Hg (+/- 21.8) to 4.8 (+/- 7.6). Coarctation luminal diameter increased from 4.6 mm (+/- 1.41) to 14.3 (+/- 3) in patients with only balloon aortoplasty and to 17.8 mm with stent placement, p = NS. Angiography in three patients with stent at 6 months did not reveal restenosis, all six patients require less antihypertensive medications. Acute and chronic complications, percentage and time of restenosis, long term results, and possible benefit of stents are yet to be determined.

Bacillus cereus infections among oncology patients at a children's hospital.

BACKGROUND: Bacillus cereus can cause severe infections in immunocompromised persons. METHODS: We report 3 cases of bacteremia/septicemia (1 fatal) among oncology patients in a children's hospital. Because all cases occurred during a 10-day period, a common source outbreak was suspected. An epidemiologic investigation was performed. Molecular comparison of patient and environmental isolates was performed by using pulsed-field gel electrophoresis. RESULTS: After an extensive investigation, no common hospital source could be found. Pulsed-field gel electrophoresis proved that the isolates were not related. CONCLUSION: Sporadic infections in immunocompromised persons do occur and can be associated with significant morbidity.

Advances in antimicrobial therapy.

Despite several decades of improved therapy and prevention of infectious diseases, infectious pathogens remain major causes of morbidity and mortality in humans worldwide. Among the most complex and daunting problems facing medical science is the evolution of antibiotic resistance among many common and once easily-treated infectious agents. This review summarizes the status of newer antimicrobial agents that have utility against pathogens infecting the central nervous system.

Intravenous ribavirin for hantavirus pulmonary syndrome: safety and tolerance during 1 year of open-label experience. Ribavirin Study Group.

Intravenous ribavirin was provided non-selectively for investigational open-label use among persons with suspected hantavirus pulmonary syndrome (HPS) in the United States between 4 June 1993 and 1 September 1994. Therapy was initiated prior to laboratory confirmation of hantavirus infection because most deaths from HPS occur within 48 h of hospitalization. Thirty patients with confirmed HPS, 105 patients without HPS and 5 patients without adequate diagnostic testing for HPS were enrolled. This observational study arguably provides the most complete information available on ribavirin-associated adverse effects. Although ribavirin was generally well tolerated, 71% of recipients became anaemic and 19% underwent transfusion. An apparent excess of hyperamylasaemia/pancreatitis was either therapy-associated or due to enrollment bias. The 30 enrolled HPS patients had a case-fatality rate of 47% (14/30). It is not possible to assess efficacy with this study design. However, comparison of survival curves for the 30 enrolled HPS patients and 34 patients who developed HPS during the same time period but were not enrolled did not suggest an appreciable drug effect. A randomized, placebo-controlled trial that enrolls patients during the prodrome phase would be necessary to assess the efficacy and further define the safety of intravenous ribavirin for HPS.

Spontaneous intestinal perforation in premature infants: a distinct clinical entity associated with systemic candidiasis.

PURPOSE: The aim of this study was to define patient characteristics, risk factors, microbiology, and outcome of spontaneous intestinal perforations (SIP) in premature infants. METHODS: To identify the characteristics and frequency of SIP, the medical records of 94 premature infants were reviewed retrospectively. RESULTS: Eleven infants experienced 12 episodes of SIP and 53 infants had 55 episodes of confirmed necrotizing enterocolitis (NEC). Compared with infants who had NEC, the infants with SIP were smaller and born more prematurely. The onset of illness was earlier and was associated with antecedent hypotension, leukocytosis, and a gasless appearance on abdominal radiograph. Blue abdominal discoloration was present in 11 of 12 babies with SIP, but in only one of the babies with NEC. Infants with SIP were significantly more likely to have systemic candidiasis. When controlling for birth weight and age, early onset, blue abdomen, and a gasless abdominal radiograph continued to be statistically significant markers of SIP. CONCLUSIONS: SIP occurs about 12-fold less frequently than NEC in preterm infants. A combination of clinical, laboratory, and radiological features distinguish very low birthweight infants with SIP from those with NEC. Obvious signs of bowel perforation are infrequent with SIP. SIP is frequently associated with systemic candidiasis.

Clinical efficacy of high-dose acyclovir in patients with human immunodeficiency virus infection: a meta-analysis of randomized individual patient data.

A meta-analysis of 8 randomized trials (1792 patients, 2947 patient-years of follow-up) showed that acyclovir (> or = 3200 mg/day) offered a significant survival benefit (P = .006 by log-rank test) in human immunodeficiency virus (HIV) infection. The treatment effect did not vary significantly in patient subgroups of different CD4 cell counts, hemoglobin levels, age, race, and sex, and with or without AIDS diagnosis. Acyclovir treatment (hazard ratio, 0.78; 95% confidence interval [CI], 0.65-0.93), higher CD4 cell count (P < .001), higher hemoglobin level (P < .001), and younger age (P < .001) reduced the hazard of mortality. Acyclovir decreased herpes simplex virus infections (odds ratio [OR], 0.28; 95% CI, 0.21-0.37) and varicella-zoster virus infections (OR, 0.29; 95% CI, 0.13-0.63) but not cytomegalovirus disease or mortality from lymphoma or Kaposi's sarcoma. A survival advantage was seen specifically in studies with high incidence of clinical herpesvirus infections (> or = 25% per year). Given the wide confidence intervals, the small effect in low-risk patients, and recent changes in HIV therapeutics, the results should be interpreted cautiously, but the meta-analysis supports the importance of pathogenetic interactions between herpesviruses and HIV.

The safety and efficacy of adefovir dipivoxil, a novel anti-human immunodeficiency virus (HIV) therapy, in HIV-infected adults: a randomized, double-blind, placebo-controlled trial.

Adefovir dipivoxil is a novel nucleotide analogue with several promising in vitro anti-human immunodeficiency virus (HIV) characteristics. To evaluate the safety and efficacy of adefovir dipivoxil monotherapy, a randomized, double-blind, placebo-controlled study was initiated involving 72 subjects with moderately advanced HIV disease. Subjects were randomly assigned in a 2:1 ratio to receive adefovir dipivoxil or placebo as a once-daily oral dose for 6 weeks, followed by 6 weeks of open-label adefovir dipivoxil. Two dose levels were studied (125 mg and 250 mg). Adefovir dipivoxil was determined to be safe and well-tolerated when administered for 12 weeks. At week 6, changes in absolute CD4 T cell levels and HIV-1 RNA levels were significantly greater with adefovir dipivoxil than with placebo. These effects were sustained through 12 weeks of treatment. As determined by standard RNA sequencing techniques, only 1 of the 24 subjects who received adefovir dipivoxil (125 mg/day) developed any genotypic change from baseline.