Invasive Group B Streptococcal Disease In Childhood

Invasive group B streptococcal disease in childhood is uncommon and occupies a unique clinical niche. We present 10 children, 1-17 years of age, with invasive group B streptococcal disease from 2010 to 2020. Seven had conditions predisposing to infection and 3 had no identifiable risk factors. With appropriate consideration of pathogenesis, source control, and treatment, all children recovered.

Group B Streptococcal Cellulitis-Adenitis Syndrome in Infants: Insights From 24 Years of Experience

This series of 28 infants with group B streptococcal (GBS) cellulitis-adenitis from a single institution over 24 years offers insights important to the early recognition, spectrum of findings, and optimal management of this rare manifestation of invasive GBS disease.

1210. Recommendations for Screening and Diagnosis of Chagas Disease in the United States

Background

Over 300,000 people in the United States are infected with Trypanosoma cruzi, the protozoan parasite that causes Chagas disease (CD). Only about 1% of estimated U.S. cases have been identified, usually through blood donor screening, and most people are unaware they have the infection. Screening is critical for increasing case detection and ensuring patients receive appropriate and timely care, but awareness of CD management strategies among healthcare providers is low. Diagnostic guidelines for CD in the United States are needed to increase provider-directed screening and diagnosis.

Methods

Screening recommendations were prepared by the U.S. Chagas Diagnostic Working Group, which consists of clinicians, researchers, and public health experts involved in CD programs. The group agreed on six main questions based on the PICO method (Population, Intervention, Comparison, and Outcome). Subgroups discussed each and proposed initial recommendations, which were then shared and validated within the larger group. The recommendations used the GRADE methodology, assigning two sets of ratings: 1) strength of the recommendation, and 2) quality of the evidence.

Results

The group recommended screening anyone who was born or lived for >6 months in South America, Central America and Mexico (Figure 1). Recent community-based studies found a prevalence of 1-3.8% in this population. Within this population, having a family member with CD, or having clinical conditions suggestive of CD, including electrocardiographic abnormalities, suggest an elevated risk. Screening women of childbearing age and infants born to seropositive women is important for preventing congenital transmission. Test performance may vary depending on several factors, including whether patients are from South America, Central America or Mexico. Confirmation therefore requires positive results on at least two serological tests based on different antigens or formats, in line with Pan American Health Organization (PAHO) recommendations. Once CD is confirmed, patients should receive an electrocardiogram and echocardiogram to monitor for development of cardiac complications.

Conclusion

These CD screening recommendations are meant to be a resource for U.S. healthcare providers to simplify testing of at-risk patients.

Disclosures

Jen Manne-Goehler, MD, DSc, Regeneron (Individual(s) Involved: Self): Scientific Research Study Investigator Caryn Bern, MD, MPH, UpToDate (Wolters Kluwer) (Other Financial or Material Support, Author Royalties)

Congenital Chagas disease: progress toward implementation of pregnancy-based screening

PURPOSE OF REVIEW

Lack of recognition of congenital Chagas disease in infants of mothers from endemic regions who are living in countries nonendemic for Trypanosoma cruzi infection suggests a high rate of underdiagnosis. Pregnancy is the optimal access point for identifying Chagas disease in at-risk mothers and their infants. In this review, we update progress toward implementation of pregnancy-based screening for congenital Chagas disease in nonendemic settings.

RECENT FINDINGS

International organizations have updated recommendations for diagnosis, treatment and prevention of congenital Chagas disease. Reports of successful implementation of pregnancy-based screening at some centers provide a model for optimizing diagnosis of congenital Chagas disease. Screening family members of index patients may identify additional T. cruzi-infected persons. Promising tests to augment current diagnostic modalities for maternal and congenital Chagas disease are in development. Universal or risk-based screening would be cost-effective. More healthcare providers are now aware that treatment of congenital Chagas disease is curative and are promoting efforts to make pregnancy-based screening for congenital Chagas disease a standard of care.

SUMMARY

Ongoing efforts to implement routine pregnancy-based screening for congenital Chagas disease in nonendemic regions will mutually benefit infants, their mothers and family members and can prevent potentially fatal Chagas cardiomyopathy.

Two Cases of Cronobacter Sakazakii Meningitis in Infants: The Importance Of Early Advanced Brain Imaging and Public Health Reporting

We report 2 infants hospitalized with Cronobacter sakazakii meningitis. Each infant had exposure to powdered infant formula at home. Both infants survived, but 1 infant had a subdural empyema drained and developed left sensorineural hearing loss. Early advanced brain imaging is recommended in infants with C. sakazakii meningitis. Reporting to state and federal public health officials may help identify outbreaks.

Chagas Disease: Implementation of Screening to Benefit Mother and Infant

Pregnancy-based screening would identify women with Chagas disease, allowing for treatment of Trypanosoma cruzi-infected women and infants to prevent potentially fatal Chagas cardiomyopathy.

A Phase 2, Randomized, Control Trial of Group B Streptococcus (GBS) Type III Capsular Polysaccharide-tetanus Toxoid (GBS III-TT) Vaccine to Prevent Vaginal Colonization With GBS III

BACKGROUND

Group B Streptococcus (GBS) frequently colonizes pregnant women and can cause sepsis and meningitis in young infants. If colonization was prevented through maternal immunization, a reduction in perinatal GBS disease might be possible. A GBS type III capsular polysaccharide (CPS)-tetanus toxoid conjugate (III-TT) vaccine was evaluated for safety and efficacy in preventing acquisition of GBS colonization.

METHODS

Healthy, nonpregnant women aged 18-40 years and screened to be GBS III vaginal and rectal culture negative were randomized to receive III-TT conjugate or tetanus diphtheria toxoid vaccine in a multicenter, observer-blinded trial. GBS vaginal and rectal cultures and blood were obtained bimonthly over 18 months. Serum concentrations of GBS III CPS-specific antibodies were determined using enzyme-linked immunosorbent assay.

RESULTS

Among 1525 women screened, 650 were eligible for the intent-to-treat analysis. For time to first acquisition of vaginal GBS III, vaccine efficacy was 36% (95% confidence interval [CI], 1%-58%; P = .044), and for first rectal acquisition efficacy was 43% (95% CI, 11% to 63%; P = .014). Two months post-immunization, geometric mean concentrations of serum GBS type III CPS-specific immunoglobulin G were 12.6 µg/mL (95% CI, 9.95 to 15.81) in GBS III-TT recipients, representing a 4-fold increase from baseline in 95% of women, which persisted. Both vaccines were well tolerated.

CONCLUSIONS

GBS CPS III-TT conjugate vaccine significantly delayed acquisition of vaginal and rectal GBS III colonization. In addition to its use for maternal immunization to passively protect infants with maternally derived antibodies, a multivalent vaccine might also serve to reduce fetal and neonatal exposure to GBS.

CLINICAL TRIALS REGISTRATION

NCT00128219.

Evaluation and Management of Congenital Chagas Disease in the United States

Chagas disease is underappreciated as a health concern in the United States. Approximately 40 000 women of childbearing age living in the United States have chronic Chagas disease. Most of them are unaware that they have an infection that is transmissible to their offspring. The estimated US maternal-to-infant transmission rate of Trypanosoma cruzi is 1% to 5%. Ten percent to 40% of neonates with congenital T cruzi infection have clinical signs consistent with a congenital infection but no findings are unique to Chagas disease. If left untreated, 20% to 40% of infants with Chagas disease will later develop potentially fatal cardiac manifestations. Molecular testing can confirm the diagnosis in neonates. Treatment is well tolerated in infancy and usually results in cure. Screening of at-risk women during pregnancy can identify maternal infection and allow early assessment and treatment for congenital T cruzi infection.

Trichosporonosis in Pediatric Patients With a Hematologic Disorder

BACKGROUND

Trichosporonosis is an emerging and often fatal opportunistic fungal infection in immunocompromised patients, particularly those with hematologic malignancy, but data in children are lacking.

METHODS

We report here 3 cases of invasive infection caused by Trichosporon asahii in pediatric patients with acute lymphoblastic leukemia at Texas Children's Hospital in Houston, Texas. We also conducted a literature review and identified 16 additional reports of pediatric patients with invasive T asahii infection and an underlying malignant or nonmalignant hematologic disorder.

RESULTS

Of the 19 cases of invasive T asahii infection, the most commonly reported underlying hematologic disorder was acute lymphoblastic leukenia (47%), followed by acute myelogenous leukemia (21%). Most of the patients (94%) had neutropenia, defined as an absolute neutrophil count of <500 cells/mm3. Antifungal prophylaxis information was available in 6 of the 19 cases, and micafungin use was reported in 5 cases. Treatment regimens frequently included voriconazole monotherapy (47%) or the combination of an azole antifungal with amphotericin B (35%). The mortality rate was 58%.

CONCLUSIONS

Recognizing that echinocandins, which are increasingly used for prophylaxis in patients with a hematologic malignancy, are not active against Trichosporon species is of critical importance. The recommended first-line therapy for trichosporonosis is voriconazole, but successful outcome depends largely on the underlying immune status of the host.

Immune Responses to Invasive Group B Streptococcal Disease in Adults

Antibodies to capsular polysaccharides and pilus proteins develop in recovering adults.

Immunization of nonpregnant adults could help prevent invasive group B Streptococcus (GBS) infections, but adult immune responses have not been investigated. We defined capsular polysaccharide (CPS) and pilus island (PI) surface antigen distribution and expression and immune responses to GBS infection in nonpregnant adults. Prospective surveillance from 7 hospitals in Houston, Texas, USA, identified 102 adults with GBS bacteremia; 43% had skin/soft tissue infection, 16% bacteremia without focus, and 12% osteomyelitis. CPS-specific IgG was determined by ELISA and pilus-specific IgG by multiplex immunoassay. CPS types were Ia (24.5%), Ib (12.7%), II (9.8%), III (16.7%), IV (13.7%), and V (12.7%); 9.8% were nontypeable by serologic methods. Pili, expressed by 89%, were most often PI-2a. CPS and pilus-specific IgG increased during convalescence among patients with strains expressing CPS or PI. All GBS expressed CPS or PI; 79% expressed both. Increased antibodies to CPS and PI during recovery suggests that GBS bacteremia in adults is potentially vaccine preventable.

Group B Streptococcal Colonization Among Pregnant Women in Delhi, India

BACKGROUND

Little is known regarding maternal group B streptococcal (GBS) colonization prevalence and capsular (CPS) serotype distribution among pregnant women in India. The objective of this prospective cohort study was to determine GBS recto-vaginal colonization prevalence in pregnant women at Dr. Ram Manohar Lohia Hospital in Delhi, India.

METHODS

Literature review identified reports from India assessing GBS colonization prevalence in pregnant women. Rectal and vaginal swabs were inoculated into Strep B Carrot Broth (Hardy Diagnostics, Santa Maria, CA) and subcultured onto GBS Detect plates (Hardy Diagnostics, Santa Maria, CA). Isolates were serotyped using ImmuLex Strep-B latex kits (Statens Serum Institut, Copenhagen, Denmark).

RESULTS

Thirteen studies were identified citing GBS colonization prevalence during pregnancy as 0.47%-16%. Among 300 pregnant women (mean age: 26.9 years; mean gestation: 34 weeks) enrolled (August 2015 to April 2016), GBS colonization prevalence was 15%. Fifteen percent of women had vaginal only, 29% had rectal only and 56% had both sites colonized. CPS types were Ia (13.3%), Ib (4.4%), II (20%), III (22.2%), V (20%) and VII (6.7%); 13.3% were nontypable. Fetal loss in a prior pregnancy at ≥20-weeks gestation was more common in colonized than noncolonized women (15.6% vs. 3.5%; P = 0.004). Employing recent census data for the birth cohort and estimating that 1%-2% of neonates born to colonized women develop early-onset disease, at least 39,000 cases of early-onset disease may occur yearly in India.

CONCLUSIONS

Using optimal methods, 15% of third trimester pregnant women in India are GBS colonized. A multivalent vaccine containing 6 CPS types (Ia, Ib, II, III, V and VII) would encompass ~87% of GBS carried by pregnant women in India.

Serotype IV Streptococcus agalactiae ST-452 has arisen from large genomic recombination events between CC23 and the hypervirulent CC17 lineages

Streptococcus agalactiae (Group B Streptococcus, GBS) causes life-threatening infections in newborns and adults with chronic medical conditions. Serotype IV strains are emerging both among carriers and as cause of invasive disease and recent studies revealed two main Sequence Types (STs), ST-452 and ST-459 assigned to Clonal Complexes CC23 and CC1, respectively. Whole genome sequencing of 70 type IV GBS and subsequent phylogenetic analysis elucidated the localization of type IV isolates in a SNP-based phylogenetic tree and suggested that ST-452 could have originated through genetic recombination. SNPs density analysis of the core genome confirmed that the founder strain of this lineage originated from a single large horizontal gene transfer event between CC23 and the hypervirulent CC17. Indeed, ST-452 genomes are composed by two parts that are nearly identical to corresponding regions in ST-24 (CC23) and ST-291 (CC17). Chromosome mapping of the major GBS virulence factors showed that ST-452 strains have an intermediate yet unique profile among CC23 and CC17 strains. We described unreported large recombination events, involving the cps IV operon and resulting in the expansion of serotype IV to CC23. This work sheds further light on the evolution of GBS providing new insights on the recent emergence of serotype IV.

Maternal group B Streptococcus-related stillbirth: a systematic review

BACKGROUND

Limited epidemiological data on the association between maternal rectovaginal group B Streptococcus (GBS) colonisation and stillbirth makes assessment of antenatal interventions for GBS stillbirth difficult.

OBJECTIVES

To systematically review the existing literature and evaluate the incidence of GBS-related stillbirth by region up to March 2015.

SEARCH STRATEGY

A systematic review of the published literature was completed using PubMed/MEDLINE, EMBASE, LILACS, and Cochrane Library, with Medical Subject Headings (MeSH) and search terms based upon the Centers for Disease Control and Prevention's (CDC) Active Bacterial Core Surveillance (ABCs) GBS-related stillbirth definition and chorioamnionitis.

SELECTION CRITERIA

Studies reporting original data on GBS-related stillbirth occurring ≥20 weeks of gestation, with GBS confirmed by autopsy or by culture from the placenta, amniotic fluid, or other normally sterile site samples from the stillborn.

DATA COLLECTION AND ANALYSIS

Descriptive analyses were performed with the absolute GBS-related stillbirth rates and proportion of stillbirths attributed to GBS calculated per study where possible. Differences in stillbirth definitions did not allow for pooled estimates to be calculated.

MAIN RESULTS

Seventeen studies reported GBS-related stillbirth rates varying from 0.04 to 0.9 per 1000 births, with the proportion of stillbirths associated with GBS ranging from 0 to 12.1%. Most studies reported data from before the year 2000 and from high-income countries.

CONCLUSIONS

The sparsely available epidemiological evidence was not reported consistently, emphasising the importance of standardised stillbirth definitions and diagnostic methods to optimally assess the effectiveness of any future antenatal interventions. Timing of stillbirth, GBS serotype, and global diversity were gaps in the current evidence.

TWEETABLE ABSTRACT

Systematic review finds Group B Streptococcus causes up to 12.1% of stillbirths, but more research is needed.

Perinatal Screening for Chagas Disease in Southern Texas

Perinatal screening for Trypanosoma cruzi in a cohort of 4000 predominantly Hispanic women in southern Texas revealed that Chagas disease occurs with sufficient frequency (0.25%) that targeted perinatal screening should be considered to identify infected mothers and infants at risk for congenital infection.

Ascending in utero herpes simplex virus infection in an initially healthy-appearing premature infant

The usual route of acquisition for intrauterine herpes simplex virus (HSV) infection is transplacental. We evaluated a premature infant with in utero acquisition of HSV resulting from ascending infection. Histopathologic evidence of chronic chorioamnionitis and positive staining with immunohistochemistry for HSV in the placenta and umbilical cord established the diagnosis. The clinical presentation was also of interest in that the infant was initially healthy appearing.

Neglected parasitic infections in the United States: Chagas disease

Chagas disease, which is caused by the protozoan parasite Trypanosoma cruzi, can lead to severe cardiac and gastrointestinal disease. Most persons acquire this infection through contact with vector bugs carrying T. cruzi in endemic areas of Latin America. Infection can also be acquired by congenital, transfusion, transplantation, and foodborne transmission. Although an estimated 300,000 persons with Chagas disease live in the United States, little is known about the burden of chagasic heart disease. It is not known how often congenital or vector-borne transmission of T. cruzi occurs in the United States, although it is known that infected mothers and infected vector bugs are found in this country. Better diagnostic tests and treatment drugs are needed to improve patient care, and research is needed to define transmission risks and develop strategies to prevent new infections and reduce the burden of disease.

Safety and immunogenicity of tetanus diphtheria and acellular pertussis (Tdap) immunization during pregnancy in mothers and infants: a randomized clinical trial

IMPORTANCE

Maternal immunization with tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine could prevent infant pertussis.

OBJECTIVE

To evaluate the safety and immunogenicity of Tdap immunization during pregnancy and its effect on infant responses to diphtheria and tetanus toxoids and acellular pertussis (DTaP) vaccine.

DESIGN, SETTING, AND PARTICIPANTS

Phase 1-2, randomized, double-blind, placebo-controlled, clinical trial conducted from 2008 to 2012. Forty-eight pregnant women aged 18 to 45 years received Tdap (n = 33) or placebo (n = 15) at 30 to 32 weeks' gestation, with crossover immunization postpartum.

INTERVENTIONS

Tdap vaccination at 30 to 32 weeks' gestation or postpartum.

MAIN OUTCOMES AND MEASURES

Primary outcomes were maternal and infant adverse events, pertussis illness, and infant growth and development until age 13 months. Secondary outcomes were antibody concentrations in pregnant women before and 4 weeks after Tdap immunization or placebo, at delivery and 2 months' postpartum, and in infants at birth, at 2 months, and after the third and fourth doses of DTaP.

RESULTS

No Tdap-associated serious adverse events occurred in women or infants. Injection site reactions after Tdap immunization were reported in 26 (78.8% [95% CI, 61.1%-91.0%]) and 12 (80% [95% CI, 51.9%-95.7%]) pregnant and postpartum women, respectively (P > .99). Systemic symptoms were reported in 12 (36.4% [ 95% CI, 20.4%-54.9%]) and 11 (73.3% [95% CI, 44.9%-92.2%]) pregnant and postpartum women, respectively (P = .03). Growth and development were similar in both infant groups. No cases of pertussis occurred. Significantly higher concentrations of pertussis antibodies were measured at delivery in women who received Tdap during pregnancy vs postpartum (eg, pertussis toxin antibodies: 51.0 EU/mL [95% CI, 37.1-70.1] and 9.1 EU/mL [95% CI, 4.6-17.8], respectively; P < .001) and in their infants at birth (68.8 EU/mL [95% CI, 52.1-90.8] and 14.0 EU/mL [95% CI, 7.3-26.9], respectively; P < .001) and at age 2 months (20.6 EU/mL [95% CI, 14.4-29.6] and 5.3 EU/mL [95% CI, 3.0-9.4], respectively; P < .001). Antibody responses in infants born to women receiving Tdap during pregnancy were not different following the fourth dose of DTaP.

CONCLUSIONS AND RELEVANCE

This preliminary assessment did not find an increased risk of adverse events among women who received Tdap vaccine during pregnancy or their infants. For secondary outcomes, maternal immunization with Tdap resulted in high concentrations of pertussis antibodies in infants during the first 2 months of life and did not substantially alter infant responses to DTaP. Further research is needed to provide definitive evidence of the safety and efficacy of Tdap immunization during pregnancy.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00707148.

Time-dependent structural changes of the dentatothalamic pathway in children treated for posterior fossa tumor

BACKGROUND AND PURPOSE

Injury to the dentatothalamic pathway that originates in the cerebellum has been suggested as a mechanism for neurologic complications in children treated for posterior fossa tumors. We hypothesized that time-dependent changes occur in the dentatothalamic pathway.

MATERIALS AND METHODS

Diffusion tensor evaluation was performed in 14 children (median age, 4.1 years; age range, 1-20 years) who underwent serial MR imaging at 3T as part of routine follow-up after posterior fossa tumor resection with or without adjuvant therapy. Tensor metrics were obtained in the acute (≤1 week), subacute (1 to <6 months), and chronic (≥6 months) periods after surgery. We evaluated the following dentatothalamic constituents: bilateral dentate nuclei, cerebellar white matter, and superior cerebellar peduncles. Serial dentate nuclei volumes were also obtained and compared with the patient's baseline.

RESULTS

The most significant tensor changes to the superior cerebellar peduncles and cerebellar white matter occurred in the subacute period, regardless of the tumor pathology or therapy regimen, with signs of recovery in the chronic period. However, chronic volume loss and reduced mean diffusivity were observed in the dentate nuclei and did not reverse. This atrophy was associated with radiation therapy and symptoms of ataxia.

CONCLUSIONS

Longitudinal diffusion MR imaging in children treated for posterior fossa tumors showed time-dependent tensor changes in components of the dentatothalamic pathway that suggest evolution of structural damage with inflammation and recovery of tissue directionality. However, the dentate nuclei did not show tensor or volumetric recovery, suggesting that the injury may be chronic.

Maternal antibody at delivery protects neonates from early onset group B streptococcal disease

BACKGROUND

Further reduction in the group B streptococcal (GBS) disease burden in neonates in the United States awaits an additional prevention strategy, such as maternal immunization.

METHODS

We performed a prospective, multicenter, case-control study of 33 mothers delivering neonates with early onset GBS infection (cases), and 99 age- and ethnicity-matched mothers colonized with the same capsular polysaccharide (CPS) types delivering healthy neonates (controls). Relative risk and absolute risk were calculated for early onset disease associated with concentrations of type Ia, III, or V CPS-specific antibody in maternal serum.

RESULTS

For GBS types Ia and III, maternal CPS-specific antibody concentrations of ≥ 0.5 µg/mL were associated with a relative risk of approximately 0.1 (95% confidence intervals [CIs], .01-.74 and 0-.72, respectively; P = .02 for each), corresponding to a 90% risk reduction (by logistic regression). For type V, the relative risk was 0.3 (95% CI, .01-3.1), corresponding to a 70% risk reduction. By Bayesian modeling, the risk of early onset disease would decrease by 70% if maternal CPS-specific antibody concentrations for these 3 GBS types were ≥ 1 µg/mL.

CONCLUSIONS

Maternal CPS-specific antibody serum concentrations of ≥ 1 μg/mL at the time of delivery appear to protect most neonates from early onset GBS type Ia and III disease.

Arterial spin-labeled perfusion of pediatric brain tumors

BACKGROUND AND PURPOSE

Pediatric brain tumors have diverse pathologic features, which poses diagnostic challenges. Although perfusion evaluation of adult tumors is well established, hemodynamic properties are not well characterized in children. Our goal was to apply arterial spin-labeling perfusion for various pathologic types of pediatric brain tumors and evaluate the role of arterial spin-labeling in the prediction of tumor grade.

MATERIALS AND METHODS

Arterial spin-labeling perfusion of 54 children (mean age, 7.5 years; 33 boys and 21 girls) with treatment-naive brain tumors was retrospectively evaluated. The 3D pseudocontinuous spin-echo arterial spin-labeling technique was acquired at 3T MR imaging. Maximal relative tumor blood flow was obtained by use of the ROI method and was compared with tumor histologic features and grade.

RESULTS

Tumors consisted of astrocytic (20), embryonal (11), ependymal (3), mixed neuronal-glial (8), choroid plexus (5), craniopharyngioma (4), and other pathologic types (3). The maximal relative tumor blood flow of high-grade tumors (grades III and IV) was significantly higher than that of low-grade tumors (grades I and II) (P < .001). There was a wider relative tumor blood flow range among high-grade tumors (2.14 ± 1.78) compared with low-grade tumors (0.60 ± 0.29) (P < .001). Across the cohort, relative tumor blood flow did not distinguish individual histology; however, among posterior fossa tumors, relative tumor blood flow was significantly higher for medulloblastoma compared with pilocytic astrocytoma (P = .014).

CONCLUSIONS

Characteristic arterial spin-labeling perfusion patterns were seen among diverse pathologic types of brain tumors in children. Arterial spin-labeling perfusion can be used to distinguish high-grade and low-grade tumors.

Effects of added chelated trace minerals, organic selenium, yeast culture, direct-fed microbials, and Yucca schidigera extract in horses: II. Nutrient excretion and potential environmental impact

The objective of this study was to test the hypothesis that an equine diet formulated with chelated trace minerals, organic selenium, yeast culture, direct-fed microbials (DFM) and Yucca schidigera extract would decrease excretion of nutrients that have potential for environmental impact. Horses were acclimated to 100% pelleted diets formulated with (ADD) and without (CTRL) the aforementioned additives. Chelated sources of Cu, Zn, Mn, and Co were included in the ADD diet at a 100% replacement rate of sulfate forms used in the CTRL diet. Additionally, the ADD diet included organic selenium yeast, DFM, and Yucca schidigera extract. Ten horses were fed the 2 experimental diets during two 42-d periods in a crossover design. Total fecal and urine collection occurred during the last 14 d of each period. Results indicate no significant differences between Cu, Zn, Mn, and Co concentrations excreted via urine (P > 0.05) due to dietary treatment. There was no difference between fecal Cu and Mn concentrations (P > 0.05) based on diet consumed. Mean fecal Zn and Co concentrations excreted by horses consuming ADD were greater than CTRL (P < 0.003). Differences due to diet were found for selenium fecal (P < 0.0001) and urine (P < 0.0001) excretions, with decreased concentrations found for horses consuming organic selenium yeast (ADD). In contrast, fecal K (%) was greater (P = 0.0421) for horses consuming ADD, whereas concentrations of fecal solids, total N, ammonia N, P, total ammonia, and fecal output did not differ between dietary treatments (P > 0.05). In feces stockpiled to simulate a crude composting method, no differences (P > 0.05) due to diet were detected for particle size, temperature, moisture, OM, total N, P, phosphate, K, moisture, potash, or ammonia N (P > 0.05). Although no difference (P = 0.2737) in feces stockpile temperature due to diet was found, temperature differences over time were documented (P < 0.0001). In conclusion, the addition of certain chelated mineral sources, organic Se yeast, DFM, and Yucca schidigera extract did not decrease most nutrient concentrations excreted. Horses consuming organic selenium as part of the additive diet had lower fecal and urine Se concentrations, as well as greater fecal K concentrations.

Preventing the broad spectrum of perinatal morbidity and mortality through group B streptococcal vaccination

The development of a group B streptococcal (GBS) glycoconjugate vaccine and its upcoming evaluation in a phase 3 trial in pregnant women highlight the importance of defining the anticipated impact of GBS vaccination upon the broad spectrum of GBS-related perinatal morbidity and mortality. We present the specific pregnancy-associated and neonatal conditions attributable, at least in part, to GBS in high and lower income countries. We offer a rationale to support our contention that implementation of GBS glycoconjugate immunization during pregnancy will reduce the global burden of GBS-related morbidity and mortality in pregnant women and their infants.

Long-term outcomes of group B streptococcal meningitis

OBJECTIVE

Group B Streptococcus (GBS) is the leading cause of meningitis in young infants. We evaluated long-term outcomes among GBS meningitis survivors. We hypothesized that despite reduced mortality, GBS meningitis would remain a significant cause of morbidity among GBS survivors.

METHODS

Ninety term and near-term infants diagnosed with GBS meningitis from 1998 through 2006 were identified from 2 children's hospitals. Five died acutely, and 5 died at 6 months to 3 years of age. Forty-three survivors (54%; mean age 6.8, range 3-12 years) were consented for evaluation and underwent physical and neurologic examinations, hearing and vision screening, and standardized developmental assessments. Associations among presenting features, laboratory parameters, neurologic status at hospital discharge, and later developmental outcomes were explored by using descriptive statistics and logistic regression.

RESULTS

Twenty-four of 43 (56%) children evaluated demonstrated age-appropriate development, 11 (25%) had mild-to-moderate impairment, and 8 (19%) had severe impairment. Admission features associated with death after hospital discharge or severe impairment included lethargy (P = .003), respiratory distress (P = .022), coma or semicoma (P = .022), seizures (P = .015), bulging fontanel (P = .034), leukopenia (P = .026), acidosis (P = .024), cerebrospinal fluid protein >300 mg/dL (P = .006), cerebrospinal fluid glucose <20 mg/dL (P = .026), and need for ventilator (P = .002) or pressor support (P < .001). Features at discharge associated with late death or severe impairment included failed hearing screen (P = .004), abnormal neurologic examination (P < .001), and abnormal end of therapy brain imaging (P = .038).

CONCLUSIONS

Survivors of GBS meningitis continue to have substantial long-term morbidity, highlighting the need for ongoing developmental follow-up and prevention strategies such as maternal immunization.

Persistence of functional antibodies to group B streptococcal capsular polysaccharides following immunization with glycoconjugate vaccines

The duration of functional activity of group B streptococcal (GBS) glycoconjugate vaccine-induced capsular polysaccharide-specific (CPS) IgG was evaluated among healthy adult responders. Opsonophagocytic activity declined significantly from a 4-week post-immunization peak, but substantial functional activity, exceeding 1 log(10) reduction in GBS cfu/mL, was retained at 18 months to 2 years post-immunization for each GBS type assessed. The persistence of functional antibody activity when GBS CPS-specific IgG concentrations decline, although remaining significantly higher than pre-immunization levels, suggests that long-term protection may be expected from candidate GBS glycoconjugates administered to this population.

A systematic review of treatment guidelines for metastatic colorectal cancer

AIM

A systematic review of treatment guidelines for metastatic colorectal cancer (mCRC) was performed to assess recommendations for monoclonal antibody therapy in these guidelines.

METHOD

Relevant papers were identified through electronic searches of MEDLINE, MEDLINE In Process, EMBASE and the Cochrane Library; through manual searches of reference lists; and by searching the Internet.

RESULTS

A total of 57 relevant guidelines were identified, 32 through electronic database searches and 25 through the website searches. The majority of guidelines were published between 2004 and 2010. The country publishing the most guidelines was the USA (12), followed by the UK (10), Canada (eight), France (eight), Germany (three), Australia (two), Spain (two) and Italy (one). In addition, eight European and three international guidelines were identified. As monoclonal antibody therapy for mCRC was not introduced until 2004, no firm recommendations for monoclonal antibody therapy were made in guidelines published between 2004 and 2006. Recommendations for monoclonal antibody therapy first appeared in 2007 and evolved as more data became available. The most recent international, European and US guidelines recommend combination chemotherapy with the addition of a monoclonal antibody for the first-line treatment of mCRC. Second-line treatment depends on the first-line regimen used. For chemoresistant mCRC, cetuximab or panitumumab are recommended as monotherapy in patients with wild-type KRAS tumours.

CONCLUSION

The study indicates that recent treatment guidelines have recognized the role of monoclonal antibodies in the management of mCRC, and that treatment guidelines should be updated in a timely manner to reflect the most recently available data.

Vancomycin dosing in obese pediatric patients

BACKGROUND

Data are lacking to guide antimicrobial dosing for overweight children. The authors hypothesized that obese children would have increased vancomycin serum trough concentrations compared with nonobese children.

METHODS

A matched study design was employed to compare retrospectively vancomycin trough concentrations.

RESULTS

Among 24 matched pairs, obese patients received 14.1 ± 1.5 mg per kilogram and nonobese children 14.9 ± 0.9 mg per kilogram of vancomycin per kilogram of vancomycin (P = .03). There was a trend toward higher vancomycin serum concentrations in obese (6.9 ± 4.30 μg/mL) versus nonobese children (4.8 ± 3.08 μg/mL; P = .052). Mean half-life in obese patients was 2.9 ± 0.29 hours and volume of distribution was 0.35 ± 0.15 L/kg.

CONCLUSIONS

Since obesity did not alter vancomycin trough concentrations, overweight children should receive vancomycin based on actual body weight. However, since vancomycin troughs were substantially lower than those recommended for adults, further studies of vancomycin metabolism in children are needed.

Intraorbital and intracranial extension of sinusitis: comparative morbidity

OBJECTIVES

We hypothesized that intracranial extension of sinusitis carries greater morbidity than extension confined to the orbit and that presenting features can raise suspicion for intracranial extension.

STUDY DESIGN

A retrospective review (1997 to 2006) identified 118 children with sinusitis complicated by intracranial extension or intraorbital extension. Presenting features and infecting organisms were compared using χ(2) or Fisher exact tests. Outcomes included duration of hospitalization, length of therapy and sequelae.

RESULTS

Thirty-three children had intracranial extension and 85 had intraorbital extension. Children with intracranial extension were older (11.4 versus 7.6 years; P ≤ .001), had more preadmission encounters (1.9 versus 1.3; P = .012), longer headache duration (9.5 versus 2.8 days; P = .009), and presented more often with vomiting (73% versus 28%; P < .001) than those with intraorbital extension. Children with intracranial extension also were hospitalized (26 versus 10 days; P < .001) and treated (36 versus 24 days; P = .001) longer. Four children (3%) had persistent sequelae.

CONCLUSIONS

Children with intracranial extension are hospitalized and treated longer than those with intraorbital extension of sinusitis but persistent sequelae are uncommon. Prolonged headache and protracted vomiting at presentation should alert caregivers to consider intracranial extension.

Escherichia coli--infected cephalohematoma in an infant

This report describes a 1-month-old female with bacteremia and meningitis complicated by an infected cephalohematoma that resulted from hematogenous seeding. This report serves as a reminder that, although occurring rarely, inflammation overlying a cephalohematoma in an infant with bacteremia can indicate focal infection that requires incision and drainage for resolution.

Group B streptococcal conjugate vaccine: a timely concept for which the time has come

Invasive disease due to group B Streptococcus (GBS) has been recognized as a threat to the health of pregnant women and their infants for almost half a century. Development of GBS vaccine candidates has progressed at an exemplary pace given lack of sponsorship by manufacturers. A trivalent or pentavalent vaccine will be required, and decisions must be made as to the criteria by which efficacy will be determined and the population in whom efficacy will be assessed. Concerns regarding durability of conjugate vaccine-derived immunity, pregnant women as a possible target group and regulatory issues required for licensing must be resolved if the prospect of impacting GBS disease burden through immunization is to become a reality.

Revascularization for atherosclerotic renal artery stenosis: the treatment of choice?

Atherosclerotic renal artery stenosis (ARAS) is an important cause of renal dysfunction and secondary hypertension, and is associated with adverse cardiovascular events and increased mortality. The natural history of ARAS is characterized by anatomic disease progression and/or renal dysfunction in only a minority of patients. Medical therapy for ARAS is directed primarily toward blood pressure control and cardiovascular risk factor reduction. Renal artery revascularization is an additional treatment option for ARAS associated with ischemic nephropathy or severe, poorly controlled hypertension despite aggressive medical therapy. Unfortunately, the benefits associated with revascularization versus medical therapy alone remain unproven. Renal artery revascularization may be accomplished through open surgical revascularization or angioplasty and stenting. Although surgical renal revascularization is associated with more durable results and relatively lower risk for postoperative renal function decline, the increased risk of death or major complications associated with this management approach limit its use in patients with significant comorbidities. Renal artery angioplasty and stenting is being utilized with increasing frequency but is of uncertain benefit and is associated with rates of post-intervention renal function improvement and deterioration that are approximately equal. Renal function outcomes associated with angioplasty and stenting may be improved through a selective treatment approach and utilization of distal embolic protection. Renal artery revascularization represents the only treatment alternative for patients unresponsive to medical management, and is therefore the ''treatment of choice'' in this select group. Results of ongoing randomized trials are eagerly anticipated and may provide useful guidance for future management of ARAS.

Unusual soft tissue manifestations of Neisseria meningitidis infections

Soft tissue involvement is an unusual presenting feature for children with meningococcal infection. We describe 2 children, 1 with conjunctivitis and another with a thyroglossal duct cyst abscess associated with Neisseria meningitidis, and review previous reports of these entities to emphasize the broad spectrum of meningococcal disease and pertinent aspects of treatment and of prophylaxis of contacts.

Is embolic protection during renal artery intervention really necessary?

Atherosclerotic renovascular disease is an increasingly recognized cause of both renal function impairment and hypertension, and its presence is associated with increased cardiovascular mortality and dialysis dependence. Although surgical renal revascularization is associated with the most favorable reported renal function outcomes, the significant perioperative mortality and complication rates have resulted in a shift to renal artery percutaneous transluminal angioplasty and stenting (RA-PTAS) as the most frequently performed method of revascularization. Renal function outcomes following RA-PTAS are less favorable, with patients experiencing functional improvement and deterioration with approximately equal frequency in reported series. Distal atheroembolization is thought to occur during RA-PTAS and has been suggested as a potential cause of the disparate renal function outcomes. Distal embolic protection devices primarily used and evaluated in the coronary and cerebrovascular circulations have also been successfully employed during RA-PTAS. Initial clinical results following RA-PTAS with distal embolic protection have been promising, with high rates of technical success, renal function outcomes that approximate those reported with open surgical revascularization, and maintenance of relatively low death and complication rates. Further investigation with controlled comparison groups is warranted before routine use of distal embolic protection can be uniformly endorsed.

Group B Streptococcus bacteremia elicits beta C protein-specific IgMand IgG in humans

Group B Streptococcus (GBS) beta C protein elicits protective antibodies in experimental animals, making beta C protein an attractive component of a human GBS glycoconjugate vaccine. We determined whether natural exposure to beta C protein elicits antibodies in humans. Geometric mean concentrations (in micrograms per milliliter) of beta C-specific immunoglobulin (Ig) M and IgG as determined by enzyme-linked immunosorbent assay were similar in serum from 16 colonized (0.82 and 0.76, respectively) and 48 age-matched noncolonized (0.96 and 0.74, respectively) pregnant women. Serum from 3 women with beta C GBS bacteremia had significantly higher levels of IgM (6.0) and IgG (52.9) (P=.01 and 0.01, respectively). Invasive disease but not colonization elicits beta C-specific IgM and IgG.

Dose-response to type V group B streptococcal polysaccharide-tetanus toxoid conjugate vaccine in healthy adults

A phase 1, dose-escalating trial was conducted in healthy adults to evaluate immunogenicity and reactogenicity of a type V group B streptococcal (GBS) capsular polysaccharide (CPS)-tetanus toxoid (TT) conjugate vaccine. Participants received one dose of unconjugated V CPS (37 microg), V-TT (2.4 microg CPS/1.1 microg TT), V-TT (9.6 microg CPS/4.3 microg TT) or V-TT (38.5 microg CPS/17.0 microg TT). Each vaccine and all doses of V-TT were well-tolerated. V CPS-specific antibodies reached a peak 4-8 weeks after immunization and were significantly higher through 52 weeks post-immunization in recipients of V-TT at each dose than in uncoupled CPS vaccinees. V-TT vaccine-induced antibodies promoted opsonophagocytic killing of type V GBS and avidity maturation of V CPS-specific IgG.

Issues of Antimicrobial Resistance in Group B Streptococcus in the Era of Intrapartum Antibiotic Prophylaxis

The implementation of a culture screening-based approach to intrapartum antibiotic prophylaxis has been associated with substantial reduction in the incidence of early-onset group B streptococcal disease. Antibiotic prophylaxis is recognized as an interim strategy awaiting the licensure of a safe and effective conjugate vaccine for prevention of group B streptococcal infections in all susceptible populations. This article addresses concerns relating to antimicrobial resistance among group B streptococci that have arisen from use of intrapartum antibiotic prophylaxis and from increases in resistance in other gram-positive bacteria related genetically to group B streptococci.

Group B streptococcal infections in elderly adults

Elderly adults account for >40% of persons with invasive group B streptococcal (GBS) disease and for >50% of GBS-associated deaths in the United States. The prevalence of colonization among healthy elderly adults (approximately 25%) is similar to that among women of childbearing age. Delineating contributions of comorbid conditions, altered integrity of anatomical barriers, and abnormalities in immune responses caused by immune senescence to pathogenesis require further investigation. Delayed clinical recognition of illness may contribute to poor outcome. Skin and soft-tissue infections and bacteremia with no identified focus are common manifestations of infection in elderly adults and younger nonpregnant adults. Urinary tract infection and pneumonia are presentations more often encountered in elderly persons than in younger adults. The safety and immunogenicity of GBS serotype V-tetanus toxoid conjugate vaccine in healthy elderly persons suggest the potential for vaccination as an approach to prevention of invasive GBS infections in elderly persons.

Group B Streptococcal Colonization and Serotype-Specific Immunity in Healthy Elderly Persons

BACKGROUND

The burden from group B streptococcal (GBS) disease in elderly persons (age, >or=65 years) has increased. Rates of colonization and prevalence of antibodies against capsular polysaccharides (CPS) that might confer protection against invasive GBS disease in such persons are not defined.

METHODS

A cross-sectional survey was conducted in an outpatient setting in Houston. GBS colonization rates in this convenience sample were assessed by self-obtained vaginal and rectal specimens (for women) and rectal and urine specimens (for men). The CPS type distribution among GBS isolates was determined, and CPS-specific antibodies against GBS types Ia, Ib, II, III, and V were quantified by enzyme-linked immunosorbent assays.

RESULTS

The GBS colonization rate among 254 healthy elderly participants (mean age, 73 years) was 21.7%. CPS types Ia (22.8%), III (12.3%), and V (47.3%) predominated, and 12.3% of colonizing isolates were nontypeable. Random selection of 1 member of 33 participating married couples did not alter the overall colonization rate (21.7%) or GBS serotype distribution. The geometric mean concentrations of CPS-specific IgG in serum specimens were low and were significantly lower for GBS type V, compared with other serotypes (P<.001).

CONCLUSIONS

Adults >or=65 years of age are colonized with GBS at a rate similar to that of younger persons, but older adults are significantly more likely to carry type V, the leading cause of invasive disease in elderly persons, and to lack type V CPS-specific serum IgG. The CPS of type V GBS should be included in candidate GBS vaccines so that adults >or=65 years of age theoretically could be protected against invasive disease.

Features of invasive staphylococcal disease in neonates

OBJECTIVE

Most clinical descriptions of invasive staphylococcal disease (ISD) in neonates date from before the mid-1980s, when neonatal viability and intensive care differed substantially from current standards. We aimed to describe the contemporary incidence, clinical features, and outcome of infants with ISD in a neonatal intensive care unit.

METHODS

A retrospective cohort study was conducted of infants who had ISD and were in the neonatal intensive care unit of the Woman's Hospital of Texas, Houston, from January 2000 to June 2002. Confirmed ISD was defined as clinical sepsis and Staphylococcus aureus (SA) isolated from > or =1 blood culture (BC) or a sterile body site excluding urine or coagulase-negative staphylococci (CoNS) isolated from > or =2 BC or from 1 BC and a sterile body site. Probable ISD was defined as CoNS isolated from 1 BC or a sterile body site for which clinical and laboratory data review by 3 infectious disease specialists indicated that antimicrobial treatment was appropriate. Confirmed and combined confirmed plus probable cases were analyzed.

RESULTS

A total of 149 episodes (83 confirmed [39 SA, 44 CoNS], 66 probable) in 137 infants (mean gestational age [GA]: 27.6 weeks [22.4-36.4]; mean birth weight: 981 g [350-2995]) were reviewed. Four (3%) infants had early-onset infection (2 SA, 2 CoNS). Median age at infection onset was similar (17 days SA; 18 days CoNS). Intravascular catheters (IVC) were in situ in a minority of infants with ISD episodes (38% SA, 43% CoNS). CoNS more than SA infections were associated with very low birth weight (<1500 g), lower GA, a history of more IVCs and concurrent total parenteral nutrition, but IVC and parenteral nutrition days were similar. By multivariate analysis correcting for birth weight and complications of prematurity, hypoxia at the time of sepsis evaluation was significantly associated with CoNS and hypotension with SA infections; other clinical features were similar. Methicillin-resistant SA caused 8% of SA infections. Among bacteremic infants, SA more frequently than CoNS involved > or =2 sites. Overall, SA had more focal complications (primarily bone and joint) than CoNS, resulting in a 2- to 3-fold higher SA-associated morbidity rate. Mortality directly attributable to either organism was similar (5% SA; 5% confirmed, 3% confirmed/probable CoNS).

CONCLUSION

CoNS ISD occurred in smaller, more premature infants than SA and was IVC associated in a minority of cases. Hypoxia and hypotension were the only presenting features that differentiated CoNS and SA. SA-associated morbidity was substantial, but SA infection carried no greater risk of death (5%) than CoNS.

Antibodies to type III group B streptococcal polysaccharide in breast milk

We compared concentrations of type III group B streptococcal capsular polysaccharide (CPS)-specific IgG and IgA in archived 2-month-postpartum breast milk from 9 women with > or =1 microg/ml and 9 with < 1 microg/ml type III CPS-specific IgG in serum. Type III CPS-specific antibodies were not detectable consistently but were measurable in breast milk from some women in both groups, indicating their potential for a role in prevention or amelioration of late onset group B streptococcal disease.

Use of Type V Group B Streptococcal Conjugate Vaccine in Adults 65–85 Years Old

One-third of the cases of invasive group B streptococcal (GBS) disease now occur in adults >or=65 years old. Serotype V is most frequent among these invasive isolates. The safety and immunogenicity of type V GBS capsular polysaccharide (CPS)-tetanus toxoid (V-TT) conjugate vaccine (CV) were assessed in 32 healthy adults 65-85 years old who were randomized to receive a single intramuscular dose of V-TT CV (n=22) or licensed tetanus-diphtheria toxoid vaccine (Td) (n=10; double-masked design). V-TT CV elicited significant increases in type V CPS-specific immunoglobulin (Ig) G, IgM, and IgA serum concentrations 4, 8, 26, and 52 weeks after immunization. V-TT-induced type V CPS-specific antibodies promoted the opsonophagocytic killing of type V GBS in vitro. Both vaccines elicited similar concentrations of TT-specific IgG in 4-week postimmunization serum samples. These results suggest the potential for prevention of invasive type V GBS infections in healthy elderly adults through immunization.

Vagal nerve stimulator pocket infections

Vagal nerve stimulator pocket infections are uncommon but can cause considerable morbidity. We describe 3 children from our institution and 8 others previously reported with infection after vagal nerve stimulator implantation for seizure control. Infection was suppressed but recurred despite appropriate antimicrobial therapy when the device remained in situ. Device removal was required in all patients to achieve cure.