Eunkyung Song

Clinical and Virologic Characteristics May Aid Distinction of Acute Adenovirus Disease from Kawasaki Disease with Incidental Adenovirus Detection.

Incidental adenovirus detection in Kawasaki disease (KD) is important to differentiate from acute adenovirus disease. Twenty-four of 25 children with adenovirus disease and mimicking features of KD had <4 KD-like features, predominance of species B or E, and higher viral burden compared with those with KD and incidental adenovirus detection.

Performance Characteristics of FilmArray Respiratory Panel v1.7 for Detection of Adenovirus in a Large Cohort of Pediatric Nasopharyngeal Samples: One Test May Not Fit All

ABSTRACT The FilmArray Respiratory Panel (RP) v1.7 assay has improved sensitivity for detection of human adenovirus (HAdV), compared to an earlier version (RP v1.6). RP v1.7 was designed for detection of species B, C, and E but may show variable detection of species A, D, and F. We sought to evaluate the clinical and analytical performance of RP v1.7 for detection of HAdV in a large pediatric cohort. Respiratory specimens obtained from a tertiary care childrens hospital between February 2014 and February 2015 were tested for HAdV by RP v1.7. If the RP v1.7 results were negative for HAdV, then the specimens were reflexed to a HAdV-specific laboratory-developed PCR (LD-PCR) assay for confirmation. A subset of specimens underwent secondary confirmatory testing using another commercially available HAdV PCR assay and a molecular typing assay for species identification. Among 4,750 specimens, a total of 146 specimens (3.1%) were HAdV positive by RP v1.7. HAdV was detected by LD-PCR in an additional 220 specimens that were negative by RP v1.7. Overall, a nearly 5% increase in HAdV detection was observed when RP v1.7-negative specimens were reflexed to LD-PCR testing. RP v1.7 did not detect HAdV with either low viral burden (threshold cycle values of >30) or nonrespiratory species (species A, D, and F), as shown in both clinical and analytic data. While the level of sensitivity of RP v1.7 may be adequate for testing among otherwise healthy children, the decreased sensitivity may be problematic for immunocompromised patients, in whom low levels of HAdV in the respiratory tract may precede systemic infection and require early intervention.

Diagnosis of Pediatric Acute Adenovirus Infections: Is a Positive PCR Sufficient?

Background: Human adenovirus (HAdV), especially species C (HAdV-C), can be detected incidentally by polymerase chain reaction in nasopharyngeal (NP) samples, making it difficult to interpret clinical significance of a positive result. We classified patients into groups based on HAdV culture positivity from respiratory specimens and the presence of an identified co-pathogen. We hypothesized that HAdV-C would be over-represented and viral burden would be lower in patients most likely to have incidental detection (ie, with a negative viral culture and documented co-pathogen). Methods: Immunocompetent children with HAdV + nasopharyngeal specimens were classified into 4 groups: group I (HAdV culture (+) and no co-infection), group II (culture (+) and co-infection), group III (culture (−) and no co-infection) and group IV (culture (−) and co-infection). Viral burden (cycle threshold) and species were compared among groups. Results: Of 483 nasopharyngeal specimens, HAdV was isolated in culture in 252 (52%); co-infection was found in 265 (55%) patients. Group I (most consistent with acute disease) had significantly lower cycle thresholds (median 23.9; interquarile range 22.2–28.1) compared with group IV (most consistent with incidental detection; median 37.3; interquarile range 35.3–38.9; P < 0.0001). HAdV-C accounted for 41% samples of group I and 83% of group IV (P < 0.0001). We identified a subset of 22 patients with bacterial or fungal co-pathogens, 18 of whom had no growth on viral culture (group IV) with a median cycle threshold of 37.4 (interquarile range 33.9–39.2). Conclusions: Species identification and viral burden may assist in interpretation of a positive HAdV result. Low viral burden with HAdV-C may be consistent with incidental detection.

Acanthamoeba granulomatous amoebic encephalitis after pediatric hematopoietic stem cell transplant

Acanthamoeba encephalitis is a rare, often fatal condition, particularly after HSCT, with 9 reported cases to date in the world literature. Our case was originally diagnosed with ALL at age 3 years, and after several relapses underwent HSCT at age 9 years. At 17 years of age, he was diagnosed with secondary AML for which he underwent a second allogeneic HSCT. He presented with acute‐onset worsening neurological deficits on day +226 after the second transplant and a post‐mortem diagnosis of Acanthamoeba encephalitis was established, with the aid of the CDC.

Human Adenovirus (HAdV) Viremia in Immunocompetent Children with HAdV Infection in Respiratory Specimens: Does Viremia Predict Severity of Illness?

Abstract Background The interpretation of HAdV PCR from upper respiratory tract (RT) specimens can be challenging due to prolonged low grade viral shedding. We hypothesized that HAdV detection in the blood (viremia) is more common in acute HAdV infection with high respiratory viral burden (VB) compared with those with low VB in the RT. We sought to determine the frequency of HAdV viremia in immunocompetent children who have detectable HAdV in the RT. Methods We prospectively identified + HAdV in RT specimens from emergency department or inpatients using semi-quantitative real-time PCR (Ct <40) or multiplex respiratory viral PCR (FILMARRAY RESPIRATORY PANEL v1.7) and prospectively collected available whole blood from 8/2013 to 2/2015. Blood was considered positive for HAdV if Ct was <40 in whole blood. We compared virologic, including HAdV type from the RT and blood, and clinical characteristics between viremic and non-viremic groups using Mann–Whitney or chi-square as appropriate. Results There were 196 unique patients with + HAdV in RT specimens as well as available blood for PCR (median age=1.3 years old). Blood and RT samples were obtained on the same calendar day in 78% of patients. Among these 196 patients, 163 (83%) were hospitalized and 58 (36%) were admitted to PICU. HAdV was detected in the blood in 33% of patients. Upper respiratory tract infections were more common (P = 0.026) and the duration of fever at the time of enrollment was longer in the viremia group (3 vs. 2 days, P = 0.043). There was no difference in ICU admission between two groups. Coinfections with bacterial pathogens from sterile sites were only found in the non-viremic group (4%); these included S. aureus or pneumococcal bacteremia, E. coli urinary tract infections, or pneumococcal pneumonia. HAdV VB in RT were significantly higher in the viremia group (Ct median 25.01 vs.. 36.38, P < 0.0001). Species C was more predominant in the viremia group compared with non C (A, B/E, D, F) (P = 0.018). RT type was 100% concordant with blood type. Conclusion HAdV viremia is relatively common in immunocompetent children with HAdV infection in the RT. Subjects with viremia had significantly higher VB in the RT, but this didn’t seem to be correlated with disease severity. HAdV viremia may be useful tool to add further evidence of acute HAdV infection. Disclosures A. Leber, BioFIre Diagnostics: Research Contractor and Scientific Advisor, Research support, Speaker honorarium and Travel expenses

A protracted course of Pneumocystis pneumonia in the setting of an immunosuppressed child with GMS-negative bronchoalveolar lavage

We report a case of Pneumocystis pneumonia in a 5-year-old male with Trisomy 21 and acute lymphoblastic leukemia. The lack of response to trimethoprim-sulfamethoxazole raised concerns for antimicrobial resistance. Further, diagnosis of Pneumocystis in this patient was complicated by a GMS-negative bronchoalveolar lavage despite molecular evidence of Pneumocystis infection.

1138Human Adenovirus (HAdV) Blood Viral Detection is Associated with Higher Viral Load in Immunocompetent Pediatric HAdV Respiratory Samples

Higher Viral Load in Immunocompetent Pediatric HAdV Respiratory Samples Eunkyung Song, MD; Amy Leber, PhD; Preeti Jaggi, MD; Octavio Ramilo, MD; Pediatiric Infectious Disease, Nationwide Children’s Hospital, Columbus, OH; Nationwide Children’s Hospital, Columbus, OH; Pediatrics, Section of Infectious Diseases, Nationwide Children’s Hospital, Columbus, OH; Pediatrics, Nationwide Children’s Hospital Columbus, OH