Search

Rotavirus and noroviruses are major causes of diarrhea. Variable rotavirus vaccination efficacy in Africa and Asia is multifactorial, including the diversity of circulating strains and viral co-infection. We describe a multiplexed assay that detects and genotypes viruses from stool specimens. It includes a one-step reverse transcriptase PCR reaction, a ligase detection reaction (LDR), then hybridization of fluorescent products to micro-beads. In clinical samples it detects rotavirus, caliciviruses (sapovirus and norovirus), mixed infections, and genotypes or genogroups of rotaviruses and noroviruses, respectively. The assay also has the capacity to detect hepatitis A. The assay was validated on reference isolates and 296 stool specimens from the US and Ghana. The assay was 97% sensitive and 100% specific. The genogroup was concordant in 100% of norovirus, and the genotype in 91% and 89% of rotavirus G- and P-types, respectively. Two rare rotavirus strains, G6P[6] and G6P[8], were detected in stool specimens from Ghana. The high-throughput assay is sensitive, specific, and may be of utility in the epidemiological surveillance for rare and emerging viral strains post-rotavirus vaccine implementation.

Information about human adenovirus (HAdV) infection in solid organ transplant (SOT) recipients is limited. We aimed to describe HAdV infection epidemiology and outcomes in a single-center retrospective cohort during the era of polymerase chain reaction (PCR) availability. SOT recipients transplanted at the Children’s Hospital of Philadelphia 2004—2013 were followed for 180 days post-transplant. HAdV infection was defined as a positive HAdV PCR from a clinical specimen. HAdV disease was defined by organ-specific radiologic and/or laboratory abnormalities. No HAdV surveillance protocols were employed during the study period; testing was solely per clinician discretion. Progression of HAdV infection was defined as HAdV disease or ≥1-log viral load increase since a corresponding site’s first positive specimen. Of the assembled 425 SOT recipients, 227 (52.6%) had ≥1 HAdV PCR. Twenty-four (10.6%) had ≥1 HAdV-positive PCR. HAdV-positive subjects were younger than uninfected subjects (2.0 years vs. 6.5, p=0.001). Infection incidence rates were highest in liver recipients (15.3%), followed by heart (8.6%), kidney (8.3%), and lung (4.2%). Four subjects (16.7%) met HAdV disease criteria at virus detection. Five subjects (20.8%) had progression of HAdV infection. All-cause mortality rates in positive and negative subjects were 0% and 3.9%, respectively. HAdV infection was infrequently detected in SOT recipients. Over one-third of HAdV-positive patients met disease criteria at detection or had infection progression, but none died. This low all-cause mortality raises questions about benefits of HAdV surveillance. Larger multi-center studies are needed to assess incidence variance by center and comparative effectiveness of therapeutic interventions.

A new method for detecting infectious disease involves the use of a genetic probe and an enzyme that is activated once the probe specifically binds the DNA of the pathogen.

BACKGROUND Human adenoviruses (HAdVs) are associated with significant morbidity and death after hematopoietic cell transplantation (HCT). In this study, we sought to determine the incidence of HAdV infection among pediatric HCT recipients in the polymerase chain reaction (PCR) testing era, identify risk factors for viremia among patients undergoing HAdV surveillance, and assess the effectiveness of preemptive cidofovir. METHODS A single-center retrospective cohort of patients who underwent a transplant within a 10-year period was assembled. The incidence of and outcomes of patients with HAdV infection and disease were determined by PCR results and chart review. A Cox regression model was used for surveilled allogeneic HCT recipients to identify factors associated with viremia. We also used a discrete-time failure model with inverse probability treatment weights to assess the effectiveness of preemptive cidofovir for infection. RESULTS Among 572 HCT recipients, 76 (13.3%) had ≥1 sample that was HAdV PCR positive (3.5% of autologous HCT recipients and 19.7% of allogeneic HCT recipients). Among 191 allogeneic HCT recipients under surveillance, 58 (30.4%) had HAdV detected from any source, and 50 (26.2%) specifically had viremia. The mortality rate was higher in allogeneic HCT recipients with HAdV infection versus those without infection (25.9% vs 11.3%; P = .01). Factors associated with infection included an age of 6 to 12 years, an absolute lymphocyte count of

Two meetings, one sponsored by the Wellcome Trust in 2012 and the other by the Global Virology Foundation in 2013, assembled academic, public health and pharmaceutical industry experts to assess the challenges and opportunities for developing antivirals for the treatment of respiratory syncytial virus (RSV) infections. The practicalities of clinical trials and establishing reliable outcome measures in different target groups were discussed in the context of the regulatory pathways that could accelerate the translation of promising compounds into licensed agents. RSV drug development is hampered by the perceptions of a relatively small and fragmented market that may discourage major pharmaceutical company investment. Conversely, the public health need is far too large for RSV to be designated an orphan or neglected disease. Recent advances in understanding RSV epidemiology, improved point-of-care diagnostics, and identification of candidate antiviral drugs argue that the major obstacles to drug development can and will be overcome. Further progress will depend on studies of disease pathogenesis and knowledge provided from controlled clinical trials of these new therapeutic agents. The use of combinations of inhibitors that have different mechanisms of action may be necessary to increase antiviral potency and reduce the risk of resistance emergence.

Human adenoviruses (HAdV) are known opportunistic pathogens in hematopoietic stem cell transplant (SCT) recipients. The detection of HAdV infection in children after SCT has been implicated as a determinant of poor outcome but specific associations between HAdV species or individual HAdV types and disease are poorly understood.Characterization of a HAdV-D strain isolated from multiple clinical specimens of an 11-year-old female recipient of a matched unrelated donor peripheral SCT for T-cell lymphoma and case report.Archived HAdV PCR-positive plasma, urine, and stool specimens were processed for virus isolation and detailed molecular typing. Complete genomic sequencing was carried out on 2 isolates.The patient tested positive for HAdV DNA by real-time PCR of a stool specimen at 44 days after initiation of a SCT conditioning regimen. In the subsequent 3 months, HAdV was detected in plasma, urine and stool specimens in association with symptoms of gastroenteritis and hemorrhagic cystitis. A novel HAdV-D with a HAdV20-like hexon gene was isolated from both urine and stool specimens. All isolates yielded identical restriction profiles with endonucleases BamHI, BglII, BstEII, HindIII, PstI and SmaI. Analysis of 2 complete genomic sequences further identified the virus as a novel intertypic recombinant HAdV-D (P20/H20/F42) closely related to HAdV42.This case highlights the identification of a previously unknown HAdV-D from an immunocompromised host. In this patient, the course of adenovirus infection is compatible with reactivation of a latent virus or a primary opportunistic infection. Adenoviremia in this patient resolved without definitive adenovirus-directed antiviral therapy.

Influenza viruses typically cause the most severe disease in children and elderly individuals. However, H1N1 viruses disproportionately affected middle-aged adults during the 2013-2014 influenza season. Although H1N1 viruses recently acquired several mutations in the hemagglutinin (HA) glycoprotein, classic serological tests used by surveillance laboratories indicate that these mutations do not change antigenic properties of the virus. Here, we show that one of these mutations is located in a region of HA targeted by antibodies elicited in many middle-aged adults. We find that over 42% of individuals born between 1965 and 1979 possess antibodies that recognize this region of HA. Our findings offer a possible antigenic explanation of why middle-aged adults were highly susceptible to H1N1 viruses during the 2013-2014 influenza season. Our data further suggest that a drifted H1N1 strain should be included in future influenza vaccines to potentially reduce morbidity and mortality in this age group.

Prior to serological testing, influenza viruses are typically propagated in eggs or cell culture. Recent human H3N2 strains bind to cells with low avidity. Here, we isolated nine primary H3N2 viral isolates from respiratory secretions of children. Upon propagation in vitro , five of these isolates acquired hemagglutinin or neuraminidase mutations that increased virus binding to cell surfaces. These mutations can potentially confound serological assays commonly used to identify antigenically novel influenza viruses.

A 17-year-old female was admitted to our hospital with a 5-day history of fever (Tmax of 38.5 o C), asthenia, and nausea, accompanied by right upper quadrant abdominal pain, back pain, emesis, and jaundice during the previous 24 hours. On physical exam at the time of presentation, she was a tall and thin adolescent with a body mass index of 14.5. She was ill-appearing with scleral icterus, scant shotty cervical lymphadenopathy, and had an abdominal exam remarkable for right upper quadrant tenderness to palpation. She had no appreciable hepatosplenomegaly. The rest of her physical exam was unremarkable. Results of the patient’s laboratory evaluation revealed a white blood cell count (WBC) of 5100 WBC/mcL (neutrophils 27%, bands 8%, lymphocytes 44%, monocytes 2%, eosinophils 1%, atypical lymphocytes 18%), hemoglobin of 9.9 g/dL, and platelets of 106 000/mL, normal electrolytes, aspartate aminotransferase (AST) level of 222 U/L, alanine aminotransferase (ALT) level of 194 U/L, total bilirubin level of 11.2 mg/dL, conjugated bilirubin level of 8.7 mg/dL, albumin level of 2.8 g/dL, alkaline phosphatase level of 130 U/L, and γ-glutamyl transferase level of 89 U/L. Electrolytes, amylase, and lipase were within normal limits. The heterophile antibody test was negative. Urinalysis showed large bilirubin, but it was otherwise normal.

The debate over whether the U.S. Food and Drug Administration (FDA) should regulate laboratory developed tests continues to divide experts in the clinical diagnostics community. However, this issue was but one of many under lively discussion during the 31st annual Clinical Virology Symposium (CVS), held last April in Daytona Beach, Fla.

Human adenovirus (HAdV) is one of the most feared infections among immunocompromised patients. In particular, in liver transplant patients, HAdV has been implicated in acute liver failure with resultant mortality. The development of current molecular techniques and surveillance testing protocols have provided tools for early detection of HAdV infection, prior to or at the early onset of HAdV disease. Although reduction in immune suppression is the mainstay of therapy, many researchers have also advocated for early administration of antiviral therapy. In multiple reports, cidofovir treatment has been associated with declines in HAdV viral loads or clinical improvement in solid organ and bone marrow transplant recipients. However, there have also been case reports that raise questions about the effectiveness of antiviral therapy in controlling systemic HAdV disease. We report a case of a 26-month-old male recipient of a liver transplantation for hepatoblastoma who developed adenoviremia with an associated hepatitis and gastroenteritis. He recovered with reduced immune suppression but without antiviral therapy, thus avoiding potential toxicities associated with cidofovir therapy. This case a contrast to previous reports, and it highlights the ambiguity regarding which patients should receive HAdV-specific antiviral therapy. Additional knowledge regarding specific pediatric host factors and HAdV factors that predict poor outcomes are needed. Such information would allow clinicians to better stratify patients by risk at the time of adenoviremia detection so that low-risk patients are not unnecessarily exposed to medications with potential toxicities.

Acute upper and lower respiratory infections are a major public health problem and a leading cause of morbidity and mortality worldwide. At greatest risk are young children, the elderly, the chronically ill, and those with suppressed or compromised immune systems. Viruses are the predominant cause of respiratory tract illnesses and include RNA viruses such as respiratory syncytial virus, influenza virus, parainfluenza virus, metapneumovirus, rhinovirus, and coronavirus. Laboratory testing is required for a reliable diagnosis of viral respiratory infections, as a clinical diagnosis can be difficult since signs and symptoms are often overlapping and not specific for any one virus. Recent advances in technology have resulted in the development of newer diagnostic assays that offer great promise for rapid and accurate detection of respiratory viral infections. This chapter emphasizes the fundamental characteristics and clinical importance of the various RNA viruses that cause upper and lower respiratory tract diseases in the immunocompromised host. It highlights the laboratory methods that can be used to make a rapid and definitive diagnosis for the greatest impact on the care and management of ill patients, and the prevention and control of hospital-acquired infections and community outbreaks.

Diarrhoea and pneumonia are common causes of childhood death in sub-Saharan Africa but there are few studies describing specific pathogens.The study aimed to describe the pathogens associated with diarrhoea, pneumonia and oropharyngeal colonization in children born to HIV-infected women (HIV-exposed infants).The Mashi Study randomized 1200 HIV-infected women and their infants to breastfeed for 6 months with ZDV prophylaxis or formula-feed with 4 weeks of ZDV. Children were tested for HIV by PCR at 1, 4, 7, 9 and 12 months and by ELISA at 18 months. Pre-defined subsets of children were sampled during episodes of diarrhoea (n = 300) and pneumonia (n = 85). Stool was tested for bacterial pathogens, rotavirus and parasites. Children with pneumonia underwent bacterial blood culture, and testing of nasopharyngeal aspirates for viral pathogens by PCR. Oropharyngeal swabs were collected from a consecutive subset of 561 infants at the routine 3-month visit for bacterial culture.The median age (range) at sampling was 181 days for diarrhoea (0-730) and 140 days for pneumonia (2-551). Pathogens were identified in 55 (18%) children with diarrhoea and 32 (38%) with pneumonia. No differences in pathogens by child HIV status (HIV-infected vs HIV-uninfected) or feeding strategy were identified. Campylobacter was the most common diarrhoeal pathogen (7%). Adenovirus (22%) and other viruses (19%) were the primary pathogens isolated during pneumonias. More formula-fed infants had oropharyngeal colonization by pathogenic Gram-negative bacteria (16.8% vs 6.2%, P = 0.003), which was associated with a non-significant increased risk of pneumonia (OR 2.2, 95% CI 0.8-5.7).A trend toward oropharyngeal bacterial colonization was observed in formula-fed infants. Although viruses were most commonly detected during pneumonia, respiratory colonization by Gram-negative bacteria may have contributed to pneumonia in formula-fed infants.

Enzyme immunoassays (EIA) have great potential for automation in diagnostic microbiology laboratories, and a number of semiautomated and fully automated immunoassay analyzers are now commercially available for the performance of a variety of viral, bacterial, fungal, and parasitic antibody and/or antigen detection tests. The majority of the automated immunoassay analyzers provide walk-away simplicity to perform assays from sample processing through interpretation of results. The instruments can automatically generate work lists of specimens to be tested, pipette specimens from primary tubes and dilute the samples, dispense all reagents, time the incubations at a desired temperature, shake the assay vessels if needed, perform washes, and read and store the final results. The use of automated immunoassay analyzers can be advantageous to the laboratory that has a shortage of trained medical technologists or that needs to reduce costs or improve the throughput and turnaround time for test results.

This chapter focuses on the various technologies that are currently available from commercial companies for the diagnosis and monitoring of human immunodeficiency virus (HIV) infections, and it is not meant to duplicate more extensive reviews of HIV. Infection with HIV type 1 (HIV-1) results in the induction of a humoral antibody response specific to viral proteins, with the production of immunoglobulin A (IgA), IgM, and IgG. The majority of the automated immunoassay analyzers provide walk-away simplicity to perform assays from sample processing through interpretation of results. The major advantage of Western blot assays over enzyme immunoassays (EIAs) is that the specific interaction of antibody and antigen can be directly visualized. Immunofluorescence assay (IFA) is a very useful and inexpensive alternative to performing Western blot assays for confirmation of HIVspecific antibody responses. The Fluorognost HIV-1 IFA is based on the specific binding of HIV-1 antibodies in a specimen to HIV-1 antigens expressed on the surfaces of immortalized human T- cells fixed to glass slides. Specific antibody-antigen complexes are then detected using an anti-human antibody conjugated with fluorescein isothiocyanate. The development of molecular assays to quantitate the levels of HIV RNA in infected patients has provided one of the most valuable tools to assess the progression of HIV disease, monitor the impact of antiviral therapy, predict treatment failure and the emergence of drug-resistant viruses, and facilitate our understanding of the natural history and pathogenesis of this virus.

A novel eSensor respiratory viral panel (eSensor RVP) multiplexed nucleic acid amplification test (GenMark Diagnostics, Inc., Carlsbad, CA) was compared to laboratory-developed real-time PCR assays for the detection of various respiratory viruses. A total of 250 frozen archived pediatric respiratory specimens previously characterized as either negative or positive for one or more viruses by real-time PCR were examined using the eSensor RVP. Overall agreement between the eSensor RVP and corresponding real-time PCR assays for shared analytes was 99.2% (kappa = 0.96 [95% confidence interval {CI}, 0.94 to 0.98]). The combined positive percent agreement was 95.4% (95% CI, 92.5 to 97.3); the negative percent agreement was 99.7% (95% CI, 99.4 to 99.8). The mean real-time PCR threshold cycle ( C T ) value for specimens with discordant results was 39.73 (95% CI, 38.03 to 41.43). Detection of coinfections and correct identification of influenza A virus subtypes were comparable between methods. Of note, the eSensor RVP rhinovirus assay was found to be more sensitive and specific than the corresponding rhinovirus real-time PCR. In contrast, the eSensor RVP adenovirus B, C, and E assays demonstrated some cross-reactivity when tested against known adenovirus serotypes representing groups A through F. The eSensor RVP is robust and relatively easy to perform, it involves a unique biosensor technology for target detection, and its multiplexed design allows for efficient and simultaneous interrogation of a single specimen for multiple viruses. Potential drawbacks include a slower turnaround time and the need to manipulate amplified product during the protocol, increasing the possibility of contamination.

OBJECTIVES To determine the prevalence of central nervous system (CNS) herpes simplex virus (HSV) infection in neonates evaluated in the emergency department and to identify factors associated with cerebrospinal fluid (CSF) HSV polymerase chain reaction (PCR) testing. An existing testing paradigm was then applied to determine its potential impact on testing frequency. METHODS This nested case-control study included infants aged 0 to 28 days who had lumbar puncture in the emergency department. Multivariate logistic regression was used to identify factors associated with CSF HSV PCR testing. RESULTS The CSF HSV PCR testing was performed in 266 (47%) of 570 neonates. The prevalence of CNS HSV infection was 0.5% compared with 1.6% for bacterial meningitis. Performance of CSF HSV PCR testing was not associated with known HSV risk factors. Application of a known HSV testing paradigm would have reduced the proportion of infants tested by 21% without missing any of the cases of CNS HSV infection. CONCLUSIONS The HSV testing remains common despite the low prevalence of HSV infection. The CSF HSV PCR testing is not well aligned with known risk factors. Future testing strategies should incorporate community HSV prevalence, known neonatal risk factors, and clinical judgment.

Background The use of corticosteroids and other immunosuppressive agents increases the risk of infection in patients with systemic lupus erythematosus (SLE). The role of human adenoviruses (HAdV) in the etiology of acute viral diseases in these patients is not known. Objectives Describe a case of acute fatal disseminated adenovirus infection in an SLE patient receiving immunosuppressive therapy. Study design Case report and detailed viral diagnosis by real time PCR and molecular typing of virus isolates by sequencing of hexon and fiber genes and restriction enzyme analysis of viral DNA. Results HAdV was detected by real time PCR in multiple clinical specimens including respiratory, urine, plasma, synovial fluid, and cerebrospinal fluid. Amplification and sequence analysis of the hexon and fiber genes identified the virus as HAdV-7-like for both coding regions. Adenoviruses isolated from respiratory and urine specimens were identical and corresponded to genome type 7d2 by restriction enzyme analysis of viral DNA. The isolated strain encodes a unique fiber gene with a 6-nucleotide deletion corresponding to amino acid positions 250 and 251 in the knob region and not previously described for closely related genomic variants of HAdV-7. Conclusions Adenovirus detection should be included in the diagnostic testing to determine the infectious etiology of fever and/or respiratory symptoms in SLE patients.

BACKGROUND: Cerebrospinal fluid (CSF) protein values decline over the first few months of life as the infant's blood-CSF barrier matures. However, published studies differ in the reported rate, timing, and magnitude of this decline. OBJECTIVE: To quantify the age-related changes in CSF protein concentration and to determine accurate, age-specific reference values for neonates and young infants. DESIGN, SETTING AND PATIENTS: This cross-sectional study included infants age 56 days or younger who had a lumbar puncture performed in the emergency department of an urban tertiary care children's hospital between January 1, 2005 and June 30, 2007. Infants with conditions associated with elevated CSF protein concentrations, including traumatic lumbar puncture and bacterial or viral meningitis, were excluded. RESULTS: Of 1064 infants undergoing lumbar puncture, 375 (35%) met inclusion criteria. The median CSF protein value was 58 mg/dL (interquartile range: 48–72 mg/dL). In linear regression, the CSF protein concentration decreased 6.8% (95% confidence interval [CI], 5.4%-8.1%; P < 0.001) with each 1 week increase in age. The 95th percentile values were 115 mg/dL for infants ≤28 days and 89 mg/dL for infants 29–56 days. The 95th percentile values by age category were as follows: ages 0–14 days, 132 mg/dL; ages 15–28 days, 100 mg/dL; ages 29–42 days, 89 mg/dL; and ages 43–56 days, 83 mg/dL. CONCLUSIONS: We quantify the age-related decline in CSF protein concentration among infants 56 days of age and younger and provide age-specific reference values. The values reported here represent the largest series to-date for this age group. Journal of Hospital Medicine 2011. © 2010 Society of Hospital Medicine.

Objective To examine whether ordering testing of cerebrospinal fluid (CSF) for herpes simplex virus (HSV) by polymerase chain reaction (PCR) in neonates and young infants is associated with increased hospital length of stay (LOS) or increased hospital charges. Study design This retrospective cohort study enrolled infants age ≤56 days who underwent lumbar puncture in the emergency department in 2005-2006. The primary “exposure” was CSF HSV PCR, and the primary outcomes were LOS and hospital charges. Results CSF HSV PCR was performed in 282 of 889 eligible infants (31.7%). The median test turnaround time was 22 hours. The median LOS was 2 days, and median hospital charge was $10 166. In multivariate analysis, CSF HSV PCR testing was associated with a LOS increase of 28% for infants age ≤28 days and 39% for infants age 29-56 days. LOS increased by 22% for every 12-hour increase in test turnaround time. CSF HSV PCR testing was associated with a 41% increase in hospital charges. Conclusions In infants evaluated by lumbar puncture in the emergency department, CSF HSV PCR testing was associated with a significantly longer LOS and higher hospital charges.

OBJECTIVE: Cerebrospinal fluid (CSF) white blood cell (WBC) counts for neonates and young infants are usually interpreted on the basis of values reported in reference texts or handbooks; however, current reference texts either present normal CSF parameters without citation or cite studies with significant limitations. The objective of this study was to determine accurate, age-specific reference values for CSF WBC counts in a large population of neonates and young infants. METHODS: This cross-sectional study included patients who were aged ≤56 days and had a lumbar puncture performed in the emergency department from January 1, 2005, to June 30, 2007. Patients were excluded from analysis for conditions that are suspected to cause CSF pleocytosis, including traumatic lumbar puncture, serious bacterial infection, congenital infection, seizure, and presence of a ventricular shunt. Children who tested positive for enterovirus (EV) in the CSF by polymerase chain reaction were also excluded. Two-sample Wilcoxon rank-sum tests were used to compare median CSF WBC values of those who had negative EV testing with those who did not have EV testing. RESULTS: A total of 380 (36%) of 1064 patients met inclusion criteria; 54% were male, 15% were preterm, and 39% presented during EV season. The median CSF WBC count was significantly higher in infants who were aged ≤28 days (3/μL, 95th percentile: 19/μL) than in infants who were aged 29 to 56 days (2/μL, 95th percentile: 9/μL; P < .001). In both age groups, infants with a negative EV PCR had a higher upper bound of the 95% confidence interval of the mean values compared with infants who did not have EV testing performed. CONCLUSIONS: We determined age-specific CSF WBC reference values in a large cohort of neonates and young infants that can be used to interpret accurately the results of lumbar punctures in this population.

Although recent recommendations for children after suspected sexual abuse incorporate nucleic acid amplification tests (NAATs) in algorithms that detect sexually transmitted infections (STIs), screening practices in the community remain uncertain.We examined screening practices over time and across a variety of pediatric settings for the evaluation of STIs in sexually abused children.A consecutive cohort of prepubertal children younger than 11 years of age who were suspected to have been sexually abused were identified between May 2002 and April 2005 at a large tertiary children's hospital and its supporting primary care network. Detailed histories and examinations based on chart abstraction were linked to hospital laboratory records to identify those who were screened for Chlamydia trachomatis and Neisseria gonorrhoeae by means of cultures, NAATs, or both. Chi-square and logistic regression analyses identified factors associated with screening, including the effects of screening location and year of study on the likelihood that particular tests were obtained.Among the initial visits of 1068 children, 32% occurred in the specialty child abuse clinic (CARE Clinic), 62% in the emergency department, and 6% in the primary care setting. Follow-up visits occurred in only 7% of children. The performance of at least one screening test increased each year, from 12% in year 1 to 18% in year 3 (P = 0.01). Among the 162 children in whom tests were obtained, there was a significant decrease in the use of culture techniques over time, from 100% in year 1 to 75% in year 3 (P0.001). At the same time, there was a steady increase in the use of NAATs in total (from 2% in year 1 to 41% in year 3, P0.001), and in the absence of culture techniques (from 0% in year 1 to 26% in year 3, P0.001). This growth in the use of NAATs alone was particularly seen in the emergency department setting, where 33% of children were screened only by NAAT by year 3 (P = 0.001).Screening rates for STIs increased over time, a trend that is explained primarily by the use of NAATs in the absence of other tests. The increasing use of NAATs will have to be addressed more fully in creating future guidelines for this population.

Herpes zoster complicated by meningitis has been mainly reported in immunocompromised patients after reactivation of wild-type varicella-zoster virus. We present one of the first cases of aseptic meningitis after herpes zoster caused by reactivation of vaccine-type varicella-zoster virus in an immunocompetent child. We also highlight the increasing role of both wild-type and vaccine strains of varicella-zoster virus as a cause of viral meningoencephalitis and the use of appropriate laboratory tools to rapidly and accurately identify the virus in order to provide prompt patient care and management.

A pentavalent rotavirus vaccine for infants became available in the United States in February 2006. By 2007, vaccination rates nationwide were estimated to be ∼50%. We studied the effectiveness of the vaccine in a real-world setting outside of a clinical trial. All children presenting to The Children's Hospital of Philadelphia with acute gastroenteritis have been monitored for the presence of rotavirus antigen in the stool by enzyme-linked immunosorbent assay (ELISA [followed by genotyping if ELISA positive]) since the 1994-1995 epidemic season, presenting a unique opportunity to assess the impact of the recently introduced vaccine. The annual number of community-acquired cases over the preceding 13 years had approached or exceeded 100, with 271 cases in 2005 to 2006 and 167 cases in 2006 to 2007. In the 2007-2008 season, only 36 community-acquired cases were identified, representing an 87% reduction from the same period in 2005 to 2006. G3 was the predominant serotype, accounting for 15 community cases (42%). Our study is limited by its observational design using historical comparisons. Nonetheless, the abrupt decline in rotavirus gastroenteritis cases during the 2007-2008 season likely resulted from vaccination. Because protection rates appeared to have exceeded vaccination rates, herd immunity may have contributed to some degree to the effectiveness of the vaccine.

BACKGROUND: When initiated within 48 hours of the onset of symptoms, oseltamivir has been shown to reduce severity and length of influenza illness. Few studies have evaluated the use of oseltamivir in patients hospitalized with influenza. OBJECTIVE: To describe the prescribing practices for oseltamivir in children hospitalized with influenza and to evaluate a mechanism to improve the rate of appropriate prescription. DESIGN, SETTING, PATIENTS: Retrospective cohort study of 929 patients aged 21 years or younger hospitalized with community-acquired laboratory-confirmed influenza (CA-LCI) during 5 consecutive seasons (2000-2005). We examined oseltamivir eligibility, which included patients 1 year of age or older with an influenza test result available within 48 hours of symptom onset. During the 2005-2006 season, an observational trial of an electronic reminder was conducted to improve the frequency of oseltamivir prescription. MEASUREMENTS: Oseltamivir prescription. RESULTS: Of 305 patients (32.8%) eligible for treatment with oseltamivir, 49 (16.1% of those eligible) were prescribed oseltamivir during hospitalization. Prescription rates for indications consistent with the US Food and Drug Administration (FDA) approval (“on label”) increased from 0% to 37.2% over 5 seasons (P 0.05). CONCLUSIONS: Oseltamivir was used infrequently for children hospitalized with influenza. In addition, use inconsistent with the FDA label of oseltamivir occurs. Mechanisms are needed to improve appropriate prescription of oseltamivir. Journal of Hospital Medicine 2009;4:171–178. © 2009 Society of Hospital Medicine.

Herpes simplex virus type 1 (HSV-1) glycoprotein C (gC) blocks complement activation, and glycoprotein E (gE) interferes with IgG Fc-mediated activities. While evaluating gC- and gE-mediated immune evasion in human immunodeficiency virus (HIV)-HSV-1-coinfected subjects, we noted that antibody alone was more effective at neutralizing a strain with mutations in gC and gE (gC/gE) than a wild-type (WT) virus. This result was unexpected since gC and gE are postulated to interfere with complement-mediated neutralization. We used pooled human immunoglobulin G (IgG) from HIV-negative donors to confirm the results and evaluated mechanisms of the enhanced antibody neutralization. We demonstrated that differences in antibody neutralization cannot be attributed to the concentrations of HSV-1 glycoproteins on the two viruses or to the absence of an IgG Fc receptor on the gC/gE mutant virus or to enhanced neutralization of the mutant virus by antibodies that target only gB, gD, or gH/gL, which are the glycoproteins involved in virus entry. Since sera from HIV-infected subjects and pooled human IgG contain antibodies against multiple glycoproteins, we determined whether differences in neutralization become apparent when antibodies to gB, gD, or gH/gL are used in combination. Neutralization of the gC/gE mutant was greatly increased compared that of WT virus when any two of the antibodies against gB, gD, or gH/gL were used in combination. These results suggest that gC and gE on WT virus provide a shield against neutralizing antibodies that interfere with gB-gD, gB-gH/gL, or gD-gH/gL interactions and that one function of virus neutralization is to prevent interactions between these glycoproteins.

We detected enteroviral RNA and cultured infectious virus from a series of banked breast milk samples from the mother of an infant with neonatal sepsis; sequencing of the enterovirus isolate identified it as echovirus type 18. In this case, it is possible that enterovirus transmission occurred through the breast milk.

Rotavirus is the most common etiologic agent of healthcare-acquired diarrhea in pediatric patients. There has been little published information on healthcare-acquired rotavirus infection.This was a retrospective cohort study of children hospitalized with rotavirus gastroenteritis at our institution between December 1999 and May 2004. Patients with community- and healthcare-acquired rotavirus gastroenteritis were compared with regards to age, time of infection, patient unit, and viral subtype as determined by reverse transcription polymerase chain reaction sequencing.Five hundred seventy-seven children were hospitalized with rotavirus gastroenteritis during the study period. One hundred twenty-one (21%) of these infections were healthcare-acquired. The incidence of healthcare-acquired infection was 4.2 cases per 10,000 patient-days. With the exception of 1 outbreak on an isolated patient unit, community- and healthcare-acquired disease affected similar patient populations, had the same temporal distribution, and were caused by viruses with similar subtypes. However, there was a significant difference between the geographic distribution of community- and healthcare-acquired disease within the hospital (P0.001). The majority (83%) of community-acquired cases were admitted to general medicine-surgery units, but only 53% of the healthcare-acquired cases occurred on these units (P = 0.005). The remaining healthcare-acquired infections occurred on units that rarely admitted patients with community-acquired disease.Healthcare-acquired rotavirus gastroenteritis seems to be caused by repeated introduction of community strains into the hospital setting. Heightened attention to infection control practices and rapid rotavirus identification is necessary on all units, especially those that infrequently admit children with rotavirus gastroenteritis, to prevent the spread of healthcare-acquired disease.

Variability in the performance of nucleic acid amplification technology (NAT)-based assays presents a significant problem in the diagnosis and management of human cytomegalovirus (HCMV) infections. Here we describe a collaborative study to evaluate the suitability of candidate reference materials to harmonize HCMV viral load measurements in a wide range of NAT assays. Candidate materials comprised lyophilized Merlin virus, liquid Merlin virus, liquid AD169 virus, and purified HCMV Merlin DNA cloned into a bacterial artificial chromosome. Variability in the laboratory mean HCMV concentrations determined for virus samples across the different assays was 2 log10. Variability for the purified DNA sample was higher (>3 log10). The agreement between laboratories was markedly improved when the potencies of the liquid virus samples were expressed relative to the lyophilized virus candidate. In contrast, the agreement between laboratories for the purified DNA sample was not improved. Results indicated the suitability of the lyophilized Merlin virus preparation as the 1st WHO International Standard for HCMV for NAT. It was established in October 2010, with an assigned potency of 5 × 106 International Units (IU) (NIBSC code 09/162). It is intended to be used to calibrate secondary references, used in HCMV NAT assays, in IU.

OBJECTIVE. The goal was to evaluate the impact of cerebrospinal fluid enterovirus polymerase chain reaction testing on the length of hospitalization and the duration of antibiotic use for infants ≤90 days of age with suspected aseptic meningitis.METHODS. This retrospective cohort study was conducted at an urban, tertiary-care children's hospital. Data were collected for 478 patients ≤90 days of age for whom cerebrospinal fluid enterovirus polymerase chain reaction testing was performed during the enteroviral seasons of 2000 to 2006. The length of hospitalization and the duration of antibiotic use were assessed.RESULTS. Cerebrospinal fluid enterovirus polymerase chain reaction test results were positive for 154 patients (34.8%). The mean length of stay was 3.65 days. The median polymerase chain reaction turnaround time was 23 hours. In multivariate analysis, having a positive cerebrospinal fluid enterovirus polymerase chain reaction result was associated with a 1.54-day decrease in the length of stay and a 33.7% shorter duration of antibiotic use. When patients were stratified according to the presence or absence of pleocytosis, both groups demonstrated significant reductions in the length of stay with positive cerebrospinal fluid enterovirus polymerase chain reaction results (1.32 and 1.38 days, respectively). Furthermore, increasing the polymerase chain reaction turnaround time by 24 hours increased the length of stay by 13.6% for patients with positive cerebrospinal fluid enterovirus polymerase chain reaction results.CONCLUSIONS. Having positive cerebrospinal fluid enterovirus polymerase chain reaction results decreases the length of hospitalization and the duration of antibiotic use for young infants. These results support the routine use of this test during periods of peak enterovirus prevalence.

OBJECTIVES. Few studies have examined the characteristics and clinical course of children hospitalized with laboratory-confirmed influenza. We sought to (1) estimate the age-specific incidence of influenza-related hospitalizations, (2) describe the characteristics and clinical course of children hospitalized with influenza, and (3) identify risk factors for prolonged hospitalization. PATIENTS AND METHODS. Children ≤21 years of age hospitalized with community-acquired laboratory-confirmed influenza at a large urban children's hospital were identified through review of laboratory records and administrative data sources. A neighborhood cohort embedded within our study population was used to estimate the incidence of community-acquired laboratory-confirmed influenza hospitalizations among children 6 days) were determined by using logistic regression. RESULTS. We identified 745 children hospitalized with community-acquired laboratory-confirmed influenza during the 4-year study period. In this urban cohort, the incidence of community-acquired laboratory-confirmed influenza hospitalization was 7 per 10000 child-years of observation. The median age was 1.8 years; 25% were infants CONCLUSIONS. Influenza is a common cause of hospitalization among both healthy and chronically ill children. Children with cardiac or neurologic/neuromuscular disease are at increased risk of prolonged hospitalization; therefore, children with these conditions and their contacts should be a high priority to receive vaccine. The impact on pediatric hospitalization of the new recommendation to vaccinate all children 6 months to

Objective To determine the characteristics, incidence, and risk factors for influenza-related neurologic complications (INC). Study design A retrospective cohort study of INC in children hospitalized with laboratory-confirmed influenza infection (LCI) from June 2000 to May 2004 was conducted. Systematic chart review was performed to identify clinical characteristics and outcomes. A neighborhood cohort was constructed to estimate the incidence of INC. Logistic regression was used to identify independent risk factors for INC. Results Of 842 patients with LCI, 72 patients had an INC: influenza-related encephalopathy (8), post-infectious influenza encephalopathy (2), seizures (56), and other (6). Febrile seizures were the most common type of seizures (27). No patient died from an INC. In our neighborhood cohort, the incidence of INC was 4 cases per 100,000 person-years. An age of 6 to 23 months (odds ratio [OR], 4.2; 95% CI, 1.4-12.5) or 2 to 4 years (OR, 6.3; 95% CI, 2.1-19.1) and an underlying neurologic or neuromuscular disease (OR, 5.6; 95% CI, 3.2-9.6) were independent risk factors for the development of INC. Conclusion Seizures are the most common neurologic complication experienced by children hospitalized with influenza. In the United States, encephalopathy is uncommon. Young children and patients with neurologic or neuromuscular disease are at increased risk for INC.

Human respiratory syncytial virus (RSV) is a major cause of severe respiratory illness in children and susceptible adults. RSV blocks the development of the innate antiviral immune response and can grow to high titers in the respiratory tract. Here we demonstrate that immunostimulatory defective viral genomes (iDVGs) that are naturally generated during RSV replication are strong inducers of the innate antiviral response to RSV in mice and humans. In mice, RSV iDVGs stimulated the expression of antiviral genes, restricted viral replication, and prevented weight loss and lung inflammation. In human cells, the antiviral response to RSV iDVGs was dominated by the expression of IFN-λ1 over IFN-β and was driven by rapid intranuclear accumulation of the transcription factor IRF1. RSV iDVGs were detected in respiratory secretions of hospitalized patients, and their amount positively correlated with the level of expression of antiviral genes in the samples. Infection of explanted human lung tissue from different donors revealed that most humans can respond to RSV iDVGs and that the rate of accumulation of iDVGs during infection directly correlates with the quality of the antiviral response. Taken together, our data establish iDVGs as primary triggers of robust antiviral responses to RSV and provide the first evidence for an important biological role for naturally occurring iDVGs during a paramyxovirus infection in humans., Author Summary Respiratory syncytial virus is a major cause of chronic lung damage, asthma exacerbations, and hospitalizations of infants, elders, and high-risk adults. Currently, there is no effective vaccine or treatment available to protect the general population from RSV infection. Here, we demonstrate that defective forms of RSV genomes naturally generated during infection effectively stimulate the antiviral response in vitro and in vivo. In human cells, RSV iDVGs trigger the antiviral response through a mechanism characterized by the potent activation of the transcription factor IRF1 and a dominant expression of the type III IFN gene IFNL1 (IFN-λ1). This study establishes for the first time that naturally occurring iDVGs trigger robust host antiviral responses to RSV in mice and humans and reveals new opportunities to potentiate the host response to RSV infection and minimize viral-induced pathology.

Post-transplant lymphoproliferative disorder (PTLD) is an Epstein-Barr virus (EBV) associated malignancy that occurs in the setting of pharmacologic immunosuppression used after organ transplantation. The presence of monoclonal gammopathy (MG) after organ transplantation is a risk factor for the development of PTLD. We retrospectively explored the characteristics of serum protein electrophoresis (SPEP) in 38 adult solid organ transplant patients with biopsy proven PTLD and SPEP. Twenty-three (61%) had MG with nine (24%) showing multiple MG. Background gammaglobulin levels were abnormal in 13 (34%) patients with five (13%) and eight (21%) having polyclonal hypergammaglobulinemia or hypogammaglobulinemia, respectively. Hypogammaglobulinemia was correlated with the presence of MG (p = 0.01) and polymorphic B-cell hyperplasia histology (p = 0.01). No correlation between SPEP findings and overall survival were noted. With median follow-up of 116 wk (range 2-261 wk), 21 (55%) patients are alive with 20 (53%) in complete remission. Response to reduction in immunosuppression was correlated with improved overall survival (262 wk vs. 68 wk, p = 0.003). Persistence of MG after complete response of the PTLD did not predict relapse. There is a high incidence of MG and gammaglobulin abnormalities in patients with PTLD.

Human immunodeficiency virus type 1 (HIV-1) evolution and changing strain distribution present a challenge to nucleic acid-based assays. Reliable patient monitoring of viral loads requires the detection and accurate quantification of genetically diverse HIV-1. A panel of 97 HIV-1-seropositive plasma samples collected from Cameroon, Brazil, and South Africa was used to compare the performance of four commercially available HIV RNA quantitative tests: Abbott LCx HIV RNA Quantitative assay (LCx), Bayer Versant HIV-1 RNA 3.0 (bDNA), Roche AMPLICOR HIV-1 MONITOR v1.5 (Monitor v1.5), and bioMérieux NucliSens HIV-1 QT (NucliSens). The panel included group M, group O, and recombinant viruses based on sequence analysis of gag p24, pol integrase, and env gp41. The LCx HIV assay quantified viral RNA in 97 (100%) of the samples. In comparison, bDNA, Monitor v1.5, and NucliSens quantified viral RNA in 96.9%, 94.8%, and 88.6% of the samples, respectively. The two group O specimens were quantified only by the LCx HIV assay. Analysis of nucleotide mismatches at the primer/probe binding sites for Monitor v1.5, NucliSens, and LCx assays revealed that performance characteristics reflected differences in the level of genetic conservation within the target regions.

During the last decade, significant advances have been made in the development and use of antiviral agents for the successful treatment of a number of viral infections.8, 51, 57 An expanding array of antiviral drugs are currently available for the management of infections caused by herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), cytomegalovirus (CMV), varicella-zoster virus (VZV), influenza A virus, respiratory syncytial virus (RSV), human immunodeficiency virus type 1 (HIV-1), papillomaviruses, and hepatitis B and C viruses. The increased number and use of antiviral agents, however, has led to the emergence of drug-resistant viruses, particularly in immunocompromised patients such as those with acquired immunodeficiency syndrome (AIDS) or hematologic malignancy or those who have undergone organ transplantation. For comprehensive reviews on specific viruses, see references 26, 41, 64, 81–83, and 102. Clinical situations that favor the development of resistance include long-term suppressive therapy, recurrent intermittent therapy, and the use of less than optimum doses of an antiviral agent. Generally, the emergence and isolation of drug-resistant viruses is associated more so with the therapeutic use of antiviral agents and does not seem to be caused by prophylactic treatment. As more patients fail to respond to appropriate therapy and additional antiviral agents are produced, it will also become important for diagnostic virology laboratories to provide rapid and practical antiviral susceptibility testing to assist physicians in defining drug resistance and choosing appropriate alternative therapies. This review describes the major antiviral agents, their mechanisms of action, and the development of drug resistance following antiviral therapy. A brief overview of the available phenotypic and genotypic susceptibility assays for detecting antiviral resistance is also discussed.

Differentiating Lyme meningitis from enteroviral meningitis remains difficult because both occur mostly in the summer and early fall. This distinction is clinically important because pathogen-specific diagnostic test results are not available immediately and only patients with Lyme meningitis require parenteral antibiotic therapy.The objective of this study was to identify clinical and laboratory features that might help clinicians distinguish patients with Lyme meningitis from those with enteroviral meningitis.This cross-sectional study compared patients diagnosed with Lyme or enteroviral meningitis evaluated at a large children's hospital between January 1, 1999 and September 20, 2002.Twenty-four patients with Lyme meningitis and 151 patients with enteroviral meningitis had median ages of 10.5 and 5.5 years, respectively (P0.0001). There was an equal proportion of boys with Lyme (63%) and enteroviral meningitis (62%; P = 1.0). The duration of symptoms before evaluation was longer for patients with Lyme meningitis (12 days) than with enteroviral meningitis (1 day; P0.0001). Cranial neuropathy was a presenting feature in 71% of children with Lyme meningitis. Cranial neuropathy, erythema migrans rash or papilledema occurred in 88% of patients with Lyme meningitis; no patients with enteroviral meningitis exhibited any of these findings (P0.0001). Lyme meningitis was unlikely when cerebrospinal fluid neutrophils exceeded 10% (negative predictive value, 99%).We identified several clinical and laboratory features that may permit early differentiation of Lyme from enteroviral meningitis. These results may assist clinicians with decisions regarding additional testing and empiric antibiotic therapy.

Human parvovirus (HPV) B19 causes significant morbidity and mortality in children with sickle cell disease (SCD), but little data are published about the epidemiology of HPV B19 infection and its associated complications in this patient population. In this study, prevalence and incidence rates of HPV B19 were determined in 633 patients with SCD followed at The Children's Hospital of Philadelphia between November 1996 and December 2001. Thirty percent (30%) were HPV B19 immunoglobulin G (IgG) positive at first testing, and the 70% without evidence of past HPV B19 infection were tested annually. One hundred ten patients developed evidence of HPV B19 infection for an incidence rate of 11.3 per 100 patientyears. Sixty-eight episodes of HPV B19–induced transient red cell aplasia occurred with the following clinical events: fever (89.7%), pain (61.8%), acute splenic sequestration (19.1%), and acute chest syndrome (11.8%). Pain, fever, and acute splenic sequestration were more frequent events with acute HPV B19 infections compared with acute events in uninfected patients. The results of this epidemiologic study, the largest and most comprehensive to date, justify the development of HPV B19 prevention strategies to diminish the frequent and often severe complications associated with HPV B19 infections in patients with SCD.

Epstein-Barr virus (EBV) is known to be involved in the majority of patients who develop post-transplant lymphoproliferative disorder after solid organ transplant. We conducted a retrospective study to determine the utility of qualitative and quantitative Epstein-Barr virus polymerase chain reaction (PCR) for the diagnosis and monitoring of post-transplant lymphoproliferative disorder in adult solid organ transplant patients. Peripheral blood leukocytes obtained from 35 adult solid organ transplant patients consecutively referred for evaluation of possible post-transplant lymphoproliferative disorder, were tested by EBV PCR at the time of initial evaluation and at time points thereafter. Eighteen of 35 (51%) patients were ultimately diagnosed with post-transplant lymphoproliferative disorder by tissue biopsy. Fifteen of 18 (83%) patients were found to have EBER-1 positive tumors by in situ hybridization. EBV PCR was positive in 7 of 15 patients, suggesting a sensitivity of 39%. Seventeen patients without post-transplant lymphoproliferative disorder and three with EBER-1 negative post-transplant lymphoproliferative disorder all had negative EBV PCR tests, suggesting a specificity of 100%. We observed that declines in EBV DNA load were associated with response to therapeutic interventions, such as reduction in immunosuppression, rituximab therapy and chemotherapy. We conclude that peripheral blood EBV PCR may have a role in the diagnosis and monitoring of post-transplant lymphoproliferative disorder in adult solid organ transplant patients.

In vitro susceptibility assays of herpes simplex virus (HSV) do not necessarily correlate with treatment outcome. An HSV type 1 (HSV-1) isolate, N4, recovered from a patient who presented with herpes keratitis with localized immunosuppression, was characterized for susceptibility. Although the 50% inhibitory concentration (IC(50)) for this isolate was less than the accepted breakpoint for defining resistance to acyclovir (>2.0 microg/mL), the following lines of evidence suggest that the isolate was acyclovir resistant: (1) the clinical history confirmed that the infection was nonresponsive to acyclovir; (2) the in vitro susceptibility was similar to that of a thymidine kinase (TK)-negative, acyclovir-resistant virus SLU360; (3) the IC(50) of acyclovir was more than 10 times the IC(50) for an acyclovir-susceptible control strain; (4) plaque-purified clonal isolates were resistant to acyclovir (IC(50)s, >2.0 microg/mL); and (5) biochemical studies indicated that the HSV-1 N4 TK was partially impaired for acyclovir phosphorylation. Although residue changes were found in both the viral tk and pol coding regions of HSV-1 N4, characterization of a recombinant virus expressing the HSV-1 N4 polymerase suggested that the TK and Pol together conferred the acyclovir-resistance phenotype.

Respiratory viruses are known to cause asthma exacerbations. There have been no previous studies in children looking at which viruses have the greatest capacity to induce an asthma exacerbation. This study attempts to identify viruses with the most asthmagenic properties. The objective of this study is to determine the prevalence of viral infections in children with asthma exacerbations, and to correlate specific viral infections with clinical severity. Nasopharyngeal and oropharyngeal swabs were collected for viral culture from 101 asthma patients presenting to the Children's Hospital of Philadelphia Emergency Department with an asthma exacerbation. Patients ranged in age from 3 years to 18 years. One hundred and one well asthmatics were recruited from the Allergy Clinic and Department of Pediatrics to serve as control patients. Control patients were enrolled within 2 weeks of study patients, and were matched by age, gender, and ethnic group. Viral isolates were correlated with the age, gender, ethnic gr...

Objective. To determine the cost-effectiveness and cost-benefit of an infection control program to reduce nosocomial respiratory syncytial virus (RSV) transmission in a large pediatric hospital. Design. RSV nosocomial infection (NI) was studied for 8 years, before and after intervention with a targeted infection control program. The cost-effectiveness of the intervention was calculated, and cost-benefit was estimated by a case–control comparison. Setting. Children's Hospital of Philadelphia, a 304-bed pediatric hospital. Patients. All inpatients with RSV infection, both community- and hospital-acquired. Intervention. Consisted of early recognition of patients with respiratory symptoms, confirmation of RSV infection by laboratory testing, establishing cohorts of patients and nursing staff, gown and glove barrier precautions, and monitoring and education of staff. Outcome Measures. The incidence density of RSV NI before and after the intervention was calculated as the rate per 1000 patient days-at-risk for infection. Intervention costs included laboratory testing, isolation, and administration of the program. The cost of RSV NI was estimated by comparing hospital charges for 30 cases and matched uninfected controls. Results. A total of 148 patients acquired NI (88 before and 60 after the intervention). The Mantel-Haenszel stratified relative risk for NI in the period before the infection control program, compared with the postintervention period, was .61 (95% confidence interval: .53–.69). By applying the preintervention stratum-specific rates of infection to the days-at-risk in the postintervention period, an estimated 100 NIs would have been expected, which in comparison to the 60 NIs observed, yielded an estimated program effectiveness of 10 RSV NIs prevented per season. The total cost of the program per season was $15 627 or $1563/NI prevented. In comparison, the mean cost to the hospital was $9419/case of RSV NI, resulting in a cost-benefit ratio of 1:6. Conclusions. A targeted infection control intervention was cost-effective in reducing the rate of RSV NI. For every dollar spent on the program, approximately $6 was saved.

Many children with influenza are treated with antibiotics. In this report, we describe the rate and indications for antibacterial use in children hospitalized with influenza. A total of 333 of 729 (46%) patients received >2 days of treatment with antibacterial medications, of whom 36% did not have an apparent indication for therapy.

In a nested case-control study of 478 infantsor =90 days of age, one-third of infants undergoing cerebrospinal fluid herpes simplex virus (HSV) testing by polymerase chain reaction were28 days of age. Recognized factors, such as mode of delivery, were not associated with HSV testing. The factors currently used by physicians in the decision to order this test do not best reflect the likelihood of HSV infection.