Novel inflammatory markers, clinical risk factors and virus type associated with severe respiratory syncytial virus infection.

BACKGROUND: Virus-induced inflammation contributes to respiratory syncytial virus (RSV) pathogenesis. We sought to determine the specific mediators that are associated with more severe illness in young children. METHODS: Children ≤ 5 years of age seen in our emergency department for respiratory symptoms from September 1998 to May 2008 were eligible for enrollment. Nasopharyngeal wash samples were collected from all eligible patients, and clinical data were recorded. Individuals were included in this study if nasopharyngeal wash samples were positive for RSV only. Patients enrolled in the study were stratified by disease severity, defined as mild (not hospitalized), moderate (hospitalized) or severe (requiring intensive care unit stay). Concentrations of individual inflammatory biomarkers in nasopharyngeal wash fluids were determined using the Luminex human 30-plex assay. RESULTS: Eight hundred fifty-one patients met study criteria: 268 (31.5%) with mild, 503 (59.1%) with moderate and 80 (9.4%) with severe illness. As expected, illness severity was directly associated with young age, prematurity, heart or lung disease, infection with RSV group A and elevated concentrations of interleukin (IL)-2R, IL-6, CXCL8, tumor necrosis factor-α, interferon-α, CCL3, CCL4 and CCL2. In addition, we report several novel and mechanistically important inflammatory biomarkers of severe RSV disease, including IL-1ß, IL1-RA, IL-7, epidermal growth factor and hepatocyte growth factor. CONCLUSIONS: In a large, longitudinal study (10 years, 851 enrolled patients) limited to RSV infection only, in which well-known risk factors are confirmed, we identified 5 novel biomarkers specifically of severe disease. These markers may ultimately serve to elucidate disease mechanisms.

Nasopharyngeal detection of respiratory viruses in febrile neutropenic children.

BACKGROUND: Although fever is common in neutropenic children, a microbiological etiology is determined in only 15% to 30% of cases. The authors investigated the frequency of respiratory virus detection in the upper airways of febrile neutropenic children with negative bacterial cultures. METHODS: This is a 3-year prospective study of children younger than 19 years, hospitalized with febrile neutropenia and negative bacterial cultures. Respiratory samples were obtained for amplification of viral nucleic acids via Luminex xTAG technology. RESULTS: There were 50 febrile neutropenic episodes among 42 patients. Respiratory viruses were detected in 26 (52%) febrile episodes. A single virus was detected in 22 febrile episodes; multiple viruses were detected in the remaining 4. Rhinovirus/Enterovirus was most frequently detected. CONCLUSION: Respiratory viruses were detected frequently in nasopharyngeal samples from febrile neutropenic patients with negative bacterial cultures, thus providing an impetus to determine the relationship between virus detection, infection, and pathology in this unique patient population.

Unrecognized viral respiratory tract infections in premature infants during their birth hospitalization: a prospective surveillance study in two neonatal intensive care units.

OBJECTIVE: To determine the frequency and effects of nosocomial respiratory viral infections (RVIs) in premature neonates, including those who may be asymptomatic. STUDY DESIGN: We performed a year-long surveillance for RVIs in infants <33 weeks gestational age admitted to 2 Syracuse neonatal intensive care units. Infants were enrolled within 3 days of neonatal intensive care unit admission and were sampled for RVIs until discharge using a multiplex polymerase chain reaction assay capable of detecting 17 different respiratory viruses or subtypes. RESULTS: Twenty-six of 50 prematurely born infants (52%) tested positive for a respiratory virus at least once during their birth hospitalization. Testing positive for a respiratory virus was significantly associated with longer length of stay (70 days vs 35 days, P = .002) and prolonged ventilatory support (51 vs 13 days, P = .002). Infants who tested positive for a respiratory virus during their birth hospitalization had more than twice the rate of developing bronchopulmonary dysplasia (P < .05). CONCLUSION: Nosocomial RVIs were frequent in our study population, despite the absence of clinical indicators of illness. Length of hospital stay was significantly longer and a diagnosis of bronchopulmonary dysplasia was more common in infants who had respiratory viruses detected.

Empyema of preexisting subdural hemorrhage caused by a rare salmonella species after exposure to bearded dragons in a foster home.

An infant had a subdural empyema caused by the rare Salmonella species enterica subspecies houtenae (IV) serotype 44:z4,z23:- after only indirect exposure to exotic reptiles in her foster home. Infants recovering from preexisting subdural hematoma are at risk for development of empyema.