Respiratory Syncytial Virus Bronchiolitis in Infants.ppt by liningnvp

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									Respiratory Syncytial Virus
Bronchiolitis in Infants


Amanda Snodgrass
Dr. Bill Grimes, Advisor
Spring 2006
          Objectives
 Mechanisms involved in RSV
  infection and severity
 Risk factors for severe RSV
  infection
 Prophylaxis and treatment of
  RSV
 Morbidity and Mortality
Case Study
RSV Facts
        Most common cause
         of bronchiolitis &
         pneumonia in children
         under 1
        25-40% of children
         develop bronchiolitis
         or pneumonia during
         first RSV infection
        31/1,000 under 1 yr.
         are hospitalized with
         RSV
        2% will die
               Presentation
   Cold-like sx
   Audible wheezing
   SOB
   Anorexia
   Poor sleeping
   Irritability
   Vomiting
   Choking
            Pathophysiology

   Negative-strand RNA virus
   Family Paramyxoviridae
   RSV season late fall to early spring
   Peak in January/February
   Incubation 4-5 days, LRI between
    days 5-7
      Severity of RSV Infection is
           Determined By:

   Inhibition of certain interferons
   Involvement of innate immune
    system
   Interleukins and chemokines
   Coinfection with other respiratory
    viruses
     Inhibition of Interferons

 Interferons believed to have
  antiviral properties
 NS1 & NS2 inhibit IFN-
  alpha/beta
 Inhibition of IFN-gamma causes
  enhanced IgE production
    Innate Immune System
 Activation contributes to
  inflammation & injury
 RSV-F glycoprotein may inhibit
  T-cell activation
 RSV-infected CD8+ cells unable
  to release IFN-gamma
      Interleukins & Chemokines

   Infection induces expression
   Chemokines mimic RSV
    glycoproteins
   Recruit monocytes, eosinophils, &
    neutrophils
   IL-8 levels positively associated
    with severity
              Coinfection

   Rhinovirus contributes to increased
    severity in children with
    bronchiolitis
   Metapneumovirus (hMPV) enhances
    or mimics symptoms of RSV
    bronchiolitis
   70% were coinfected w/ hMPV &
    required amission to PICU
Risk Factors
         Premature Birth

 Likely to have chronic lung
  disease
 Hypersensitive to stimuli

 Underdeveloped airway &
  immunity
 Lack adult maternal levels of IgG
              CHD

 Are more often hospitalized
 Are more often admitted to PICU

 Are more likely to die

 Complications from pulmonary
  hypertension and increased
  hypoxia
 Environmental & Demographics

 Male infants
 Age & birth month of infant

 Crowding & day care
  attendance
 Secondhand smoke
Factors NOT Positively Correlated

 Socioeconomic status
 Malnourishment

 Breastfeeding
              Prophylaxis

   RSV-IGIV (RespiGam)
   Children under 24 mo. w/ CHD or
    less than 35 wks. Gestation
   Given IV monthly during RSV
    season
   Volume overload possible
   Not for infants w/ hemodynamically
    significant heart disease.
               Prophylaxis

   Palivizumab (Synagis)
   Given IM monthly
   Can reduce hospitalization of high
    risk infants by 45%
   Expensive
   Many providers reluctant to give
   Many parents unaware
           Treatment

 Mostly symptomatic
 Salbutamol MDI drug of choice

 Also use epinephrine,
  ipratropium bromide, & oral
  steroids only if hospitalized
          Morbidity & Mortality

   More likely to visit a specialist
   More likely to use respiratory
    therapy
   More likely to receive diagnostic or
    therapeutic procedures
   More likely to be hospitalized again
   Subsequent hospitalization will be
    3x as long
          Morbidity & Mortality

   More likely to suffer recurrent
    infections
   Many have recurrent acute otitis
    media
   Many likely to be hospitalized with
    another episode of acute respiratory
    distress
          Morbidity & Mortality
   Adolescents suffer from allergic
    asthma, allergic rhinoconjunctivitis,
    & more sensitive to inhaled
    allergens
   More likely to have asthma,
    bronchial reactivity to methacholine,
    and reduced lung function
   RSV ind. risk factor for reduced
    FEV% (FEV1/FVC)
Follow Up
                                             References
   ALA (2004) Respiratory Syncytial Virus referenced online October 15, 2005 http://www.ala.org
   Braciale, Thomas J. (2005). Respiratory syncytial virus and T cells interplay between the virus and the host adaptive immune
    system. Proc Am Thorac Soc 2:141-146
   Bradley, Joseph P., Bacharier, Leonard B., Bonfiglio, JoAnn, Schechtman, Kenneth B., Strunk, Robert, Storch, Gregory, Castro,
    Mario. (2005). Severity of respiratory syncytial virus bronchiolitis is affected by cigarette smoke exposure and atopy. Pediatrics
    115;7-14
   CDC. (2005). Respiratory Syncytial Virus referenced online October 15, 2005 http://www.cdc.gov
   Dakhama, Azzeddine, Park, Jung-Won, Taube, Christian, Chayama, Kosuke, Balhorn, Annette, Joetham, Anthony, Wei, Xu-Dong, et
    al. (2004). The role of virus-specific immunoglobulin E in airway hyperresponsiveness. Am J Respir Crit Care Med 170:952-959
   Greensill, Julie, McNamara, Paul S., Dove, Winifred, Flanagan, Brian, Smyth, Rosalind L., Hart, Anthony. (2003). Human
    metapneumovirus in severe respiratory syncytial virus bronchiolitis. Emerging Infectious Diseases 9:3:372-375
   Hoffman, Scott J., Laham, Federico R., Polack, Fernando P. (2004). Mechanisms of illness during respiratory syncytial virus
    infection: the lungs, the virus and the immune response. Microbes and Infection. 6:767-772
   Kafetzis, D.A.; Astra, H.; Tsolia, M.; Liapi, G.; Mathioudakis, J.; Kallergi, K. (2003) Otitis and respiratory distress episodes following
    a respiratory syncytial virus infection. Clin Microbiol Infect 9:1006-1010
   Korppi, Matti, Kotaniemi-Syrjanen, Anne, Waris, Matti, Vainionpaa, Raija, Reijonen, Tiina. (2004). Rhinovirus-associated wheezing
    in infancy comparison with respiratory syncytial virus bronchiolitis. The Pediatric Infectious Disease Journal 23:11;995-999
   Korppi, M.; Piippo-Salvolainen, E.; Korhonen, K.; Remes, S. (2004) Respiratory morbidity 20 years after RSV infection in infancy.
    Pediatric Pulmonology 38:155-160
   Meissner, H. Cody, Long, Sarah and the Committee on Infectious Diseases and Committee on Fetus and Newborn (2003). Revised
    indications for the use of palivizumab and respiratory syncytial virus immune globulin intravenous for the prevention of respiratory
    syncytial virus infections. Pediatrics 112:6;1447-1452
   Moynihon, James; Kim, Tommy; Young, Tammy; Checchia, Paul (2004) Rate of palivizumab administration in accordance with
    current recommendations among hospitalized children. Journal of Pediatric Health Care 18:224-227
   Plint, Amy; Johnson, David; Wiebe, Natasha; Bulloch, Blake; Pusic, Martin; Joubert, Gary; Pianosi, Paul; Turner, Troy; Thompson,
    Graham; Klassen, Terry. (2004) Practice variation among pediatric emergency departments in the treatment of bronchiolitis. Acad
    Emerg Med 11;4:353-360
   Sampalis, John (2003) Morbidity and mortality after RSV-associated hospitalizations among premature Canadian infants. Journal of
    Pediatrics 143:S150-S156
   Sigurs, Nele; Gustaffson, M.; Bjarnason, Ragnar; Lundberg, Fredrik; Schmidt, Susanne; Sigurbergsson, Fredrik; Kjellman, Bengt.
    (2005) Severe respiratory syncytial virus bronchiolitis in infancy and asthma and allergy at age 13. Am J Respir Crit Care Med
    171:137-141
   Smoes, Eric (2003) Environmental and demographic risk factors for respiratory syncytial virus lower respiratory tract disease.
    Journal of Pediatrics 143:S118-S126
   Stevens, Timothy, Hall, Caroline. (2004). Controversies in palivizumab use. The Pediatric Infectious Disease Journal 23:11;1051-
    1052
   Welliver, Robert C. (2003). Review of epidemiology and clinical risk factors for severe respiratory syncytial virus (RSV) infection. J
    Pediatr 143:S112-S117

								
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