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Parainfluenza Virus Treatment & Management

  • Author: Subhash Chandra Parija, MBBS, MD, PhD, FRCPath, DSc; Chief Editor: Mark R Wallace, MD, FACP, FIDSA  more...
Updated: Oct 07, 2015

Approach Considerations

Because it is often difficult to distinguish pneumonia caused by HPIV from pneumonia caused by bacteria, patients with viral pneumonia are sometimes inappropriately treated with antibacterial antibiotics. In the setting of HPIV infection, antibiotics are used only if bacterial complications (eg, otitis and sinusitis) develop. Antiviral agents are of uncertain benefit for treatment of HPIV infection.

It is important to document an examination at time of discharge—for example, “Patient is breathing comfortably and is alert and consolable, without tachypnea, stridor, or retractions.” A pulse oximetry reading can also be included if available. If there are any concerns about the patient’s stability for discharge, always err on the side of admission.


Initial Management

Prehospital care includes fever control and attempts to alleviate respiratory symptoms and patient anxiety.

Respiratory symptoms commonly improve with benign measures such as sitting in a bathroom with a steaming shower and allowing vapor droplets to soothe inflamed airways. Another option includes exposing the child to the cool night air. Often, the patient’s symptoms resolve en route to the hospital. Attempts at calming or distracting the child can be beneficial.

Antipyretics may assist with fever control. Moderate or severe croup requires medical evaluation in the office or emergency department (ED). Consultations may include pulmonologists and infectious disease specialists.

Indications for hospitalization in patients with HPIV infection include the following:

  • Respiratory distress
  • Dehydration
  • Stridor at rest, even after receiving therapy
  • Need for repeated doses of racemic epinephrine
  • Rebound laryngospasm in patients who receive racemic epinephrine

A common issue in pediatric ED charts concerns variations in patient assessments. All notes on the chart (eg, from triage, nurses, and residents) should be examined. If any of these assessments differ from the physician’s assessment, the physician should address the differences in his or her notes. At discharge, ensure that proper discharge instructions, both written and oral, are given to the patient.


Supportive Care and Pharmacologic Therapy

Supportive care is mandatory. Oxygen mist is often helpful. Corticosteroids and nebulizers may be used to treat respiratory symptoms and to help reduce the inflammation and airway edema of croup.

Management of croup caused by HPIV infection depends on the severity of disease.

Mild croup

Management of mild croup consists of cool blow-by oxygen mist, fever control, and observation to determine whether the airway appears compromised.

Moderate croup

Cool oxygen mist and steroids are common therapies for moderate croup. Controlled trials of steroids for the palliation of croup symptoms have yielded conflicting results, and routine use of dexamethasone in this disease remains controversial. Traditionally, dexamethasone was administered intramuscularly (IM); however, some studies have documented the use of oral steroids.

In patients who fail to improve, administration of racemic epinephrine with a nebulizer has been beneficial. If racemic epinephrine alleviates symptoms, observe the patient for a minimum of 3 hours to ensure that his or her condition does not worsen (eg, because of possible rebound laryngospasm as the racemic epinephrine dose wears off). If the patient is asymptomatic at the end of the observation period, he or she can be discharged with proper follow-up care.

In moderate croup, oral intake may be lacking; therefore, it is essential to evaluate the patient’s hydration status. Intravenous (IV) fluids may be required.

Severe croup

The same measures are indicated for severe croup as for moderate croup. Observe the patient for signs of impending respiratory failure.

Repeat racemic epinephrine nebulization may be needed, in addition to intensive care monitoring. Racemic epinephrine nebulizations can be repeated at 1-hour to 2-hour intervals as needed. Endotracheal intubation followed by a tracheotomy may be required in patients with severe respiratory obstruction. Fortunately, fewer than 5% of patients who are admitted require artificial airway support.

Antiviral therapy

Ribavirin is a broad-spectrum antiviral agent that has been shown to be effective against HPIV-3 infection in vitro and possibly in vivo. Although results are mixed, ribavirin aerosol or systemic therapy has been used to treat HPIV infections in children and adults who are severely immunocompromised. Use at this time is of uncertain clinical benefit.



Passively acquired maternal antibodies may play a role in protection from HPIV-1 and HPIV-2 in the first few months of life, an observation that highlights the importance of breastfeeding.

Currently, there are no effective vaccines for prevention of infections by HPIVs. Among the HPIVs, the HPIV-3 is the most virulent with ability to cause bronchioloitis and pneumonia in infants. Therefore, attempts are being made for the development of human vaccine against the HPIV-3.

In the late 1960s, field trials of formalin-killed whole HPIV-1, HPIV-2, and HPIV-3 vaccines failed to protect children against natural infections. Subsequent approaches to the development of HPIV vaccines have included intranasal administration of live attenuated strains, subunit strategies using hemagglutinin-neuraminidase (HN) and fusion (F) proteins, recombinant bovine human viruses, and strains engineered by means of reverse genetics.

Antigenically and genetically stable attenuated strains of HPIV-3 have been developed with cold adaptation (CA); their stability is enhanced because of multiple markers of attenuation in tissue culture. CA strains of HPIV-1 and HPIV-2 have been developed, and attenuation in tissue culture and animal models has been demonstrated.

BCX 2798 and BCX 2855 were found to be effective inhibitors of HPIV-3 HN in a mouse model, as well as potentially promising candidates for prophylaxis and treatment of HPIV-3 infection in humans.[23] A live attenuated vaccine against respiratory syncytial virus (RSV) and HPIV-3 was found to be safe and immunogenic in a phase 1 study.[24] Reverse genetics produced an attenuated chimeric HPIV-1 that contains type 3 internal proteins in conjunction with type 1 HN and F surface glycoproteins.[25]

Some of the potential vaccine candidates are the HPIV-3 cp45 nasal vaccine, which is derived from the JS wild-type strain of HPIV-3 and the rB/HPIV3b vaccine, which is a cDNA-derived chimeric HPIV-3. An intranasal vaccine has been developed against HPIV-3. The investigators determined that the vaccine is appropriately attenuated and immunogenic in infants as young as 1 month. Further development of this vaccine is warranted.[26, 27] .

Two vaccines against HPIV-3 were determined to be safe and immunogenic in phase I trials involving HPIV-3–seronegative infants and children; vaccines against HPIV1 and HPIV2 were found to be less advanced.[26]

However, the major limitation of these vaccines is their potential to cause actual infection in immunocompromised hosts and children. In order to overcome this limitation, subunit vaccines that target the HPIV-3 HN and F proteins are being investigated. In a recent study, intranasal coadministration of oligomannose-coated liposome-encapsulated HN with the poly(I:C) adjuvant was found to induce adequate viral-specific immunity against HPIV-3 in a mouse model.[2]

Strict attention to infection control should decrease or prevent spread of infection. Frequent handwashing and avoidance of sharing items such as cups, glasses, and utensils with an infected person should decrease the spread of viruses to others. In a hospital setting, the spread of HPIVs can and should be prevented by strict attention to contact precautions, such as handwashing and wearing of protective gowns and gloves.


Long-Term Monitoring

If the patient has a pediatrician or other primary care provider, attempt to contact the provider to ensure proper follow-up care. The pediatrician can also be consulted on management issues if the treating physician has concerns or doubts.

Helpful long-term measures may include the following:

  • Bed rest
  • Use of vaporizers producing moist air
  • Administration of acetaminophen or ibuprofen for fever
  • Increased oral fluid intake
Contributor Information and Disclosures

Subhash Chandra Parija, MBBS, MD, PhD, FRCPath, DSc Director-Professor of Microbiology, Head of Department of Microbiology, Jawaharlal Institute, Postgraduate Medical Education and Research, India

Subhash Chandra Parija, MBBS, MD, PhD, FRCPath, DSc is a member of the following medical societies: Royal College of Pathologists, Indian Society for Parasitology, Indian Medical Association, National Academy of Medical Sciences (India), Indian Association of Medical Microbiologists, Indian Association of Biomedical Scientists, Indian Association of Pathologists and Microbiologists, Indian Academy of Tropical Parasitology

Disclosure: Received salary from Jawaharlal Institute of Postgraduate Medical education & Research , Pondicherry , India for employment.


Thomas J Marrie, MD Dean of Faculty of Medicine, Dalhousie University Faculty of Medicine, Canada

Thomas J Marrie, MD is a member of the following medical societies: Alpha Omega Alpha, American College of Physicians, American Society for Microbiology, Association of Medical Microbiology and Infectious Disease Canada, Royal College of Physicians and Surgeons of Canada

Disclosure: Nothing to disclose.

Chief Editor

Mark R Wallace, MD, FACP, FIDSA Clinical Professor of Medicine, Florida State University College of Medicine; Clinical Professor of Medicine, University of Central Florida College of Medicine

Mark R Wallace, MD, FACP, FIDSA is a member of the following medical societies: American College of Physicians, American Medical Association, American Society for Microbiology, Infectious Diseases Society of America, International AIDS Society, Florida Infectious Diseases Society

Disclosure: Nothing to disclose.


Jeffrey D Band, MD Professor of Medicine, Oakland University William Beaumont School of Medicine; Director, Division of Infectious Diseases and International Medicine, Corporate Epidemiologist, William Beaumont Hospital; Clinical Professor of Medicine, Wayne State University School of Medicine

Disclosure: Nothing to disclose.

Richard B Brown, MD, FACP Chief, Division of Infectious Diseases, Baystate Medical Center; Professor, Department of Internal Medicine, Tufts University School of Medicine

Richard B Brown, MD, FACP is a member of the following medical societies: Alpha Omega Alpha, American College of Chest Physicians, American College of Physicians, American Medical Association, American Society for Microbiology, Infectious Diseases Society of America, and Massachusetts Medical Society

Disclosure: Nothing to disclose.

Joseph Domachowske, MD Professor of Pediatrics, Microbiology and Immunology, Department of Pediatrics, Division of Infectious Diseases, State University of New York Upstate Medical University

Joseph Domachowske, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Pediatrics, American Society for Microbiology, Infectious Diseases Society of America, Pediatric Infectious Diseases Society, and Phi Beta Kappa

Disclosure: Nothing to disclose.

Ashir Kumar, MD, MBBS, FAAP Professor Emeritus, Department of Pediatrics and Human Development, Michigan State University College of Human Medicine

Ashir Kumar, MD, MBBS, FAAP is a member of the following medical societies: American Association of Physicians of Indian Origin and Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Russell W Steele, MD Head, Division of Pediatric Infectious Diseases, Ochsner Children's Health Center; Clinical Professor, Department of Pediatrics, Tulane University School of Medicine

Russell W Steele, MD is a member of the following medical societies: American Academy of Pediatrics, American Association of Immunologists, American Pediatric Society, American Society for Microbiology, Infectious Diseases Society of America, Louisiana State Medical Society, Pediatric Infectious Diseases Society, Society for Pediatric Research, and Southern Medical Association

Disclosure: Nothing to disclose.

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Medscape Salary Employment

Roy M Vega, MD Assistant Professor of Pediatrics, Albert Einstein College of Medicine; Director, Pediatric Emergency Services, Department of Emergency Medicine, Bronx Lebanon Hospital Center, Bronx, NY

Roy M Vega, MD is a member of the following medical societies: American Academy of Pediatrics

Disclosure: Nothing to disclose.

Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

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Transmission electron micrograph of parainfluenza virus. Two intact particles and free filamentous nucleocapsid.
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