CME REVIEW ARTICLE Influenza-Like Illness Diagnosis and Management in the Acute Care Setting Sharon G. Humiston, MD, MPH, FAAP and Thuylinh N. Pham,MD,FAAP pandemic for children.” That is, each winter, 10% to 40% of chil- Abstract: During influenza season, acute respiratory illness due to in- dren are infected with influenza, an attack rate similar to that re- fluenza is difficult to distinguish from other influenza-like illnesses, but ported for children during the 2009 H1N1 pandemic.2,3 The testing should be reserved for situations when timely results will influ- large number of infections and the virulence of certain strains lead ence management or infection control measures. Immunization status to the pediatric burden of seasonal influenza disease: a large num- and timing of disease onset notwithstanding, a neuraminidase inhibitor ber of hospitalizations, emergency department visits, and outpa- should be offered immediately for certain high-risk children; neuramini- tient visits among children.4,5 dase inhibitor treatment should be considered if shorter illness is warranted This article is designed to serve as a practical review for acute or an at-risk sibling may be protected. Antipyretics and cough control may care health care professionals trying to stay afloat in the annual be useful. Immunization with an age-appropriate dose of an inactivated in- tsunami of febrile coughing children. We will focus on patient di- fluenza vaccine is the cornerstone of prevention for health care personnel agnosis and treatment as well as on preventing influenza in your- and our patients. self and others. The questions posed are meant to represent the Key Words: influenza, influenza-like illness, acute respiratory illness, questions that might run through your head as you are seeing your immunization twenty-third patient with ILI. (Pediatr Emer Care 2016;32: 875–884) BACKGROUND TARGET AUDIENCE This CME activity is intended for physicians who care for Question children. Physicians and allied health professionals working in What are the key facts on influenza epidemiology? (Note: This emergency and pediatric emergency departments, urgent care is included in the American Board of Pediatrics “Content Outline” and pediatric urgent care centers, as well as pediatric and family for General Pediatrics, but not Pediatric Emergency Medicine). medicine primary care practices will find this article helpful. Influenza virus causes disease worldwide. Importantly, influ- enza type A viruses may infect both humans and animals, but LEARNING OBJECTIVES humans are the only known reservoir of influenza types B and After completion of this article, the reader should be able to: C. There is no chronic carrier state. Adults can transmit influenza from the day before symptom onset to approximately 5 days af- 1. Identify how to diagnose influenza and differentiate it from ter symptoms begin; children can transmit the virus for 10 or more days. People spread the virus via secretions spewed when other causes of influenza-like illness. μ 2. Understand the different treatment and management options coughing or sneezing. Large virus-laden droplets (>5 mindiam- eter) settle on the upper respiratory tract mucosa of susceptible for influenza. 6 3. Understand methods for protecting oneself and one's patients persons who are within 6 f. of infected persons. Alternatively, from the spread of influenza. the virus is spread indirectly when a susceptible host touches a contaminated surface and autoinoculates his eyes, nose, or 7 veryone who has worked in an acute care setting through even mouth. Influenza Avirus can survive on hard, nonporous surfaces one of the annual winter-spring spikes in patient volume fears (eg, doorknobs, keyboards, pens) for 24 to 48 hours and on porous E materials (eg, cloth, paper) for less than 8 to 12 hours in ambient and loathes influenza disease and the other illnesses that present 8 9 with similar acute respiratory symptoms (ie, influenza-like ill- temperatures and much longer if the surface is moist or wet. nesses [ILI]). Effler1 points out that “Every year is an influenza Unlike tropical areas where influenza occurs all year, in the United States, peak influenza activity usually occurs in February (14 of the past 34 seasons), followed by December (7 seasons), March (6 seasons), and January (5 seasons).10 The Influenza Divi- sion of the Centers for Disease Control and Prevention (CDC) pre- Professor of Pediatrics (Humiston) and Urgent Care Pediatrician (Pham), Children's Mercy Hospital Kansas City, Kansas City, MO. pares a weekly influenza surveillance report regarding influenza The authors and staff in a position to control the content of this CME activity activity in the United States. The most recent US flu activity and their spouses/life partners (if any) have disclosed that they have no map is available at http://www.cdc.gov/flu/weekly/usmap.htm. financial relationships with, or financial interest in, any commercial organizations pertaining to this educational activity. Dr. Humiston has disclosed that the U.S. Food and Drug Administration has not Question yet approved the use of intravenous zanamivir as discussed in this article. It My patient's mother just asked me, “If it isn't the flu, what is an investigational product that, according to CDC's Advisory Committee ” on Immunization Practices, “may be obtained on a compassionate use basis could it be? What viruses cause acute respiratory illness other for seriously ill children, especially those who are immunocompromised or than influenza? cannot tolerate or absorb orally or enterically administered oseltamivir.” Several respiratory infections cause a syndrome clinically in- Reprints: Sharon G. Humiston, MD, MPH, FAAP, Division of Emergency distinguishable from influenza. A succinct review of these has pre- Medicine, Department of Pediatrics, Children’s Mercy Hospital, 2401 11 Gillham Rd, Kansas City, MO 64108 (e‐mail: [email protected]). viously been published in Pediatric Emergency Care. Afew Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. examples of viruses that cause such respiratory infections can be ISSN: 0749-5161 found in Table 1. Pediatric Emergency Care • Volume 32, Number 12, December 2016 www.pec-online.com 875 Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. Humiston and Pham Pediatric Emergency Care • Volume 32, Number 12, December 2016 TABLE 1. Viruses Other Than Influenza That Cause Pediatric Febrile Respiratory Illness (ie, ILI) Name Disease Seasonality Notes Respiratory syncytial Major cause of lower respiratory tract The incidence of RSV infection Children are at increased risk for a virus (RSV) disease (specifically bronchiolitis and generally peaks between more severe course of illness if they pneumonia) in children before January and March. have a history of prematurity or their first birthday underlying cardiac/respiratory disorders. Human metapneumovirus Produces a disease spectrum much like In areas with a temperate climate, Approximately 3/4 of children will (HMV) that of RSV including upper respiratory disease activity increases from be seropositive by 5 y, and >90% tract infections, bronchiolitis, and December to May with peaks will be seropositive by 10 y. pneumonia. Mean and median ages in March and April, slightly Not surprisingly, children who of HMV infection range from 6-20 mo, after that of RSV. attend day care are at increased slightly older than for RSV,but like risk of infection. RSV.There is an association between HMV infection and subsequent development of wheezing. Adenovirus Causes several different syndromes The winter seasonal peak can be including upper and lower respiratory followed by a second peak in tract disease, keratoconjunctivitis, spring/summer. hemorrhagic cystitis, and gastroenteritis with diarrhea. The diarrhea often accompanies the respiratory tract symptoms. Parainfluenza viruses Primarily known as the cause of croup, Late fall/winter peak types 1 to 4 but up to 15% of bronchiolitis/ pneumonia can be attributed to this Human coronaviruses* Human coronavirus NL63, first described Seasonal peaks from January to Human coronavirus HKU1, also in 2004, can cause fever and LRI, but March in temperate climates relatively newly described, causes usually causes URI. Coinfections are URI and LRI in children <2 y. commonly reported. HKU1 also has been associated with febrile seizures. Human bocavirus Studies have shown that bocavirus causes Most authors in temperate climates HBoV,a recently discovered (HBoV) both URI and LRI. It seems to be a have observed a higher occurrence type of parvovirus, is relatively common pediatric respiratory of HBoV detections during the frequently a copathogen. virus with a disease spectrum similar winter and spring months. to that of RSV and HMV. *Other than the severe acute respiratory syndrome (SARS) coronavirus. LRI indicates lower respiratory infection; URI, upper respiratory infection. Question INFLUENZA TESTING I am seeing so many kids with fever and malaise…Iamwor- In September 2016, the American Academy of Pediatrics ried that I will get lax and miss something important. What might (AAP) Committee on Infectious Diseases published their Recom- Imiss? mendations for Prevention and Control of Influenza in Children, Of course, you do not want to become so jaded that you miss 2016–2017.14 This policy statement will be referred to frequently a child with serious dehydration or poor oxygenation because you throughout the remainder of this review. walk into the room