Swine Origin H1N1 2009,Clinical AspectsJaveed Siddiqui M.D.,M.P.H Division of Infectious and Immunologic Diseases Center for Health and Technology School of Medicine University of California, Davis,Clinical Case,September 2009,Clinical Case,Clinical Case,Clinical Case,Clinical Case,Clinical Presentation,The symptoms of pandemic H1N1 influenza of 2009 are essentially the same as the seasonal flu, although some have noted an increased frequency of gastrointestinal symptoms, including vomiting and diarrhea. It has been noted some have observed the absence of fever in a significant number with virologically proven cases.,CDC. Interim guidance for clinicians on identifying and caring for patients with swine-origin influenza A (H1N1) virus infection. June 2009. Available at: http:/www.cdc.gov/h1n1flu/identifyingpatients.htm Accessed September 16, 2009.),S-OIV H1N1 Clinical Findings,Incubation: mean of 3-9 days Range 1-7 days Symptoms: Fever (90%) Cough (100%) Headache (60%) Diarrhea (30%),Shinde V et al NEJM May 7 2009,Clinical Features of S-OIV H1N1,The incubation period for H1N1 influenza is 1-4 days, possibly as long as 7 days. clinical features of influenza: Sudden onset of fever (usually high) Headache Extreme tiredness Dry cough Sore throat Runny nose Muscle aches and stomach symptoms - more common in children. (CDC. Interim guidance for clinicians on identifying and caring for patients with swine-origin influenza A (H1N1) virus infection. June 2009. Available at: http:/www.cdc.gov/h1n1flu/identifyingpatients.htm Accessed September 16, 2009.),Symptoms in virologically confirmed cases,Cough (98%) Subjective fever (96%) Fatigue (89%) Headache (82%) Sore throat (82%) Abdominal pain (50%),Diarrhea (48%) Dyspnea (48%) Joint pain (46%) The measured mean peak fever in this group was 102.2 F.,During an outbreak of H1N1 in a New York City high school, a sample of New York City school students (median age, 15 years) with virologically confirmed cases.,http:/www.cdc.gov/mmwr/preview/mmwrhtml/mm58d0430a1.htm Accessed November 7, 2009 MMWR Morb Mortal Wkly Rep Dispatch. 2009;58:1-3,The CDC Definitions influenza-like illness (ILI),fever of 100 F (37.8 C) plus cough and/or sore throat in the absence of a known cause other than influenza.acute respiratory illness (ARI), defined by the presence of 2 of the following 4 symptoms: fever, cough, sore throat, or rhinorrhea.,http:/www.cdc.gov/mmwr/preview/mmwrhtml/mm58d0430a1.htm Accessed November 7, 2009),Symptomatology Associated with pandemic influenza in New York City April - May 2009,In the outbreak of pandemic influenza in New York City, 95% of virologically proven cases satisfied the ILI definition.,http:/www.cdc.gov/mmwr/preview/mmwrhtml/mm58d0430a1.htm Accessed November 7, 2009 MMWR Morb Mortal Wkly Rep Dispatch. 2009;58:1-3,Case Definitions for S-OIV H1N1,Confirmed case: Patient with ILI plus laboratory evidence confirmed by real-time RT-PCR or viral culture.Probable case: ILI plus laboratory test positive for influenza A and negative for human H1 and H3 by RT-PCR; and,Interim guidance for clinicians on identifying and caring for patients with swine-origin influenza A (H1N1) virus infection. June 2009.http:/www.cdc.gov/h1n1flu/identifyingpatients.htm Accessed November 7, 2009.,Case Definitions for S-OIV H1N1,Probable case Optional: ILI without negative H1N1 test and previously healthy person 65 years hospitalized for ILI; epidemiologic link to confirmed or probable case in past 7 days; or ILI plus travel to a state or country with confirmed or probable cases.,Interim guidance for clinicians on identifying and caring for patients with swine-origin influenza A (H1N1) virus infection. June 2009.http:/www.cdc.gov/h1n1flu/identifyingpatients.htm Accessed November 7, 2009.,Complications of S-OIV H1N1,Related Risk for Infection, Hospitalization, and Lethal Outcome,Age-related risk. Rates for H1N1 for May-July 2009 by AgeAge Cases/100,000 Hospitalization/100,000 Death % 0-4 yrs 23 4.5 7 (2%)a 5-24 yrs 27 2.1 48 (16%) 25-49 yrs 7 1.1 124 (41%) 50-64 yrs 4 1.2 71 (24%) 65 yrs 1.3 1.7 26 (2%)a % of total deaths. Age data not available for 15%. Rate expressed /100,000 populationUS age data(Novel Swine-Origin Influenza A (H1N1) Virus Investigation Team; Dawood FS, Jain S, Finelli L, et al.Emergence of a novel swine-origin influenza A (H1N1) virus in humans. N Engl J Med. 2009;360:2605-2,Complications of S-OIV H1N1,Exacerbation of underlying chronic disease; Complications related to the upper airways, including sinusitis or otitis; Pulmonary complications, including bronchitis, asthma (sometimes with status asthmaticus), and acute exacerbations of chronic bronchitis; Miscellaneous conditions, including cardiac (myocarditis and pericarditis), myositis, rhabdomyolysis, central nervous system complications (encephalopathy, encephalitis, seizures), toxic shock syndrome, and secondary bacterial pneumonia.,Severe complications of S-OIV H1N1,In June 2009, the University of Michigan reported severe pulmonary complications of 2009 H1N1 influenza infection in 10 patients with a median age of 49 years. All 10 patients were referred for severe hypoxemia, ARDS, and inability to oxygenate with conventional ventilation methods. All had severe multilobar pneumonia on x-ray, none had evidence of bacterial pneumonia, and 4 had CT scan-confirmed pulmonary embolism.,