Oseltamivir-Resistant Pandemic (H1N1) 2009 Virus, Mexico

During May 2009–April 2010, we analyzed 692 samples of pandemic (H1N1) 2009 virus from patients in Mexico. We detected the H275Y substitution of the neuraminidase gene in a specimen from an infant with pandemic (H1N1) 2009 who was treated with oseltamivir. This virus was susceptible to zanamivir and resistant to adamantanes and oseltamivir

Hospital triage system for adult patients using an influenza-like illness scoring system during the 2009 pandemic--Mexico.

Pandemic influenza A (H1N1) virus emerged during 2009. To help clinicians triage adults with acute respiratory illness, a scoring system for influenza-like illness (ILI) was implemented at Hospital Civil de Guadalajara, Mexico.A medical history, laboratory and radiology results were collected on emergency room (ER) patients with acute respiratory illness to calculate an ILI-score. Patients were evaluated for admission by their ILI-score and clinicians' assessment of risk for developing complications. Nasal and throat swabs were collected from intermediate and high-risk patients for influenza testing by RT-PCR. The disposition and ILI-score of those oseltamivir-treated versus untreated, clinical characteristics of 2009 pandemic influenza A (H1N1) patients versus test-negative patients were compared by Pearson's Chi(2), Fisher's Exact, and Wilcoxon rank-sum tests.Of 1840 ER patients, 230 were initially hospitalized (mean ILI-score = 15), and the rest were discharged, including 286 ambulatory patients given oseltamivir (median ILI-score = 11), and 1324 untreated (median ILI-score = 5). Fourteen (1%) untreated patients returned, and 3 were hospitalized on oseltamivir (median ILI-score = 19). Of 371 patients tested by RT-PCR, 104 (28%) had pandemic influenza and 42 (11%) had seasonal influenza A detected. Twenty (91%) of 22 imaged hospitalized pandemic influenza patients had bilateral infiltrates compared to 23 (38%) of 61 imaged hospital test-negative patients (p<0.001). One patient with confirmed pandemic influenza presented 6 days after symptom onset, required mechanical ventilation, and died.The triaging system that used an ILI-score complimented clinicians' judgment of who needed oseltamivir and inpatient care and helped hospital staff manage a surge in demand for services

Influenza Scoring System at the Hospital Civil de Guadalajara during the (H1N1) pandemic 2009—Mexico_‡.

<p>Influenza Scoring System at the Hospital Civil de Guadalajara during the (H1N1) pandemic 2009—Mexico_‡.</p

Histogram of patients seeking care for acute respiratory infections at Hospital Civil de Guadalajara during the (H1N1) pandemic 2009—Mexico.

<p>Histogram of patients seeking care for acute respiratory infections at Hospital Civil de Guadalajara during the (H1N1) pandemic 2009—Mexico.</p

Demographic Characteristics of Patients Seeking Care for acute respiratory infection at the Hospital Civil de Guadalajara during the (H1N1) pandemic 2009—Mexico.

<p>*Difference between seasonal influenza and pandemic (H1N1), 2009, p = 0.0007.</p><p>¥2% of pandemic (H1N1) 2009 missing risk assessment information.</p><p>‡Includes all hospitalized cases regardless of influenza RT-PCR test results.</p><p>∞Includes all hospitalized cases and ambulatory patients treated with oseltamivir who tested positive for influenza A.</p

Typical radiological findings of Pandemic (H1N1) 2009 patient at the Hospital Civil de Guadalajara—Mexico.

<p>Typical radiological findings of Pandemic (H1N1) 2009 patient at the Hospital Civil de Guadalajara—Mexico.</p

Patients seeking care with acute respiratory infections at the Hospital Civil de Guadalajara during the (H1N1) pandemic 2009—Mexico.

<p>Patients seeking care with acute respiratory infections at the Hospital Civil de Guadalajara during the (H1N1) pandemic 2009—Mexico.</p

Symptoms of Patients Seeking Care for Acute Respiratory Infections at the Hospital Civil de Guadalajara during the (H1N1) pandemic 2009—Mexico_◊.

<p>‡Includes all hospitalized cases regardless of influenza RT-PCR test results.</p><p>∞Includes all hospitalized cases and ambulatory patients treated with oseltamivir who tested positive for influenza A.</p><p>◊Insufficient data available from patients discharged from triage without oseltamivir to include in table.</p