Volume 18, Number 2—February 2012
Dispatch
Oseltamivir-Resistant Pandemic (H1N1) 2009 Virus Infections, United States, 2010–11
Table 1
Characteristics of patients with oseltamivir-resistant pandemic (H1N1) 2009 virus infection, United States, October 1, 2010–July 31, 2011*
| Characteristic | No. with characteristic/total no. (%), n = 35 |
|---|---|
| Male sex | 19/35 (54) |
| Exposed to oseltamivir before specimen collection† | 9/34 (26) |
| Exposed to another person using oseltamivir | 0/15 (0) |
| Received 2010–11 influenza vaccine | 6/22 (27) |
| Any chronic medical conditions | 22/33 (67) |
| Chronic pulmonary disease, including asthma | 10/33 (30) |
| Chronic cardiac disease | 6/33 (18) |
| Diabetes mellitus | 8/33(24) |
| Immunocompromising condition‡ | 8/33(24) |
| Pregnancy | 1/33 (3) |
| Other§ | 10/33 (30) |
| Lived in a single-family household | 14/22 (64) |
| Lived in a residential facility | 1/22 (4) |
| Others in the household/residence were ill before patient’s illness | 2/15 (13) |
| Traveled within 7 d before illness | 2/18 (11) |
| Hospitalized during influenza illness | 14/33 (42) |
| ICU admission | 8/14 (57) |
| Died | 3/34 (9) |
*The median age of patients was 33 y (range 1 mo–78 y). ICU, intensive care unit.
†Nine patients began oseltamivir treatment prior to specimen collection; none received oseltamivir chemoprophylaxis.
‡Includes HIV/AIDS, malignancy, autoimmune disorder, solid organ transplant, stem cell transplant, and history of taking immunosuppressive therapy in the past year.
§Includes morbid obesity, obstructive sleep apnea, chronic liver disease, and neurologic or developmental disorders.
1Additional members of the US Antiviral Resistance Surveillance Working Group who contributed data are listed at the end of this article.