Volume 21, Number 12—December 2015
Research
Infection Risk for Persons Exposed to Highly Pathogenic Avian Influenza A H5 Virus–Infected Birds, United States, December 2014–March 2015
Carmen S. Arriola
, Deborah I. Nelson, Thomas J. DeLiberto, Lenee Blanton, Krista Kniss, Min Z. Levine, Susan C. Trock, Lyn Finelli, Michael Jhung, and the H5 Investigation Group
, Deborah I. Nelson, Thomas J. DeLiberto, Lenee Blanton, Krista Kniss, Min Z. Levine, Susan C. Trock, Lyn Finelli, Michael Jhung, and the H5 Investigation Group
Table
Location and characteristics of highly pathogenic avian influenza A H5 virus outbreaks among birds and minimum number of exposed persons, United States, December 15, 2014–March 31, 2015
| Variable |
No. (%) outbreaks among birds, n = 60 |
No. (%) virus-exposed persons,* n = 164 |
|---|---|---|
| State | ||
| Arizona | 1 (2) | 2 (1) |
| California | 8 (13) | 30 (18) |
| Idaho | 8 (13) | 16 (10) |
| Kansas | 2 (3) | 5 (3) |
| Minnesota | 3 (5) | 17 (10) |
| Missouri | 4 (7) | 26 (16) |
| Montana | 1 (2) | 2 (1) |
| New Mexico | 1 (2) | 1 (1) |
| Nevada | 1 (2) | 5 (3) |
| Oregon | 10 (17) | 20 (12) |
| Utah | 1 (2) | 1 (1) |
| Washington | 19 (32) | 37 (23) |
| Wyoming |
1 (2) |
2 (1) |
| Influenza virus subtype† | ||
| H5N1 | 2 (3) | 3 (2) |
| H5N2 | 37 (59) | 103 (63) |
| H5N8 | 22 (35) | 56 (34) |
| H5‡ |
2 (3) |
2 (1) |
| Outbreak setting | ||
| Wild | 38 (63) | 64 (39) |
| Captive | 5 (8) | 13 (8) |
| Backyard farm | 9 (15) | 25 (15) |
| Commercial farm |
8 (13) |
62 (38) |
| No. birds per outbreak | ||
| 1–5 | 42 (70) | 71 (43) |
| 6–500 | 9 (15) | 29 (18) |
| >500 | 9 (15) | 64 (39) |
*Excludes persons who participated in culling activities.
†Three outbreaks involved a combination of influenza virus subtypes: H5N1/H5N2 (n = 1) and H5N2/H5N8 (n = 2).
‡No virus was isolated, but specimens were positive by the H5 (intercellular adhesion gene cluster) PCR assay, which targets the Eurasian H5 clade 2.3.4.4 viruses that were detected in the United States in December 2014.
1Members of the H5 Investigation Group are listed at the end of this article.
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Page updated: November 16, 2015
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