An outbreak of avian influenza more commonly known as bird flu, is affecting bird populations in countries throughout Southeast Asia. The outbreak is caused by the H5N1 subtype of influenza A. Human cases also have been reported. Effective immediately and until further notice, CDC is banning the importation of all birds (Class Aves) from the following Southeast Asian countries: Cambodia; Indonesia; Japan; Laos; People's Republic of China, including Hong Kong SAR; South Korea; Thailand; and Vietnam. Exceptions exist for certain categories of birds and processed bird products. This order complements a similar action taken by the U.S. Department of Agriculture (USDA). This order may be amended as necessary as the situation develops, for example, to add or remove countries.
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This embargo is effective on February 4, 2004, and will remain in effect until further notice.
For further information contact: ↑
Paul Arguin, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Mailstop C-14, 1600 Clifton Rd., Atlanta, GA 30030, telephone 404-498-1600.
Supplementary information: ↑
H5N1 avian influenza is a subtype of the type A influenza virus. Wild birds are the natural hosts of the virus, which circulates among birds worldwide. It is very contagious among birds and can be deadly to birds, particularly domesticated birds like chickens. Infected birds shed virus in saliva, nasal secretions, and feces. Avian influenza viruses spread among susceptible birds when they have contact with contaminated excretions.
Since mid-December, outbreaks of influenza A (H5N1), infection have been detected in the poultry populations of Cambodia, China, Hong Kong (in a single peregrine falcon), Indonesia, Japan, Korea, Laos, Thailand, and Vietnam. The virus does not typically infect humans, but in recent months, Vietnam has reported hospitalized cases of serious respiratory illness, primarily among children, most of whom have died. Thirteen of these patients were confirmed as having avian influenza A (H5N1), and nine of the confirmed cases have been fatal. The Ministry of Health of Thailand announced four confirmed cases of avian influenza A (H5N1) in humans; all four of the patients have died. It is believed that most cases of H5N1 infection in humans have resulted from contact with infected poultry or contaminated surfaces.
The incubation period for influenza is one to four days, with an average of two days. Uncomplicated influenza illness is characterized by the abrupt onset of constitutional and respiratory signs and symptoms (e.g., fever, myalgia, headache, severe malaise, nonproductive cough, sore throat, and rhinitis). Among children, otitis media, nausea, and vomiting are also commonly reported characteristics of influenza illness.
Influenza illness typically resolves after a limited number of days for the majority of persons, although cough and malaise can persist for more than two weeks. Among certain persons influenza can exacerbate underlying medical conditions (e.g., pulmonary or cardiac disease), lead to secondary bacterial pneumonia or primary influenza viral pneumonia, or occur as part of a co-infection with other viral or bacterial pathogens. Young children with influenza infection can have initial symptoms mimicking bacterial sepsis with high fevers, and less than or equal to 20% of children hospitalized with influenza can have febrile seizures. Influenza infection has also been associated with encephalopathy, transverse myelitis, Reye syndrome, myositis, myocarditis, and pericarditis. Influenza-related deaths can result from pneumonia as well as from exacerbations of cardiopulmonary conditions and other chronic diseases.
Public Health Risks ↑
So far, H5N1 viruses have not been capable of efficient human-to-human transmission. The co-circulation of human and highly pathogenic animal influenza viruses is of serious concern to the World Health Organization (WHO), CDC, and other health authorities worldwide, since an exchange of genes between the two viruses might occur if individuals were co-infected with both human and avian influenza viruses. This gene exchange could give rise to a new influenza virus to which humans would have little or no immunity and which could be transmitted efficiently from person to person. If an avian influenza virus were able to infect people and gain the ability to spread easily from person to person, an “influenza pandemic” could begin. A pandemic is an outbreak of an infectious disease that rapidly spreads worldwide resulting in large amounts of morbidity and mortality. Three such pandemics occurred during the 20th century and resulted in many more deaths and hospitalizations than occur during a typical influenza season because the human population did not have underlying immunity to the newly circulating virus.
There is no current vaccine specifically formulated to provide immunity against H5N1 subtype of influenza. In addition, of the four antiviral agents currently licensed in the United States for treatment of influenza, genetic sequencing of influenza A (H5N1) virus samples from human cases in Vietnam shows antiviral resistance to two of them (amantadine and rimantadine). The remaining two antivirals (oseltamavir and zanamavir) should still be effective against this strain of H5N1.
The principal measures to control an outbreak of H5N1 in birds are the culling (killing) of sick and exposed birds and the restriction of movement of potentially exposed birds to unaffected areas. So far over 45 million birds have been culled. According to the U.S. Fish and Wildlife Service, the United States imports over 20,000 live birds from countries affected by the outbreak of avian influenza.
Introduction of influenza A (H5N1) infected birds into the United States could lead to outbreaks of disease in the human population, a significant public health threat. Banning the importation of all avian species from affected countries is an effective means of limiting this threat. CDC is therefore taking this action to reduce the chance of introduction or spread of influenza A (H5N1) into the United States. This order complements a similar action taken by the U.S. Department of Agriculture.
Because there is no current evidence suggesting that birds infected with influenza A (H5N1) have been imported and are causing disease in the United States, this order does not include restrictions upon the domestic movement of birds already in the United States.
Immediate Action ↑
Therefore, pursuant to 42 CFR 71.32(b) and in accordance with this order, no person may import or attemptto import any birds (Class: Aves), whether dead or alive, or any products derived from birds (including hatching eggs), from the following Southeast Asian countries:
People's Republic of China, including Hong Kong SAR;
This prohibition is effective immediately and until further notice. This prohibition does not include pet birds which originated in the United States (as defined in 9 CFR 93.100), provided that the importation of such birds complies with USDA requirements, which includes a 30-day quarantine in a USDA facility. This prohibition also does not apply to any person who imports or attempts to import products derived from birds if, as determined by federal officials, such products have been properly processed to render them noninfectious so that they pose no risk of transmitting or carrying the influenza A (H5N1) virus and which comply with USDA requirements. This order may be amended as necessary as the situation develops, for example, to add or remove countries.Dated: February 5, 2004. Julie Louise Gerberding, Director, Centers for Disease Control and Prevention.