Avian Influenza (AI) An Agricultural Perspective Andrea Morgan, DVM, MS United States Department of Agriculture Animal and Plant Health Inspection Service Veterinary Services Emergency Management

AI Fundamentals

The AI Virus Worldwide, there are many strains of AI virus which can cause varying degrees of illness in poultry A unique characteristic of influenza viruses is that they are constantly changing or mutating AI viruses can infect chickens, turkeys, pheasants, quail, ducks, geese, and guinea fowl as well as a wide variety of other birds, including migratory waterfowl In birds, AI viruses are further divided into two groups: low pathogenic or “low path” (LPAI), and highly pathogenic or “high path” (HPAI)

The AI Virus, cont. Of primary concern is H5N1, a strain of AI virus that has mutated into dozens of high path varieties and has infected humans To date, 15 countries have confirmed HPAI H5N1 within avian populations (commercial poultry and / or wild) The 15 countries are: Vietnam, Cambodia, Lao PDR, China, South Korea, Thailand, Japan, Malaysia, Croatia [wild birds only - swans], Indonesia, Kazakhstan, Mongolia [wild birds only], Romania, Russia, and Turkey. In January 2004, Hong Kong SAR [part of China] also had H5N1 infections confirmed only within wild bird populations. To date, only Japan, Malaysia, and South Korea have been able to eradicate HPAI H5N1 from poultry

The AI Virus, cont. LPAI signs are typically mild: decreased food consumption, respiratory signs (coughing and sneezing), and a decrease in egg production Birds with HPAI have a greater level of sickness and may die suddenly. Other clinical signs include lack of energy and appetite and decreased egg production. The virus can be spread through direct contact between healthy and infected birds, infected fecal matter, and contact with the outer surface of unwashed egg shells

The AI Virus, cont. Wild waterfowl are a natural reservoir for AI Wild ducks sometimes introduce LPAI into domestic flocks raised on a range or in open flight pens through fecal contamination Once introduced in domestic poultry, LPAI can mutate into a high pathogenic one and cause significant disease. In a poultry house, transfer of the HPAI virus between birds can also occur via airborne secretions.

History of HPAI in the U.S. HPAI has been found in poultry in the United States three times—1924, 1983 and 2004 The 1983 outbreak was the largest, ultimately resulting in the destruction of 17 million birds in Pennsylvania and Virginia before that virus was finally contained and eradicated By contrast, an isolated HPAI incident in a flock of 6,600 birds in Texas was quickly found and eradicated in 2004

The USDA Communication Effort The United States Department of Agriculture (USDA) and other Federal agencies are communicating and collaborating with Federal public health agencies, including the CDC for preparedness of an AI outbreak by focusing on the following components: Surveillance Diagnostics Response Recovery

Prevention, Surveillance, and Emergency Preparedness

Prevention

APHIS Efforts to Prevent HPAI Import restrictions on poultry and poultry products from countries affected by H5N1 Quarantining and testing bird imports Developing a risk assessment to specifically address the threat of HPAI from Southeast Asia Increased monitoring of domestic commercial markets for illegal activities Extensive education and outreach on biosecurity for backyard flocks

APHIS Domestic Activities The President and Congress have approved additional funds to enhance USDA’s AI prevention and preparation efforts. On the domestic front these funds will go in part to: Increase the current animal vaccine stockpile and stock other response supplies Enhance preparedness training, surveillance and biosecurity measures to rapidly contain or exclude H5N1 AI virus from poultry farms or premises Enhance smuggling interdiction and trade compliance Continue research on AI

Biosecurity APHIS receives support from the U.S. commercial poultry industry in terms of producers’ vigilance in applying and adhering to good biosecurity practices on the farm “Biosecurity for the Birds” is a major outreach campaign that places informational materials directly into the hands of those raising poultry in their backyards, as well as commercial poultry producers

Surveillance

Surveillance APHIS continues to work diligently to keep HPAI from becoming established in the U.S. poultry population More than one million AI tests are conducted in the U.S. each year USDA’s Agricultural Research Service developed—and APHIS validated—a rapid test for AI that has proven highly effective in screening for the disease The test has been distributed to National Animal Health Laboratory Network labs all across the country

Surveillance, cont. The National Poultry Improvement Plan has a program for breeder flocks (in place since 1998) and has established an “AI free” category of certification for commercial companies that require testing flocks for AI This ongoing program helps commercial companies monitor their breeding flocks for LPAI State and university laboratories test suspect cases and industry, working with states, conducts export testing at slaughter States conduct surveillance in areas where AI has historically been a concern (e.g., live bird marketing system) USDA has also been working closely with State and industry representatives to increase surveillance at live bird markets in the northeastern U.S.

Wildlife Monitoring Biologists within the Department of Interior’s Fish and Wildlife Service and U.S. Geological Survey, as well as USDA, will be sampling migratory birds for H5N1 in the Pacific Flyway starting in April 2006 APHIS’ Wildlife Services has also provided assistance to minimize threats to public and animal health through its National Wildlife Disease Surveillance and Emergency Response Plan

Response

Incident Command System (ICS) ICS puts in place personnel and material resources to the site of the incident. APHIS will implement activities in the field in response to any event. Incident Command Teams will typically be on site within 24 hours of a presumptive diagnosis of AI or any other significant foreign animal disease

The ICS Structure