Avian Influenza

Covered Topics What is avian influenza? Avian influenza and humans Symptoms of avian influenza Avian influenza treatment Avian influenza and Pandemic influenza

Avian influenza “Bird flu” Occurs naturally in birds Wild birds carry the viruses in their intestines, but don’t usually get sick. Can make chickens, ducks, and turkeys very sick and kill them. It is very contagious to birds

Avian Influenza A H5N1 virus A type of influenza that occurs mainly in birds Outbreaks have occurred in poultry in Asian countries. Humans have gotten sick in many Eastern Asian countries. This is the type of flu that many scientists are watching for a possible worldwide outbreak

Bird flu human infection Avian influenza (bird flu) viruses usually do not make humans sick. Avian influenza does not spread easily from bird to humans. Avian Influenza H5N1 is the kind of bird flu that has made some people sick in Asia. As of October 2005, the World Health Organization (WHO) reports 117 confirmed cases of H5N1 bird flu in humans. Sixty of those 117 people died. Most people got sick because of contact with sick poultry (chickens, ducks, turkeys) or by touching contaminated surfaces. There is no evidence that H5N1 can spread from person to person. Since 2002, more than 100 human cases of avian influenza have occurred in Eastern Asia; however, this is a small number compared to the large number of birds affected and the many opportunities for human exposure.

Avian Influenza Symptoms in Humans Symptoms may vary depending on the type Typical flu like symptoms Fever Headache Muscle aches Cough Sore throat Eye Infections Pneumonia Acute respiratory distress

Spread of Avian Influenza Wild birds pass it on to each other. Infected birds shed the virus and other birds become infected. Poultry become infected by the wild birds or by other poultry. Humans become infected by infected poultry or contaminated surfaces.

Treatment for Avian Influenza The same medication used for regular seasonal flu may work for bird flu infections in humans. Check with a physician about specific treatment plans. Two drugs, oseltamirvir (commercially known as Tamiflu) and zanamivir (commercially known as Relenza) can reduce the severity and duration of the illness caused by seasonal influenza. For human cases of H5N1, the drugs may increase a person’s chance of survival, if administered early, but data is limited. The H5N1 virus is expected to be susceptible to the neuraminidase inhibitors. M2 inhibitors, amantadine and rimantadine, could be used against pandemic influenza, but drug resistance can develop rapidly and could limit their effectiveness. Antibiotics may be used for secondary bacterial infections that often times develop.

Avian Influenza Vaccine An experimental H5N1 vaccine has been made. It is now in the clinical trial process to see if the vaccine will be effective.

U.S. Outbreak Risk The current risk in the United States is low. The H5N1 virus has not been found in the U.S. and there have been no human cases. It is possible for travelers to countries in Asia to become infected. The Centers for Disease Control and Prevention (CDC) recommends that travelers to countries in Asia with known outbreaks of H5N1 influenza avoid poultry farms, contact with animals in live food markets, and any surface that appears to be contaminated with poultry or animal feces.

Sources: Asian Development Bank; Australasian Wader Study Group; World Organization for Animal Health; World Health Organization; Food and Agriculture Organization of the United Nations; Recombinomics, Inc.; Wildlife Conservation Society; NEW SCIENTIST; ProMed

Pandemic (Worldwide Influenza Outbreak) vs. Avian Influenza “Avian influenza” only refers to kinds of flu that usually affect birds. Avian influenza viruses can change to make people sick (like with H5N1). Avian influenza cannot spread from person to person yet. A flu pandemic (a worldwide flu outbreak) happens when humans become sick by a new type of flu that they have not had before so their bodies cannot fight it off. Since their immune systems cannot fight off sickness, people can become sicker, quicker. If avian influenza learns to spread from person to person, it could possibly turn into pandemic influenza.

Past Influenza Pandemics 3 in the last century “Spanish influenza” 1918 40-50 million people died worldwide One of the deadliest outbreaks in human history “Asian influenza” 1957 2 million people died worldwide “Hong Kong influenza” 1968 1 million people died worldwide

What if Avian Influenza starts to make Americans sick? Use good hygiene practices. If you have contact with an animal, birds included, wash your hands. Clean any surfaces where poultry has been. If you or one of your family members feels sick and has a fever, keep that family member home. If you or one of your family members gets bird flu, you will be asked to stay at home and the health department will call you everyday to check your temperature and symptoms. If you are too sick to stay at home, go to your nearest hospital.

What if Avian Influenza starts to make Americans sick? (continued) To control the spread of the bird flu from person to person People may be asked to stay at home. Large events where people would gather (such as concerts or festivals) may be cancelled. Movement from home out to the public (such as going shopping) may be restricted. Schools may be closed.

References World Health Organization (WHO), www.who.int Centers for Disease Control and Prevention (CDC), www.cdc.gov National Geographic Society, www.nationalgeographic.com