Mary D. Nettleman, MD, MS, MACP is the Chair of the Department of Medicine at Michigan State University. She is a graduate of Vanderbilt Medical School, and completed her residency in Internal Medicine and a fellowship in Infectious Diseases at Indiana University.
Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
Bird flu (also referred to as avian flu), as the name implies, is an infection in birds caused by an influenza virus. Influenza viruses that infect birds often do not cause illness in birds. Since the viruses are highly contagious, danger to humans arises when domesticated birds (for example chickens, ducks, and turkeys) become infected. While bird flu usually poses no threat to humans, instances of transmission of bird flu to humans have been reported since 1997, and over 100 people were infected in an outbreak that began in Southeast Asia in mid-2003. In November 2010, officials in Hong Kong announced that a woman had contracted bird flu, the first reported case of the condition in seven years. The 59-year-old woman had recently traveled to mainland China but reported no contact with live poultry or visits to farms.
Bird flu refers to strains of influenza that primarily
affect wild and domesticated birds.
Bird flu is also known as avian flu or
avian influenza.
Although bird flu is contagious and spreads easily among
birds, it is uncommon for it to be transmitted to humans.
In the late 1990s, a
new strain of bird flu arose which was unusually severe ("highly pathogenic"),
resulting in the deaths of hundreds of millions of birds, including poultry.
Control efforts, including culling infected flocks and vaccinating healthy birds,
have limited the spread of highly pathogenic bird flu.
In 2011, a mutated
strain of highly pathogenic bird flu appeared, which is concerning because the
existing poultry vaccines are not very effective against the new strain.
Human
infection with the highly pathogenic strain of bird flu is uncommon, with fewer
than 600 cases reported since 1997.
Human infection occurs primarily in people
who have close contact with sick poultry in countries where the virus is found.
There have been isolated cases of human-to-human transmission.
Human infection
with bird flu is fatal in approximately 60% of cases.
Bird flu from the highly
pathogenic strain is not found in the United States at this time.
What is bird flu?
Bird flu (avian influenza) is a disease caused by an influenza virus that
primarily affects birds. In the late 1990s, a new strain of bird flu arose that
was remarkable for its ability to cause severe disease and death, especially in
domesticated birds such as ducks, chickens, or turkeys. As a result, this strain
was called highly pathogenic (meaning very severe) avian influenza.
Since the
identification of highly pathogenic influenza, infected birds have been found in
Asia, Europe, the Middle East, and Africa. Careful control measures, including
destroying infected flocks and vaccinating healthy birds, have reduced the number
of cases, but the virus continues to exist in poultry flocks in areas of Asia
and Africa. Bird flu from the highly pathogenic strain is not found in the
United States at this time.
The virus spreads from bird to bird through infected
birds shedding the virus in their saliva, nasal secretions, and droppings.
Healthy birds get infected when they come into contact with contaminated
secretions or feces from infected birds. Contact with contaminated surfaces such
as cages might also allow the virus to transfer from bird to bird. Symptoms in
birds range from mild drops in egg production to failure of multiple major
organs and death.
The first human case of illness from highly pathogenic avian
influenza was identified in 1997, and more than 560 cases have been identified
since then, with deaths worldwide exceeding 300. Human cases of highly
pathogenic bird flu have been largely confined to Southeast Asia and Africa.
However, mutations often occur in the virus, and it is possible that some
mutations could create a more contagious virus that could cause a regional
epidemic or a worldwide pandemic of bird flu among humans. Fortunately, the
mutations that have occurred to date have not made the virus more contagious,
although the concern remains.
Most sore throats are caused by viruses or mechanical causes (such as mouth breathing) and can be treated successfully at home. However, a person should be seen by a health care professional if they have a sore throat that has a rapid onset, and is associated with a fever or tenderness of the front of the neck; a sore throat that causes the person to have difficulty swallowing (not just pain swallowing) or breathing; or if a sore throat lasts for more than a week.
Diarrhea is a change is the frequency and looseness of bowel movements. Cramping, abdominal pain, and the sensation of rectal urgency are all symptoms of diarrhea. Absorbents and anti-motility medications are used to treat diarrhea.
Chronic cough is a cough that does not go away and is generally a symptom of another disorder such as asthma, allergic rhinitis, sinus infection, cigarette smoking, GERD, postnasal drip, bronchitis, pneumonia, medications, and less frequently tumors or other lung disease. Treatment of chronic cough is dependant upon the cause.
Nausea is an uneasiness of the stomach that often precedes vomiting. Nausea and vomiting are not diseases, but they are symptoms of many conditions. The causes of vomiting differ according to age, and treatment depends upon the cause of nausea and vomiting.
Although a fever technically is any body temperature above the normal of 98.6 degrees F. (37 degrees C.), in practice a person is usually not considered to have a significant fever until the temperature is above 100.4 degrees F (38 degrees C.). Fever is part of the body's own disease-fighting arsenal: rising body temperatures apparently are capable of killing off many disease- producing organisms.
Influenza (flu) is a respiratory illness caused by a virus. Flu symptoms include fever, cough, sore throat, runny nose, headache, fatigue, and muscle aches. The flu may be prevented with an annual influenza vaccination.
Novel H1N1 influenza A virus infection (swine flu) is an infection that generally is transferred from an infected pig to a human, however there have been reported cases where infection has occured with no contact with infected pigs. Symptoms of swine flu are "flu-like" and include fever, cough, and sore throat. Treatment is generally with the antibiotics oseltamivir (Tamiflu) or zanamivir (Relenza).
Travelers should prepare for their trip by visiting their physician to get the proper vaccinations and obtain the necessary medication if they have a medical condition or chronic disease. Diseases that travelers may pick up from contaminated water or food, insect or animal bites, or from other people include malaria, meningococcal meningitis, yellow fever, hepatitis A, typhoid fever, polio, and cholera.
Common viruses, including the viruses that cause
mononucleosis (mono) and the
flu. Some viruses can also produce blisters in the mouth and throat ("aphthous stomatitis").
Breathing through the mouth or
smoking can produce throat dryness and
soreness.
Sinus drainage (post nasal drip)
Bacterial infections. The two most common bacteria to cause a sore throat are
Streptococcus (which causes
strep throat) and Arcanobacterium haemolyticum.
Arcanobacterium causes sore throats mainly in young adults and is sometimes associated with a fine red
rash.
Sore throat appearing after treatment with antibiotics,
chemotherapy, or other immune-compromising medications may be due to
the yeast Candida,
a condition commonly known as "thrush."