Bird flu is transmitted to humans when these viruses, which are part of a group called avian influenza A viruses, travel from the saliva, mucus, or droppings of an infected bird into a person’s eyes, nose, or mouth. Humans can become infected by breathing in the virus, which can survive in air droplets or dust, or touching a surface that’s harboring the virus and transferring it to eyes, nose, or mouth. Rarely, the virus also can spread from person to person. (2)
ConjunctivitisFever greater than 100.4 degrees F (38 degrees C)CoughSore throatHeadachesDifficulty breathingFatigueNausea and vomitingMuscle achesAbdominal painBleeding from the nose or gums
Gastrointestinal symptoms such as nausea, vomiting, and diarrhea are more commonly seen in people who have the H5N1 infection; conjunctivitis is more commonly seen in people who are affected by H7 forms of the virus. (3) While bird flu infections are rare, most of them occur in people who’ve had unprotected contact with an infected bird or a contaminated surface. There have, however, been some instances in which a person has become infected without making direct contact with a bird. More rarely, the virus has spread from person-to-person, but this type of transmission has been limited, and does not seem to happen easily. (5) Open-air markets can also be a source of bird flu, since eggs and birds can be sold in unsanitary conditions. There have been a few cases of H5N1 in humans who’ve eaten food made with raw, contaminated poultry blood, but there’s no evidence that people have been infected with bird flu from eating properly cooked poultry. (3) Eating undercooked poultry has also been associated with infections other than influenza, including salmonella (1). Some people are more at risk than others for being very sickened with bird flu, including pregnant women, adults over the age of 65, and people with weakened immune systems. (2) The test is most accurate when the sample is taken within the first few days of a person’s illness; it can be hard to detect the virus in someone who is no longer very ill or has fully recovered. It may be possible, however, to find antibodies that a person has produced to fight off the virus. (1)
Prognosis of Bird Flu
While symptoms may be mild, more severe cases of bird flu can be deadly. For those patients hospitalized with avian influenza, mortality is more than 50 percent for all of the strains combined. The mortality rate for H5N1 has been estimated to be 60 percent. (6) The mortality rate for H7N9 is around 40 percent. (7) The World Health Organization says that people with bird flu should be treated with antiviral medications for at least five days, but can continue taking them until their symptoms improve. (3)
Medication Options
Antiviral medications can work best when they’re prescribed as soon as possible, ideally within 48 hours after the symptoms appear. The medications used to treat bird flu include:
oseltamivir (Tamiflu)zanamivir (Relenza)peramivir (Rapivab)baloxavir marboxil (Xofluza)
Prevention of Bird Flu
There is no widely available vaccine to prevent bird flu in the United States. The best way to prevent bird flu is to avoid the sources of the exposure. People who work with poultry should follow infection control practices, such as wearing personal protective equipment and following proper hand hygiene protocols. Wild birds can also be a source of the infection, so it’s best to let local or state agencies dispose of a dead bird. If a large number of birds are dying in the same area, a wildlife organization will likely investigate the cause. People shouldn’t get too close to birds, and should avoid touching surfaces that are contaminated with bird droppings. The CDC tells people who are traveling to countries with avian flu to avoid visiting areas where birds are raised or sold, including poultry farms and open-air market, and to avoid visiting places where eggs and birds are sold in unsanitary conditions. (1) They also advise making sure that any poultry or eggs you eat are fully cooked and to avoid dishes that contain blood from animals. (1) People who’ve been in contact with an infected bird may be given antivirals preventatively, as these medications can also help prevent infection. The U.S. Food and Drug Administration has approved three vaccines to prevent the H5N1 bird flu virus, and at least one is being held in reserve by the U.S. government in case an outbreak occurs. (8) The seasonal flu vaccine doesn’t protect against avian flu.
PneumoniaConjunctivitis (pink eye)Kidney dysfunctionRespiratory failureSepsis (blood infection)Heart problems
In total, this strain of bird flu has been detected in poultry and wild birds in more than 50 countries in Africa, Asia, Europe, and the Middle East. (9) In January 2014, Canada reported the first human infection of H5N1 in the Americas, which occurred in a person who recently returned from China. (9) Bird flu virus H7N9 was first reported to infect humans in China in March 2013. Between 2013 and 2017, according to the WHO, more than 1,500 people have been infected with H7N9. Most of these cases occurred in China, but some infections been reported in other countries among travelers who had just returned from China. (11) In 2015, a husband and wife in the United States became ill with H7N9 after a trip to China; the United States has not had any cases of H5N1. (12) However, it has had a few other types of bird flu infections in humans. For instance, in 2002, a person in Virginia working to dispose of poultry infected with H7N2 there developed an infection. (13) In 2016, there was an outbreak of H7N2 in New York City among cats in an animal shelter, and one person who was exposed to the sick cats became infected. (14) The CDC’s website provides updates on bird flu activity worldwide. The site details who may be most likely to contract the virus and what precautions at-risk people can take to avoid becoming sick. World Health Organization (WHO) The WHO works with countries around the world to combat diseases such as influenza. Their website provides information about bird flu and other zoonotic infections.
