How is avian influenza detected in humans?

Avian influenza cannot be diagnosed by symptoms alone, so a laboratory test is required.swab collect from the nose or throat during the first few days of illness and then sent to a laboratory for molecular test for virus dectation If it is late in the illness, it may be difficult to find an avian influenza virus directly using these methods.If this is the case, it may still be possible to diagnose avian influenza by looking for evidence of the body's response to the virus.however This is not always an option because it requires two blood specimens (one taken during the first few days of illness and another taken some weeks later).

How humans get bird flu?

Migratory waterfowl, and ducks in particular, carry the viruses that cause bird flu. Often unaffected themselves, the host birds spread the infection to susceptible species, especially domesticated chickens, turkeys and geese, resulting in severe epidemics that sicken and kill large numbers of birds - sometimes in a single day.
Avian viruses generally don't affect humans, but in 1997, an outbreak of bird flu in Hong Kong infected 18 people, six of whom died. Since then, human cases of bird flu have been reported in Asia, Africa, the Pacific, Europe and the Middle East. Most were traced to contact with infected poultry or surfaces contaminated by sick birds.
Often, flu viruses that cross from animals to humans originate in areas where people live in proximity to chickens and pigs. That's because pigs are susceptible to infection with both avian and human viruses and so are an ideal "mixing bowl" in which viruses can exchange genes.
But at least some bird flu viruses don't need a third party. Instead, they shuffle and rearrange their genetic material directly in humans. That seems to be the case in most instances of human-acquired bird flu. People become sick after direct contact with infected birds or bird-contaminated surfaces, not from contact with pigs or other animals.

H5N1: Prelude to a pandemic?

In the current epidemic, two influenza subtypes have proved especially dangerous - H7N7, which sickened poultry workers in the Netherlands, and H5N1, which has been responsible for the majority of human and avian deaths in Asia. Of these, H5N1 is of particular concern for several reasons:


Direct transmission. H5N1 became the first known bird flu strain to jump directly from birds to people when it surfaced in Hong Kong in 1997. It has since infected people in many countries. Other strains have caused illness in humans, but none is as severe as H5N1.

Virulence. The virus is especially lethal, killing close to 100 percent of susceptible birds and more than half of infected people. Birds that do survive can shed the virus for at least 10 days, greatly increasing the flu's spread.

Rapid spread. Since 2003, hundreds of millions of birds have died, a loss that's ecologically and economically devastating. It's also alarming from a public health standpoint - widespread infections among birds may lead to more human disease

how transmitted the bird flu.

Direct bird-to-human transmission works like this:

Wild birds shed the virus. Infected migratory waterfowl, the natural carriers of bird flu viruses, shed the virus in their droppings, saliva and nasal secretions.


The virus spreads to domesticated birds. Domestic poultry become infected from contact with these birds or with contaminated water, feed or soil. They may also catch the disease the same way humans contract conventional flu - by inhaling the airborne virus. Bird flu spreads quickly and lethally within domestic flocks and is inadvertently transported from farm to farm on tractors and other equipment, on cages, and on workers' shoes and clothing. Heat destroys the virus, but it can survive for extended periods in cool temperatures


Markets provide pathways to humans. Open-air markets, where eggs and birds are often sold in crowded and unsanitary conditions, are hotbeds of infection and spread the disease into the wider community. Cockfighting, common throughout much of Asia, has also been implicated in the spread of bird flu because fighting roosters are often trucked long distances and smuggled across borders. At any point along the way, humans may pick up the virus through close contact with sick birds or contaminated surfaces.

What is the bird flu?

Bird flu (also known as avian influenza) has led to the deaths of hundreds of millions of wild and domestic birds and to a small number of human deaths. Right now, however, bird flu remains difficult for humans to contract. Most people who have developed symptoms have had close contact with sick birds, though in a few cases, bird flu has passed from one person to another.

Health officials are concerned that a major bird flu outbreak could occur in humans if the virus mutates into a form that can spread more easily from person to person. protect people in the event of a bird flu pandemic.The grimmest scenario would be a global outbreak to rival the flu pandemic of 1918 and 1919, which claimed millions of lives worldwide. For now, researchers are trying to develop a vaccine that would