Facts and other details about Bird Flu

Ahmedabad: Over 900 birds in the city have been culled (read killed) after confirmation of bird flu virus in some of the birds brought from Mumbai here and the Ahmedabad civil hospital has started an isolation ward as precautionary measure.

District administration has declared Hathjan area as infected zone and 10 kms around it as alert zone and a close watch on the poultry and human population in the 30 villages under the alert area is being kept.

So far no confirmed or suspected case of its spread in human beings have been found here. The only such human death in Gujarat was reported in 2006 when a young poultry farm owner from neighbouring Maharashtra had died of it at a hospital in Surat.

Presented below are facts about the dreaded infectious disease including its origin, reasons, symptoms, prevention and treatment –

– Bird flu, or avian influenza, is a viral infection spread from bird to bird. Currently, a particularly deadly strain of bird flu — H5N1 (which was found in the dead birds of the animal shelter of Asha foundation, an animal care outfit of Ahmedabad)– continues to spread among poultry in certain parts of Asia and Africa. It’s deadly to most birds. And it’s deadly to humans and to other mammals that catch the virus from birds. The disease among birds and poultry was known since as early as 1878 but the first human case was reported in 1997 in China when 18 people were found infected of whom 6 died, H5N1 or its variants has so far killed nearly 60% of the people who have been infected,according to a report. The figure of deaths was around 400. Millions of birds have been culled so far owing to this infection in countries in Asia, Africa, the Pacific, Europe, and the Middle East.

But unlike human flu bugs, H5N1 bird flu does not spread easily from person to person. The very few cases of human-to-human transmission have been among people with exceptionally close contact, such as a mother who caught the virus while caring for her sick infant. Migrating water fowl — most notably wild ducks — are the natural carriers of bird flu viruses. It’s suspected that infection can spread from wild fowl to domestic poultry. Avian influenza is most often spread by contact between infected and healthy birds, though can also be spread indirectly through contaminated equipment. The virus is found in secretions from the nostrils, mouth, and eyes of infected birds as well as their droppings. HPAI infection is spread to people often through direct contact with infected poultry, such as during slaughter or plucking. In China, there have been reports of infection via inhalation of aerosolized materials in live bird markets. It’s also possible that some people were infected after swimming or bathing in water contaminated with the droppings of infected birds. And some infections have occurred in people who handle fighting cocks.Though the virus can spread through airborne secretions, the disease itself is not an airborne disease. Highly pathogenic strains spread quickly among flocks and can destroy a flock within 28 hours; the less pathogenic strains may affect egg production but are much less deadly.

Although it is possible for humans to contract the avian influenza virus from birds, human-to-human contact is much more difficult without prolonged contact. Some strains of avian influenza are present in the intestinal tract of large numbers of shore birds and water birds, but these strains rarely cause human infection.

Studies have confirmed that people don’t catch the virus from eating fully cooked chicken or eggs.

As long as the bird flu virus doesn’t change into a human flu virus, it won’t spread far in people. But sometimes — after close personal contact — a person who gets bird flu does infect another person.

In Indonesia in 2006, bird flu spread to eight members of one family. Seven of them died. It’s not yet clear exactly how this happened.

There are many subtypes of avian influenza viruses, but only some strains of five subtypes have been known to infect humans: H5N1, H7N3, H7N7, H7N9, and H9N2.[17] At least one person, an elderly woman in Jiangxi Province, China, died of pneumonia in December 2013 from the H10N8 strain, the first human fatality confirmed to be caused by that strain.

Most human cases of the avian flu are a result of either handling dead infected birds or from contact with infected fluids. It can also be spread through contaminated surfaces and droppings. While most wild birds mainly have only a mild form of the H5N1 strain, once domesticated birds such as chickens or turkeys are infected, it can become much more deadly because the birds are often in close contact. There is currently a large threat of this in Asia with infected poultry due to low hygiene conditions and close quarters. Although it is easy for humans to contract the infection from birds, human-to-human transmission is more difficult without prolonged contact.

Symptoms-

Bird flu symptoms in people can vary. Symptoms may start out as normal flu-like symptoms like running nose, mild fever, head-ache etc. This can worsen to become a severe respiratory disease that can be fatal. In February 2005, researchers in Vietnam reported human cases of bird flu in which the virus infected the brain and digestive tract of two children. Both died. These cases make it clear that bird flu in humans may not always look like typical cases of flu.

If a person — or a susceptible animal — gets infected with bird flu and human flu at the same time, the bird and human flu viruses could swap genes. Even without swapping genes, H5N1 could mutate into a form that more easily infects humans.

Bird Flu Vaccine-

There are bird flu vaccines for certain variants including the H5N1 but the further tests are still on. On April 17, 2007, the FDA in the US had announced its approval of the first vaccine to prevent human infection with one strain of the bird flu. The vaccine was purchased by the U.S. federal government to be distributed by public health officials if needed. The vaccine was not made commercially available to the general public. Other bird flu vaccines are being developed by other companies. And the World Health Organization has a stockpile of the vaccine, with plans to quickly produce more if needed. When given along with immunity-boosting agents called adjuvants, experimental H5N1 vaccines offer good cross-protection against different H5N1 variants. And several companies are working on universal flu vaccines and antivirals that would protect against all known strains of influenza.

Treatment for Bird Flu-

The flu drugs oseltamivir (Tamiflu), zanamivir (Relenza), or peramivir (Rapivab) work against bird flu, although more studies are needed. These drugs must be given soon after symptoms appear. Unfortunately, H5N1 in humans can be a severe illness requiring hospitalization, isolation, and intensive care. Doctors, however, suggest use of Tamiflu, also used in Swine flu ( caused by HIN1 virus) by the person only when he/she has visible symptoms of bird flu. The blood serum should also be sent for test as quickly as possible even the symptoms prolong and worsen.