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Avian influenza is a severe influenza typically caused by H5N1 subtype of the influenza A virus. According to Flu.gov, over 400 cases were reported globally as of the end of 2009, with about 60 percent mortality. There have been no reported cases of the H5N1 virus in humans or animals in the United States. It is usually spread by direct contact with sick or dead infected birds.
The avian flu virus typically produces severe respiratory illness, which rapidly progresses to respiratory failure in a matter of days. Other organs are also rapidly involved with the appearance of multi-organ failure.
Treatment of Avian flu
According to the WHO guidelines, suspected cases should be admitted to the hospital for adequate treatment, which usually involves early aggressive respiratory support.
Antivirals are to be given within 48 hours of the onset of symptoms. The current recommended drugs are oseltamivir (Tamiflu) and zanavir (Relenza). These two are shown to be active against the virus, with good response if given early. Adding amantadine to the treatment with Tamiflu or Relenza is thought to be helpful, but amantadine is not reliable as the only agent for treatment, as there is demonstrated resistance to amantadine in the avian flu virus.
Immune serum given early has proved effective in shortening the course of the disease and preventing complications. This can also be given in combination with the antivirals. The immune serum is obtained from the blood of convalescing survivors, so there are limits to its availability.
Antibiotics can also be used, particularly in those who have acquired a secondary bacterial infection due to the devastation of the local immune system of the lungs by the H5N1 virus. In these cases, there should be a suspicion of bacterial pneumonia co-existing with the viral destruction of the lungs.
Other treatment modalities are supportive, involving oxygen therapy and ventilation support. The rapidly progressive respiratory failure caused by the virus also affects other organs and further worsens the effects of the virus. Supported breathing helps give the other organs a fighting chance of surviving the invasion of the virus.
Follow up issues
The virus remains infective almost three weeks from the onset of infections. Apart from the usual spread of the flu by coughing and sneezing, the body fluids of the patient, including feces and urine, are also infective in the avian flu patient. Thus, after discharge, the patient is followed up for relapse and possible development of disease in the immediate contacts.
