Further tests needed

The first case of bird flu in the Philippines was reported in a local broadsheet 12 years ago coming from a duck egg and chicken farm in Calumpit, Bulacan. The low-risk H5 strain was found to be the culprit and not the H5N1 virus that has killed more than 54 people in Asia.

Infectious diseases caused by the avian or bird flu is fatal to man when pneumonia sets in as one of its major complications, further developing respiratory distress, acute cardiac failure and eventually, death. The incidence of pneumonia formation is about 10 percent and the majority of patients can still be salvaged.

There are three types of the flu virus. They are flu A, B, and C of the three types. Flu A is responsible for most epidemics and all pandemics from country to country. Flu B may sometimes be the cause of epidemics and flu C is very mild and never causes an epidemic.

The capacity of the flu virus to cause a disease is attributed to two structures on its surface. One is called hemagglutinins (H) which help the virus attach on to a healthy cell and the other is called neuraminidases (N) which facilitate the release of viral particles from infected cells.

Flu virus in its cell has 15 hemagglutinins
labelled as H1 to H15 and 9 neuraminidases (N) numbered N1 to N9 subtypes. There can be so many combinations of the different H&N subtypes depending on their antigenic properties. As of now, medical researchers have found out that only the H5N1 strain so far is the virulent form and lethal to man, transmitted primarily from fowls to humans.

Also, in 2005, Thailand reported about a mother and daughter who succumbed to bird flu and now is very suggestive that there is a very high probability of human-to-human transmission that could lead to a global health problem because the flu can be transmitted by droplet infection through coughing, talking and sneezing. The virus, too, can be suspended in the air for quite sometime and ultimately cause infection more easily.

I, for one, would recommend that the blood test result done locally be brought to Australia because of the many subtypes of the H&N combination and to know specifically whether it is virulent (lethal) or nonvirulent. Up to now, we don’t know whether the bird flu found in Pampanga is the H5N1 strain that is fatal to man.

ELISEO R. REBLANDO, MD, FPAFP, DFM, past president, Private Hospitals Association of the Philippines