JEDDAH, 16 March 2006 — Veterinarians in the Kingdom are growing concerned over the increase in bird deaths over the past two months. The Ministry of Agriculture is blaming the deaths on Newcastle Disease Virus (NDV).
Last week, the local press reported that an eagle fell out of the sky dead near Taif, causing further alarm among residents who had noticed the increase in the number of bird deaths in the area. After laboratory analysis, the Ministry of Agriculture determined that the cause of the eagle’s death was not the H5N1 virus (bird flu), but NDV which causes only mild conjunctivitis in humans.
NDV and H5N1 are both variants of H5, also known as Highly Pathogenic Avian Influenza (HPAI). It is a disease caused by the influenza virus A/H5. Though they share similar characteristics and symptoms, only the N1 strain causes fatalities in humans whereas NDV, as mentioned above, causes only mild conjunctivitis.
According to veterinary sources, NDV is a contagious and fatal viral disease affecting all species of birds. Much like H5N1, it attacks the respiratory, digestive and nervous systems with a 100 percent fatality rate among birds. Affecting most countries, NDV has been around — and under control — for years but has not attracted the same press interest as H5N1 which has been responsible for some 90 human deaths. Although the two diseases are distinctly separate and readily distinguishable, in 2003 and early 2004, Indonesia insisted that its H5N1 infections were NDV. Similarly, China reported an unusually high frequency of NDV infections before finally reporting H5N1.
When five falcons died at a Riyadh veterinary clinic in January, the Ministry of Agriculture was quick to investigate. In a statement, the ministry said that tests conducted on the dead birds showed that they had succumbed to H5 avian flu, but not to the much-feared H5N1 strain. In a telephone interview, Saleh Al-Tuwaijri, a Ministry of Agriculture official, told Arab News, “I am not yet sure of the results. It could have been H5N1 or it could have been NDV. I really don’t know. Check the ministry’s website.”
A review of the website revealed that H5N1 has been suspected in numerous bird deaths but, upon further testing, it was discovered that in all cases, the birds had succumbed to H5 rather than to H5N1.
“The manner in which NDV and H5N1 attack the respiratory systems of birds is similar, but there is a marked difference in the way that they die. NDV takes longer than H5N1 to kill a bird. Birds brought to us had died within 24 hours,” a veterinarian told Arab News.
Since there are no laboratories available to veterinary practitioners and the general public in Saudi Arabia, all suspected H5N1 afflicted birds are turned over to the Ministry of Agriculture for testing.
“With H5N1 cases being discovered in South Asia, Turkey, some European countries, Egypt and Kuwait and with Saudi Arabia lying on a major migratory bird route, the H5N1 virus could arrive in Saudi Arabia,” the veterinarian said.
