Migrant birds have tested positive for the H7 strain of bird flu, reports Reem Leila The H7 strain of the bird flu virus has been detected in Egypt for the first time. Nine migrant birds, all of them ducks, tested positive for the virus when 6,432 samples were taken from the approximately one million birds that annually migrate over Al-Manzalah Lake in the Sharqiya governorate from central and eastern Europe. The recently identified H7 strain is thought to pose little risk, certainly in comparison with the virulent H5N1 strain of the virus. The H7 strain samples are now being tested at both the Ministry of Health and Population (MOHP) and Naval Medical Research Unit (NAMRU) laboratories in order to determine the N subtype. Avian Influenza has 16 H and nine N subtypes. Only viruses of the H5 and H7 subtypes comprise the pathogenic form of the disease though not all H5 and H7 subtypes cause severe disease in poultry. Abdel-Rahman Shahin, spokesman at the MOHP, explains that the H5 and H7 viruses are usually introduced to poultry in a low pathogenic form. It is only after several months that they mutate into highly pathogenic strains. The appearance of the H7 strain is therefore a cause for concern. The virus has been known to infect humans but is less virulent than the H5N1 strain. Shahin also warned that Egypt must remain alert for yet other strains of the virus given that it lies on major bird migration routes. Minister of Health and Population Hatem El-Gabali confirmed the presence of the new bird flu strain while addressing the Health Committee of the Shura Council. He warned people against direct contact with live birds. Since the H5N1 virus was first detected in poultry in Egypt in February 2006,38 cases of human infection have been reported, of which 15 resulted in fatalities. The most recent case was 25-year-old Naema Abdu Gamil from Damietta governorate, 150km north of Cairo, who tested positive for the deadly H5N1 bird flu virus in late July. The first human infection by the H7 virus was reported in Britain in 1996 after a woman had come into direct contact with infected ducks was diagnosed. A second case was reported in the US in 2002. A year later 89 people tested positive, 83 in Holland and the remaining six in Germany and Belgium. Only one human fatality has been reported following contact with poultry infected with the H7 strain. Veterinary experts, though, warn that the presence of both the H7 and H5N1 viruses in Egypt could facilitate further genetic mutations, which can be caused by the combination of the two types of avian influenza virus which are currently present in Egypt. A combination of the genetic patterns of both viruses, says veterinarian Sami Taha, could result in the appearance of a human-to-human mutation. The H7 strain's poultry-to-poultry transmission patterns are very similar to those of the deadlier H5N1 virus which means, says Taha, it could develop similar poultry-to-human propensities. "Air temperature has no impact on the spread of the virus... it can easily flourish in high and low temperatures infecting massive numbers of poultry." Shahin insists the H7 strain poses no threat as yet to Egypt's recently recovered poultry industry, which currently produces two million birds daily. Poultry remains safe to eat, and he stresses that the new strain has only been detected in migratory birds. Meanwhile, Minister of Agriculture and Land Reclamation Amin Abaza issued a press release saying that 38 per cent of poultry in Egypt had been vaccinated against the H5N1 bird flu virus. Abaza notes that while the ministry has managed to contain the virus the fact that an estimated five million people continue to raise poultry at home, especially in the rural areas, constitutes an ongoing threat. According to Shahin, vaccines used to combat the H5N1 strain will be used for the H7 virus until new drugs are developed.
