GENEVA, Switzerland, April 24 (UPI) -- The World Health Organization issued a warning Thursday against an outbreak of a strain of influenza virus normally found in birds but now beginning to appear in humans.
So far, the virus has infected more than 80 people and caused one death in the Netherlands.
The virus –- the so-called avian influenza virus, or A H7N7 -- is "highly pathogenic" and was first detected in Dutch poultry farms in February, WHO said in a written statement.
"While avian influenza strains normally infect exclusively poultry, Dutch authorities have reported that the H7N7 strain has now jumped the species barrier, causing one death and more than 80 cases of mild disease in humans," WHO said.
The flu strain also has been reported in poultry in Belgium recently, WHO officials added.
The one person who died was a 57-year-old veterinarian who visited a poultry farm in an unspecified location in the Netherlands that had been infected with the H7N7 strain. The veterinarian died April 17 from acute respiratory distress syndrome. Post-mortem tests detected the H7N7 flu virus.
So far, 83 people have been infected with H7N7, although nearly all of the cases have been mild, and WHO called the veterinarian's death an "isolated" case.
WHO officials said so far the virus does not appear to be communicable among humans but the health agency also noted three family members of two poultry workers developed a minor respiratory disease, "suggesting a possible chain of human-to-human transmission."
The H7N7 outbreak is similar to previous situations in Hong Kong, where strains of avian influenza infected humans. In 1997, the H5N1 strain infected 18 people there and caused six deaths. The strain reared its head again in Hong Kong as recently as February, infecting two people and causing one death.
Officials said poultry infected with the H7N7 strain in the Netherlands are being slaughtered to help curtail the spread of the virus and prevent further human cases.
The agency also advised countries that detect H7N7 infections to enhance their surveillance for the virus in both humans and animals -- including chickens, turkeys and pigs.
Officials in the Netherlands and Belgium have recommended the use of oseltamivir, an antiviral drug, in agricultural workers who have had contact with poultry infected with the H7N7 virus but have not yet exhibited symptoms.
Any people who have had contact with infected birds "should be on guard for any signs and symptoms of respiratory disease," WHO officials said. "If symptoms arise, they should consult a doctor, who will then initiate laboratory testing and reporting to health officials."
In the meantime, the agency is developing a test kit for H7N7, which it anticipates "will be ready for use in three weeks." WHO researchers also are attempting to develop a vaccine against the virus.
