Bird flu spreads to humans in the Netherlands
GENEVA, Switzerland (CNN) -- A strain of bird flu has jumped from poultry to humans, infecting more than 80 people in the Netherlands and killing one of them, the World Health Organization said Thursday.
Outbreaks of the strain of avian influenza virus A (H7N7) have been reported in a number of poultry farms in the Netherlands since February and in Belgium more recently.
But the latest development is the first report of the strain jumping the species barrier, WHO said in a written statement, citing Dutch health officials.
The fatality was a 57-year-old veterinarian who had visited a poultry farm hit by the strain of the virus.
He died April 17 of acute respiratory distress syndrome in the Netherlands, the statement said. The other human cases were described as "mild disease."
Tests were able to isolate no pathogens other than the one for H7N7 avian influenza, WHO said.
It is not the first time a form of avian flu has crossed species to affect humans.
In 1997, the H5N1 strain of avian influenza caused its first outbreak in humans, with 18 cases and six deaths in Hong Kong.
In mid-February, again in Hong Kong, the same strain infected two people, killing one.
Of the 83 confirmed cases of human H7N7 infection in the Dutch outbreak, 79 people showed conjunctivitis, and 13 had mild flulike symptoms.
Three family members of two poultry workers also have fallen ill with a minor respiratory disease, suggesting human-to-human transmission is possible, WHO said.
Affected poultry in the Netherlands are being slaughtered as a control measure. In the two Hong Kong outbreaks, mass culling of poultry proved effective in preventing further cases in humans.
Investigations so far have revealed no transmission of the severe form of the disease to other people, WHO said.
"Based on available evidence, WHO concludes that the death is an isolated case, as no efficient human-to-human transmission of the avian H7N7 influenza virus strain has been detected," it said.
Still, WHO recommended that health officials in countries where cases of H7N7 have been found strengthen their surveillance and diagnosis of the virus in humans and susceptible animals, which include chickens, turkeys and pigs.
Workers in contact with diseased poultry are also urged to take an antiviral drug recommended by national authorities in the Netherlands and in Belgium and to consult a doctor if they develop symptoms of respiratory disease.