Two poultry workers were apparently infected with H5N1 strain Avian Influenza following exposure while depleting an infected farm.  There was no evidence of subsequent person-to-person transmission. The workers were in contact with an infected flock in Guadalajara Province in late September. 

Three days after commencing the project, 12 workers were sampled by nasopharyngeal swabbing with the virus detected in two workers.  Samples from close contacts of the first affected individual were negative by RT-PCR assay.  The second worker yielded a positive nasopharyngeal swab on October 13th, three weeks after participating in cleaning and disinfection.  Two contacts of the infected individual tested negative on sampling. 

The two asymptomatic cases in Spain are reminiscent of the single case reported in the U.S. in a worker participating in depopulation and disinfection on an infected farm in the Midwest. These rare cases indicate the need to immunize all people coming into contact with poultry by administering the current seasonal influenza vaccine. Workers should be screened daily for any febrile reaction in order to prevent a possible gene interchange between avian and human strains of influenza virus with the potential for a zoonotic strain of avian influenza.