Open Access Highly Accessed Research article

Protective measures and H5N1-seroprevalence among personnel tasked with bird collection during an outbreak of avian influenza A/H5N1 in wild birds, Ruegen, Germany, 2006

Wei Cai1, Brunhilde Schweiger2, Udo Buchholz1, Silke Buda1, Martina Littmann3, Jörg Heusler4 and Walter Haas1*

Author Affiliations

1 Department for Infectious Disease Epidemiology, Robert Koch Institute, DGZ Ring 1, 13086 Berlin, Germany

2 German National Reference Centre for Influenza, Robert Koch Institute, Nordufer 20, 13353 Berlin, Germany

3 State Office of Health and Social Affairs Mecklenburg-Western Pomerania, Gertrudenstrasse 11, 18057 Rostock, Germany

4 Health Office Ruegen, Gartenstrasse 1, 18528 Bergen, Germany

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BMC Infectious Diseases 2009, 9:170  doi:10.1186/1471-2334-9-170

Published: 18 October 2009



In Germany, the first outbreak of highly pathogenic avian influenza A/H5N1 occurred among wild birds on the island of Ruegen between February and April 2006. The aim of this study was to investigate the use of recommended protective measures and to measure H5N1-seroprevalence among personnel tasked with bird collection.


Inclusion criteria of our study were participation in collecting wild birds on Ruegen between February and March 2006. Study participants were asked to complete a questionnaire, and to provide blood samples. For evaluation of the use of protective measures, we developed a personal protective equipment (PPE)-score ranging between 0 and 9, where 9 corresponds to a consistent and complete use of PPE. Sera were tested by plaque neutralization (PN) and microneutralization (MN) assays. Reactive sera were reanalysed in the World Health Organization-Collaborating Centre (WHO-CC) using MN assay.


Of the eligible personnel, consisting of firemen, government workers and veterinarians, 61% (97/154) participated in the study. Of those, 13% reported having always worn all PPE-devices during bird collection (PPE-score: 9). Adherence differed between firemen (mean PPE-score: 6.6) and government workers (mean PPE-score: 4.5; p = 0.006). The proportion of personnel always adherent to wearing PPE was lowest for masks (19%). Of the participants, 18% had received seasonal influenza vaccination prior to the outbreak. There were no reports of influenza-like illness. Five sera initially H5-reactive by PN assay were negative by WHO-CC confirmatory testing.


Gaps and variability in adherence demonstrate the risk of exposure to avian influenza under conditions of wild bird collection, and justify serological testing and regular training of task personnel.