Euro Surveill. 2009;14(44):pii=19388.
Publication
Euro Surveill. 2008;13(43):pii=19015.
PLoS Med. 2008 Apr 15;5(4):e89. doi: 10.1371/journal.pmed.0050089. PMID: 18416600; PMCID: PMC2288622.