Contact Tracing for Influenza A(H1N1)pdm09 Virus–infected Passenger on International Flight

Ananda G. Shankar, Kulsum Janmohamed, Babatunde Olowokure

, Gillian E. Smith, Angela H. Hogan, Valerie De Souza, Anders Wallensten, Isabel Oliver, Oliver Blatchford, Paul Cleary, and Sue Ibbotson

Author affiliations: Health Protection Agency, West Midlands Region, Birmingham, UK (A.G. Shankar, K. Janmohamed, B. Olowokure, G.E. Smith, V. De Souza, S. Ibbotson); Health Protection Agency, Southwest Region, Gloucester, UK (A.H. Hogan, A. Wallensten, I. Oliver); Swedish Institute for Communicable Disease Control, Solna, Sweden (A. Wallensten); NHS National Services Scotland, Glasgow Scotland, UK (O. Blatchford); Health Protection Agency, Northwest Region, Liverpool, UK (P. Cleary)

Abstract

In April 2009, influenza A(H1N1)pdm09 virus infection was confirmed in a person who had been symptomatic while traveling on a commercial flight from Mexico to the United Kingdom. Retrospective public health investigation and contact tracing led to the identification of 8 additional confirmed cases among passengers and community contacts of passengers.

On April 27, 2009, influenza A(H1N1)pdm09 virus infection was confirmed in a passenger who had traveled on a commercial flight from Mexico to the United Kingdom (UK) (1). This was the first identified imported case of A(H1N1)pdm09 infection in the UK. The person departed Mexico on April 20, 2009, and arrived in Birmingham, UK, 9.5 hours later on April 21, 2009. We describe the contact-tracing investigation of passengers on the flight and estimate the risk for transmission of A(H1N1)pdm09 virus to the passengers.