Research Results in a New Tool to Fight Disease Outbreaks

Fred Hutchinson Cancer Research Center's infectious disease researchers announced the confirmation that the 2006 avian influenza A (H5N1) virus (aka bird flu) outbreak spread from person to person within a family in Indonesia. The conclusions of the study by biostatistician, Ira M. Longini, Jr., Ph.D., et al, will be available online and in the print edition of Emerging Infectious Diseases, a journal of the Centers for Disease Control and Prevention. Biostatisticians M. Elizabeth (Betz) Halloran, M.D., D.Sc. and Yang Yang, Ph.D. as well as epidemiologist Jonathan Sugimoto, M.H.S., a pre-doctoral research associate, all members of the Hutchinson's Center's Public Health Sciences Division and Vaccine and Infectious Disease Institute, were participants in the research and co-authors.

The researchers traced the history of the outbreak within an extended family in northern Sumatra from its inception until the spread of the virus was contained. Data gathered reflecting the number of people infected, the probable number exposed, the virus incubation period, and other factors were input into a computerized disease-transmission model. The results equaled the first ever statistical confirmation of whereby humans contracted the disease from one another rather than from an infected bird.

History of the Cluster

The inception of the outbreak was traced back to a 37-year old aunt who had been exposed to dead poultry and chicken feces and is believed to be the original source of the infection. A ten-year old boy then passed it to his father and this was supported by genetic sequencing data. Other transmissions of the disease between persons are documented with statistical data in this same manner. The infection spread to include eight members within the same family, all who had sustained close contact with those who were ill--a vital factor necessary for transmission of this type of flu strain. Health authorities eventually acted by placing the 50 surviving relatives and close contacts under voluntary quarantine in an effort at containment of the virus.