Binational influenza sentinel surveillance, New Mexico and Chihuahua, Mexico, 2007-2008

Background: To improve regional influenza surveillance and promote pandemic influenza preparedness, the New Mexico Department of Health (NMDOH) partnered with Chihuahua State Health Services (CSHS) to add one influenza sentinel surveillance site in Juarez, Mexico.

Methods: During the 2007-2008 influenza season, Juarez provided weekly to NMDOH the following information: number of patients with influenza-like illness (ILI); total number of patients seen in the clinic that week; number of patients testing positive for influenza by rapid influenza test; and influenza cultures on patients with ILI and a positive rapid test at three predetermined weeks during the season. NMDOH has compiled a weekly border-area influenza surveillance report, and has analyzed ILI, rapid test and culture data to describe influenza trends in the border region. Weekly reports are disseminated to stakeholders and posted at the NMDOH website.

Results: Since 10/1/2007, bi-directional reporting has occurred weekly. The Mexico site has reported 11,858 patient visits; 0.2% (26) met the CDC ILI case definition. Six of 26 rapid tests were positive. Specimens for viral culture were transported across the international border. Influenza A and B were isolated by culture at the NMDOH State Laboratory.

Final results are pending conclusion of the 2007-2008 influenza season.

Conclusions: Regional influenza surveillance and NMDOH's ability to identify circulating viral strains has improved. The increased bi-national collaboration has strengthened pandemic influenza preparedness.