WKU News

ACHA Pandemic Influenza Surveillance
Influenza Like Illness (ILI) in Colleges and Universities

With preliminary epidemiologic data on novel H1N1 flu suggesting significant risk among those in the college setting, ACHA deems it epidemiologically valuable to identify disease burden and population based attack rates of influenza like illnesses (ILI) [ICD-CM Diagnosis 487.1] on college campuses. ACHA has thus undertaken an effort to enlist (on a voluntary basis) interested institutions of higher education to submit data on a weekly basis regarding the number of new cases of ILI.

New ILI cases reported include those seen in the student health service, those triaged over the phone by a health care professional but simply told to self-isolate and not be seen in the health service, and those known by the health service to have been seen in a local emergency department or urgent care center.

The links below depict weekly case data for the period September 26-October 2, 2009 as reported to ACHA, as well as ACHA's cumulative case data and an epicurve chart reflecting weekly case counts and weekly attack rates.

In this weekly period of influenza activity, a total of 6,326 new ILI cases were reported (nine hospitalizations) among campus populations totaling over 3.3 million. Ninety-two percent of the 273 colleges and universities reported new ILI cases, as compared to 91 percent reporting new cases the prior week. The nationwide attack rate was 18.9 cases/10,000 students, six percent lower than the prior week's rate.

The highest rates of activity are in states in the Mid-Atlantic region (Virginia, District of Columbia, South Carolina, North Carolina, and Pennsylvania). The Northeast has the highest rates in New Hampshire and Rhode Island. The Southeast is experiencing declining rates of disease activity except for Mississippi and Kentucky. The Midwest continues to experience sustained activity in Minnesota and Missouri. The Rocky Mountain region has not seen widespread activity though Montana and Wyoming have rates significantly greater than the national average. In the West and Southwest, significant increases in activity are observed in Oregon and Alaska, while Washington continues to experience declines in incidence of disease. Several states in this region continue to experience very low rates of disease. Again, no deaths were observed among the reporting institutions for the weekly period of September 26th through October 2nd.

"The population surveyed by ACHA represents nearly one fifth of all college students nationally. Assuming proportionate distribution of ILI across most campus populations, we would estimate that about 183,000 cases have occurred among approximately 18 million college students nationwide. The outbreaks of influenza like illness thankfully remain relatively mild disease on our campuses. Among nearly 34,000 cases among 3.3 million students, there have been 57 hospitalizations and no deaths reported to ACHA. Students, parents, faculty and staff should continue to be reassured by the findings thus far," according to Dr. James C. Turner, president of the American College Health Association and executive director of the department of student health at the University of Virginia.

Weekly College Case Data [ICD-CM Diagnosis 487.1]

Cumulative Data Since Report Inception [ICD-CM Diagnosis 487.1]

Epicurve Chart [ICD-CM Diagnosis 487.1]

Note: These data do not represent all institutions of higher education, nationwide.

Limitations: State case counts and rates do not represent the complete incidence of ILI in the state's population, nor the incidence of ILI among all institutions of higher education in the state. The case counts and rates only represent those institutions of higher education that participate in the surveillance program.

Suggested Citation: American College Health Association. American College Health Association Influenza Like Illnesses (ILI) Surveillance in Colleges and Universities Fall 2009: Weekly College ILI cases reported. Linthicum, MD: American College Health Association; 2009.