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

With epidemiologic data on novel H1N1 flu suggesting significant risk among those in the college setting, ACHA deemed 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. Therefore, in the summer of 2009 ACHA undertook 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. Additionally, given reports of significant variability of H1N1 vaccine availability across the nation, beginning October 30, 2009, ACHA began reporting on the availability of the H1N1 vaccine, as well as the vaccine uptake in a continuing effort to assist the CDC, public health officials, and all college health professionals in tracking national vaccine trends for the college population.

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 the final week's case data for the period April 24-30, 2010, as reported to ACHA, as well as ACHA's cumulative case data and an epicurve chart reflecting weekly ILI case counts and weekly attack rates. The fourth link below provides summary information on the availability of the H1N1 vaccine and the vaccine uptake among reporting institutions.

In this period of influenza activity, a total of 162 new ILI cases were reported (with no hospitalizations or deaths) among campus populations totaling nearly 2 million. Twenty-eight percent of 170 colleges and universities reported new ILI cases, compared to 34 percent reporting new cases for the previous week. The nationwide attack rate was very low, now at just 0.8 cases per 10,000 students, 11 percent lower than the previous week’s rate. Nationally, the reported disease incidence has remained below 5 cases per 10,000 students for nearly five months, with attack rates over the past eight weeks averaging just over 1 case per 10,000. Consistent with CDC surveillance data, some low level activity is still occurring; ACHA’s surveillance indicates that disease incidence in colleges and universities is less than three percent of the peak level seen last fall. 

"As we curtail our surveillance project, we continue to see no definitive evidence of a third wave of ILI disease, and there appears to be no sustained transmission occurring on college campuses. The H1N1 surveillance project was an important milestone for college health.  Through the efforts of ACHA's national office and participating schools, the project resulted in an accurate representation of the epidemiology of the H1N1 outbreak on college campuses nationally. The data was invaluable to schools, local, and state health departments, and the CDC. Additional research will likely be forthcoming from public health experts who will study the spread of H1N1 from campuses to the contiguous community. If campuses turn out to be the epicenter of influenza outbreaks, community mitigation strategies may eventually include specifically targeting college students with vaccination campaigns. In addition, it is hoped that this is the first of many similar projects that will help clarify and define epidemiologic trends on college campuses and will supplement data derived from the ACHA-NCHA survey," 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.

ACHA is especially grateful to all of the colleges and universities that volunteered to be a part of this project. They have helped to demonstrate the importance of college health and its professionals as valuable contributors to the public health of our nation.

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: ACHA. American College Health Association Influenza Like Illnesses (ILI) Surveillance in Colleges and Universities 2009-2010: Weekly College ILI cases reported. Linthicum, MD: American College Health Association; 2010.

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