Tennessee School Closings Raise Pandemic Concerns Recombinomics Commentary 11:13
September 2, 2009

Mounting illnesses have forced the Alcoa City Schools to close through Labor Day.

The 1,800-student system decided Tuesday to extend the holiday for its elementary school, middle school and high school after the absentee rate hit 30 percent. Normally it's around 5 percent.

According to Director of Schools Tom Shamblin, some of the illnesses are confirmed flu cases. Other illnesses included stomach viruses, fevers and upper respiratory infections. Shamblin said middle schoolers were impacted the most, with a nearly 30% absentee rate.

The above comments describe a large pandemic H1N1 outbreak in schools in Alcoa, TN, which is just south of Knoxville (see zoomed map).  Although other schools in the area also have high absenteeism rates (see broader view), they have followed the CDC recommendations on keeping schools open.  These other schools also cite a wide range of symptoms, as noted above.  All of these symptoms have been previously reported for swine flu, and it is likely that the vast majority of these students are H1N1 infected.  The number of infected students is much high than confirmed cases, due to limited testing of patients who meet the CDC case definition, as well as the high frequency of infections which do not develop a fever (and therefore do not meet the H1N1 case definition).

The absence of fever has been reported previously in Mexico and Chile, but a fever is included in the CDC case definition, so the symptoms listed for hospitalized H1N1 confirmed cases is 93%, leading many to assume the lack of a fever signals the lack of infection.  Consequently, a runny nose is frequently diagnosed as allergies, and gastro-intestinal problems are called "stomach flu", and other flu-like symptoms are called "upper respiratory infections" and in some cases an influenza A positive result is interpreted as seasonal or "normal" flu, even though 99% of influenza A positive patients at this time are swine flu because the traditional flu season has not begun.

Thus, the swine flu cases are easily noticed, even though the diagnoses, as seen above, are incorrect.  These misdiagnoses, especially those which attribute symptoms to allergies, lead to more H1N1 infections because these students come to school, and remain in school because they have no fever.  Moreover, the lack of testing leads to misconceptions about the H1N1 frequency in the area.

This lack of testing has been prevalent for months, so confirmed cases suggest that H1N1 levels in the region are low, and the explosion of cases creates "sticker shock" for returning students and parents.  The high level of infections cited above is not limited to Tennessee.  H1N1 is widespread throughout the south because the school year began in early August.  However, high levels are being reported elsewhere.  Almost 30% of students are also absent in Iowa, where there were large outbreaks last spring and around Marshalltown (see map).  However, the limited number of swine flu testing kits shipped by the CDC precluded testing of the hundreds of symptomatic patients at the local clinic.  Therefore these patients were not confirmed, even though attending physicians were certain that the patients were H1N1 infected.

Thus, the limited testing of H1N1 coupled with a case definition that includes fever has led to a significant under-reporting of cases, even in schools were absenteeism is approaching 30%.  Moreover, sick students without fever continue to attend school, leading to massive outbreaks as described above.  Therefore the explosion of cases in the south is likely to spread throughout the northern hemisphere as a new flu season begins in the absence of an effective vaccine and amid growing concerns of antiviral resistance.

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