Thursday, June 25, 2009

Dennis McBride MD, Milford Health Director Comments on Swine Flu

Until a vaccine of novel H1N1 influenza (H1N1) is made, public health can only try to slow down but not eliminate the spread of the virus. While most people can tolerate H1N1, many with preexisting medical conditions (e.g. asthma, diabetes, etc.)cannot. To those people, H1N1 is not a “mild” flu.

Since the majority of H1N1 cases have occurred in persons under 18 years, schools are the focus of social distancing strategies.

The Centers for Disease Control and Prevention (CDC) website ( is a wealth of information. However, in the beginning of the H1N1 outbreak , CDC issued “Interim Guidance on School Closures” that was perplexing. Most state health departments, including Connecticut, follow CDC guidelines. (Note: NYC Department of Health stated that some actions they took in response to H1N1 were not following the CDC school closure guidelines.)

CDC stated that: “K-12 Schools: School dismissal is not advised for a suspected or confirmed case of novel influenza A (H1N1) and, in general, is not advised unless there is a magnitude of faculty or student absenteeism that interferes with the school’s ability to function.” Yet in other guidance CDC endorses school closure during a pandemic. Public health literature is replete with school closures as strategies to quell an influenza pandemic.

On the other hand, many advocate for school closure during this H1N1 pandemic. I pose a road less travelled—partial school closure. In the face of an outbreak of influenza-like-illness (ILI) at Foran High School, I elected not to close the school but to work with Dr. Harvey Polansky, Superintendent of Schools, to devise a plan to reduce the spread of ILI and yet continue essential education work. If we had been presented with an extremely virulent virus, such as a virus that caused the 1918Influenza pandemic, I would have closed the school. We were not in that situation. The decision to use partial closure of the high school was made to minimize risk of ILI transmission.

It is commonly accepted by public health and medical authorities that, for the most part, influenza transmission relies on close contact (less than 6ft)with symptomatic persons and length of time spent in with that person. The more close contacts a person has with symptomatic persons (through coughing, sneezing, or talking) and the longer the time spent with that person, the greater the risk of contracting the disease.

Dr. Polansky proposed 1/2 day of classes and no lunch in the cafeteria. The proposal met the public health criteria to decrease the time of the students exposure to a potentially infected student and the number of personal contacts that each student would have.

In public health and medicine, sometimes decisions have to be made before all of the data are in. The scientific literature on partial school closure for flu outbreaks is lacking, but “absence of evidence is not evidence of absence.” Using modeling research data from Glass’ 2008 study “Social contact networks for the spread of pandemic influenza in children and teenagers,” we have determined that contact hours can be reduced significantly with a partial closure schedule. With the two measures (decreasing class time and eliminating cafeteria lunches), we estimate a decrease in student contact exposure hours of about 40%.

In addition, school staff and teachers are on full alert to refer symptomatic students to the school nurse. The school building was cleaned and sanitized using CDC guidelines for H1N1.

After the partial closure was implemented, some positive things happened:

1. Those students that were ill with ILI stayed home.

2. The number of students presenting to the nurses with ILI symptoms decreased to
less than 3 per day.

3. School custodians report increased use of hand soaps and students report using
more hand sanitizers.

4. The absenteeism rose on the first day (by worried parents and sick students) but dropped significantly on the second day to moderately above absenteeism rates for this time of year.

5. School nurses contacted families of students known to have serious underlying
medical conditions and advised them to consult their doctors about antiviral medications.

6. Students are still on track to finish out the school year as scheduled.

In Milford, each school has a school nurse and they have been tracking school absenteeism and ILI for five years. When H1N1 cases were confirmed in the U.S., I requested that the ILI and absenteeism reporting efforts be shifted from weekly to daily reports. Thus we were able to detect approximately 20 students with ILI over a
24-hour period. This was the only school in Milford with an ILI outbreak. Partial school closure may not work everywhere, but should not be dismissed as an option to stem the pandemic.

The battle against H1N1 is far from over. Only thru strong community partnerships can we meet future challenges.

Original Letter Posted HERE

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