Here’s how the flu season has played out in my own family (parents (38 and 40) and three kids, a daughter 10 years old, and twin boys 6 years old). I’ve added a couple of references for comparison with public health recommendations and published swine-flu info.
Late August 09: The boys were coughing and had slight fever, our daughter was coughing only. One son, the daughter and the father (me) tested positive for fluA, but negative for SwineFlu. At this time the public health information available said that only SwineFlu was going around since “Any widespread influenza activity in August is uncommon.” (ref). Clearly not in our family though – we had seasonal flu of some sort.
Late September 09: Our daughter gets high fever and headache. I felt scruffy, but did not have any fever. None of us were tested since we were abroad on holiday. We, gave our daughter Tamiflu®, since symptoms suggested possible SwineFlu infection.
Early November 09: One of the boys gets Swine flu vaccinated since he is in one of the risk groups (asthma). I get vaccinated for seasonal flu.
Mid November 09: The other boy gets high fever and headache. He is given Tamiflu®. He is later tested positive for SwineFlu. I tested negative. The rest of the family was not tested since they had no symptoms.
Late November 09: Our daughter is scheduled for SwineFlu vaccination.
This fall our family has had influenza two times, possibly three. We had seasonal flu first and this at a time where seasonal flu is not expected to be common. This infection had very mild symptoms in my family. Two of us then had more severe flu symptoms a month later, but this infection was not confirmed by testing. Some weeks later one of us gets a confirmed SwineFlu infection while the rest of the family apparently escapes disease.
One should not draw epidemiological conclusions based on results from one family, but nevertheless, working in a diagnostic lab being able to test so often has been an interesting experience. If i may, I’d like to speculate a little bit:
1. Seasonal flu may not be as “seasonal” as we think since seasonal flu can give very mild symptoms and remain undiagnosed.
2. Vaccination has worked fine in our family since the vaccinated boy did not get infected through his brother.
3. Seasonal flu does not protect against SwineFlu in children (same boy tested positive for seasonal flu and later on SwineFlu), but may protect against SwineFlu in adults. This is supported by a recent NEJM publication.
4. Following infections longitudinally could give valuable insight into the epidemiology of influenza and other seasonal viral infections.
5. Frequent testing reduces worrying to a minimum. While I realize that I am subjective since I have my own laboratory to develop tests in (and run them as often as I want), I strongly recommend that such frequent testing be performed for everyone.