Wednesday, November 4, 2009

H1N1: Two weeks in, and what to expect now ...

It has been two tiring weeks for anyone involved in the public or acute care health systems, whether as workers, patients or family members.

Tonight on the radio, I heard an announcer discussing the possibility that the immunization program in Nova Scotia might start to slow down the rate of new cases.  I noticed that the spokesperson for public health was careful not to support this notion ... she correctly pointed out that, although the immune system starts to react almost immediately on contact by the vaccine, it generally takes two weeks for the shot to generate maximum benefit.  We have just begun the immunization campaign in Nova Scotia; according to the CBC, about 9% of the population has been immunized to date.

From a viral perspective, in other words, there is still a lot of food to eat on the table.

Australia has it's peak flu season in our summer, so they have already been through one H1N1 season.  According to their surveillance data,  the peak of the epidemic occurred 9 weeks after onset, and the incidence of new cases only fell to below the level seen at two weeks (where we are now) after 15 weeks.  That's nearly four months, for those of you with plans to hold off on that immunization.  A long, long time to hold your breath in public.

Canada will probably do better.  The H1N1 vaccine was not available in July, when Australia was facing its outbreak.  Australia has a high quality medical system; nonetheless, their intensive care units were stressed by the load of patients requiring ventilators.  While this is a very rare thing in children with this disease, and very uncommon even in adults, if 1/3 or 1/2 of your entire nation is sick with the flu, the numbers of "rare" things start to become significant.  There is every reason to believe that the vaccine will reduce the overall rate of disease, and therefore the stress on critical areas like ICU's and Emergency Departments.

All this depends, of course, on us getting enough individuals immunized in time.  The Harper government was on record last week that Canada will be amongst the first to offer full immunization to its citizens, and that the current timeline to complete that process is .... Christmas.  I don't want to criticize public health officials, who have been working flat out on this problem since the spring.  But we do have to recognize that Christmas is 9 weeks into our national pandemic ... or at about the same time the Australians experienced their peak.

Finally, H1N1 isn't the only kid on the block.  Beginning every year in late December and peaking in February, a bug called RSV comes to town.  If during those months you have a nasty, snotty nose and a bad cough, or your baby / toddler is wheezy and hot, odds are good that you have RSV.  As a westerner I have always thought of RSV as the cash crop of emergency pediatricians ... February is certainly the month you find us toiling in the fields.  It is usually the busiest month of the year, with the greatest number of hot, coughing  children.  Sound familiar?

So ... my forecast is for a pediatric heat wave, with associated hack, wheeze and a whole lot of snot right through until April.  Get out your wellies, folks...

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