Part One
I've been getting a tad squirrelly with all the information coming out in the past week. Too much over too short a time frame & currently, I have about 400 pages of online reading piled up. Yeah, I can plough through that in 4 hours but that's pointless. Reading for comprehension & comparison is going to at least double that.
And when there's that much info, on top of what I've read it blurs, it becomes depersonalised. It's the latter part that scares me. When it's all theoretical places & numbers, it's easy to become 'lost in the data' & forget you're thinking about potential impacts on real people, not least of whom may be yourself... or your spouse/children.
I found some data on my city - a concise little summary on last year's flu season & compared that with a bit of demographic data, then projected rather wildly based on known epidemic influenza curves to see what the effect might be here. The results were sobering & this is an exercise some may wish to mirror - can help to convince people that Not All Will Be Well during pandemic. Wish I could submit the danged thing for a mark somewhere...
The city population is currently listed at roughly 113,000. 17.8% of those are over 56. 100k are urban, the rest rural. 25% are between 0 - 19, 33% are between 20 - 39 & the 24% are 40 - 59.
Most households consist of 1 or 2 people, (62%) & there are roughly 44k households.
I'll show how this applies to pandemic - scarier than I thought.
Unemployment is high at 13% & the average pay somewhat lower than most larger urban centers. Crime rates are tolerable, little violent crime with weapons & we have a federal prison population of roughly 1200. These are 10 year old data however, I had to tweak them a bit
We have 482 acute care beds & up to 600 long term care beds. The last number is fuzzy but the best I could come up with. We probably have mothballed space for another acute care beds.
Flu season last year was light with only 97 cases reported. The health unit itself cautions this is under-reporting. I'd agree - few specimens are tested & if in a setting, 1 test comes back positive for a certain strain, it's safe to assume 20 - 50 similar cases in that facility or setting with similar symptoms have it & judging simply by anecdotal stuff, I'd estimate a nice round 10k cases over the course of the winter. But the CONFIRMED data are here:
http://www.healthunit.on.ca/pdf/flucase04.pdf
Most cases occurred in the 0-4 age group whereas previously most cases occurred in the 65+ cohort. Towards the end of the season though, more seniors came down with flu as their vaxes wore off. 90% reported having been vaccinated - that's 90% of confirmed cases. 3 cases had pneumonia - no deaths.
Most contracted flu through school & most were unvaccinated. Of those who felt exposure occurred at home, half had been vaxed, half not. Makes sense, A/Fujian was predominant followed closely by the previous H3N2. No one who felt they were exposed through work had been vaxed.
Okay, enough boring stats. Here's a bit about the city, then I'll do a separate reply on how this might all play out in terms of how an epidemic would hit & play out.
Much employment here is government bases - lots of corrections & provincial government services. We have a medium sized industrial base, most of it light to medium & consisting of small plants, save for Dupont. Increasingly call centers are opening. A LOT of people on some form of government cheque - as high as 1/3. We are not any sort of transport hub but the main national rail/passenger line goes through the northern end of the city as does the trans-Canada highway.
There are several human 'choke points' - a new Walmart store - only one in town & a few similar 'one of a kind in town' big box stores. We have 2 movie theatres & only 1 large shopping mall. Many live in the west end & work at the other end of town & vice versa. We have a significant population of homeless & a great many ex psych inpatients now 'benefiting' from care in the community. Which means they're getting squat in terms of help & the soup kitchens & homeless shelters, (few), act as perfect amplification points. We have an excellent university with lots of foreign students & an excellent regional community college.
All these factors translate to close to ideal conditions for epidemic spread of influenza & once I do the dishes, (blech!), vacuum & wash the floors, I'll 'play it out'.
Projecting these things becomes frustrating
when you're missing an important, 'fat' number to plug into your calculations. What I cannot seem to find is a reasonably accurate number for what percentage of the world's population actually CAUGHT Spanish Flu. Many news reports from local regions of many countries would lead me to think it was in the order to 10 - 20%. Some areas saw almost 100% of people catching it while a few lucky areas saw very few cases. Pandemic planning is operating on a worst case scenario of 50% of any given population catching it.
That's a nice 'fun' & easy number to work with but too general to do anything but make me uneasy. Not being trained in either statistics or epidemiology means I find it terribly confusing when I try to give weight to various factors. The tons of unknowns about a potential pandemic H5N1 subtype doesn't help at all, either.
Not all pandemics are equal obviously but it makes sense to plan for the worst & hope for the best. Planning for the worst still has to be tempered with reason. It doesn't strike me as reasonable to plan using a 50% 'catch rate' combined with the current CONFIRMED almost 78% death rate. I know of no pandemic event that's even come close to that. New pathogens as a rule, do not hold high levels of virulence over time - they mutate to adapt a little more 'kindly' to their hosts & the human body adapts to them. Measles is estimated to have had a 50% mortality rate when it first jumped to humans - now it's a childhood disease with most cases resolving totally.
Other factors I had to consider... pandemics can & often do start with a milder wave. The good thing about that today is we'd know what the strain was or at least, it's earliest genetic manifestation before it alters even further as a result of infecting many humans. This 'wave' might initially be hard to spot as it more closely resembles fairly small outbreaks scattered over different parts of the world - are we seeing that now in Vietnam, Thailand, Sri Lanka, the Philippines...? A bit early yet I think as it's not transmitting easily. The second wave will be 'the big one'. Will it have mutated enough to be able to infect anyone or only those who didn't catch it during the first wave?
What age group will it hit hardest? Pandemic strains tend to skew downwards in age with younger & normally healthier people being disproportionately hit. More ominously it, seems retroactive examinations of data showed that 23-70% of pregnant woman died of Spanish Flu. God forbid H5N1 doing that. The US military reported anywhere from 5-10% mortality rates - higher than the estimated world wide toll but the reasons aren't complicated. High levels of stress, massive 'lifestyle changes', crowding in barracks & trenches... other countries, especially developing ones had higher death rates. India suffered badly but was also under the influence of a massive drought.
Recent experiments with genetically modified H1N1 strains similar to the Spanish Flu genotype suggest, (in mice), that cytokine storms may have done most of the damage. These are overactive immune responses so may explain the higher death toll in young, healthy adults. Young, strong people have strong immune systems & would be most likely to 'over-react'.
The Asian Flu pandemic in 1957-58 resulted from a known strain reassorting & picking up avian genes - we're seeing H5N1 & other avian 'H' subtypes doing that now. It began in Singapore in February & reached the US by June - not a long time at all. During the early part of this pandemic in the US - 40% of deaths occurred in the under 65 age cohorts.
The 1968 Hong Kong flu also came about through reassortment - 2 duck flu genes were added into a current H3N2. Only the H, not the N changes & it's thought that contributed to a lower death rate. Change both H & N substantially & it seems the potential for complications/deaths rises much higher. Will H5N1 do that? Antibodies to any currently circulating N are thought to modify the severity of disease - that would be good.
http://www.cidrap.umn.edu/cidrap/co...cts/panflu.html
So a lot of wildly varying factors can influence the course of a pandemic, it's morbidity & mortality rate & thus our ability to respond. For my city's scenario, I'm going with a 25% attack rate & a 5% death rate. I'll explain the impact of other factors as needed, as I go.
For the sake of keeping this short I'm going to 'ignore' what's going on outside my community. Certainly at the provincial/national & international level a great deal will be happening but I'm going to leave that out of it unless it has immediate & direct impact on what's about to happen in my city, (theoretically). as otherwise this will just get too convoluted.
This will be a 'classic' 2 wave outbreak & rates of increase, complications etc. I use I'm going to have cobbled together based on reading. It may not play out that way in reality but no one is in a position to know that until we're actually hit with pandemic. I will describe local conditions & reactions based on what I know of the city & the local government as well as area demographics. That's all I can go on, really.
The end of February has seen a sharp rise in H3N2 cases in Kingston due to the emergence of A/California. As is typical here this time of year, the health care system has been heavily impacted. The hospital is full & elective procedures cancelled. Due to other concerns related to availability of beds, many non-elective procedures have been cancelled. Health care workers are succumbing to A/California in spite of almost universal vaccination against flu of staff - that subtype has drifted too far off the vax strain.
Against this backdrop, the first half dozen or so cases of pandemic H5N1 escape notice. The health care system has been on guard for any since the pandemic began in Asia nine weeks ago but none have yet been identified. Initially these patients feel no worse than if they have a heavy bout of A/California or similar strain. They all feel badly enough Monday to call in sick to work & in one case, school but not badly enough to seek health care attention. One woman goes to emergency Wednesday evening with some difficulty breathing but that case raises no great alarm - her patient files show she has asthma. She's admitted as a precaution.
By Friday, cases are silently spreading throughout the city. It doesn't help that the spouse of one of the initial cases is an agency employed registered nursing assistant. This week, she's worked 2 long term care facilities as well as done her usual shirts with her 3 home care patients. 2 more of the original cases have presented to emergency, one a school child who has developed what is assumed to be a secondary, bacterial pneumonia. That girl & the other who came in with severe respiratory distress WERE tested.
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