• FluTrackers.com Inc. does not provide medical advice. Information on this web site is collected from various internet resources, and the FluTrackers board of directors makes no warranty to the safety, efficacy, correctness or completeness of the information posted on this site by any author or poster. The information collated here is for instructional and/or discussion purposes only and is NOT intended to diagnose or treat any disease, illness, or other medical condition. Every individual reader or poster should seek advice from their personal physician/healthcare practitioner before considering or using any interventions that are discussed on this website. By continuing to access this website you agree to consult your personal physican before using any interventions posted on this website, and you agree to hold harmless FluTrackers.com Inc., the board of directors, the members, and all authors and posters for any effects from use of any medication, supplement, vitamin or other substance, device, intervention, etc. mentioned in posts on this website, or other internet venues referenced in posts on this website.
  • We are not asking for any donations. Do not donate to any entity who says they are raising funds for us.

Review finds parallels between 1957 and 2009 pandemics

Shiloh

Editor, Senior Moderator
Source: http://www.cidrap.umn.edu/cidrap/content/influenza/swineflu/news/aug0509panflu57.html


Review finds parallels between 1957 and 2009 pandemics

Lisa Schnirring * Staff Writer

Aug 5, 2009 (CIDRAP News) ? Though infectious disease experts say it is impossible to predict how severe the next wave of the novel H1N1 pandemic will be, experts from the University of Pittsburgh Medical Center (UPMC) observe that it so far resembles the 1957-58 influenza pandemic in several ways. They report that the earlier pandemic caused minimal disruptions, in part because public health officials didn't close schools, cancel public events, or impose travel restrictions.

The group, from UPMC's Center for Biosecurity, published a review of US events during the 1957-58 pandemic in an early online edition of Biosecurity and Bioterrorism: Biodefense Strategy, Practice, and Science. Their findings come a day after Homeland Security Secretary Janet Napolitano said in an editorial board meeting with USA Today that the novel H1N1 pandemic would likely mirror the 1957 pandemic rather than the more severe 1918 episode.

One of the authors of the UPMC report is Dr. D.A. Henderson, who was instrumental in setting up a flu surveillance system at the US Centers for Disease Control and Prevention during the early stages of the 1957 pandemic, according to a UPMC press release. The group's report is based on his experiences, surveillance reports, and contemporary news reports.

"There is need for an understanding in national policy circles of the options for dealing with a pandemic, and time is short if states and local communities are going to be prepared," Henderson said in the press release.

The authors wrote that though no one can predict how a pandemic will unfold, "we would be ill-served if we did not consider past experience." The 1957 pandemic resembles the 2009 pandemic in that both viruses circulated in the summer months in the United States while the virus hit the southern hemisphere during its normal influenza season. Current disease patterns are also similar to the 1957 pandemic: illnesses are generally mild and the virus predominantly strikes younger people. The 2009 pandemic strain also appears to cause a similar case fatality rate to the 1957 strain, they add.

Appearing first at military camps on the East and West Coasts in June 1957, the disease spread quickly. The Association of State and Territorial Health Officers (ASTHO) had a special meeting in August to discuss the threat and response strategies. Epidemiologists weren't sure if the outbreaks would intensify in September or during the normal flu season.

ASTHO recognized that a vaccine could help prevent illnesses and deaths but probably wouldn't be available for at least 2 or 3 months. The group emphasized the role of home care for reducing the burden on hospitals and stated that closing schools and curbing public gatherings would have little impact on preventing the spread of the disease.

Community outbreaks intensified when schools resumed in September, but flu activity started leveling off by the end of November. Schools had 20% to 30% absenteeism rates, but the pandemic had little impact on work absenteeism except in schools and healthcare institutions. The authors estimated that up to 25% of the US population was infected with the virus.

Hospital admissions increased, but facilities had the surge capacity to handle the extra load, the authors reported.

Flu vaccine trials began in July, with efficacy findings ranging from 53% to 60%. From six domestic vaccine producers, 4 million doses were released in August, 9 million in September, and 17 million in October. They produced enough to vaccinate about 17% of the US population. The authors wrote that the vaccine apparently had little effect on the pandemic because of limited availability and efficacy.

One unusual feature of the 1957 pandemic was a 3-month wave of excess flu and pneumonia deaths that began in January 1958, they reported. Surveillance was showing no widespread community outbreaks at the time, and there were no spikes in school closures or work absences. A CDC official at the time speculated that the deaths could have resulted from smaller sporadic outbreaks that didn't attract much public attention.

The 1957-58 pandemic had little or effect on the US and Canadian economies, they found.

Henderson DA, Courtney B, Inglesby TV, et al. Public health and medical responses to the 1957-58 influenza pandemic. Biosecur Bioterr 2009 Aug, early online publication;7(3):[Full text]

See also:

Aug 5 UPMC press release

Aug 4 USA Today story
 
Re: Review finds parallels between 1957 and 2009 pandemics

Current disease patterns are also similar to the 1957 pandemic: illnesses are generally mild and the virus predominantly strikes younger people. The 2009 pandemic strain also appears to cause a similar case fatality rate to the 1957 strain, they add.

Anybody else catch this? First off, the same can be said of 1918 (mild illnesses, attacking mostly the young). But the other is the CFR bit. The whole of the '57 pandemic had a CFR between 0.1-0.3%? What was the CFR in the summer?
 
Re: Review finds parallels between 1957 and 2009 pandemics

JimO while I understand your argument, I would think infections are more likely to be revealed than deaths, even at a factor of 2-to-1 (which would extremely high) then your CFR is cut in half.
 
Re: Review finds parallels between 1957 and 2009 pandemics

current CFR estimated at 0.0004% - 0.06%

CFR: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19255


what was it in summer 1957 ?
Compare Australia,NZ with 1957 !



Ferguson in May compared it with 1957 too:
http://www.bloomberg.com/apps/news?pid=20601100&sid=aiWTCf0j63kI

---------------------------
However the 1957 pandemic in New Zealand was ... essentially one long wave,
lasting about 3 months, with a very high total attack rate (possibly 70% - 80%
of the whole population) and no significant following waves. The mortality was very low.
-------------------------
Detailed records were kept of the spread of the 1957 influenza epidemic in northern England.
This began in the urban centres. They formed the foci, since their high population densities
made transmission more effective. By September the surrounding areas were also affected,
but it was not until October that the truly rural areas had cases at an epidemic level.
-----------------------
36% of deaths in 1957 and 48% in 1968 were < 65
most deaths in the 1957 pandemic were due to secondary bacterial pneumonia
1957 in USA: 25%infected, 0.04% died,CFR=0.16%, CFR(worldwide)=0.3%
----------------------
 
Re: Review finds parallels between 1957 and 2009 pandemics

current CFR estimated at 0.0004% - 0.06%

CFR: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19255


what was it in summer 1957 ?
Compare Australia,NZ with 1957 !



Ferguson in May compared it with 1957 too:
http://www.bloomberg.com/apps/news?pid=20601100&sid=aiWTCf0j63kI

---------------------------
However the 1957 pandemic in New Zealand was ... essentially one long wave,
lasting about 3 months, with a very high total attack rate (possibly 70% - 80%
of the whole population) and no significant following waves. The mortality was very low.
-------------------------
Detailed records were kept of the spread of the 1957 influenza epidemic in northern England.
This began in the urban centres. They formed the foci, since their high population densities
made transmission more effective. By September the surrounding areas were also affected,
but it was not until October that the truly rural areas had cases at an epidemic level.
-----------------------
36% of deaths in 1957 and 48% in 1968 were < 65
most deaths in the 1957 pandemic were due to secondary bacterial pneumonia
1957 in USA: 25%infected, 0.04% died,CFR=0.16%, CFR(worldwide)=0.3%
----------------------



I question the approaches used to estimate CFR in the Eurosurveillance paper (linked above).

A definition of CFR that I think is appropriate is:

"case fatality rate the ratio of the number of deaths caused by a specified disease to the number of diagnosed cases of that disease".

My italics

See:

http://medical-dictionary.thefreedictionary.com/case+fatality+rate

CFR is not defined in the Eurosurveillance paper. Estimates are based on extrapolation of the estimated total infections (using a variety of assumptions) NOT the # of diagnosed cases.

If the definition of the CFR is taken as above, the July 6 WHO update (the last date prior to the relaxation of testing/ reporting by countries) is:

429/ 94512 = 0.45%

and this would be an under-estimate given the lag between confirmation of cases and deaths.

However, given the value of the CFR is purely comparative - it is obviously important to know how past pandemic CFR's were estimated - were those CFR denominators based on estimated total number infected or (hospital/GP) diagnosed cases?
Does anyone know?
 
Last edited:
Re: Review finds parallels between 1957 and 2009 pandemics

no, it doesn't make sense to consider "diagnosed" cases.
It depends on the method of diagnosis and reporting.

This would not be so much a problem, if fatal cases
were diagnosed as normal cases, but they aren't.
A fatal case is much more likely to be diagnosed
than a normal case.

You might consider all diagnosed cases and _then_ see
how many of them die. But that's still biased because
severe cases are more likely to be diagnosed.

We must estimate the total number of cases and the total number
of deaths.

Make a questionnaire how many were infected in a wave
and compare with the number of excess-deaths
in that period.(plus late deaths occurring later but caused by infection)

However excess deaths are not so many and hard to measure as
compared with the huge number of total deaths.


So take a small city with a wave, measure all cases and deaths
accurately, determine/estimate the ratio of cases and deaths
which by usual reporting escape detection, and assume
that ration for other locations with less accurate reporting
too.
 
Re: Review finds parallels between 1957 and 2009 pandemics

USA : popu=300M,all=42127(14m%),hosp.=2386(795my%),dead=413(138my%)
Utah: popu=2.7M,all=684(25m%),hosp=294(10889my%),dead=17(630my%)
NYC : popu=8.5M,all=1300(15m%),hosp=900(10588my%),dead=50(588my%)
Argentina : popu=40M,5710(14m%),hosp=3846(9615my%),dead=337(843my%)
UK: popu=62M,all=12261(20m%),hosp=6000?(9677my%),dead=40(65my%)
Australia:popu=21M,all=24000(114m%),hosp=3000(14286my%),dead=77(367my%)



we saw a typical wave in NYC,London,Melbourne,
Salt Lake City,Boston,NZ,Buenos Aires,Mexico City

everywhere it was a typical flu-wave, attacking mainly the young,
with few deaths and no visible increase of total deaths
as seen in seasonal pictures.

So why do they compare it with 1957 which caused 70000 deaths
in USA in 1957/8 ?


Looks more like ~10000 to me, so the total number of flu-related deaths
in USA should decline in the next 2 years since ** is replacing oldflu
which caused


however, as I said before these are often healthy, young people,
so their deaths weight more. And the burdon from disagreable
disease is larger than usual, more people are infected.
 
Re: Review finds parallels between 1957 and 2009 pandemics

no, it doesn't make sense to consider "diagnosed" cases.
It depends on the method of diagnosis and reporting.

This would not be so much a problem, if fatal cases
were diagnosed as normal cases, but they aren't.
A fatal case is much more likely to be diagnosed
than a normal case.

You might consider all diagnosed cases and _then_ see
how many of them die. But that's still biased because
severe cases are more likely to be diagnosed.

We must estimate the total number of cases and the total number
of deaths.

Make a questionnaire how many were infected in a wave
and compare with the number of excess-deaths
in that period.(plus late deaths occurring later but caused by infection)

However excess deaths are not so many and hard to measure as
compared with the huge number of total deaths.


So take a small city with a wave, measure all cases and deaths
accurately, determine/estimate the ratio of cases and deaths
which by usual reporting escape detection, and assume
that ration for other locations with less accurate reporting
too.


Well, if the objective is to compare current and past fatality rates to draw conclusions on the relative virulence of current/ past pandemic strains (which I understand is what is being attempted) there is a lot of sense in defining what is being measured. Apples vs oranges - I think someone noted above.

A medical definition of CFR is I think appropriate. However, I suspect CFR for past events were estimated ex post facto - when all deaths had been recorded and sufficient hospital/ out-patient data were available to make some reasonable approximations on the scale of population infected.

But your last paragraph implies a level of confidence in the data from some localities thus justifying extrapolations to a global/ national/ regional level. I question whether that's appropriate. Any initial errors (unknown but very likely large) will be magnified many-fold so as to make global/ national/regional estimates - and comparisons with historical events - essentially meaningless.

In any case, even if the measurement errors were known, I question the validity of the conclusions being drawn. Perhaps differences in CFR actually indicate the efficacy of anti-viral and other (medical) interventions in preventing larger numbers of deaths in the current episode...?
 
Re: Review finds parallels between 1957 and 2009 pandemics

The math here is so fuzzy it may be meaningless. Record keeping is problematic; not enough tests, everyone isn't counted, misdiagnosed cases both getting well and dying, cases dying of secondary causes frequently not counted, governments deliberetly skewing numbers to keep the citizens calm. The only real number will be those garnered after the event is concluded. Until then we can keep a count but it must include a number of caveats as to just how many of the numbers are conjectures.
 
Re: Review finds parallels between 1957 and 2009 pandemics

... Until then we can keep a count but it must include a number of caveats as to just how many of the numbers are conjectures.

The list will need to be very long. All the numbers are conjectures. And, as I say, such (necessary) qualifiers make comparisons essentially meaningless...
 
Re: Review finds parallels between 1957 and 2009 pandemics

The list will need to be very long. All the numbers are conjectures. And, as I say, such (necessary) qualifiers make comparisons essentially meaningless...

Indeed, if you goal is data comparison.

No qualifiers are necessary if you are searching for trends. As long as you are consistent in your data collection efforts, trends will be recognizable. The tracking of deaths here at FT is a good example. Despite general news reports that imply that H1N1 infections and deaths have leveled out, this is not the case, as deaths continue to rise, especially in the southern hemisphere.
 
Re: Review finds parallels between 1957 and 2009 pandemics

math isn't "fuzzy". Language is, interpretation is.
The big number of samples statistically overcomes
the fuzzy cases.
 
Re: Review finds parallels between 1957 and 2009 pandemics

> They produced enough to vaccinate about 17% of the US population.
> The authors wrote that the vaccine apparently had little effect
> on the pandemic because of limited availability and efficacy.


there must have been regions with larger and smaller coverage.
there must have been an analysis how cities went in the pandemic
depending on their vaccine coverage.

there must have been studies, how much % of the infected
had been vaccinated

why isn't it mentioned ?
 
Re: Review finds parallels between 1957 and 2009 pandemics

CDC estimated that 45M had become infected in Oct and Nov 1957 (4)
[including asymptomatic case ? , how many in 2nd wave Feb.1958,
how many in both waves]


peak was in week 42
peak in deaths in week 45.5

highest attack rates in school children

Oct57-Mar58 , 892000 death certificates (830000 expected)



early in Tangipahoa parish , pop=60000 :
CAR in schools = 40%-60%
50% of those reporting no ILI still had Antibodies (3)
2 deaths





[3] Carey Dunn Robinson JAMA 1958
[4] $46 , Trotter,Dunn,Drachman AmJHyg 1959
 
Re: Review finds parallels between 1957 and 2009 pandemics

Indeed, if you goal is data comparison.

No qualifiers are necessary if you are searching for trends. As long as you are consistent in your data collection efforts, trends will be recognizable. The tracking of deaths here at FT is a good example. Despite general news reports that imply that H1N1 infections and deaths have leveled out, this is not the case, as deaths continue to rise, especially in the southern hemisphere.

I missed the news about deaths leveling off. Could you provide a link?
 
Re: Review finds parallels between 1957 and 2009 pandemics

weekly reported confirmed new deaths since 24.April :
(source:WHO,wikipedia)

10,36,19,21,13,26,20,35,83,79,118,340,268,287,344


almost stable since 3 weeks ... but we had that before ...
 
Back
Top Bottom