A Journey Through The World of Pandemic Influenza

Vaccination and morality

 

Sometimes the truth just needs to be said, and sometimes it is said so well that nothing needs to be added.

 

From the blog Denialism:

Excerpt:

Vaccination and morality

Category: Anti-Vax Denialism
Posted on: July 21, 2008 11:08 AM, by PalMD

Who has the moral high ground in the vaccination wars?

My initial response is that I do, "I" meaning the medical and public health fields---those of us who prevent disease, disability, and death.

But it's much more complicated. Many anti-vaccine activists are "true believers". They really believe that vaccines do more harm than good. But, without getting all Godwin, being a true believer doesn't insulate one from moral responsibility.

Those of us who are professionals have made the evidence available. The science is clear---vaccination is a good thing, and more important, it is better than the alternative. True believers will never be convinced by something as simple as truth.

On the front lines, though, are individual parents. They make good or bad decisions based on available information, propaganda and otherwise. The anti-vaccination cults are very effective at communicating lies to these parents, interfering with their ability to make good decisions. It is the equivalent of telling people "water purification is bad. It interferes to our individual rights, and you shouldn't do it. I keeps us from being exposed to vital immune boosters." This leaves individuals wondering what to believe, and the often try to pick the "safest" choice.

In the case of vaccines, this often means that parents chose not to vaccinate. (I don't have statistics on this, but the resurgence of vaccine-preventable illnesses points in this direction.)

Continues…

Hand washing dramatically reduces disease

 

I recently posted about "germie" ice in restaurants [here] because there are those who seem to have difficulty grasping the concept of washing their hands after certain bodily functions are performed. Today I found a wonderful article about the benefits of hand washing:

In safe hands 
By : KASMIAH MUSTAPHA 
2008/07/21

Poster used in the Cape Town study to educate children on proper ways to wash their hands.

IT's a simple thing to do. 

Yet many tend not to make it a habit to wash their hands — after using the toilet, before and after handling food, or anytime their hands are exposed to germs. 

By using soap and clean water to disinfect, the risk of infectious diseases can be reduced significantly.

Studies show that such diseases are usually spread through hand-to-hand contact.

The germs are spread when people touch food or surfaces that have been handled by dirty hands. Diarrhoea, the common cold, pneumonia and acute respiratory and skin infections are some of the illnesses that can ensue as a result.

Inadequate hand washing and cross-contamination is responsible for as much as 40 per cent of food-borne diseases, including salmonella, hepatitis A, shigellosis, staphylococcus, streptococcus, E. Coli and many yet unidentified and dangerous viral infections.

In a study presented at the 13th International Congress on Infectious Diseases in Kuala Lumpur recently, a strong association with fewer illnesses was found when families practised hand hygiene.

The study's sample consisted of communities living in squatter and residential areas in Cape Town, South Africa. 

[snip]

The communities were chosen based on several criteria: those with only communal access to clean water and communal latrines/buckets (i.e. squatter areas); communities whose under-five mortality rate is at least four times higher than other areas; and areas that spent only 40 per cent of the total health-care expenditure on a public health system that serves 80 per cent of the population, among others.

These communities were taught proper hand washing methods, given "hand washing stations", had their food vendors induced to practise hygienic food preparation and instructed on how to manage communal toilets.

In residential neighbourhoods, the study found there was a 78.5 per cent reduction of respiratory diseases, 77.3 per cent in skin diseases, and 81 per cent in gastrointestinal diseases in children under five years old.

In "shack communities", there was a 56.2 per cent reduction in respiratory diseases, 84.1 per cent in gastrointestinal illnesses and 64.2 per cent in skin infections under the same age bracket.

[snip]

He [Cole, a professor in the Department of Health Science at Brigham Young University] said about 1.9 million die from acute respiratory infections annually, with 70 per cent of them from Africa and Southeast Asia.

The major respiratory pathogens are streptococcus pneumoniae, haemophilus influenzae type B, respiratory synctial virus, parainfluenza virus type 3 and the influenza virus. 

[snip]

Sungai Buloh Hospital head and consultant of infectious diseases Dr Christopher K.C. Lee said that a wide range of non-medical interventions — from personal hygiene to wearing masks, quarantine and the screening of travellers — can potentially reduce the spread of germs.

"Hand hygiene remains a pre-requisite for preventing the transmission of disease," he said.

In H5N1, an influenza virus subtype, hand hygiene, which includes hand washing with soap and the use of alcohol-based hand rubs, is critical to prevent possible contamination of the nose, mouth and conjunctivae by unwashed hands."

He said in public buildings, minimising the exposure of humans to viruses is the key to reducing risks of infection. 

Preventive measures in such places include encouraging frequent hand washing, ensuring the building's occupants and visitors have access to facilities for proper personal hygiene, and ensuring surfaces are cleaned regularly.

"It is so easy to stop the spread of germs and infectious diseases by washing your hands. While many of us do make the effort to ensure hand hygiene, there are also others who take it lightly. 

"We should no longer think of hand hygiene as insignificant."

Continues….

 

There are those who have ridiculed the campaign espousing "hand hygiene" as a vital [and worth trumpeting] part of pandemic NPIs (Non-pharmaceutical Interventions) and, honestly, their little snits of ridicule generally evoke a bit of snit from me, as I believe hand washing to be akin to the First and Last line of defense against pandemic influenza. Of course, there's a whole passel of other things in between first and last – just to be clear on that.

 

We don't fully know the role surface and hand contamination plays in the transmission of diseases in general, and we are even more ignorant when it comes to the transmission of the influenza virus and the degree fomite transference plays. The study this article references may alleviate some of that ignorance – to say nothing of the snits of ridicule.

 

SZ

Pandemic Mitigation II

Last night I addressed pandemic mitigation from a general, community level (here), tonight I would like to discuss the issue on an individual level.

There are 300 million +/- people in the US and according to the 2000 US Census 69% percent of us live in areas that have a population of 50,000 or more, in 3,629 urban areas. For a breakdown of percentage by state see here. I was quite surprised to learn that my state (SC) is the least urban density in the nation—a good thing in a moderate to severe pandemic.

 

Using official estimates of what could be anticipated for a severe pandemic a 30% CAR (clinical attack rate) and 2% CFR (case fatality ratio) we can glimpse into our crystal balls and see what might be in store for our states and our cities.

For my area, the city, (Charleston), has 425,000+/- residents. That would mean that my city would see roughly 127,500 PanFlu illnesses and 2,550 illnesses directly attributed to those illnesses. Were I to figure it for the entire area, known locally as The Tri-County the figures are as follows: 603,500 residents, 181,050 PanFlu illnesses, and 3,621 PanFlu deaths.

Of course, we have no way of knowing what the CAR/CFR of the next pandemic will be, should one occur, but currently H5N1 has a cumulative CFR of just over 60%. Assuming a pandemic of H5N1 for my purposes here, a drop of 90% in the current CFR would still leave us dealing with a CFR of 6%, and that would translate to 7,650 deaths for my city and 10,863 for my entire area. When I type "deaths" and you read "deaths", it is important to remember that those numbers represent people: men, women and children. In the case of the figures I quoted those are my neighbors, co-workers, friends and family members.

 

I went through all the effort to type all of the above out because I feel it is important to be crystal clear about what I am addressing in this entry, what we, as individuals, can do to reduce our chances of being included in our community's statistics.

 

So, what can we reasonably do to protect ourselves? Until we have a vaccine released to our demographic/cohort, (for a draft guidance of vaccine priority sees here), we will have to rely on Non-pharmaceutical Interventions—NPI's.

• Keep your children out of school no matter what your school's official policy is. Not only are children the most efficient spreaders of influenza, schools are over crowed and perfect amplification points for any infectious disease.
• Maintaining social distancing: 3 feet or more.
• Frequent hand washing
• Avoiding touching our faces
• Avoiding touching common surfaces: anything someone else may have touched. Both influenza A and B viruses survived for 24-48 hr on hard, nonporous surfaces such as stainless steel and plastic but survived for less than 8-12 hr on cloth, paper, and tissues. Measurable quantities of influenza A virus were transferred from stainless steel surfaces to hands for 24 hr and from tissues to hands for up to 15 min. Virus survived on hands for up to 5 min after transfer from the environmental surfaces. J Infect Dis. 1982 Jul;146(1):47-51
• Use alcohol based hand sanitizer liquid or gel any time you touch a common surface
• Work from home if at all possible
• Stay home if possible (known as SIP or Shelter in Place by Flubies)
• Minimize physical contact
• Wear a mask: N95, surgical, homemade (in order of effectiveness and difficulty of obtaining during a pandemic) My blog entry for the CDC's offering on a homemade mask here, and a discussion thread about masks, as well as tossing around ideas on mask workarounds in general on P4P here.
• Stay home if you become ill with any illness; you will not know if it is PanFlu or not for a day or three and you do not want to be out spreading germs.

   

 

Will doing these things guarantee you will not get PanFlu should we suffer a pandemic? I cannot give you a definitive yes to that question, but they will reduce your chances of becoming infected, and short of an effective vaccine, that is probably the best we will be able to manage—reduce our chances of becoming infected. An aside: For the latest release on the steps and timeline involved in producing a PanFlu vaccine see the WHO's PDF here; the pandemic is likely to be over before we have an effective vaccine.

 

 

Here's hoping none of us end up as a PanFlu statistic.

 

SZ

Basics: Pandemic Severity

I often use the phrase "moderate to severe PanFlu", when I do so I generally use my own criteria for what will constitute severe.

Generally I qualify any CFR at 5% or less as a moderate pandemic, where the CDC has settled on the criteria below 2%.

And just for clarity's sake I hold the opinion that a CFR above 15% would be catastrophic to everyone and everything.

I should probably adjust my phrasing but I won't, I am used to the mental constructs that have informed my thinking up to this point.

Early this year the CDC (Centers for Disease Control and Prevention) developed and published a way to judge pandemics, in the pre-pandemic planning stage, by severity, assigning categories reminiscent of hurricane strength classifications.

The model assumes that 30% of the overall population will get the pandemic strain of the virus, although different age groups and population centers may experience significant differences in the percentages, both overall and in the specific age groups.

Age groups can be thought of as preschoolers, elementary school children, students in upper grades, working adults, older adults, and finally, the elderly.

Official assumptions seem to be that the age group that will experience the highest level of illness is the younger children, picked up in daycare centers and school.

The percentage of the population expected to become ill is termed the Case Attack Rate, sometimes stated as the acronym CAR.

The numbers of those ill who are expected (statistically) to die are the Case Fatality Ratio (CFR).

From Wikipedia:

The pandemic severity index levels are:

• Category 1, CFR of less than 0.1% (example: seasonal flu)
• Category 2, CFR 0.1% to 0.5% (examples: Asian Flu and Hong Kong Flu)
• Category 3, CFR 0.5% to 1%
• Category 4, CFR 1% to 2%
• Category 5, CFR 2% or higher (example: Spanish flu

Recommendations for a response to a flu pandemic were based on the history of the last three major flu pandemics, mathematical models, seasonal flu transmission, and input from experts and citizen focus groups.

It should be noted that the Category 5 on the CDC's pandemic scale has a fatality ratio of 2% or greater. Currently the CFR is just a bit over 60%, both cumulative since 2003, and also if one only includes the cases thus far in 2007. The yearly CFR can, and has, varied from the cumulative CFR, sometimes markedly.

1.8 million deaths in the United States are estimated for a Category 5 pandemic with a CAR of 30% and CFR of 2%. An increase of 1% in the CFR would result in 2.7 million deaths, or an increase of 10% in the CAR would result in 2.4 million deaths.

Each 1/10^th of the total US population translates to 30,000 people. Living, breathing, loving, laughing, men, women, and children, not abstract numbers. Something I fear often gets consigned to oblivion as we toss out numbers, levels, categories, and statistics in our presentimental predictions.

There are other variables that drive the severity or mildness of an influenza pandemic, but I will save them for another day.

Finally, while an influenza pandemic based on the officially sanctioned criteria for severe, 30% CAR and 2% CFR would be bad, it could be a great deal worse. At this time no one knows what the next pandemic will be in terms of pathogen, lethality, or numbers likely to be stricken. The range is wide, from barely above "normal" all the way to atrociously catastrophic. We watch, we analyze, we guess; we plan for the worst and hope to have it prove to have been done in vain.

SZ