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Bird flu facts and fiction

From a biologist, a rant on what works and what doesn’t for H5N1. Below: fiction, then fact, then what to do. I apologize in advance for the hectoring tone, but I’m fed up with the balderdash I keep hearing. Eat tamiflu, and barricade yourself into Fortress Wherever with a gun to keep out the feverish hordes. I mean, honestly.

(Nov 1, update, at end)

Fiction 1: We’re all going to die.
It makes for a good movie script, but this is not the way diseases work. The most lethal disease on record, Marburg hemorrhagic fever, causes death in over 90% of patients in the worst outbreaks. Ebola’s rate hovers around 80%. (Aids, a long-term illness, is in a different category, but even untreated Aids is not 100% fatal. See the research on prostitutes with immunity in Nigeria.) Both Marburg and Ebola are very different from flu. Sars is more closely related, and it had a fatality rate of around 15%.

Obviously, these are all very high fatality rates, and the only good rate is zero. The point I’m trying to make is that exaggerating risk does not help anyone to deal with it.

There is some early data coming out of Indonesia that suggest 100% fatalities. What the number means is that 100% of the people diagnosed as definitely having H5N1 virus have died. These tests are done at hospitals. People don’t normally go to hospital for flu, certainly not in the Global South. The people seen at the hospital are in a very bad way when they’re brought in, and many fatalities are expected in a group in that condition. But in order to know what the chance of surviving the disease is, you’d need to know the total number of people who have the virus. You’d need to know how many carry the virus without symptoms, how many recover, and how many die. We know none of this, so we have no idea what the rate is. It could be 100%, it could be 5%. H5N1 is a very bad strain of flu with pandemic potential. The intelligent thing would be to deal with the real threat (more on that below), and the stupid thing would be to do nothing but stock up on tamiflu. [Update Oct 8, below, on antivirals.]

Fiction 2. Quarantine outbreak areas to contain the disease.
You feel the first twinges of something that could be bird flu. Imagine two different scenarios. In the first, you go to the hospital, get tested, receive free medication, your whole family and all your contacts are tested and also receive any necessary medication. In the second, you go to the hospital, get tested, are quarantined for an unspecified length of time, your family is quarantined and unable to go to work, pay the rent, go to school, or do anything they have to do. The money spent on finding and quarantining you and yours is not available to provide an adequate supply of drugs. It’s a no-brainer that in the second case you’ll rush to the hospital and turn yourself in. Not.

Non-punitive quarantine is an essential public health measure. Punitive quarantine just makes people hide disease symptoms, infecting other people the whole time, until they physically collapse. What’s true on an individual level is also true on a national level in that governments try to cover up problems, citizens try to evade border controls, and the spread of the disease becomes unknowable and can’t even be tracked.

None of this is smart. It satisfies the need to spend money on oneself rather than others, but unfortunately that’s the only thing it accomplishes. In the case of flu, quarantine doesn’t achieve containment of the disease, and it doesn’t stop an ever-widening number of people from getting sick. It does, however, cost lots of money. Spending the same amount of money on an actual solution would be smarter, even if it meant we had to donate to others.

Fact 1. Flu viruses mutate.
Flu viruses mutate a lot. There are uncountable trillions of them, all changing in various ways. Some of those changes make them able to infect bats, or civet cats, or Canada geese, or humans. The way they do this is the same way spaghetti sticks to the wall when you throw it to see how done it is. Most of it slides off, but a few noodles hang on. In the case of viruses, the ones who manage to hang on have a whole new defenceless host to grow in. After a few years, the host learns how to unstick that particular kind of virus, and the hunt is on for yet another new home. The point of all this is that sooner or later, any flu virus will have a mutation that allows it to pass between humans. If one outbreak of lethal human flu is stopped, that’s not the end of the danger. A few months later, there will be another outbreak.

That’s another reason why quarantine, by itself, doesn’t solve the problem. All you’re doing–if it works!– is putting out brush fires, while the viruses keep pouring on fuel just out of reach.

Fact 2. Flu and cold viruses are transmitted mainly by touch. (Some recent work on that reported in the BBC Oxford & Lambkin, 2005, Journal of Infection, August 2005, pages 103-9)

A small amount of cold and flu transmission is by the dreaded droplet infection and inhalation of the virus. The risk is especially high for air travellers because the airlines save money by recirculating air without filtering it well enough, by keeping the air too dry because that’s cheaper, and by keeping its oxygen content too low, likewise because that’s cheaper. Airlines should be kicked, repeatedly, until they do what is necessary for the safety and health of their passengers and flight attendants, especially so since air travel is the best way for the virus to hop continents.

For the rest of us, however, the most effective flu prevention is washing hands or using alcohol wipes after touching doorknobs, phones, toilet handles, and anything else touched by many different people. Basically, you should be cleaning your hands about six times a day. The next most important thing is cleaning and disinfecting surfaces that are touched often (counters, phones, desks, etc.). The virus is activated when virus-laden fingers touch our mouths, nose or eyes. It is truly amazing how difficult it is not to touch one’s face, and how unconscious and automatic the process is. One of the interesting effects of wearing rubber gloves is that you find out how often you touch your face.

Most face masks are useless for stopping viruses. Viruses are *tiny*. They’re just big molecules, after all. Any face mask that is easy to breathe through has a pore size that looks like chicken wire to a virus. However, what face masks can do, and do very effectively, is stop you from touching your nose or mouth.

Fact 3. The public health system in the US has become inadequate to deal with a flu pandemic.
Any system will be stressed by a big outbreak of flu, but ours has fallen down on three important counts. The first is vaccine production. Production has been allowed to concentrate in very few plants. Problems at even one plant, as in the 2004 flu season, then cause nationwide problems. The second issue is vaccine distribution. This is part of the great nationwide infrastructure decay that makes it difficult to provide any emergency supplies to where they’re needed. We’ve had all the proof we need of how bad the situation is during the 2005 hurricane season. Vaccine distribution is bad, too. The 2004 season proved that.

The third issue is tailoring vaccines to current outbreaks. The approved method involves sterile incubation of virus in chicken eggs and takes months. A flu season gears up around November and extends into spring. About nine months earlier, scientists have to *guess* what the next epidemic strain will be, and then start the months-long process of designing a vaccine for it. It then takes a couple of months, at best, to distribute it. For decades, there was no alternative.

Now, DNA-based methods could make a tailored vaccine in *weeks*. There are valid reasons to make sure the method is safe enough to apply to millions of people, so it should have been pushed through testing at the earliest opportunity and the fastest speed. It hasn’t been. It’s still sitting on the shelf. If it wasn’t, we wouldn’t have to guess about the right vaccine to use for the current flu season. And if a new strain showed up suddenly, we could deal with it right then and there. As for distribution, I’d bet UPS could give the government a hint or two that would get that time down to weeks as well.

Take home message: Vaccines are the best personal preventive measure. Get shots if you can. Assume government response to a pandemic will be reasonably useless.

Some links for more information:
Dr. Charles paints a plausible doomsday scenario if we do everything wrong.

Centers for Disease Control “what’s new” page with links to other CDC info on transmission, vaccines, and prevention.

The 2005-2006 flu season US vaccine contains two A series elements (related to H5N1): A/New Caledonia/20/99-like (H1N1) and A/California/7/2004-like (H3N2). The third element is from B, the other major group, B/Shanghai/361/2002-like viruses.
Update Oct 11: Dr. Chris Grant, writing in comments on the excellent BBC article on bird flu: “H5N1 is a description of two tiny virus peptides (H = hyaluronidase type 5 and N = Neuraminidase type 1). (Fun factoid: Hyaluronidase is the same stuff on the surface of sperm to help them make a way into the egg.)

World Health Organization, data on confirmed cases and transmission.

Wikipedia, facts and figures about avian flu and its history.

Things to do:

  • Get your and your family’s flu shots, even if you have to pay for it yourself out of the milk money, and even if it’s not for bird flu. Different strains of flu are related, though not identical. Immunization against one strain may help reduce the effect of another strain, even if it doesn’t eliminate it.

    If and when H5N1 vaccine is needed and is available, get that if you can without depriving more needy people. These are, in more-or-less order, frontline public health workers (nurses, ambulance drivers, and the like); school-age and day care-age children (the main vectors); the elderly, infants, and the immune-suppressed; people who deal with the public a lot (teachers, hairdressers, police, funeral workers, and so on), and, finally, the rest of us.

  • Wash your hands a lot during flu season, clean surfaces, and don’t touch your face.
  • Vote for people who care enough about public health to fund it intelligently.
  • Help the source areas for flu implement vaccination, treatment, information for the population, and other useful public health measures.
  • Get a bottle of tamiflu if you want, by all means, but don’t go crazy.
  • Stop whingeing. (Definition for non-Aussies: whine + cringe + complain + do nothing useful)

[Update, Oct. 8.] More on tamiflu, and flu antivirals. They are not useless, but:

Tamiflu (oseltamivir phosphate) reduces the severity of flu and/or shortens its duration IF treatment is started within hours of the first symptoms. It does not work against colds. When self-medicating without positive diagnosis, you need to differentiate between cold and flu symptoms within the first 4-12 hours of onset. Tamiflu can have side effects, the main ones being nausea, vomiting, stomach pain, diarrhea, bronchitis, or dizziness. Relenza (zanamavir), the other major antiviral, is likewise strong medicine.

Flu viruses are growing resistant to antivirals: “…in a special online edition of The Lancet, scientists at the Centers for Disease Control and Prevention reported that 12% of influenza A strains worldwide have developed resistance to the most widely used flu medications.” Bird flu (H5N1) has already shown some resistance to tamiflu. Whether the strain that mutates into human-to-human transmission will be susceptible or resistant can’t be known until the strain actually evolves. Resistance is arising the same way antibiotic resistance did. Amantadine and rimantadine are apparently ineffective against H5N1, and many other flu viruses, some say because the drugs are widely used to medicate poultry in China. Tamiflu is widely prescribed in Japan for any flu-like illness.

Stockpiling and self-medicating with tamiflu will likely exacerbate viral resistance. Anybody who doesn’t take the full course will help the evolution of resistant viruses. There are always plenty of people who “save some for next time.” So, by trying to take care of number one, instead of everyone, we’ll end up breeding resistant disease, potentially in a matter of weeks, and we’ll all be defenseless.

When is it sensible to take an antiviral? When it is part of the public health measures to contain an outbreak, (or, on an individual level, when you or someone you live with has a diagnosed case of flu). This is the main reason why there aren’t enough doses of antivirals for everyone. We don’t need enough for everyone. We need enough to blanket regions with outbreaks, and we need those viruses not to be already resistant to the only drugs available because people have been using them wrongly. Outbreak regions involve a few million people at most. This is not to say our current public health system has enough doses even for that, but the shortfall is nowhere near as stark as the scaremongering about, “There’s only two million doses for three hundred million Americans!”

Update, Oct 11. My earlier information was too sanguine. The WHO recommends enough antivirals to cover 25% of the population. In the US, that’s closer to 80 million than a few million. So we have a BIG shortfall. As I said, expect the government response to be pretty useless. The shortfall doesn’t change all the other points made about incorrect usage, viral resistance, and promoting the spread of the virus, potentially to yourself.

Containing outbreaks is better for everyone than stockpiling drugs uselessly, depleting supplies until outbreaks are uncontainable, or, worst of all, breeding resistant strains. Getting yours while you can could be worse-than-useless by making it MORE difficult to contain an outbreak, an outbreak just as capable of infecting you as anyone else.

This is one of those difficult situations where, if we’re all sensible and unselfish, there won’t be a problem, but if we try to take care of ourselves, we’ll end up hurting ourselves. A minute’s thought shows how stupid selfishness is in this case, but it feels so right, people will invariably do it unless there is strong leadership to the contrary. I think part of the reason there is so much pressure for self-centered (and useless) actions is the assumption of an adversarial, or at least uncaring, relationship between people and government. The sad thing is that unless the government is doing its job, there is no way for an individual to solve the problem. It would be like trying to have a mass transit system all by yourself.

[Update: Nov. 1 2005]
File this under “OMIGOD, I can’t bel-eeeeve it!” I wonder what the CDC threatened them with to make them listen? Or is the Shrub’s popularity so low, somebody in the Administration decided they can’t be complete screw-ups about absolutely everything? Somebody’s even figured out that cell culture-based vaccine-making methods are Important. I am shocked. Shocked!

From the BBC:

“Bush unveils bird flu action plan

“…At the heart of the plan is a request for $2.8bn to accelerate development of vaccines using cell-culture technology. …

“The strategy entails:

  • $1.2bn for the government to buy enough doses of the vaccine against the current strain of bird flu to protect 20 million Americans
  • $1bn to stockpile more anti-viral drugs that lessen the severity of the flu symptoms
  • $2.8bn to speed the development of vaccines as new strains emerge, a process that now takes months
  • $583m for states and local governments to prepare emergency plans to respond to an outbreak

“To equip Americans with accurate information on how to protect themselves and their families, the government is launching a website:”

Technorati tags: bird flu, avian flu, H5N1, pandemic, epidemic, public health