Over the last eighteen months or so, you’ve probably learned more about public health policy and practice than you ever thought about wanting to know. Of course, you’ve learned most of it from the media which is only slightly less competent than Wikipedia for technical information. To be fair, there are separate law books just for public health – I’ve seen them and even used them – so it’s not exactly simple stuff.
My expertise is in sexually transmitted disease but the key differences are mainly vector (how the disease organism gets to where it needs to be to cause infection) and then the particulars of the disease morphology. Sounds complicated but it just means the way a disease transmits and how a particular disease behaves are all that really change from STD to other infectious diseases.
That doesn’t make me an expert in C19 – but those literally do not exist yet. Too little is fully understood to use the term ‘expert’ for C19. There are plenty of experts working on C19 and they know quite a bit – but it’s like the difference between knowing the definition of gravity and actually understanding the force of gravity. That’s not a dig – it’s the nature of novel diseases. You know a lot about diseases but nothing about this one – at the beginning of the outbreak.
What I bring to the table is nearly two decades of field experience in disease control. I know what good public health is supposed to be – and what it is not.
Let’s cut to the chase – you probably don’t care about the niceties of contact tracing or the exact morphology of C19. But the framework is important to understand so you have a much better idea how reliable what you are being told is likely to be. What I’m going to discuss is how public health attempts to control disease with the tools it has available.
Disease control:
Very simply, the role of public health in disease control is two prong: breaking transmission and eliminating vectors. Eliminating vectors is what the Environmentalists do – they supervise septic systems, insect (mosquito) control measures and similar measures to keep the transmission of disease from beginning. This is not an option with C19.
The other prong is the workhorse of public health – breaking the line of transmission. There are four main interventions (stuff we do to stop disease transmission – Nature has a couple of her own but they don’t apply to policy – that’s because self resolution is either a bad policy or a disease that doesn’t need a policy):
- Treatment
- Quarantine
- Vaccination
- Education (prevention)
Treatment: For the majority of cases, this is the gold standard public health intervention once there is an outbreak. Treatment will almost always break the line of transmission within a much shorter time frame than vaccination. That’s simply because it takes less time to help the body kill off the pathogen than it does to help the body build up antibodies to fight off infection. So if we treat an infected person, they quickly stop being infectious where if we vaccinate a healthy person it will often take two or more weeks before they are actually immune to infection – and yes, they can get infected in the meantime.
Quarantine: This is only effective with confirmed cases and usually forceful enforcement. Isolating the sick until they are no longer infectious does slow transmission – to a point. But sick people need caretakers and those folks can themselves become infected. Even with strict precautions, caregivers can spread infection. The only way to ensure that doesn’t happen involves doing things that are MUCH WORSE than any disease. Quarantine is never used as a standalone measure – it does have a place in containing highly infectious disease but only in conjunction with treatment and education. And even then, moral, ethical and legal constraints are necessary to limit the destructive force of quarantine. It’s used most commonly in hospitals and rarely in public health.
Vaccination: This is used to prevent transmission by making the healthy immune to the disease. It has a couple drawbacks – first being that it takes time to work in the body to make someone actually immune. The second is that not everyone can take a vaccination. Most of the known contraindications (indicators that you shouldn’t be receiving a medication or vaccine) usually only affect a small number of people. But there are other problems getting people to take what is NOT a medically necessary* shot – political, mental health and legal. Basically, it can be complex to convince the public that they need to be vaccinated. On the bright side, with most vaccines, this isn’t a real issue – once the majority of people are immune, the odds of transmission to new people fall to negligible levels. Vaccination is most effective to prevent outbreaks but it can also slow outbreaks.
Education: This one is the ugly stepchild. It’s what we used originally against HIV since none of the other three options existed. Does it work? Depends on the program. Uganda’s ABC program had a double digit reduction in transmission (21% if memory serves) where no developed nation even broke 10%. How well it works depends on what you teach. So did it work at all in the US? Yes, it did – but what really slowed the spread of HIV was effective treatment. Although there is no cure, treatment reduces how infectious a person with HIV becomes – if they aren’t very infectious, they don’t spread the virus. Education is the public health equivalent of telling you kids how to do something you want them to do that they don’t want to do – and gets about the same results.
I have listed these in terms of intervention effectiveness – not prevention effectiveness. Vaccination is the gold standard for prevention effectiveness – there is no outbreak if most people are immune. That doesn’t mean there is no disease – we get measles and mumps cases every year even when people are vaccinating their kids. Life isn’t mathematical – stuff goes wrong even with the best vaccines both on the manufacturing end and the patient’s body. Those are statistically very rare events – but they do happen. However, if we want to stop an outbreak from ever happening, we use vaccination because it works and works well.
It took years to eradicate small pox. Breaking the cycles of polio, measles, mumps, rubella, and a number of others took years of vaccination programs. THEY WORKED. Don’t get this wrong – vaccination most certainly is effective. But as a public health intervention, it’s very, very slow compared to treatment.
That doesn’t make treatment a panacea. Not everyone can take the medication – and those patients may require quarantine for a short time if the danger is significant enough. Treatment is usually easier to get people to agree to – but not always. Some people really don’t want to be treated – some are wary of any government involved intervention – yes, these are the same problems with vaccination.
And yes, there’s an elephant in the room – none of these interventions are going to be available 100% of the time. There may be no treatment – or no treatment that doesn’t involve hospitalization. Indeterminate quarantine is a civil rights abuse and frankly, silly – so quarantine doesn’t work if the disease won’t resolve (either go away of be cured) AND doesn’t kill 100% of the time (quarantine is not a nice topic, really it’s not). Vaccines take time to create and only certain diseases cause immunity – without that, no vaccine works. Education depends not only on what you teach but how much people trust you – and even then, if you’re asking them to do something really difficult, it probably won’t work for long if at all.
Intervention methods are just tools – and used correctly, they do work and can do great things. Used incorrectly – well, just imagine trying to hammer a small nail with a running table saw. Doesn’t work and can do far more damage than good.
*Medically necessary means it is of direct benefit to the patient. Vaccines are indirect. That doesn’t mean they aren’t beneficial but to be medically necessary an intervention has to directly affect that person’s health to their good. Make them better – direct; Keep them from getting sick – indirect.
