Tag: epidemiology

What Happens When You Research the Disease?

We know how anti-vaccine folks think.

Anti-vaccine math…

And now we know how they do their research

How Anti-Vaccine Folks Research Disease

If you’re like me, you are probably wondering why they picked 2016 as the year to research.

Why look just at 2016?

And, there you see it.

In the past 6 years, 2016 was the year with the fewest cases of measles. Why not choose 2017 or 2018 to do their research?

But let’s look at 2016, even though the information isn’t complete:

  • 86 cases
  • cases in 19 states, including Alabama, Arizona, California, Colorado, Connecticut, Florida, Georgia, Hawaii, Illinois, Massachusetts, Michigan, Minnesota, New York, North Carolina, Oregon, Tennessee, Texas, and Utah
  • a large outbreak in Arizona (31 cases) linked to a private detention center and all that is known is that 7 of 9 staff members who got measles had received at least one dose of MMR, and 3 had received their dose very recently
  • a large outbreak in Shelby County, Tennessee, at least 7 cases, including 6 unvaccinated and one partially vaccinated child
  • a large measles outbreak (17 cases) in Los Angeles County and Santa Barbara County that was linked to the Los Angeles Orthodox Jewish community
  • two cases in Colorado, including an unvaccinated toddler and an unvaccinated adult – outbreaks which cost at least $68,192 to control

And of th cases in 2016, it seems that just 16% were vaccinated.

What about the claim that 26% were vaccinated?

That wasn’t 26% of the total number of cases, but rather 26% of the cases among US residents.

So if you do the math, that’s just 14 cases that were vaccinated, and out of 86 cases, that’s really just 16%. And a lot of those cases are skewed by the one outbreak at the detention center, in which they may have only received one dose of MMR and nearly half may have gotten vaccinated after the caught had already started!

What about the claim that “the odds of dying from the measles are like 0.00000013%” using numbers “before the vaccine was introduced in 1963?”

“Before a vaccine became available in 1963, measles was a rite of passage among American children. A red rash would spread over their bodies. They would develop a high fever. Severe cases could cause blindness or brain damage, or even death.”

CDC says measles almost eliminated in U.S.

In the pre-vaccine era, your odds of getting measles were very high. Remember, everyone eventually got measles.

And looking at statistics of reported measles cases and reported measles deaths, we know that death occurred in about 1 to 3 in every 1,000 reported cases.

So everyone got measles, but not everyone survived having measles.

Even if you use a more liberal count of 1 death in 10,000 cases, when all kids get measles, that’s a lot of deaths. Remember, about 450 people used to die with measles each year.

What about your odds of dying with measles now?

If you are fully vaccinated, then they are extremely low.

They are pretty low if you are unvaccinated too, in most cases, because you are benefiting from herd immunity and the fact that most folks around you are vaccinated, reducing your risk of being exposed to measles. Still, the risk is much higher than most anti-vaccine folks expect, because they often make the mistake of using the entire population of the United States in their calculations. They should instead just use the folks who are unvaccinated and susceptible, a much smaller number.

Want to increase your risk?

  • travel out of the country
  • hang out in a cluster with other unvaccinated people
  • stay unvaccinated

The odds aren’t in your favor to avoid measles if you are unvaccinated. Eventually, your luck might run out.

Starting to see the mistakes anti-vaccine folks make when they say they have done their research?

“How do they know how many people would have gotten measles and how many of them would have died?!?”

It’s not rocket science.

It’s epidemiology.

“We constructed a state-space model with population and immunisation coverage estimates and reported surveillance data to estimate annual national measles cases, distributed across age classes. We estimated deaths by applying age-specific and country-specific case-fatality ratios to estimated cases in each age-country class.”

Simons et al on Assessment of the 2010 global measles mortality reduction goal: results from a model of surveillance data.

Unfortunately, after years of improvements, measles deaths increased in 2017. And they will continue to increase, as our risk of getting measles continues to increase if folks don’t get vaccinated and protected.

Lastly, why does it “sound like millions of people would have died without the measles vaccine?”

Maybe because millions of people died in previous years, before they were vaccinated and protected.

Indeed, do your research, but you will find that vaccine-preventable diseases aren’t as mild as anti-vaccine folks believe. That’s why it is important to get vaccinated and protected.

More on Researching Vaccine-Preventable Disease

Were More Than Half of the Kids with Severe or Fatal Influenza in California Last Year Vaccinated?

We know that the flu is deadly and that most kids who die with the flu aren’t vaccinated.

Would it be news to anyone if Bob Sears was pushing misinformation about pediatric flu deaths in California?
Would it be news to anyone if Bob Sears was pushing misinformation about pediatric flu deaths in California?

That’s likely why some folks might have been surprised when Dr. Bob Sears said that “half of the patients admitted to ICUs for severe or (eventually) fatal cases of influenza last year were vaccinated.”

He seemed to be citing a news report from the California Department of Public Health.

Were More Than Half of the Kids with Severe or Fatal Influenza in California Last Year Vaccinated?

So what did the report from CDPH actually say?

“Influenza vaccination information was available for 455 (47.8%) of the 952 adult cases reported with severe or fatal influenza; 211 (46.4%) received the 2017–2018 influenza vaccine. One hundred twenty (64.2%) of the 187 reported pediatric cases >6 months of age had influenza vaccination information available; 61 (50.8%) received the 2017–2018 influenza vaccine.”

Influenza Surveillance Report 2017–2018 Season

When you do the math, you quickly see that only 61 of 187 kids, or 33% of the pediatric patients were known to be vaccinated.

The numbers are even lower for adults with severe or fatal flu – only 211 of 952 adults, or 22% were known to be vaccinated.

Melissa Floyd does not seem to understand basic epidemiology.
Melissa Floyd does not seem to understand basic epidemiology.

So the majority of kids and adults were either unvaccinated or their vaccination status was unknown. While an unknown vaccinated status doesn’t mean that they weren’t actually vaccinated, it certainly doesn’t mean that they were.

What about the idea that these vaccinated patients would “eventually” turn into fatal cases, as Dr. Bob posted?

Although there were 18 fatal pediatric flu cases in California during the 2017-18 flu season, and that is more than any of us want to see, it should be clear, with 194 non-fatal ICU cases, that most severe cases weren’t eventually fatal.

Hopefully it isn’t a newsflash to anyone that most kids who die with the flu aren’t vaccinated.

More on Flu Deaths in California

The 2018-19 Flu Season Update

Breaking News: Flu season continues, as influenza activity continues to decrease in the United States, but remains elevated. (see below)

We are nearing the end of flu season - a long flu season.
We are nearing the end of flu season – a long flu season.

While flu season typically peaks in February, it is very important to understand that there are few things that are typical about the flu.

Since 1982, while we have been twice as likely to see a flu activity peak in February than other winter months, we have been just as likely to get that peak in December, January, or March. That makes it important to get your flu vaccine as soon as you can.

You really never know if it is going to be an early, average, or late flu season. That’s why it is best to not try and time your flu vaccine and to just get it as soon as you can.

Flu Season Facts

There will likely be some surprises this flu season – there always are – but there are some things that you can unfortunately count on.

Among these flu facts include that:

  • there have been over 1,660 pediatric flu deaths since the 2003-04 flu season, including 185 flu deaths last year
  • of the average 118 kids that die of the flu each year – most of them unvaccinated
  • antiviral flu medicines, such as Tamiflu, while recommended to treat high-risk people, including kids under 2 to 5 years of age, have very modest benefits at best (they don’t do all that much, are expensive, don’t taste good, and can have side effects, etc.)
  • a flu vaccine is the best way to decrease your child’s chances of getting the flu
  • FluMist, the nasal spray flu vaccine, is once again available for healthy kids who are at least 2-years-old

You can also count on the fact that even in a mild flu season, a lot of kids get sick with the flu.

What about reports that the flu shot won’t be effective?

Don’t believe them. The flu vaccine works and besides, it has many benefits beyond keeping you from getting the flu

This Year’s Flu Season

As of mid-April, the CDC reports that flu “influenza activity continues to decrease in the United States, but remains elevated.”

The CDC has also recently reported that:

  • 11 states, Arizona, California, Connecticut, Delaware, Maine, Massachusetts, New Hampshire, New York, Ohio, Rhode Island and Virginia, are still reporting widespread flu activity
  • 20 states, Alabama, Florida, Georgia, Illinois, Kentucky, Louisiana, Maryland, Michigan, Missouri, Montana, Nevada, New Jersey, New Mexico, North Dakota, Pennsylvania, South Carolina, Tennessee, Utah, Washington and Wisconsin, are still reporting regional flu activity
  • 17 states, Alaska, Arkansas, Colorado, Hawaii, Idaho, Iowa, Kansas, Minnesota, Mississippi, Nebraska, North Carolina, Oklahoma, Oregon, South Dakota, Vermont, West Virginia and Wyoming, are now reporting local flu activity
  • 2 states, Indiana and Texas, are now reporting sporadic flu activity
  • no states are reporting no flu activity yet
  • the proportion of people seeing their health care provider for influenza-like illness (ILI) was down 2.4%, which is still above the national baseline of 2.2%, but far below the 7.5% we saw last year
  • The overall hospitalization rate was 62.3 per 100,000. The highest rate of hospitalization was among adults aged ≥65 (206.5 per 100,000 population), followed by adults aged 50-64 (77.8 per 100,000 population) and children aged 0-4 (71.0 per 100,000 population).
  • there have already been 91 pediatric flu deaths this year, including 5 new deaths this past week

While influenza A(H1N1)pdm09 viruses predominated from October to mid-February, influenza A(H3N2) viruses have been more commonly identified since late February.

Some good news?

The “majority of influenza viruses characterized antigenically and genetically are similar to the cell-grown reference viruses representing the 2018–2019 Northern Hemisphere influenza vaccine viruses..”

And the interim estimates of flu season effectiveness are fairly good, with an overall vaccine effectiveness of 61% in children and teens.

Are you going to get your kids a flu vaccine this year?

“CDC recommends that everyone 6 months and older get a  flu vaccine as soon as possible.”

CDC Influenza Situation Update

Although flu season has started, it is definitely not too late to get a flu vaccine.

For More Information on the 2018-19 Flu Season

Updated February 25, 2019

Save

Save

Save

Save

Save

Save

Save

How Do They Figure out Who Starts an Outbreak?

As we continue to see outbreaks of vaccine-preventable diseases in the post-vaccination era, it is important that these outbreaks be quickly contained.

But it is important to understand that these outbreaks don’t simply stop on there own. A lot of work goes into containing them.

Working to Contain an Outbreak

And that work containing outbreaks is expensive. Much more expensive than simply getting vaccinated.

For example, the total personnel time and total direct cost to the New York City Department of Health and Mental Hygiene responding to and controlling the 2013 outbreak in NYC were calculated to be at least $394,448 and 10,054 personnel hours.

Why it is so expensive is easy to see once you understand all of the work that goes into containing an outbreak. Work that is done by your local health department as soon as a case of measles, or other vaccine-preventable disease, is suspected.

Work that, for a measles outbreak for example, includes:

  • initiating a case and contact investigation
  • quickly confirming that the patient actually has measles, including testing
  • assessing the potential for further spread – identifying contacts who aren’t immune to measles and are at risk for getting measles
  • isolating people with measles and quarantining contacts who aren’t immune to measles for at least 21 days after the start of the measles rash in the last case of measles in the area, including everyone who is intentionally unvaccinated
  • offering postexposure vaccination, a dose of the MMR vaccine within 72 hours of exposure to contacts who are not fully immune so that they can get some protection maybe don’t have to be quarantined
  • having targeted immunization clinics in the affected population, such as a school or church, to get as many people vaccinated as possible, even after 72 hours, so they have can be protected in the future

That’s an awful lot of work.

Work that continues until the outbreak officially ends.

Finding the Source of an Outbreak

Another big part of the work that goes on to contain an outbreak is identifying the source of the outbreak.

Was it someone who had recently been traveling overseas, a visitor from out of the country, or someone that was already part of an another outbreak?

Why is that so important?

If you don’t find the source of the outbreak, then you can’t be sure that you have found all of the people that have been exposed, and the outbreak might go on for an extended period of time.

And no, it is never shedding, a vaccine strain, or a recently vaccinated child that causes these measles outbreaks.

Anatomy of a Measles Outbreak

A closer look at the measles outbreak in San Diego, California in 2008 can help folks understand even better what happens during one of these outbreaks.

A 7-year-old who is unvaccinated because his parents have a personal belief vaccine exemption travels to Switzerland with his family.

A week after returning home from the trip, he gets sick, but returns to school after a few days. He then develops a rash and sees his family physician, followed by his pediatrician, and then makes a trip to the emergency room because he continues to have a high fever and rash (classic measles symptoms).

He is eventually diagnosed with measles, but not before eleven other children are infected with measles. This includes two of his siblings, five children in his school, and four children who were exposed at his pediatrician’s office.

It is not as simple as that though.

During this measles outbreak:

  • Three of the children who became infected were younger than 12 months of age, and were therefore too young to have been vaccinated
  • Eight of the nine children who were at least 12 months old were intentionally unvaccinated because they also had personal belief vaccine exemptions
  • About 70 children were placed under voluntary quarantine for 21 days after their last exposure because they were exposed to one of the measles cases and either didn’t want to be vaccinated or were too young
  • One of the infants with measles traveled to Hawaii, raising fears that the measles outbreak could spread there too

All together, 839 people were exposed to the measles virus.

This family didn't have a choice about their son getting sick - he was too young to be vaccinated when he was exposed to an unvaccinated child with measles.
This family didn’t have a choice about their son getting sick – he was too young to be vaccinated when he was exposed to an unvaccinated child with measles.

At least one of them was a 10-month-old infant who got infected at his well child checkup, was too young to have gotten the MMR vaccine yet, and ended up spending three days in the hospital – time his parents spent “fearing we might lose our baby boy.”

The parents of this 10-month-old weren’t looking for a vaccine exemption and didn’t want their child to catch measles, a life-threatening, vaccine-preventable disease. Instead, they were counting on herd immunity to protect him until their child could be protected with an MMR vaccine. They were one of “those who come into contact with them” that got caught up in a decision of some other parents to not vaccinate their child.

The kids who are at risk and get a vaccine-preventable disease because they are too young to get vaccinated, have an immune system problem that prevents them from getting immunized or their vaccine from working, and the kids who simply didn’t get protected from a vaccine are the hidden costs of these measles outbreaks that we don’t hear about often enough.

What to Know About Finding the Source of an Outbreak

Without all of the hard work that goes into containing outbreaks, the outbreaks of measles, pertussis, mumps, hepatitis A, and other vaccine preventable diseases would be even bigger.

More on Finding the Source of an Outbreak