Tag: measles outbreaks

How Contagious Is Measles?

Did you hear about the folks in New York who got quarantined isolated on the Emirates plane from Dubai?

Turns out that about 10 passengers had the flu or other cold viruses.
Although the worry was likely about MERS, it turns out that about 19 passengers had the flu or other cold viruses.

News like that and folks getting exposed to other infectious diseases, probably has them wondering just how contagious these diseases are. Do you have to be sitting next to someone to get them? In the same row? On the same floor?

Understanding Your Risk of Catching a Disease

Fortunately, most diseases are not terribly contagious.

We worry about some things, like SARS and Ebola, because they are so deadly, not because they are so contagious or infectious.

Wait, contagious or infectious? Aren’t they the same thing?

To confuse matters, some infectious diseases aren’t contagious, like Lyme disease. And some vaccine-preventable diseases are neither infectious nor communicable. Think tetanus. You may have never thought of it that way, but you aren’t going to catch tetanus from another person. Of course, that’s not a good reason to skip getting a tetanus shot!

To understand your risk of getting sick, you want to understand a few terms, including:

  • infectious disease – a disease that can be transferred to a new host
  • communicable – an infectious disease that can be transferred from one host to another
  • non-communicable – a non-infectious disease which can not be transferred from one host to another
  • contagiousness – an infectious disease that is easily transferred from one person to another
  • infectivity – the ability of an infectious agent to cause an infection, measured as the proportion of persons exposed to an infectious agent who become infected. Although this doesn’t sound much different from contagiousness, it is. The Francisella tularensis bacteria is highly infectious, for example, to the point that folks exposed to a culture plate are given antibiotics or put on a fever watch. Few of us get tularemia though, because transmission is through tick bites, hunting or skinning infected rabbits, muskrats, prairie dogs and other rodents, or inhaling dust or aerosols contaminated with F. tularensis bacteria. So if you get exposed, you will probably get sick, but there is a low probability for getting exposed.
  • incubation period – the time it takes to start having symptoms after you are exposed to an infectious disease. A longer incubation period increases the chances that someone will get exposed to a disease and travel home before getting sick. A shorter incubation period, like for influenza, means that a lot of people can get sick in a short amount of time.
  • contagious period- the time during which you can spread the illness to other people and may start before you have any symptoms
  • quarantine – used to separate people who have been exposed to a contagious disease and may become sick, but aren’t sick yet
  • isolation – used to separate people who are already sick with a contagious disease
  • transmission – how the disease spreads, including direct (direct contact or droplet spread) vs indirect transmission (airborne, vehicleborne, or vectorborne)
  • R0 (r nought) – the basic reproductive number or the number of new infections originating from a single infectious person among a total susceptible population
  • Rn – the net reproductive number, which takes into account the number of susceptibles in a community
  • infectious period – how long you are contagious

Got all that?

How Contagious Is Measles?

If not, understanding how easily you can get measles should help you understand all of these terms.

Measles is highly contagious, which is likely why all of the Brady kids got sick.
Measles is highly contagious, which is likely why all of the Brady kids got sick.

Measles is highly contagious, with a very high R0 number of 12 to 18.

That’s because:

  • the measles virus can live for up to two hours on surfaces and in the airspace where an infected person coughed or sneezed
  • infected people are contagious for up to four days before they have a rash and even know that they have measles, so expose lots of people even if they get put in isolation once they get diagnosed
  • infected people continue to be contagious for up to four days after the rash appears, so can continue to expose people if they aren’t put in isolation

So you don’t need to have someone with measles coughing in your face to get sick. If they coughed or sneezed at the grocery store, on the bus, or at your doctor’s office and then you entered the same area within two hours, then you could be exposed to the measles virus and could get sick.

Why don’t we see at least 12 to 18 people in each measles outbreak anymore?

That’s easy. The definition for R0 is for a total susceptible population. Most folks are vaccinated and protected, so even if they are around someone with measles, they typically won’t get sick.

Still, up to 90% of folks who aren’t immune and are exposed to measles will catch it. That includes infants too young to be vaccinated, kids too young to be fully vaccinated, and anyone who has a true medical exemption to getting vaccinated.

The measles has a very high R0 is easier to see when you compare it to those of some other diseases

 

Infection R0
Diphtheria 6-7
Ebola 1.5-2.5
Flu 1.4-4
MERS 2-8
Mumps 4.7
Pertussis 5-17
Polio 2-20
RSV 3
SARS 2-5
Smallpox 5-7
Varicella 8-10

Why such a big range for some diseases?

These are estimates and you are more or less contagious at different stages of each illness.

Fortunately, in most cases you can just get vaccinated and protected and don’t have to worry too much about them.

More on the Contagious Periods of Diseases

What Are the Recommended and Minimum Ages and Intervals Between Doses of Vaccines?

Most parents likely don’t think about the minimum age or minimum intervals between vaccines, as they just get their kids vaccinated according to the routine immunization schedule.

Things don’t always go according to schedule though…

Recommended and Minimum Ages for Vaccines

After their birth dose of the hepatitis B vaccine, your baby’s next vaccines are usually at two months.

Can you get them earlier?

When necessary, many vaccines can be given earlier and faster than the standard schedule.
When necessary, many vaccines can be given earlier and faster than the standard schedule.

Yes. The minimum age for the first dose of rotavirus, DTaP, IPV, Hib, Prevnar, is 6 weeks.

Some other vaccines can be given earlier than their recommended age too, including:

  • the first MMR vaccine, which can be given as early as age 6 months in certain high risk situations, like traveling out of the country or in an outbreak situation, although this dose will have to be repeated once the child is 12 months old
  • the 4th dose of DTaP, which can be given as early as age 12 to 15 months, as long as at least 4 to 6 months have passed since the third dose
  • the 2nd dose of Varivax, which may be given as early as 1 to 3 months after the first dose
  • the Tdap vaccine, which can be given as early as age 7 years, instead of the more typical 11 to 12 years
  • the HPV vaccine, which can be given as early as age 9 years, instead of the more typical 11 to 12 years

Why would you get a vaccine early?

What if you are going to be traveling just before you infant is going to be 2 months old? Or your 9 year old stepped on a rusty nail, and it had been just over 5 years since his last tetanus (DTaP) shot?

Recommended and Minimum Intervals for Vaccines

In addition to earlier ages, you can sometimes get vaccines more quickly, on an accelerated schedule.

For example:

  • the minimum interval between the 1st and 2nd dose of rotavirus, DTaP, IPV, Hib, Prevnar is 4 weeks, instead of the standard 2 months
  • the minimum interval between the 2nd and 3rd dose of rotavirus, DTaP, IPV, Hib, Prevnar is 4 weeks, instead of the standard 2 months
  • the minimum interval between the 1st and 2nd dose of HPV is either 4 weeks (3 dose schedule) or 5 months (2 dose schedule)
  • the minimum interval between the 2nd and 3rd dose of HPV is 12 weeks
  • the minimum interval between the 1st and 3rd dose of HPV is 5 months, instead of the standard 6 months

Why give these vaccines more quickly than usual?

The usual reason is that a child is a little behind and is working to get caught up.

Absolute Minimum Ages for Vaccines

It is important to remember that in some cases, there are some hard and fast rules about minimum ages. That means that if you get these vaccines any earlier, they won’t count and you will likely have to repeat them, including getting :

  • the 3rd dose of hepatitis B before 6 months (24 weeks) or sooner than 8 weeks after 2nd dose and  16 weeks after 1st dose
  • the first dose of MMR, Varivax or hepatitis A before 12 months
  • the 4th dose of Hib before 12 months
  • the 4th dose of Prevnar before 12 months
  • the 4th dose of DTaP before 12 months
  • the 5th dose of DTaP before 4 years
  • the 4th dose of IPV before 4 years

Sticking to the routine schedule helps to avoid vaccine errors, like giving a vaccine too early. In some situations, the 4 day grace period helps if a vaccine is given a little early.

More on Recommended and Minimum Ages and Intervals Between Doses of Vaccines

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

 

Does Having Measles Protect You from Cancer?

Anti-vaccine folks often try to tout the benefits of natural immunity.

So that's why Big Pharma wants you to get measles! So you will get cancer.
So that’s why Big Pharma wants you to get measles! So you will get cancer.

That measles reduces your risk of cancer is probably one that you haven’t heard.

Neither are you likely to have heard of the conspiracy theory that Big Pharma wants you to get vaccinated and protected so that you don’t get measles, just so you are at increased risk of cancer later.

Does Having Measles Protect You from Cancer?

The idea of a viral infection protecting you from cancer doesn’t make much sense, after all, many viral infections actually cause cancer.

That’s why we have vaccines to protect us against hepatitis B and HPV infections! So much for the idea that Big Pharma wants you to get cancer. If they did, then why did they develop vaccines that prevent cancer?

But Brandy Vaughn has evidence for her claim, doesn’t she?

Kind of. She has a study, “Febrile infectious childhood diseases in the history of cancer patients and matched control,” that was published 20 years ago in the journal Medical Hypothesis. A study that consisted of a questionnaire that was sent to cancer patients who were seen by anthroposophic general practitioners in Switzerland.

Anthroposophic general practitioners? Think Rudolf Steiner and Waldorf Schools.

Understand the connection with vaccines now?

That’s right, a “study” done by alternative health providers who are against vaccines found a benefit to getting febrile infectious childhood diseases, many of which are vaccine preventable.

What Are the Benefits and Risks of Measles?

Not surprisingly, few other people talk about any benefits to having a natural measles infection.

Unfortunately, we also don’t hear enough about the complications of these infections either, mostly because they are rather uncommon these days since most folks are vaccinated and protected.

Not uncommon enough though, as we still do have outbreaks.

Measles Benefits Measles Risks
natural immunity death
can miss 7-10 days of school or work encephalitis
SSPE
seizures
pneumonia
7 to 10 days of high fever and irritability
can trigger an outbreak
a few years of immune amnesia

Immune amnesia?

That’s a risk that you might be unfamiliar with, but it is the increasing popular theory that a natural measles infection resets your immune system to that of a newborn, so that you are once again susceptible to many infectious diseases. That’s likely why mortality rates from other diseases besides measles goes down when folks start to get vaccinated against measles.

Measles and Cancer Risks

What about the association of measles and cancer?

Unlike the idea that a natural measles infection might be protective against cancer, there are more than a few studies that actually associate measles with a risk of developing cancer, including:

  • lung cancer
  • Hodgkin’s lymphoma
  • endometrial cancer
  • breast cancer

Are these associations real?

Probably not, after all, why don’t rates of these cancers go way down after measles gets under control or eliminated?

Still, most of us know that measles isn’t a mild disease and don’t need any extra benefits to getting vaccinated and protected.

We know what life was like when measles was a common childhood disease and see what is happening in parts of the world where measles is still much more common than it is in the United States.

And we understand the most dangerous association between measles and cancer that affects the most people – when unvaccinated people get measles and expose children and adults on chemotherapy who are immunosuppressed and can’t be vaccinated.

More on Measles and Cancer

Fake News About Measles Outbreaks?

Many news organizations ran with a story about a multi-state measles outbreak recently.

The CDC tweeted a correction about the multi-state measles outbreak story.
The CDC tweeted a correction about the multi-state measles outbreak story.

They got something wrong though.

There is no ongoing, single, multi-state outbreak of measles this year.

Fake News About Measles Outbreaks?

Is it understandable that some media outlets would have been confused by recent CDC reports?

Not really.

The CDC Measles Cases and Outbreaks page hadn’t been updated since late-July and is still reporting case numbers that are “current as of July 14, 2018,” so there really was no recent CDC report to generate all of this extra attention.

“From January 1 to July 14, 2018, 107 people from 21 states (Arkansas, California, Connecticut, Florida, Illinois, Indiana, Kansas, Louisiana, Maryland, Michigan, Missouri, Nevada, New Jersey, New York, North Carolina, Oklahoma, Oregon, Pennsylvania, Tennessee, Texas, and Washington) and the District of Colombia were reported to have measles.”

CDC on Measles Cases and Outbreaks

Although it has been changed to say “107 individual cases of measles have been confirmed in 21 states,” there was nothing to indicate it was a single outbreak that the CDC was monitoring as many sites reported:

Few sites were immune to using a click-bait title to scare folks about the "outbreak."
Few sites were immune to using a click-bait title to scare folks about the “outbreak.”

Unfortunately, many of these reports are still online.

How did it happen?

It’s likely because you have reports from organizations and websites that seem to want to push out content, but don’t have much of a budget to pay health or medical writers to make sure it is accurate.

2018 Measles Cases and Outbreaks

It’s also unfortunate that some of these sites, in trying to correct the idea of a single, nation-wide outbreak, are now trying to minimize this year’s measles outbreaks.

No, there isn’t one large outbreak that is spreading across the United States, but there are a lot of smaller outbreaks, some of which are still ongoing.

And these outbreaks are not something that should still be expected, as we have had a safe and effective measles vaccine for over 50 years and measles was declared eliminated in the United States in 2000!

There is also something very much different about 2018, that not surprisingly, no one is reporting about.

With over 107 cases, things seem very similar to last year right, when we had about 118 cases?

The thing is, in 2017, there was one large outbreak, in Minnesota, with 79 people.

In 2015, at least 139 of 189 cases were from just three large outbreaks, in California (Disneyland), Illinois, and South Dakota.

See what’s different?

This year seems to have more individual cases in more states, each with the potential to grow into one of those big outbreaks.

Why?

You can blame the rise in measles outbreaks in Europe and other parts of the world. And some folks not getting vaccinated and protected and exposing the rest of us when they get sick.

Putting us at risk even though measles is a life-threatening infection, a safe and effective vaccine has been available for 50 years, and every anti-vaccine myth that scares folks has been refuted a thousand times.

That’s the story.

Who’s telling it?

More on Reporting on Measles Outbreaks

Measles on a Plane, Train, and a Cruise Ship

What to most folks worry about when they go on a cruise?

That’s right. Norovirus…

While it isn’t as common as most folks think, norovirus is still often thought of as the cruise ship disease.

Measles on a Plane, Train, and a Cruise Ship

Not surprisingly, many of the same conditions that put you at risk for getting norovirus, including that it is very contagious and you are in close quarters with a lot of other people on a ship, puts you at risk for getting other diseases.

Even measles?

Especially measles.

In 2014, 136 people got measles after an unvaccinated person developed measles on a cruise ship, including 28 people on the cruise.

More recently, an unvaccinated teenager exposed others to measles on a Norwegian Cruise Lines ship while visiting Alaska. It seems like the same person also exposed folks to measles on a few planes and trains too.

How did they get measles? In Thailand.

This is almost certainly the same person who arrived at Vancouver International Airport from Tokyo on an Air Canada flight (July 30), leaving for Portland on Air Canada Jazz that same day.

While in Portland, they exposed people to measles at multiple locations:

  • Leno Medoyeff Bridal, 710 NW 23rd Ave., Portland, 3:30—5:30 p.m. (July 31)
  • Tom’s Pancake House, 12925 SW Canyon Rd., Beaverton, 7—9:30 a.m. (Aug. 1)
  • Max Red Line, Beaverton Transit Center to Pioneer Square, 12:30—1 p.m. (Aug. 2)
  • Max Red Line, Pioneer Place to Beaverton Transit Center, 5:30—6 p.m. (Aug. 2)
  • Verde Cocina, 5515 SW Canyon Ct., Portland, 2—4:30 p.m. (Aug. 5)

They weren’t done yet though.

You really shouldn't have to worry about measles when you board a plane, train, or cruise ship with your kids.
You really shouldn’t have to worry about measles when you board a plane, train, or cruise ship with your kids.

They then traveled back to Vancouver International Airport on an Alaska Airlines flight (August 6) and boarded a Norwegian Jewel cruise ship to Alaska.

Fortunately, the teen was placed in medical isolation shortly after boarding the ship and may have left the typically 7 day cruise early, as they were transferred to PeaceHealth Ketchikan Medical Center on August 8.

How can you protect yourself?

Get vaccinated. You never know when someone who is unvaccinated is going to expose your family to measles or put them at risk for other vaccine-preventable disease.

More on Measles on a Plane, Train, and a Cruise Ship

When is Shedding Season?

Have you heard of shedding season?

Shedding season is starting?
Shedding season is starting?

I’ll give you a hint, we aren’t talking about cats and dogs…

When is Shedding Season?

So it seems that some folks are really worried about vaccines and shedding.

Precautions against viral shedding? Was he giving out smallpox or oral polio vaccines?
Precautions against viral shedding? Was he giving out smallpox or oral polio vaccines?

While some vaccines do actually shed, it is really only the oral polio vaccine and the smallpox vaccine that we get concerned about with shedding.

And even then, shedding from the oral polio vaccine would only be a concern for someone with an immune system problem. Since the oral polio vaccine contains an attenuated virus, if that attenuated virus shed to someone else, they wouldn’t get polio except in the very rare situation when the virus mutates. Instead, they would get protection against polio. That’s one of the benefits of using the oral polio vaccine!

Still, we don’t use the oral polio vaccine in the United States anymore.

Although the smallpox vaccine can shed, it is from the site of injection, where a scab forms in the days to weeks after getting vaccinated. Covering the site should prevent other people from getting exposed to shed virus and fortunately, this vaccine is only used in very special situations.

And the rotavirus vaccine sheds, but you just have to wash your hands after changing diapers to avoid this attenuated virus. Are you going to get rotavirus if you are exposed to an infant who was recently vaccinated? Infants who get the vaccine don’t get rotavirus, so why would you if you are exposed to them?

And other vaccines?

While some live vaccines might shed in very specific situations, like if they caused a rare vaccine-induced disease, they otherwise don’t shed. That’s why we don’t worry about most folks with immune system problems getting exposed to people who have recently been vaccinated.

Don’t believe me?

Every time there is an outbreak of measles, someone insists that it was caused by a vaccine strain of measles that was shed from someone who was recently vaccinated. How often is that true?

So when is shedding season?

Anti-vaccine folks consider the start of the school year to be shedding season, because that’s when they think kids get caught up on their vaccines. Is that why we see big outbreaks of measles, chicken pox, and rotavirus at the start of the school year?

Oh wait, we don’t…

“Live vaccine virus shedding is a possible source of transmission of vaccine-strain viral infection but how frequently that occurs is unknown. There is no active surveillance of live virus vaccine shedding and most vaccine strain virus infections likely remain unidentified, untested and unreported.”

NVIC on The Emerging Risks of Live Virus & Virus Vectored Vaccines: Vaccine Strain Virus Infection, Shedding & Transmission

Despite the best efforts of anti-vaccine folks to scare parents about shedding, folks should know that this is no shedding season.

Cases of vaccine strain virus infections from shedding are unidentified and unreported because they don’t happen!

This is why some folks believe in shedding season...
This is why some folks believe in shedding season…

Do you need to teach your kids to fist bump instead of shaking hands during shedding season???

Think about it.

If there were a shedding season, then why wouldn’t there be more outbreaks? Because everyone has learned to fist bump and avoid shaking hands in school?

What to Know About Vaccine Shedding and Shedding Season

Shedding season isn’t a real thing.

More on Vaccine Shedding and Shedding Season