Tag: incubation period

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

The Latest Measles Outbreak in Kansas

Several things are troubling about the measles outbreak in Kansas.

For one thing, it involved a lot of infants who were too young to be vaccinated. Their parents didn’t get to make a choice about getting vaccinated or getting measles. They got measles.

There are at least 18 cases of measles in current Kansas outbreak.
An ongoing measles outbreak in Kansas is up to 18 cases.

Also, as the case count climbed to 22 before ending, we are only now learning how the outbreak got started.

Greg Lakin, the chief medical officer for the Kansas Department of Health and Environment, said the current outbreak started when an infant who was too young to be vaccinated picked up the virus in Asia. That infant then returned to a Johnson County day care.

What You Need to Know About the JoCo Outbreak

But what does too young to be vaccinated mean?

Remember that if you are traveling out of the country, infants should get their first MMR early, as early as six months of age.

Update on the Measles Outbreak in Kansas

Since the outbreak in a daycare in Johnson County was discovered on March 8, a total of 22 measles cases have been identified, including:

  • 14 Johnson County residents
  • three Linn County residents
  • one Miami County resident not associated with the daycare

The latest cases could have exposed other people to measles at:

  • Cornerstone Presbyterian Church in the Lobby and Sanctuary; 13300 Kenneth Rd., Leawood, KS; April 8 from 10:30 a.m.to 1:30 p.m.
  • Blue Mound Federated Church; General Delivery, Blue Mound, KS; April 1 from 10:00 a.m. to 1:00 p.m.
  • Olathe Health Family Medicine; 302 N.1st St, Mound City, KS; March 26 and 28 from 8:00 AM to 5:30 PM
  • Olathe Health Family Medicine; 1017 E. Market St, La Cygne, KS; March 27 from 8:00 AM to 5:30 PM, March 29 from 8:00 a.m. to 5:30 p.m, March 30 from 8:00 a.m. to 2:30 p.m., and April 2 from 8:00 a.m. to 3:30 p.m.
  • Casey’s General Store; 207 S. 9th St, Mound City, KS; March 26 from 11:30 AM to 2:00 PM, March 28 from 12:00 PM to 2:30 PM, March 30 from 1:00 p.m. to 3:00 p.m., and April 2 from 7:30 a.m. to 9:30 a.m
  • Casey’s General Store; 406 E. Market St, LaCygne, KS;March 27 from 12:00
    PM to 2:30 PM
  • Linn County Judicial Building; 318 Chestnut St., Mound City, KS; March 30 from 1:30 p.m. to 5:00 p.m.
  • Applebee’s; 16110 W. 135thSt., Olathe, KS; March 30 from 5:30 p.m. to 8:30 p.m.
  • Main Street Liquor; 411 E. Main St., Osawatomie, KS; March 30 from 9:30 p.m. to 11:00 p.m.
  • Dollar General; 110 S. 9thSt., Mound City, KS;March 29 from 5:45 p.m. to 8:00 p.m.
  • Auburn Pharmacy; 625 E Main. St, Mound City, KS; on March 13th from 4:15 PM to 6:45 PM
  • Aldi’s; 15290 W. 119th St Olathe, KS 66062; on March 2nd from 3:00 PM to 5:00 PM
  • Payless Discount Foods; 2101 E. Santa Fe St, Olathe, KS; on March 6th from 10:00 AM to 12:30 PM
  • El Potro Mexican Café; 602 N Pearl St, Paola, KS on March 7th from 4:00 PM to 8:00 PM
  • Children’s Mercy Hospital Kansas Emergency Department; 5808 W 110th St, Overland Park, KS on March 8th and March 10th in the morning
  • AMC Dine – In Studio 28; 12075 S. Strang Line Rd, Olathe, KS; March 9th from 3:30 PM to 7:30 PM
  • Budget Coin Laundry; 798 E Main St, Gardner, KS; on March 9th from 8:00 PM – 11:00 PM
  • Olathe YMCA swimming pool and locker room; 21400 W. 153rd St, Olathe, KS; on March 10th from 9:30 AM to 1:00 PM
  • Bath and Body Works at Legends Outlets; 1803 Village W Pkwy, Kansas City, KS; on March 10th from 1:00 PM to 3:00 PM
  • Crazy 8 at Legends Outlets; 1843 Village W Pkwy, Kansas City, KS ; on March 10th after 1:00 PM to 3:00 PM
  • Orange Leaf; 11524 W 135th St Overland Park, KS; on March 10th from 3:00 PM to 6:00 PM
  • Chick-fil-A; 12087 S Blackbob Rd, Olathe, KS on March 24th 8:15 PM till Close
  • Olathe YMCA – ENTIRE FACILITY INCLUDING CHILDCARE AREA; 21400 W. 153rd St, Olathe, KS on March 22nd and 23rd from 8:00 AM to 3:00 PM
  • Walgreens; 7500 Wornall Rd, Kansas City, MO on March 22nd, 6:00 PM to 8:00 PM
  • Chuck E. Cheese’s; 15225 W 134th Pl, Olathe, KS on March 21st, 1:00 PM to 4:00 PM

If you were exposed and aren’t immune to measles (two doses of the MMR vaccine provide good protection), then you should watch for signs and symptoms to develop 10 to 21 days after your last exposure (in quarantine).

With the new exposures, that means that we could expect to see new cases associated with this outbreak any time between now and April 29th (the last exposure and the longest incubation period).

A History of Measles Outbreaks in Kansas

Some folks probably recall that this isn’t the first big measles outbreak in Kansas.

One of the largest measles outbreaks of 2014 was in the Kansas City metropolitan area. That year, at least 28 people developed measles, including a newborn who was only two weeks old.

In addition to the outbreak in Kansas City, there was another large outbreak that year in Sedgwick County – Wichita, Kansas.

And like most measles outbreaks, other states were affected too. Someone from Texas developed measles after getting exposed to measles at a softball tournament in Wichita.

More recently, outbreaks in Kansas have included:

  • a suspected case at William Allen White Elementary School in Lyon County, Kansas which has led to the quarantine of unvaccinated students for 3 weeks (2017)
  • a case in Butler County, Kansas. (2017)
  • a case in Sedgwick County, Kansas, a child too young to be vaccinated who may have been exposed at a church. Three other exposed infants who were too young to be vaccinated and who were considered at risk to get measles in this outbreak received immunoglobulin treatment. (2017)
  • a second case in the Wichita, Kansas area, this time in Sedgwick County, with exposures at a church, dental office, elementary school, and multiple stores over at least 3 days. (2017)

Why are there still so many measles outbreaks in Kansas?

Like in other places with outbreaks, it is likely explained by relatively high levels of non-medical exemptions and clusters of unvaccinated children and adults.

Hopefully this outbreak will be a good reminder that vaccines are necessary and everyone will get their kids caught up and protected.

What to Know About the Measles Outbreak in Kansas

Kansas is in the middle of another large measles outbreak and as usual, it is mostly among those who are unvaccinated, including many too young to be vaccinated.

More on the Measles Outbreak in Kansas

Updated on April 21, 2018

Measles Returns to California

Breaking News – There are now six cases of measles in the San Francisco Bay Area, all unvaccinated, in an ongoing outbreak that has also spread to Nevada.

There are now six cases of measles in the San Francisco Bay Area as the outbreak grows.

Is anyone surprised that a student in California has measles?

Actually, a lot of folks are probably surprised. After all, didn’t lawmakers in California recently pass a law that mandated everyone in school get vaccinated?

Well yeah, but SB277 didn’t apply to all students. Only new students and those transitioning to a new grade span (for example, moving from K-6th to 7th grade) have to meet the new minimum immunization requirements. That means it will take more than a few years until all of the kids already in school whose parents have skipped or delayed any vaccines have gotten caught up or have graduated.

And that means we will still see some of these outbreaks of vaccine preventable diseases.

There is also a little issue with medical exemptions somehow rising being abused after the personal belief exemption was eliminated in the state…

Measles Outbreaks in California

When you think of measles and California, most people probably think of the 2015 Disneyland outbreak, which was linked to:

  • 134 cases in California, including at least 50 cases without a known source
  • 13 cases in Arizona, Nebraska, Utah, Colorado, Washington, and Oregon
  • 1 case in Mexico
  • 159 cases in Canada

The Disneyland outbreak included a lot of intentionally unvaccinated kids and kept unvaccinated kids from school, closed daycare centers, and led to hospitalizations of more than a few people.

“The ongoing measles outbreak linked to the Disneyland Resort in Anaheim, California, shines a glaring spotlight on our nation’s growing antivaccination movement and the prevalence of vaccination-hesitant parents.”

Majumder et al. on Substandard Vaccination Compliance and the 2015 Measles Outbreak

Schools in California were closed for at least two weeks in 1917 because of measles epidemics.

The Disneyland outbreak wasn’t the first big measles outbreak in California in recent years though.

No, I’m not talking about the really big outbreaks from the pre-vaccine era. Or even the outbreaks in the late 1980s, just before we started giving an MMR booster. Believe it or not, 75 people died between 1988 and 1990 with measles – just in California.

More recently, there was the 2008 outbreak in San Diego that was triggered by an unvaccinated 7-year-old boy who had traveled to Switzerland with his family.

He returned with measles and got at least 10 other unvaccinated children sick, including four infants who were too young to be vaccinated and were unknowingly exposed at their pediatrician’s office.

“Almost 100 children (including babies who were too young for the MMR vaccine) were quarantined or hospitalized after they were exposed at the pediatrician’s office, Whole Foods or day care. In all, 11 children caught the measles. As it turns out, the boy who spread measles is a patient of Dr. Bob Sears…”

OC’s Dr. Bob Sears discusses measles outbreak on NPR

One of those infants was hospitalized when his fever spiked to 106 degrees and he wouldn’t eat or drink.

“We spent 3 days in the hospital fearing we might lose our baby boy. He couldn’t drink or eat, so he was on an IV, and for a while he seemed to be wasting away. When he began to be able to drink again we got to take him home. But the doctors told us to expect the disease to continue to run its course, including high fever—which did spike as high as 106 degrees. We spent a week waking at all hours to stay on schedule with fever reducing medications and soothing him with damp wash cloths. Also, as instructed, we watched closely for signs of lethargy or non-responsiveness. If we’d seen that, we’d have gone back to the hospital immediately.”

Megan Campbell on 106 Degrees: A True Story

Measles cases also began rising in 2011, as unvaccinated travelers brought measles back from trips to Europe, Asia, and Africa, where there were large outbreaks.  There were 31 measles cases in California in 2011.

While 31 cases might not seem like much, consider that between 2001 through 2006, there were just 66 cases in California, with only 4 cases in 2005!

Will we ever get to a year with just 4 cases in California again?

It didn’t happen in 2017.

Last year started with a big outbreak in Los Angeles County that grew to include at least 24 cases and a few surrounding counties. There was also a case involving an unvaccinated student at Laguna Beach High in Orange County which led to the quarantine of at least 6 unvaccinated students.

The Latest California Measles Outbreak

What kind of a measles year will we see in 2018 in California?

There is just one case, so far.

Well, it was just one case. There are six cases now… Seven if you count the linked case in Nevada.

Did you eat lunch at the Westgate Center food court on Friday, March 2?
Did you eat lunch at the Westgate Center food court on Friday, March 2?

It started when an unvaccinated student returned from a trip to Europe and developed measles, exposing others between February 28 through March 2 in Santa Clara County at a school in Campbell and at the Westgate Center food court in San Jose.

An infant hospitalized during a measles outbreak in the Philippines in which 110 people died.
The measles rash begins 3-5 days after other measles symptoms, which is why measles is often hard to diagnose.

With an average incubation period of 10 to 12 days, that means exposed people might begin to show symptoms by March 14. Keep in mind that the incubation period can be as long as 21 days though, so be on the watch for measles symptoms until at least March 23 if you could have been exposed.

Since we don’t know when the new cases began to show symptoms, it is hard to know how much longer we can expect to see new cases. Hopefully these folks were already in quarantine and didn’t expose anyone else.

Would you recognize measles?

It is important to understand that the first symptoms of measles don’t include a rash. Instead, you get a high fever, runny nose, cough, and pink eye. The measles rash comes a few days later, as the high fever continues.

It is also important to understand the the MMR vaccine is safe and works very well to prevent measles.

This exposure is a great reminder that vaccines are necessary and that you shouldn’t wait for your kids to get exposed to get them caught up and vaccinated and protected.

What to Know About Measles Outbreaks in California

A recent outbreak of measles in California, this time in Santa Clara County, is a good reminder that the MMR vaccine is necessary to keep your kids protected.

More on Measles Outbreaks in California

Updated April 7, 2018

Mumps at the National Cheerleaders Association All-Star National Championship

The boys and girls at the 2018 National Cheerleaders Association All-Star National Championship in Dallas were hoping to go home with a trophy.

Some got a little more – exposure to mumps.

Mumps at the National Cheerleaders Association All-Star National Championship

If you don’t have a kid in competitive cheer, you should know that the NCA All-Star Nationals is a big deal.

Over 1,300 teams with more than 23,000 cheerleaders were competing. They came from 9 countries and 38 states for a 3 day competition at the Kay Bailey Hutchison Convention Center in downtown Dallas.

The Texas Department of State Health Services has issued a warning that a person with mumps was present at the NCA All-Star Nationals.
The Texas Department of State Health Services has issued a warning that a person with mumps was present at the NCA All-Star Nationals.

They worked hard, but they had fun.

And some of them may have been exposed to mumps.

What to Do If You Were Exposed to Mumps at the NCA All-Star Nationals

So what do you do if you were exposed to mumps in Dallas?

While mumps is a vaccine-preventable disease, even kids who have gotten two MMR shots can still get mumps. That’s because waning immunity causes the vaccine to become less effective over time.

Still, mumps is not nearly as contagious as other vaccine-preventable diseases, such as measles. You generally have to have close contact with someone with mumps to catch it.

“The mumps virus replicates in the upper respiratory tract and spreads through direct contact with respiratory secretions or saliva or through fomites. The risk of spreading the virus increases the longer and the closer the contact a person has with someone who has mumps.”

CDC on Mumps for Healthcare Providers

Unless you were on the same team as the person with mumps (if it was a cheerleader), your risk of getting sick probably isn’t that high. Of course, the risk goes up the more contact you had.

Mumps is not just for kids anymoreUnfortunately, neither a post-exposure dose of MMR nor immune globulin work to prevent mumps after you are already exposed.

At this point, whether or not your child is vaccinated, all you can do is wait and watch to see if they develop signs or symptoms of mumps.

With an incubation period of 12 to 25 days, that means that those who were exposed could get sick between March 7 and March 22.

While there is no treatment for mumps, you do want to watch for complications and make sure you don’t expose anyone else.

And if your child is unvaccinated, this exposure is a good reminder that outbreaks still happen, vaccines are necessary, and this is a good time to get caught up.

Mumps and Cheer

Not surprisingly, this isn’t the first time we are hearing about mumps at a cheer competition.

In 2016, mumps exposures at several cheer competitions in North Texas led to at least 11 cases of mumps.

Why cheer? It’s not cheer, but the nature of cheer competitions. You just have a lot of older kids together at these competitions from a lot of different places and the MMR vaccine is known to have an issue with waning immunity.

Fortunately, most of these kids are vaccinated, which helps keep these outbreaks from really getting out of control, like they did in the pre-vaccine era.

What to Know About Mumps at the NCA All-Star Nationals

Tens of thousands of kids could have been exposed to mumps at a cheerleader competition in Dallas.

More on Mumps at the NCA All-Star Nationals