I mentioned last week that Iowa’s suffering from a large outbreak of mumps. An update, from the March 30th Morbidity and Mortality Weekly Report:

In the United States, since 2001, an average of 265 mumps cases (range: 231–293 cases) have been reported each year,* and in Iowa, an average of five cases have been reported annually since 1996. However, in 2006, by March 28, a total of 219 mumps cases had been reported in Iowa, and an additional 14 persons with clinically compatible symptoms were being investigated in three neighboring states (11 in Illinois, two in Nebraska, and one in Minnesota) in what has become the largest epidemic of mumps in the United States since 1988.

Note that it’s spread into all many of our neighboring states. More below…

Of the 219 cases reported in Iowa, the median patient age was 21 years (range: 3–85 years), with 48% of patients aged 17–25 years; 30% (34 of 114) were known to be college students. Of the 133 patients with investigated vaccine history, 87 (65%) had documentation of receiving 2 doses, 19 (14%) 1 dose, and eight (6%) no doses; vaccine status could not be documented in 19 (14%) patients. Among the 114 patients for whom symptomatic information was available, the most common symptoms were parotitis in 94 (83%) patients, submaxillary/sublingual gland swelling in 46 (40%), fever in 41 (36%), and sore throat in 36 (32%); average duration of illness was 5.1 days. Six (5%) patients reported complications (e.g., orchitis); one suspected case of encephalitis is being investigated. As of March 28, 2006, investigators had determined that only 36 (16%) of the 219 cases were linked epidemiologically (i.e., a source of infection was identified), suggesting frequent unapparent transmission.

The source of the Iowa epidemic is unknown; however, the United Kingdom (UK) experienced a recent mumps epidemic that peaked during 2005 with approximately 56,000 cases and a high attack rate among young adults. The mumps strain in the UK epidemic also was identified as genotype G, and the UK epidemic has been linked to a 2005 mumps outbreak in the United States.

The report of the previous introduction of mumps from the UK can be found here, where a counselor at a summer camp apparently brought the virus back from the UK. It’s not known yet whether something like this actually happened with the current outbreak or not, but a more thorough molecular analysis of the strains collected here in Iowa and during the 2005 UK outbreak could show how closely related they are.

Comments

  1. #1 Scott Kirwin
    April 4, 2006

    So what’s the deal?
    Bad MMR vaccine or none?

  2. #2 Tara C. Smith
    April 4, 2006

    Probably a combination. Clearly there’s at least some of those affected who’ve not received the vaccine; others have received less than the recommended doses. As I mentioned in the previous post, I’m not sure how similar the vaccine mumps strain is to the serotype G one that’s circulating here; it’s possible there’s not enough cross-reaction to provide high levels of protection.

  3. #3 Paul Orwin
    April 4, 2006

    I know there has been a movement to refuse MMR (especially in GB) because of autism related fears. Is it possible that the unvaccinated population has risen to a high enough level to sustain viral transmission? Do you know what the vaccine status of the overall population is? And whether Iowa is special for any reason?

    Also, the population seems to be college age. Might that have to do with the presumable decline in protection over time of the vaccine (so that a person with only a partial vaccination as a child becomes vulnerable.

    Finally, what’s the patient spectrum for mumps. I know its a “childhood” disease, but is that because the virus can’t infect adults (seems unlikely, given the patients in this outbreak)? If not, is there a risk for fully vaccinated adults that a sustained outbreak could include them as well (that would suck!) Yes, I am avoiding work, why do you ask?

  4. #4 Lancelot Gobbo
    April 4, 2006

    I believe I’m right in saying vaccines work by two mechanisms: acquired immunity for the vaccinated individual, and reduced chance of meeting the pathogen because of others having had the vaccine. I suspect this is why we see so much vaccine-modified pertussis these days, but did not a few years back – the kids who get the vaccine are being exposed to pertussis by those who haven’t either had the vaccine, or not had enough doses. Consequently we see mild cases of whooping cough where once it was a forgotten disease like diphtheria (OK, just waiting in the sidelines for its chance). Could it be that the MMR acceptance rates are low enough to allow this? In my last year practising medicine in the UK (1985) I saw lots of measles because the uptake of the single measles-only vaccine at that time was only about 60% in London. At that time, parents were shunning it as it was supposed to be linked to autism, which made me laugh when I heard of British parents more recently blaming MMR and asking for the measles-only vaccine!
    For myself, I had mumps long before the vaccine, and enjoyed mumps pancreatitis as a result. So glad it wasn’t orchitis!

  5. #5 Algerine
    April 4, 2006

    I think the increase in pertussis is also due to the fact that clinicians are more aware it’s endemic and that there’s a good chance that any cough lasting 2+ weeks is pertussis. That whole “childhood disease” label really screws things up.

    It’ll be fun to see how the new adult Tdap vaccine will impact rates.

  6. #6 Matt McIrvin
    April 4, 2006

    The thing that burns me is that I know the anti-vaccine people are going to spin this their way: see, the MMR vaccine doesn’t protect you anyway! And they’re probably contributing to the problem.

  7. #7 Steve
    April 5, 2006

    Hi Matt,

    Youre spot on. Being an Engineer myself and someone who has access to and researches the scientific world a lot, I am adamantly anti-vaccine.

    First let me say I admire scientists for their effort in wanting to protect people from disease – 10/10.

    But as you realise ( including the CDC who have published a paper illustrating the DTaP is also responsible for spreading Pertussis in the community…oh joy…. ) that eventually people wake up to the fact that (1) They dont work (2) they cause documented damage and (3) they kill. I’d suggest going to http://www.jabs.org.uk to see why many GB parents shun the MMR ( rightly ) as a danger to their children. Wakefield got it right and was “shut down”. My own efforts to obtain vaccine status of cases was like pulling teeth and treat you like a leper when you question the vaccine “religion”. In the end the pro-vaccine camp shot themselves in the foot as far as I was concerned by deliberately obsfucating and avoiding questions and treating educated people as morons.

    In a closing comment – I obtained stats in Australia from the NSW and Victorian Depts of Health re: rates of disaease and vaccination status.
    Simply put ( and I can post these if anyone is interested ) that in 2003 85% of children 5-9 who contrcated pertussis were vaccinated.

    Sorry dudes, vaccination is a joke.

    Cheers,

    Steve.

  8. #8 Tara
    April 5, 2006

    including the CDC who have published a paper illustrating the DTaP is also responsible for spreading Pertussis in the community…oh joy….

    Hi Steve–can I get a link for that claim?

    You do realize the Wakefield study has been rejected by even most of his co-authors?

  9. #9 Algerine
    April 5, 2006

    Post the relevant cites for the 85% number too. What was the percent of immunized pertussis cases to the total immunized immunized population and the percent of unimmunized pertussis cases to the total unimmunized immunized population?

  10. #10 Tara
    April 5, 2006

    Re: Paul’s questions…

    Is it possible that the unvaccinated population has risen to a high enough level to sustain viral transmission? Do you know what the vaccine status of the overall population is? And whether Iowa is special for any reason?

    Vaccination coverage is still pretty high here–probably above 90%, although it’s tough to get completely accurate numbers. I doubt Iowa is special–we were probably just unlucky enough to have someone import the virus and spread it to enough people to begin an epidemic.

    Also, the population seems to be college age. Might that have to do with the presumable decline in protection over time of the vaccine (so that a person with only a partial vaccination as a child becomes vulnerable).

    That’s one thing they’re looking into. The MMR vaccine is good and immunity remains pretty high for decades, but again, especially if the mumps virus circulating is more distantly related to the vaccine strain than typical viruses in the US, it could be a problem. Newer reports I’ve read suggest the strain is fairly common and should be covered, though.

    Finally, what’s the patient spectrum for mumps. I know its a “childhood” disease, but is that because the virus can’t infect adults (seems unlikely, given the patients in this outbreak)? If not, is there a risk for fully vaccinated adults that a sustained outbreak could include them as well (that would suck!)

    Adults have definitely been affected. If you look at the MMWR article, while most cases have been in the late teens-early 20s, cases span the age range.

  11. #11 snoey
    April 5, 2006

    >Being an Engineer myself

    Is it time to expand the scope of the Salem hypothesis?

  12. #12 steve
    April 5, 2006

    Howdy all,

    OK, figures for the 85% were for whole of state of NSW in Australia in 2003. I wasnt given individual city break down and just getting these figures was something of a coup. 85% were immunised ( by NSW Dept of Health standards ) and 15 not immunised ( no shots).

    CDC comment on DTaP being a silent spreader:
    http://www.cdc.gov/ncidod/eid/vol6no5/pdf/srugo.pdf

    Yes, a lot of people backed away from Wakefield. Reading between the lines its highly probable they could see their research funding drying up….so natural reaction ( especially after their wives had a word…)would be backing away. Science puruses grants to stay afloat so I’m not surprised they were worried about their mortgages. All Wakefield did was stick his head over the top of the parapet and got it shot off.

    I should back up this claim with a few other comments and an experiment for all of you to try before ytou have a pop at my reasoning here – next time someone you know or your child is due a vaccine – refuse it. Then observe the medical peoples’ reaction. Record it. Then on the next occasion when the next jab is due ( assuming the local health nurse hasnt hassled you by this stage ) refuse it again. Record the medical peoples response again. Get many people to do this ( say 10 ). Compare notes. What you will observe is what others have called the “medical mafia” in operation.
    Likely Result – You will likely find thinly veiled harassment and intimidation. This is a fact of life for those who think outside the square – questioning “popular science” is not tolerated.

    The other thing you have to remember is when you start from an anti-vaccination stance, digging out info on vaccine failure and REAL vaccine stats is damn hard. Even being incredibly polite and dilligent and determined, its VERY hard to get people to admit vaccines fail, and regularly.

    Salem hypothesis? – I had no idea this is a religious debate…….specifically as it relates to Creation…not vaccination. Are you making a wild leap assuming “no vaccine = religious connection”?

    Interstingly, a study found that most who refused vaccination had a disproportionate level of health professionals and were highly educated and wealthy. Contrastingly, those who more likely to vaccinate where poor and poorly educated. I’ll dig it out at some stage….

    Cheers,

    Steve.

  13. #13 Tara
    April 6, 2006

    Steve,

    CDC comment on DTaP being a silent spreader:
    http://www.cdc.gov/ncidod/eid/vol6no5/pdf/srugo.pdf

    and your original claim that “including the CDC who have published a paper illustrating the DTaP is also responsible for spreading Pertussis in the community…oh joy….”

    Please note that the paper you linked in no way supports your contention that the vaccine is “responsible for spreading pertussis in the community.” It merely suggests that vaccinated individuals may remain asymptomatic carriers–which they likely would have been anyway, plus had the additional risk of developing whooping cough. This is nothing new–and it’s a reason why boosters have been recommended for older children and adults.

    Even being incredibly polite and dilligent and determined, its VERY hard to get people to admit vaccines fail, and regularly.

    Too funny–I just received this notice in my email box via ProMed:

    Follow-up reports have been completed on 154 cases. Of those, 68 percent occurred in people who had received the recommended 2 doses of the measles-mumps-rubella (MMR) vaccine. Iowa, according to Harris, is a state with a high vaccination rate, and she anticipates the majority of mumps infections will occur in people who are considered safe on the basis of their immunization records. “But we know the vaccine doesn’t work in everyone,” she said. Harris said published data suggest that the vaccine failure rate for mumps is about 5 percent. “So by my estimate, there are about 200 000 people in Iowa who have received the recommended vaccinations but who have no immunity to mumps.”

    (Emphasis mine). We acknowledge this all the time. Even when kids get vaccines, they get papers noting the effectiveness of the vaccine they’ve been given. Even if it’s 95% effective as the MMR is, you can see that the 5% adds up quickly in a highly-vaccinated population.

    Interstingly, a study found that most who refused vaccination had a disproportionate level of health professionals and were highly educated and wealthy. Contrastingly, those who more likely to vaccinate where poor and poorly educated.

    That’s not surprising. Many of them will have heard of Wakefield’s research but not followed up on it and realized it was garbage. It’s generally a case of “a little bit of information is dangerous.”

  14. #14 Algerine
    April 6, 2006

    Dang, Tara beat me to the article comment.

    It’s no secret at all that vaccines aren’t 100% effective. I’m right now writing up a little report on a varicella outbreak we’re having. A third of the cases were vaccinated against varicella. When that stat came up, was I thinking “National Immunization Conference, here I come!?” Nope. I just kinda went, “hmmm, interesting,” and moved on to the next stat.

    Oh, the vaccinated kids were 25 times more likely to have milder symptoms than unvaccinated kids, if anyone’s wondering.

    As for your little experiment, is that really surprising? Replace ‘refusing to vaccination’ to ‘refusing to use a car seat’ and you’d get the same amount of harrassment. Why? Because public health officials believe vaccinations (and car seats) are very effective at keeping kids from dying. Why? Because there’s several boatloads of evidence saying they will. Believe me, we ain’t doing it to get rich.

    On another note, how do y’all do that quotey thing?

  15. #15 Tara C. Smith
    April 6, 2006

    Hi Algerine–

    To do the “quotey thing,” use the tags [blockquote] and [/blockquote], only change the brackets to the triangle ones (sorry, I can’t get them to show up alone!) So if I were to quote you, it’d be like:

    [blockquote]Oh, the vaccinated kids were 25 times more likely to have milder symptoms than unvaccinated kids, if anyone’s wondering.[/blockquote]

    and fixing the brackets gives you:

    Oh, the vaccinated kids were 25 times more likely to have milder symptoms than unvaccinated kids, if anyone’s wondering.

  16. #16 Algerine
    April 6, 2006

    Aaaaaah. It’s [blockquote]. I was using just [quote].

    Muchas gracias!

  17. #17 Paul, ARNP
    May 2, 2006

    I’m an ARNP who has had the MMR vaccine twice, administered once in 1979 and again in 1984. I’m 29 years old and live in Kansas, and yes, I have recently recovered from mumps. My symptoms in chronological order included mild fever for one day at 99.8 degrees Fahrenheit, parotitis, swollen mandibular lymph glands, sore throat. Most symptoms retreated within 14 days after the onset of swelling of the parotids on the left side. However, an opportunistic S. pneumonidae infection immediately followed the mumps infection, causing mild inflammation of the tonsils and acute bronchitis, lasting about 10 days. Azithromycin 3-pak was ineffective, thereby extending the duration of the symptoms, but Augmentin 875/125 (Amoxicillin/K Clavulanate) was effective in treating the bacterial infection that followed the mumps symptoms.

    All students enrolled at the University of Kansas, where I am not a student, but do work in the health center, are required to have received the MMR vaccine twice or must demonstrate immunity via blood test (Titer). Nonetheless, we have had 74 reported cases among students with none linked to the Iowa outbreak. However, we expect in reality that 200 or more students have been infected and have no visible symptoms. The outbreak does appear to have peaked in about the third week in April of this year.

    Keep on vaccinating! A third MMR vaccination is a very good idea at this point, and we are recommending it to all students in the residence halls, but more useful than that would be research into Genotype G to determine the duration of vaccine effectiveness, especially since we are noticing this trend in people who have not had the vaccine in over a decade. Children are not getting sick. We’ve had too many cases in the past three years in heavily vaccinated populations to discount the possibility that the MMR vaccine is failing to protect the general adult population from mumps for extended time periods.

  18. #18 muhabbet
    March 26, 2009

    thanks..