Iowa Mumps Outbreak: Two Articles

[Guest guest]

I am wondering how the statistic that the MMR shot is considered 95% effective obtained any validity? Since it is not possible to know how many people were exposed to this mumps strain, no one can know how effective it has been in Iowa.

Joy

http://www.medpagetoday.com/InfectiousDisease/PublicHealth/tb/2979

Iowa Mumps Outbreak Spreads Quickly to Other States

By Peggy Peck, Managing Editor, MedPage Today Reviewed by Zalman S. Agus, MD; Emeritus Professor at the University of Pennsylvania School of Medicine. April 03, 2006

MedPage Today Action Points

Explain to patients who ask that difficulty swallowing caused by parotitis may be caused by mumps, but laboratory tests are needed to confirm the diagnosis.

Explain to patients who ask that current recommendations are for the first dose of mumps/measles/rubella vaccine at 12 to 15 months with a second dose at ages four to six years.

Review

DES MOINES, Iowa, April 3 - The mumps outbreak that started in Iowa has spread to Illinois, Minnesota, Nebraska, South Dakota, and Wisconsin, an epidemiologist with the Iowa Department of Public Health said today.

Meghan , M.P.H., said all states bordering Iowa -- with the exception of Missouri -- have reported cases of mumps. Moreover, said , the end is no where in site.

"You can expect the numbers that we report tomorrow to be up [from cases reported March 30] and the numbers that will be reported Thursday are likely to be higher again," she said in an interview.

The Iowa Department of Public Health said will update mumps information tomorrow and again on Thursday.

The 245 confirmed, probable, or suspected cases of mumps reported to the Iowa Department of Public Health already represent the nation's largest mumps outbreak in 17 years.

Early on most of the Iowa cases were reported in college-age students. The mean age at onset was 21, and almost 35% of the cases occurred in 19-year-olds. But said that no single college or university was implicated in the outbreak.

"We can assume that this outbreak is associated with some aspects of college life such as living in dorms or mixing together at the same clubs," she said. The best explanation, according to , is that college students "in general have a higher risk of sharing saliva."

The probable cases of mumps were those that met the clinical case definition but had no confirmed serologic or virologic testing. Suspect cases were those with positive IgM serology and confirmed cases were those that met clinical definition that were also laboratory-confirmed or epidemiologically linked.

Follow-up reports have been completed on 136 cases of which 66% were in patients who had received two doses of the measles/mumps/rubella vaccine, which is considered sufficient to guarantee full immunity.

Blaise Congeni, M.D., director of infectious diseases at Akron Children's Hospital in Ohio, said that with any vaccine there is always a chance of primary vaccine failure, "meaning that the vaccine never achieved conversion, or the possibility of secondary vaccine failure, meaning that immunity wanes over time."

The current recommendation is that a first dose of measles-mumps-rubella (MMR) vaccine be administered at 12 to 15 months with a second dose at four to six years, but Dr. Congeni said that "if the second dose is missed it can also be administered during adolescence."

Based on published reports, Dr. Congeni speculated that secondary vaccine failure may be a factor in the mumps outbreak, but said that theory failed to pan out after investigation. "There is no correlation between time since immunization and outbreak," she said. "There are cases among people who were immunized two years ago and other who were immunized 23 years ago. There is also no correlation with lot number of the vaccine, manufacturer, or physician who gave the immunization."

Dr. Congeni also speculated that it may be difficult to identify an index case because the primary symptom of mumps -- parotitis -- is often not fully evaluated by clinicians. "If the patient's record indicates that he or she has been received two MMR doses, the assumption would be that this is caused by another virus," he said. If the symptoms abate, the episode would be little more than a notation in a medical record.

agreed that Dr. Congeni's theory best explains what has happened in Iowa, especially since the mumps strain is the same one that caused outbreaks in England over the past few years. That suggests that mumps arrived with a recent visitor from Britain, but "because these symptoms are often overlooked -- especially in people who have received the required vaccinations -- we doubt we will ever identify the index case," she said.

Dr. Congeni said, however, that a mumps outbreak does not carry the potential for public health disaster that would be associated with a measles or rubella outbreak.

"There is a small risk that some kids will develop viral meningitis and orchitis is a concern, but we know that orchitis doesn't cause sterility," Dr. Congeni said. As of March 30, 5% of cases included orchitis among symptoms and one case of encephalitis was being investigated.

Also, http://www.foxnews.com/story/0,2933,190040,00.html

Mumps 'Epidemic' in Iowa, Health Officials Confirm

Friday, March 31, 2006

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New Children's Vaccine Targets Four Major Diseases

DES MOINES, Iowa — A mumps epidemic is sweeping across Iowa in the nation's biggest outbreak in at least 17 years, baffling health officials and worrying parents.

As of Thursday, 245 confirmed, probable or suspected cases of mumps had been reported to the Iowa Department of Public Health since mid-January.

The federal Centers for Disease Control and Prevention said it is the nation's only outbreak, which the CDC defines as five or more cases in a concentrated area.

"We are calling this an epidemic," said Iowa state epidemiologist Dr. Quinlisk, explaining that mumps has spread to more than one-third of the state and does not appear to be confined to certain age groups or other sectors of the population.

Quinlisk said Iowa has had about five cases of mumps a year in recent years, and this is the first large outbreak in nearly 20 years.

"We're trying to figure out why is it happening, why is it happening in Iowa and why is it happening right now. We don't know," she said.

CDC spokeswoman Lola said the federal agency has no answers yet. But Quinlisk said one theory is that the infection was brought over from England — perhaps by a college student — because the strain seen in Iowa has been identified by the CDC as the same one that has caused tens of thousands of cases of the mumps in a major outbreak in Britain over the past two years.

"It may have been a college student, since we did see the first activities on college campuses, but we can't prove that," Quinlisk said. The Public Health Department said 23 percent of the 245 reported patients are in college.

The CDC said it is the nation's biggest epidemic of mumps since 269 cases were reported in County, Kan., from October 1988 to April 1989.

Mumps is a viral infection of the salivary glands. Symptoms include fever, headache, muscle aches and swelling of the glands close to the jaw. It can cause serious complications, including meningitis, damage to the testicles and deafness.

A mumps vaccine was introduced in 1967. Iowa law requires schoolchildren to be vaccinated against measles and rubella, and the mumps vaccine is included in the same shot. The state's last major outbreak was in 1987, when 476 people were infected.

Of the 245 patients this year, at least 66 percent had had the recommended two-shot vaccination, while 14 percent had received one dose, the Public Health Department said.

The vaccine is working," Quinlisk said. "The vaccine certainly was made to cover this particular strain, because it's a fairly common strain of mumps." Quinlisk said the vaccine overall is considered about 95 percent effective.

Quinlisk said the mumps outbreak started in eastern Iowa and is spreading statewide and possibly into the neighboring states of Illinois, Minnesota and Nebraska. Those states may have one or two cases, she said.

When 11-year-old Will Hean of Davenport starting feeling sick in mid-January, his family thought he had a bad case of the flu. But his face and throat swelled and his temperature climbed to 103. His parents took him to the doctor, and he was diagnosed to their surprise with full-blown mumps.

About two weeks later, the Heans' daughter, Kate, 21, came down with the mumps, too.

Both children had gotten the measles, mumps and rubella vaccine, or MMR. So had their other son, 13-year-old Jimmy, who did not get the mumps.

"He had all the shots and everything. You don't think you're going to get the mumps after you've been inoculated," said Will's father, Wayne Hean.