Wednesday, March 23, 2011

Climbing Numbers in Minnesota Measles Outbreak

Note: For further updates on the numbers, follow the post Minnesota Measles Outbreak by the Numbers: A Timeline.

Update: As of the morning of April, 2011, the total cases are up to 15. See the link above for the total numbers. According to the Minnesota Department of Health, 12 of the cases are linked to the index case of the infant who acquired the measles infection in Kenya. One case was infected in Florida, and one person was infected in India.

Update: As of the morning of March 30, 2011, there have been 14 confirmed cases of measles in Minnesota. The latest case is a 51-year-old of unknown vaccination status. For those keeping track, there have been, to date, 5 infants too young to be vaccinated, 6 children old enough to be vaccinated but who were not and 3 people (two adults) with unknown vaccination history. Of the 14 confirmed cases, 8 have been hospitalized.

Update: On the afternoon of March 29, 2011, the outbreak has reached 13 confirmed cases, and 2 more have been hospitalized. The newest case was too young to be vaccinated. The totals are now: 5 too young to be vaccinated, 6 of age for the vaccine but not vaccinated and 2 of unknown vaccination status. A total of 8 have been hospitalized.

Update: As of March 28, 2011, there are 12 confirmed cases of measles in Minnesota. Four children were too young to be vaccinated, 6 were old enough but were not vaccinated and two have unknown vaccination status. There have been 6 hospitalizations so far.

Update: On March 25, 2011, the MDH stated that the total number of hospitalizations in the outbreak has risen from 5 to 6. Thankfully, there are still no deaths.

Update: As of this afternoon, MDH has reported an 11th case of measles in a 35-year-old. The latest case has unknown vaccination status.

This morning, the Minnesota Department of Health (MDH) updated their information page on the current measles outbreak. Since February, there have been ten confirmed cases of measles in the Minneapolis area. According the the MDH, the outbreak most likely began when an infant returned from a trip to Kenya. The infant, too young to be vaccinated, had contracted the infection. Since then, it has spread to nine others. The ages of the children range from 4 months to 4 years.

I decided to look at the history of measles cases in Minnesota. Thankfully, the MDH has a handy table and links to the details of past outbreaks.

In the past month, the number of measles cases has exceeded the total for any single year since before 1997, when 8 cases were reported. In the period from 1997-2010, a total of 22 cases were reported, only slightly over double the numbers reported in the past several weeks. The department provides some details on the outbreaks from 2000 to 2009, which I have summarized here:
Source: http://www.health.state.mn.us/divs/idepc/diseases/measles/

From 2000 to 2009, there were ten cases of measles. Four of those were in infants too young to be immunized, including an infant only 2 weeks old. Of the remaining six, one had been immunized, but was in the minority of those for whom the vaccine did not take. One other was immunized, but antibodies from the child's mother were likely passed to the child, neutralizing the vaccine before the 16-month old could develop antibodies of his or her own. The vaccination status for two was unknown, and the final two cases were old enough, but had not been immunized.

In the current outbreak, four of the children were too young to be vaccinated; they rely on herd immunity for protection. Five of the children, half of the current outbreak, were old enough to be vaccinated but were not due, demonstrably, to fears instilled in them by folks like Generation Rescue and Age of Autism's J.B. Handley, who spoke to families in the Somali community in Minnesota, claiming that vaccines caused autism. The vaccination status of the tenth child is unknown.

Early reports of the outbreak indicated at least 3 infected children were from the Somali community. As I mentioned, fear of vaccines had been stoked in this community by J.B. Handley and others. According to a story from 2009 in The New York Times, Handley:

warned [the Somali families] not to trust the state health department and suggested they slow down their children's shots and get exemptions to school vaccination requirements. He also offered to pay for some to attend an antivaccine conference [Autism One].

The antivaccinationists set the stage for this outbreak. Their actions sowed fear of vaccines within the Somali community, leading to drops in vaccination uptake. Furthermore, by telling these families not to trust the state health department, they have increased the likelihood that, like with smallpox outbreaks in the late 19th century, new cases will go unreported. With this atmosphere, public health workers will have their hands full trying to contain the outbreak, and the virus will spread to more and more people.

So far, we have had 10 reported and confirmed cases. There may be more that have not been reported to state health officials. Luckily, none have died, though half of the current cases have been hospitalized.

Unfortunately, the outbreak is likely to get much worse before it gets any better. My heart goes out to the families who were deceived by Handley and other antivaccinationists. I cannot, in good conscience, blame any of the parents of the Somali children who have been infected. Their trust was abused; they were taken advantage of by groups like Generation Rescue; and now their children and the children of other innocent parents are paying the price.
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Related Posts:
More Cases of Measles in Minnesota, 3 of 4 Hospitalized
Minnesota Infant Contracts Measles - Why Immunization Is Important
Autism in Certain Minnesota Populations

3 comments:

  1. Our friend, Dr. Jay Gordon, recently tweeted that it made sense for him if 15% of a cruise ship was sick with Noro, but it didn't make sense that 7 cases in a population of over 5 million would be called an outbreak. I really don't know where the mental block is occurring...

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  2. @Ren

    The problem is that he does not seem to understand the difference between total population and susceptible population. He also does not understand the definition of "outbreak" (i.e., 1 more case than expected). With 0-1 cases per year, on average, it does not take many cases to define an outbreak. In the case of MN, 2 cases would be an outbreak. 10 cases (when there should not be any) is extremely worrying!

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  3. Nope. He doesn't grasp any of that, and he continues to ignore that, up to now, all the cases have been related to each other (epidemiologically linked), another factor in calling it an outbreak.

    ReplyDelete

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