Evidence of immunity to mumps may have waned over time
BY KEITH ROACH, M.D.
DEAR DR. ROACH: I am a 67-year-old woman who works with young children. I get a physical each year for my job, and until this year it was acceptable to say that because I was born before 1957, I was presumed to have immunity to measles, mumps and rubella. This year I was required to get an immunization titer, and it came back that I do not have immunity to mumps, although I clearly remember having the mumps. Is mumps as prevalent and as serious as measles? Can I be a carrier and not know it? — M.B.
ANSWER: Mumps is a highly infectious viral illness. Although both natural infection, like you remember having, and vaccination lead to lifelong immunity in most people, evidence of immunity by blood testing wanes over time. So it is possible that you are still immune to mumps. A high antibody titer is very good evidence of protection, but some people can still fight off reexposure despite low antibody titers.
However, it is strongly recommended that health care workers and others who might be exposed get two doses of MMR vaccine to be sure of protection. The MMR vaccine covers measles, mumps and rubella; there is no vaccine available just for mumps.
Mumps, as a disease, is normally fairly benign; there are no carriers. However, there are still risks of serious complications. Men must be concerned for orchitis: Mumps can directly affect the testes, potentially causing infertility. Inflammation of the ovaries in women is less common, happening in 5% of women who get the disease after puberty. Meningitis (inflammation of the lining of the brain) and encephalitis (inflammation of the brain itself) are rare complications. Given the choice between contracting mumps and the far more serious measles, it’s best to get vaccinated and avoid both.
DEAR DR. ROACH: There are a number of gut tests being offered by different companies to look at a person’s microbiome. I have been recommended to use one to look at my gut microbial ecology. Can you comment on the reliability and usefulness of these tests? — B.N.
ANSWER: It is increasingly clear that the trillions of bacteria that live in our gut have significant impacts on our overall health, but we are just beginning to understand the complex associations. I believe that a comprehensive evaluation of the microbiome — a term used to describe the number and types of bacteria — may lead to important insights into development of specific medical conditions. However, I am pretty sure that we aren’t yet at a place where consumer testing is likely to lead to benefits for an individual.
Before ordering any test, it is worthwhile to ask, How will the test result change my behavior? What will I do differently, and what benefit can I expect? This is true with any clinical laboratory or radiology test a doctor orders, and now that consumers can order this test and others, they should consider whether it’s worth it. I have not found convincing evidence that there are specific actions a person should take based on the results.
There is strong evidence that a diet high in vegetables, legumes, fruits and whole grains, and low in saturated fats, in addition to the known benefits in reducing risk for both cancer and heart disease, also increases the diversity in the microbiome, which is considered a measure of overall gut health.
In my opinion, there isn’t enough knowledge yet to make commercial microbiome testing likely to lead to an individual benefit.