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Volume CXXXIII, Number 3 |
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Meningitis and college life
JEFF BENSON, M.D.
DUDLEY COE HEALTH CENTER
Dear Dr. Jeff: I didn't get vaccinated for meningitis this summer. Should I get vaccinated now? -M.J.
Dear M.J.: Like most issues in medicine, this one is less than black and white. First, let's go over the facts as I understand them.
Meningitis is an infection of the central nervous system (brain and spinal cord), caused most often by viruses but also by bacteria and other pathogens. The "meningitis vaccine" is meant for meningococcal meningitis, which is caused by the bacterium Neisseria meningitides. Meningococcal meningitis usually begins as a vague, flu-like illness, and can progress extremely rapidly, with the development of headache, fever, stiff neck, and vomiting. A characteristic rash appears late but usually just prior to collapse and coma. If treated promptly, meningococcal meningitis is highly curable. Untreated, it is likely fatal.
Fortunately, meningococcal meningitis is quite rare. There are about 3,000 sporadic cases per year in this country. Between 100 and 125 of them occur on college campuses. The case fatality rate is about 10 percent. That means that nationwide, about 10 to12 college students are likely to die each year of meningococcal meningitis. There has not yet been a case on a Maine college campus.
The natural reservoir of meningococcus is the back of our throats. In fact, Neisseriae can be cultured from up to 15 percent of randomly selected healthy individuals. These "asymptomatic carriers" do not themselves develop meningitis. They may spread the bacteria by sneezing or coughing, however, and others may be more susceptible.
Carriage rates rise to 40 percent among close contacts of people with active meningitis. During a meningitis outbreak, the carriage rate in "closed populations" like college dormitories or military barracks are likely to be higher still-up to 75 percent.
Vaccination does not prevent people from carrying the bacteria. Carriers can be treated with antibiotics and cleared of Neisseria, at least temporarily. That's the reason for treating all close contacts of people with active meningitis. The same rationale underlies treating all residents of dormitories and barracks during a meningococcal outbreak.
So, why not test everyone and treat all carriers before there's an outbreak?
Remember that meningococcal meningitis is rare. The risk of disease among first-year college students in residence is about 1 in 300,000. For purposes of comparison, that's about three times more likely than your lifetime risk of being struck by lightning.
From a public health point of view, it makes little sense to test 100 percent of a population then treat up to 15 percent in order to prevent an illness that will affect only 0.00033 percent. Plus, you never know when you might become a carrier, or for how long.
What about requiring the vaccine? There are five serotypes of Neisseria bacteria that cause meningitis. The vaccine is about 90 percent protective against four of them. These four serotypes collectively cause about 65 percent of meningococcal meningitis cases. Therefore, if everyone in the country received the vaccine, about 60 percent of meningococcal meningitis cases could be prevented.
The vaccine has almost no significant side effects or risks, and its protective effects last three to four years. It is expensive, and it is 2003-09-26ly manufactured under patent by one company and being aggressively marketed by that company to doctors and college health centers.
The federal Centers for Disease Control have made the following calculation. Vaccination of all first-year college students might prevent 37 to 69 cases of disease, and two to four deaths each year. The cost per case prevented would be about $3 million, and the cost per death prevented about $48 million. That's many, many orders of magnitude more expensive than any other public health intervention.
The Health Center's cost for a vaccine, on the other hand, is $59, and that's what you will pay if you choose to be vaccinated here.
To return to your original question: should you get vaccinated against meningococcal meningitis? The only "down sides" to the vaccine are the cost and a mildly sore arm. On the "upside," you'll be protected against four of the five serotypes of Neisseria for a few years, and so reduce your risk of infection by well over 50 percent. That is a significant reduction.
One final caveat. In the event of an actual case of meningococcal meningitis on campus, all close contacts would need to take antibiotics whether or not they had been vaccinated. The serotype of the infecting Neisseria would take days to determine, but antibiotics are immediately effective against all five strains of meningococcus.
All of us at the Health Center would be happy to discuss any questions or concerns you may have. The final decisions, of course, are yours.
Jeff Benson, M.D.
Dudley Coe Health Center
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