Changing Carriage Rate of Neisseria meningitis Among University Students

abstract & commentary

Synopsis: Freshman college students, particularly those who live in dormitories, are at a modestly increased risk for meningococcal disease.

Source: Neal KR, et al. BMJ 2000;320:846-849.

Neal and colleagues note that during the 1990s there have been major increases in the incidence of invasive meningococcal disease in many developed countries, with serogroup C disease being the most common, especially among teenagers and young adults. They also note that university undergraduates have higher rates of invasive meningococcal disease than young adults of the same age who are not attending a university. This longitudinal study was performed to determine rates of carriage and acquisition of Neisseria meningitis, together with risk factors for both, among university students in the absence of outbreaks.

The study was performed at Nottingham University in England. Students were recruited during their first week of attendance (October 1997). A detailed questionaire was completed to determine medical, immunization, and travel history, as well as risk behavior during the week prior to the survey (smoking, alcohol, bar attendance, kissing, etc.). Detection of N. meningitidis was accomplished by culture of a posterior pharyngeal swab. A follow-up culture was obtained during either the first week of November or December 1997. During the study period, one case of serogroup C disease occurred (2 more cases occurred in the spring of 1998).

The study revealed that of the 2453 first-year students who participated, a rapid increase in carriage of N. meningitidis occurred during the first week (from an initial 8% to 23%). Risk factors included male sex, active and passive smoking, intimate kissing, visits to halls and night clubs, and resident housing in coed halls. That is, factors that promote social mixing are those that also promote spread of the organism. Neal et al conclude, "Our findings support the recent introduction of meningococcal vaccination for university students."

Comment by Michael K. Rees, MD, MPH

In 1998, the CDC in collaboration with the Council of State and Territorial Epidemiology and the Vaccine Preventable Disease Task Force initiated two studies to define the risk of meningococcal disease associated with college campuses. The results are essentially identical to this Nottingham study: freshman college students, particularly those who live in dormitories, are at a modestly increased risk for meningoccal disease.

A polysaccharide meningococcal vaccine is now available for the prevention of bacterial meningitis caused by N. meningitidis (meningococcus) serogroups A, C, Y, and W-135. It is most effective against serogroups C and Y. It does not protect against serogroup B. Protection lasts for 3-5 years. In a press release dated Oct. 20, 1999, the Advisory Committee on Immunization Practice advised that colleges take a more active role in alerting students and parents to the potential dangers of meningococcal disease. The American College Health Association now recommends that all college students, especially freshman living on campus, consider getting the vaccine (average cost is $65). The vaccine is routinely given to U.S. Army recruits. It should also be recommended for travelers under certain situations. For example, on April 21, the CDC reported meningitis in three New York City residents who either traveled to Saudi Arabia during the month of travel to Mecca or had close contacts who were diagnosed with the infection.

For current information on meningococcal infection and the vaccine, see the CDC website, http://www.cdc. gov/ncidod/dbmd/diseaseinfo, and the American College Health Association website, special-prj/men/faq.htm.

The polysaccharide vaccine against Neisseria meningitis provides some level of protection against all of the following serogroups except:

a. A

b. B

c. C

d. Y

e. W-135