NEW YORK — Crowded environments, increased risky behavior and diverse populations typical within the college setting were associated with increased risk for disease outbreaks on campus, according to a presentation here.
“There are specific characteristics and features of a college campus that promote the spread of infectious diseases,” James C. Turner, MD, a professor of internal medicine at the University of Virginia, said during his presentation. “Congregate living and learning environments, increased sexual experimentation or increased intimate contact among students, very crowded social gatherings, and the profound geographic diversity of students both domestically and internationally, are contributory to disease transmission in the college setting.”
Turner specifically discussed mumps and invasive meningococcal disease, as there have been numerous outbreaks of each of these diseases on college campuses within the last year.
James C. Turner
Contributing factors to mumps outbreaks
Measles-mumps-rubella vaccination is the best way to prevent mumps, according to the CDC. However, two doses of MMR are 88% protective and one dose is 78% protective, leaving a possibility for infection even in the most immunized settings.
“Even in a highly immunized setting, mumps vaccine is only about 88% to 90% effective,” Turner said. “If you sprinkle a virus into a community that is highly vaccinated there is still a 10% to 12% chance that that population could come down with that disease.”
Due to the incomplete protectiveness of MMR vaccine, vaccinated students may present with far fewer complications, according to Turner.
“We see lower attack rates among colleges with high vaccination rates,” Turner said. “Students who are vaccinated against mumps have far fewer complications. They have less viral shedding, diminished acute antibody response, and tend to have unrecognized disease. They may present with mild malaise and the physician may not diagnose it as mumps. Then they reenter the community with the potential to spread the virus.”
Despite CDC and the American College Health Association recommendations for all college students to receive two doses of MMR, some US states do not require MMR vaccination for college entry. Turner noted that it can be difficult for a school to enforce CDC recommendations without legislative backing.
The changing epidemiology of invasive meningococcal disease
Epidemiological data from 2001 indicated rates of 3 to 23 cases of invasive meningococcal disease per 100,000 college freshman, particularly those living in dormitories, according to Turner.
These rates were attributed to crowding, dormitory residence, alcohol use, respiratory infections and smoking.
Fortunately, since polysaccharide and conjugate vaccines for meningococcal disease have become available, 65% to 75% of adolescents and/or college students have been vaccinated.
However, epidemiology of invasive meningococcal disease has shifted. There were 780 cases of meningococcal disease among patients aged 11 to 24 years between 1997 and 1999, of which 18% were group B meningococcal disease. From 2010 to 2012, there were an estimated 106 cases, of which 27% were group B, according to Turner.
Recently, University of California, Santa Barbara and Princeton University experienced outbreaks of group B meningococcal disease. With special permission from the CDC and the FDA, an unlicensed recombinant vaccine Bexsero (4CMenB; Novartis) was used with high success rates.
Trumenba (Pfizer) was recently approved by the FDA for prevention of Neisseria meningitidis serogroup B among individuals aged 10 to 25 years.
“Meningococcal group B vaccines have been under development for many years; it’s exciting that we are so close to having them widely available,” Turner said.
However, Bexsero and Trumenba have not been shown to decrease carriage rates, so a herd immunity may not be attainable from these vaccines.
Physicians are awaiting interim guidelines for these vaccines from the CDC, but the future looks bright, according to Turner.
“We are awaiting recommendations from the CDC’s Advisory Committee on Immunization Practices regarding either the permissive or universal use of these vaccines, but we will definitely have vaccines available for an outbreak setting,” he said.
For more information:
Turner JC. “College health and infectious diseases.” Presented at: IDC NY 2014; November 22-23, 2014; New York.
Disclosure: Turner reports financial ties with the CDC, Pfizer, Novartis, and the NFID.