Measles - Continued vaccinated. The Student Health Services and DPHS Immunization Program staff vaccinated or obtained proof of immunity for 2,528 (86.5%) of the 2,923 students identified as possibly susceptible. By the end of May, 4,508 (91.9%) of the 4,903 total students had documented proof of measles immunity in their health records. All schools, day-care centers, colleges, and universities in New Hampshire were notified early in the outbreak of the possibility of indigenous measles, with a recommendation that the immune status of children, students, and employees in these facilities born after 1956 be reviewed. DPHS also informed other health-care providers, hospitals, and town health officers in the state, as well as public health officials in states bordering New Hampshire and in the Province of Quebec, Canada, that measles had occurred in the state. This fall, Dartmouth College began routinely notifying new students who did not provide adequate documentation of measles immunity on enrollment health forms that the college FIGURE 2. Chain of transmission, measles outbreak, Dartmouth College and Mary Hitchcock Memorial Hospital - Hanover, New Hampshire, April 3, to June 4, 1984 28 31 3 6 9 12 15 18 21 24 27 30 3 6 9 12 15 18 21 24 27 30 25 MAR APR MAY JUN RASH ONSET (3-day periods) 'Possible transmission from hospital employee. Measles - Continued strongly recommended vaccination. In addition, those students enrolled in the 1983-1984 academic year who still lacked documentation of measles immunity in June were recontacted on return to campus regarding their need for vaccination. Although it is unclear how measles spread to the hospital, several routes of transmission are possible. A surgical house officer who developed measles shared an apartment with a noninfected Tuck graduate student. He continued to work after the onset of prodromal symptoms and was subsequently hospitalized for 6 days, during which he developed viral pneumonia and corneal ulcerations. The laboratory technician, believing himself immune because of age (27 years old), had drawn blood samples from individuals suspected of having measles at the Student Health Services clinic. The neurosurgical patient had onset of rash 11 days after admission. She was either exposed during her hospitalization or before admission, when she had been on campus and in the hospital for preadmission tests. Five of the 37 individuals who developed measles visited the hospital emergency room. Because of the risks arising from nosocomial measles at the hospital, DPHS recommended that: (1) all professional staff, other employees, and hospitalized patients under 35 years of age either provide proof of immunity or be vaccinated, unless contraindicated; (2) all susceptible patients exposed to a known measles patient be vaccinated or given immune globulin, as medically indicated; and (3) susceptible persons in the community born after 1949 or vaccinated before 1968 be advised not to visit the hospital. The hospital conducted its own vaccination clinic starting April 13 (Figure 1). Eighty-six individuals voluntarily received vaccinations through May 17. On May 18, the day after the first hospital case was publicized, an additional 400 persons received vaccine. By June 1, the hospital had vaccinated 876 persons, most of whom were among the hospital's 2,200 personnel. Hospital policy now requires serologic testing of all new employees for evidence of immunity to measles and rubella and vaccination of those found to be seronegative. Reported by JH Turco, MD, DN MacKay, MD, R Smith, MD, B Conant-Sloane, PhD, NM Watkins, Dartmouth College, Dartmouth Medical School, Mary Hitchcock Memorial Hospital, Immunization and Epidemiology Programs, Bureau of Communicable Disease Control, E Schwartz, MD, State Epidemiologist, New Hampshire Div of Public Health Svcs; Div of Immunization, Center for Prevention Svcs, Div of Field Svcs, Epidemiology Program Office, CDC. Editorial Note: Since the measles elimination campaign began in 1978, indigenous measles has been eliminated from most of the United States. In 1983, a record low 1,497 measles cases were reported. From 1980-1983, however, an increasing proportion of measles cases have occurred on college campuses (Table 1). Of the 1,497 measles cases reported in 1983, 570 (38.1%) were college or collegeassociated cases: 296 (19.8%) occurred on college campuses; 274 cases off campus were epidemiologically linked to those on campus (within two generations). Most of the college TABLE 1. Reported measles cases on college and university campuses 1980-1984. United States, Measles - Continued associated cases (92.1%) were related to four campus outbreaks: Indiana University (IU)-385 cases (180 on campus, 205 spread); Miami University of Ohio-82 cases (20 on campus, 62 spread); University of Houston-32 cases (29 on campus, three spread); and Louisiana State University-26 cases (25 on campus, one spread) (1). In the first 37 weeks of 1984, the number of reported measles cases on campuses has declined substantially, compared to the same period in 1983. Nevertheless, the college outbreak cited here is one of the larger reported campus outbreaks. Measles outbreaks on college campuses are of particular concern because measles is a more serious disease among adults than among schoolchildren (2). Measles transmission among college students may be sustained by several factors (3): (1) many children growing up in the mid-1960s may have missed measles vaccination in the first years following the licensure of measles vaccine; (2) many students may not have been immunized under comprehensive school laws now in effect in many states involving students in kindergarten through grade 12; (3) many colleges and universities lack immunization requirements; (4) many students may have escaped natural measles infection because of decreasing transmission; (5) some students may have been vaccinated with the ineffective formalin-inactivated ("killed") measles vaccine, which was administered to 600,000900,000 individuals from 1963 to 1967; (6) many students may have been vaccinated with live virus vaccine before their first birthday, when measles vaccine is known to be less effective (immunization of infants 6-11 months of age was previously recommended when prevalence of measles made exposure of these infants likely); and (7) the tendency of college students to congregate in large numbers (e.g., dormitories, fraternities and sororities, and social and sporting events). Approximately 5%-15% of college-aged individuals are estimated to be + susceptible to measles, according to serologic studies (1). In May 1983, the American College Health Association adopted a Pre-admission Immunization Policy. It recommends that, by September 1985, colleges and universities require all students born after 1956 to present documentation of immunity to measles and other vaccine-preventable diseases as a prerequisite to matriculation or registration. The Immunization Practices Advisory Committee has likewise recommended since 1980 that college and university administrations strongly consider establishing such requirements (5). A strategy for planning, implementing, and evaluating college-based immunization programs has been developed (6). Measles outbreaks on college campuses are costly, disruptive to college routine, and difficult to control. The Dartmouth outbreak required disease control and prevention activities that cost over $30,000. The known direct costs of control activities in the IU outbreak exceeded $225,000. It is more cost-effective to prevent measles outbreaks than to attempt to control them (4). Transmission of measles to teaching hospitals and other medical settings is of particular concern because of possible spread among unvaccinated pediatric patients (especially infants under the age of routine vaccination), pregnant patients, and patients with immune deficiencies. Teaching hospitals may be at greater risk for measles transmission, since they typically have younger personnel, including many in training programs, who are less likely to have natural immunity. In addition, nosocomial spread may have more serious consequences in teaching facilities, since, as referral centers, they often treat patients with more serious illnesses *Attack rates in the Indiana University outbreak were four to five times higher for students living in dormitories and fraternity or sorority houses than for those living off campus, where student congregation is generally much less (4). Measles - Continued Health-care personnel are at risk of measles exposure, because patients with measles frequently seek medical attention and are occasionally hospitalized. Although the risk of acquiring measles in medical settings is probably low, CDC received reports in 1980 from 16 states of 32 episodes in which measles had probably been transmitted in medical settings (7). These episodes included a total of 57 cases-31 among medical staff and 26 among patients and visitors. Only one of the 32 episodes included both patients and staff. CDC has continued to receive reports of measles transmission in medical settings each year since 1980. One 1982 outbreak involved airborne transmission in a pediatrician's office up to 75 minutes after an infectious patient had left (8). To minimize the risk of nosocomial spread of measles, all hospital personnel who are considered to be at increased risk of contact with patients infected with measles should be protected (9). Normally, persons born before 1957 can be considered protected because of likely exposure to natural measles (10). The vaccination of persons born after 1949 was recommended in this outbreak because several of the measles patients were born between 1949 and 1957. Hospitals should follow appropriate guidelines for the care and isolation of patients with suspected or confirmed measles (11). (Continued on page 559) TABLE I. Summary-cases of specified notifiable diseases, United States *The 1983 reports which appear in this table were collected before AIDS became a notifiable condition "Four of the 14 reported cases for this week were imported from a foreign country or can be directly traceable to a known internationally imported case within two generations. |