As an outbreak of conjunctivitis continues to sweep the campus, several peculiarities in the strain afflicting Hanover have attracted sufficient attention from College and state authorities to prompt a visit from the Centers for Disease Control.
The track of the recent infections, contrary to the usual patterns in the spread of pink eye, is one factor that has thus far baffled experts.
Since the outbreak's onset nearly a month ago, 15 to 20 new student cases of pink eye presented themselves at Dick's House nearly every day, Director of College Health Services Jack Turco said.
Ordinarily, cases of such an infection would appear, rise in frequency and then dwindle. At present, however, the incidence of new cases is remaining at a constant level.
"It was very puzzling for us and for the CDC," Turco said, noting that this tenacity suggests a high degree of contagion -- some 400 individuals had reported cases to Dick's House as of Sunday.
The CDC's goals for this visit include determining what causes the infection, how it spreads, how many persons are afflicted and what measures can be taken to prevent further infections.
To this end, representatives from the CDC and the New Hampshire Public Health Department will be camped out in the Collis Center today, conducting a second day of clinics aimed at determining how many students are carrying the infection. In addition to the hundreds of students manifesting symptoms, many more are likely carrying the infection but will not develop symptoms.
Some 130 students took part in a similar clinic last Friday. To conduct a meaningful statistical analysis, Turco said, the organizers need a combined total of 300 participants by the end of today.
The decision to dispatch representatives from the CDC to Hanover occurred after the federal organization was notified by the N.H. Public Health Department. Turco alerted the state department about the situation nearly three weeks ago, setting off a series of ongoing conference calls with state and CDC officials.
Ultimately, the state extended an invitation to the CDC to participate in on-site clinics and carrier surveys.
Both CDC Medical Epidemiologist Dr. Michael Martin and Turco stressed the importance of student participation in both today's clinic and the associated online carrier survey. These efforts provide investigators with clues as to how the infection transmits from one person to another and which groups may be particularly at risk.
Martin noted that investigators can not yet ascertain the chief source of the infections. Though the majority of outbreaks of conjunctivitis occurring outside of elementary schools are viral, many current cases at Dartmouth show signs of bacterial origin, a point Martin described as "a little bit surprising."
Additionally, the symptoms appearing in Hanover this month have generally been milder than bacterial conjunctivitis infections usually produce.
The strain does show some similarity to two other outbreaks of bacterial conjunctivitis since the early 1980s, one in New York and one in Illinois, according to Turco and Martin. The CDC is attempting to obtain samples from each of these cases to compare with samples taken from swabs conducted on Dartmouth students.
Turco speculated that such a strain of low-grade bacteria may also have appeared in smaller outbreaks on other college campuses and been incorrectly dismissed as viral.
CDC visits to college campus -- or, for that matter, military barracks and other settings where people live in close contact -- are not a rarity, according to Martin.
Martin and a fourth-year medical student compose the CDC's team visiting Hanover; the New Hampshire Public Health Department also dispatched a doctor and nurse.
As of Sunday, approximately one-third of students had responded to the survey. The CDC's desired response rate falls between 60 and 80 percent, Martin said.
Despite the need for additional respondents, Martin praised the efforts of students who have thus far assisted the CDC in its investigation.
"Students are appropriately concerned about the outbreak," Martin said, noting that they also seem enthusiastic about the investigation and bringing the surge of infections to a close.
College Health Services also posted flyers across campus advising students to wash their hands with frequency and not share such items as utensils, glasses and towels. The poster also encourages students to take the online survey and make appointments at Dick's house or elsewhere if they suspect they have contracted pink eye.
