Welcome to Eurotimes

Daniel Keller PhD

WHEN an outbreak of bacterial conjunctivitis affected almost one quarter of first years at a rural college in New Hampshire, US last winter, the college's email system proved an unlikely ally in studying the epidemic, controlling it and allaying student fears.
Jack Turco MD, Director of the Dartmouth College Health Service, noticed 12 consecutive cases of conjunctivitis which were culture-positive for one strain of Streptococcus pneumoniae and immediately notified state health officials and the US Centres for Disease Control and Prevention (CDC).
He also called in Michael E Zegans MD, Assistant Professor of Surgery at Dartmouth Medical School and Director of the Cornea Service at Dartmouth-Hitchcock Medical Centre.

“It's not an unusual etiology, but it's often hard to get positive cultures from conjunctivitis, so to have so many consecutive patients coming back with the same result was surprising,” Dr Zegans said.

Before it was over, the outbreak affected 698 students, mostly undergraduates. Dr Zegans said the infections were easily treated with topical antibiotics. During similar periods in 2000 and 2001, 66 and 92 students respectively received a diagnosis of conjunctivitis of any cause.
Dr Zegans noted that ophthalmologists tend to think about big, disruptive outbreaks of conjunctivitis, related to adenovirus, so-called epidemic keratoconjunctivitis (EKC).

“I think it's important to note that they can also be caused by bacterial conjunctivitis and that the characteristics for transmission and interventions you may want to make are different depending on the etiology. So it just stresses the importance of identifying the causative agent,” Dr Zegans said.
Dartmouth, ranked as the fifth ‘most wired’ college in the country, quickly put its email and protected web sites to good use to acquire data from students, analyse them and institute public health measures.

Health authorities on campus quickly alerted students to the outbreak, provided messages about prevention, administered a survey to determine prevalence and risk factors and recruited subjects for a study on carriage of the organism. The students could book appointments electronically to visit the student health centre to participate in the study.

Based on the system already in place at the college, data collection and analysis and a response to the outbreak were accomplished within days.
“It allowed us to both get information out very quickly and organise a clinical study in ways that would have been much more difficult if you had been making phone calls or sending leaflets or having to get things returned to you,” Dr Zegans said.

In addition to campus-wide emails, the college used posters and the college newspaper to notify students, faculty and staff. Prevention messages encouraged them to wash their hands often, avoid sharing eating utensils and to seek treatment if they developed symptoms of conjunctivitis. Alcohol-based hand gel was distributed through the college mailroom, but students reported that they did not use it very often.
Through a student health service, as well as articles in the CDC's Morbidity and Mortality Weekly Report, Dartmouth College physicians notified other student health services in the US about the outbreak.

A similar contemporaneous outbreak at Princeton University in New Jersey, US involved the same strain of S pneumoniae, suggesting transmission between the two campuses. These two Ivy League schools compete in sports matches and hold social events together.

The Dartmouth outbreak largely subsided after Spring break. Health officials do not know if their interventions or the break, or both, helped limit further transmission.
However, the holiday period was also a cause for concern because many students with active conjunctivitis or those carrying the organism left campus to travel to popular destinations for college students. But there was no excess of cases reported in the community surrounding Dartmouth.

On multivariate analysis, risk factors associated with developing conjunctivitis were having close contact with someone with the infection, attending a party or living at a fraternity or sorority house, wearing contact lenses and being a first-year student. Membership on a sports team also put students at risk.

“Strep pneumoniae typically is said not to be able to exist outside of the human body well. So close hand-to-hand transmission is probably important,” Dr Zegans said.
Identifying the organism and the risk factors for transmission was an important aspect of the response to this outbreak.

“From this epidemic and other epidemics we may learn more and more about what the key college health interventions are and therefore we can tailor our response to the organism,” he said.

During this outbreak of S pneumoniae conjunctivitis, no health care workers contracted the disease. However, many adenovirus-related EKC epidemics have been amplified by health care workers.

“In the case of EKC, you would often focus on controlling the clinic, which is a source of spreading the epidemic, whereas with this you need to be more out in the community,” Dr Zegans said.

In epidemics which can be amplified in the clinic setting and in which patients do not necessarily need to be seen by health care providers, communication by email and other remote means may limit interpersonal contact and therefore have additional benefits beyond data collection and processing.
The S pneumoniae causing this outbreak was unusual in that it was unencapsulated.

Normally, the polysaccharide capsule is considered a key virulence factor.
Researchers proposed that the lack of a capsule may have allowed this organism to colonise the conjunctival membranes but not cause more serious pneumococcal infections. They reported that among thousands of pneumococcal isolates causing invasive disease, 99.6% had an identifiable capsular serotype.

In this case the investigators at the CDC determined by pulsed-field gel electrophoresis that the S pneumoniae strain in this outbreak was identical to those that caused outbreaks of conjunctivitis among college students in New York and California in 1980. No other outbreaks related to this strain have been reported for 20 years.

“What you're really managing is the fears and concerns of the community, because on an individual basis, this really wasn’t a horrible disease,” Dr Zegans said.
He advises health care providers to reassure people that care is available and to keep everyone informed so lives and routines are disrupted as little as possible.

Michael Zegans MD
Email: michael.e.zegans@dartmouth.edu

Top