We’re in the Business of the Trees.

My title this month came to me after an animated conversation with Rick Heffernan, MPH, Director, Data Analysis Unit, Bureau of Communicable Disease, New York City Department of Health and Mental Hygiene (NYDOHMH). I had received, several days earlier, an email message including the “emergency department syndromic surveillance quarterly report.” Just what is this mouthful and why should it matter to us in the ED? Well, as Rick and I agreed in conversation, the health department is “in the business of the forest” and since we see patients one-by-one, we’re in the business of the trees. Together, we can and should learn more about the community population both the health department and we serve. More about working with your local health department later.

The health department’s Quarterly Report of Syndromic Surveillance was replete with graphs comparing visits to our ED with citywide ED visits secondary to complaints of diarrheal, respiratory and fever-flu syndromes in patients 13 and older, as well as overall ED visits. (See graph examples [editor: please correct plural if only one graph used]) These quarterly reports are of more academic than practical interest, but they presage a future with more real-time scrutiny of patient populations in our own emergency departments.

I’ve yet to find a succinct formal definition for syndromic surveillance, so bear with me as I try to explain what’s happening in New York City and in many other urban centers around the country.

Syndromic surveillance is the organized observation and analysis of patients seeking medical care as part of a monitoring effort for a community at risk of bio-terrorism. In the immediate post-September 11, 2001 period, the Centers for Disease Control and the New York City Department of Health and Mental Hygiene with the cooperation of 15 hospitals set up a manual system watching for a secondary bio-terrorism attack that some feared was likely in the aftermath. The subsequent anthrax bio-terrorism, which was not discovered through syndromic surveillance, was nonetheless another spur for creating automated, rather than manual systems. It is through this approach, which is already being refined that we may find syndromic surveillance operating some day in the future in our own ED.

In the long run, syndromic surveillance must provide value for the physician working in the ED and that will only happen if we are “cued” to look for an illness we otherwise wouldn’t expect. The prepared mind will recognize a pattern that the unprepared will not—that’s why practitioners read and study. Tracking the presenting complaints of our patients and notifying the team on duty in the ED at the time a patient presents with a complaint that’s appearing at higher than usual frequency may encourage the emergency physician and nurse team to contemplate a broader differential diagnosis—even illnesses associated with bio-terrorism.

We could have used such a system earlier this year, when we experienced an outbreak of measles (rubeola) in our community. A colleague missed the diagnosis in a teenage patient who had received the vaccine, both as a toddler and at age 12. We were alerted by the pediatrician a day later—how embarrassing reporting the miss to the health department. On the other hand, we had at least not had the child and parent wait in the waiting room, but had brought them into the ED to a closed room because of the rash and concomitant respiratory complaints. This all occurred during the SARS surveillance we all experienced in April-May 2003 and all of us were focusing on respiratory illness and travel history, not rash. It’s doubtful most physicians would have made the diagnosis in any case given the history of immunization and the relative rarity of an acute presentation.

This one case of measles did alert us to its presence in our community so we—just as you would—created handouts with photos and the key signs for recognizing the disease on presentation. Sure enough, a few days later another child presented to the ED and the treating physician recognized the presentation as most likely measles and obtained infectious disease consultation. Serum for antibody titers was drawn and the pediatrician who had seen the child in a crowded office earlier the same day was called and alerted and advised to check immunization records of the children who had been in his office at the time. Still, we once again missed a required step. No one called the health department for this reportable disease. Over the next week we saw several additional cases of measles and I know from colleagues that the outbreak, and the initial failure to recognize and report the disease, occurred repeatedly across the Brooklyn, Queens and nearby suburban communities. The health department did a marvelous, but onerous job, of contact tracing every identified measles patient and those exposed to them so that vaccine could be administered and isolation encouraged as appropriate.

I enjoyed my conversation with Mr. Heffernan and others at the NYDOHMH. We’ve let our entire physician, nurse and technical support staffs know that the health department wants notification on suspicion of communicable disease and not to wait for confirmation. The group at the health department we worked with around the measles outbreak was not the same as Mr. Heffernan’s group. Yet our experience of the outbreak made our entire staff more aware of the value the NYDOHMH brings across the board. While I think that syndromic surveillance is a wonderful theory, we who see the patients one at a time will be alerting the authorities before they alert us for some time yet—because we’re in the business of the trees.