For three weeks beginning in January, about 700 workers and patients at St. Barnabas Hospital in the Bronx, including 238 infants, were exposed to tuberculosis by an infected nurse.
During that time, after the unidentified, foreign-born woman had developed a cough, she continued to report for regular shifts in the maternity ward and the nursery at the facility. When she finally reported her cough to a doctor, he noticed that she’d earlier tested positive for latent TB. A chest X-ray showed that the disease had turned infectious.
Following Centers for Disease Control and Prevention guidelines, the nurse was isolated in her home while she began a drug regimen. The hospital also notified the city’s Bureau of Tuberculosis Control, which sent a team of epidemiologists into action. They marshaled months of hospital records and tried to track down every person who had crossed paths with the infectious nurse.
On March 15, when almost two months had passed since the investigation began and 271 potential victims still remained at-large, the city’s Department of Health reached out to local media in an effort to track those patients down. More than 100 have come forward since then, and seven people in total have tested positive for latent tuberculosis, which they developed after being exposed to the infectious nurse.
Both nurses fit an emerging profile. According to a recent report by the Bureau of Tuberculosis Control, the majority of health care workers with infectious tuberculosis are foreign- born female nurses between the ages of 35 and 54 who work in a hospital setting and have previously tested positive for latent infection.
Although the incidence of TB in New York City has declined steadily over the past decade, the percentage of cases in health care workers actually increased slightly over the same time periodófrom 3 percent at the height of the tuberculosis epidemic in the early 1990s to 4 percent in 2002, a small but significant change.
A nationwide nursing shortage is responsible for a large influx of foreign-born workers, many of them coming from regions of the world where TB persists in epidemic proportions.
“TB in foreign-born health care workers is increasingly likely to come from reactivation of old infections,” Munsiff says, “acquired overseas, not in New York City.”
Health care workers, however, know that latent tuberculosis cannot be transmitted, does not cause symptoms, and in the overwhelming majority of cases, never progresses to the infectious state.
“A lack of symptoms diminishes people’s sense of urgency,” Munsiff says. “And with health care workers it’s worse, because they already know the odds of developing active TB are small.”
On top of that, the treatment for latent tuberculosis infection is burdensome, and in rare cases can lead to serious side effects.
“Taking Isoniazid every day for nine months is a big pain,” explains Neil Schluger, an epidemiology professor at Columbia University’s Mailman School of Public Health. “Doctors and nurses are a great example of ‘Do as I say, not as I do.’ “Schluger points out that health care workers’ resistance to treatment goes beyond their sense of inconvenience.
“Many of them are extremely nervous about going on Isoniazid,” he says. “But in 15 years of working with it, I’ve never seen a case of serious side effects.”