Mycobacterium tuberculosis cluster with developing drug resistance, New York, New York, USA, 2003-2009

Abstract

In 2004, identification of patients infected with the same Mycobacterium tuberculosis strain in New York, New York, USA, resulted in an outbreak investigation. The investigation involved data collection and analysis, establishing links between patients, and forming transmission hypotheses. Fifty-four geographically clustered cases were identified during 2003-2009. Initially, the M. tuberculosis strain was drug susceptible. However, in 2006, isoniazid resistance emerged, resulting in isoniazid-resistant M. tuberculosis among 17 (31%) patients. Compared with patients with drug-susceptible M. tuberculosis, a greater proportion of patients with isoniazid-resistant M. tuberculosis were US born and had a history of illegal drug use. No patients named one another as contacts. We used patient photographs to identify links between patients. Three links were associated with drug use among patients infected with isoniazid-resistant M. tuberculosis. The photographic method would have been more successful if used earlier in the investigation. Name-based contact investigation might not identify all contacts, particularly when illegal drug use is involved.

Figure 1

Cluster of 54 cases of tuberculosis (TB), by year of diagnosis, New York, New York, USA, 2003–2009. The 54 cases include 1 in a patient in the city of New York who was given a diagnosis of drug-susceptible Mycobacterium tuberculosis infection in 2007 that was counted by New York State.

Figure 2

Residences of patients (n = 54) at time of tuberculosis diagnosis, by neighborhood, New York, New York, USA, 2003–2009. Forty-two neighborhoods were designated by the United Hospital Fund. Each neighborhood is defined by several adjoining ZIP codes (www.nyc.gov/html/doh/html/epi/mapgallery.shtml).

Figure 3

IS6110 restriction fragment length polymorphism patterns for tuberculosis patients, New York, New York, USA, 2003–2009. Left lane, molecular mass ladder; lane A, n = 48; lane B, n = 1; lane C, n = 1; lane D, n = 4. Spoligotype results (octal code designation) were 777777774020771 for 54 patients. Twelve-loci mycobacterial interspersed repetitive-unit variable-number tandem repeat results were 225313153321 for 53 patients and 2253131–3321 for 1 patient; the dash indicates that there was no peak at this locus for this 1 patient, and the patient with this isolate met the original cluster case definition.

Figure 4

Common characteristics among 54 patients infected with Mycobacterium tuberculosis, by year of tuberculosis diagnosis and drug susceptibility testing results, New York, New York, USA, 2003–2009.