BMC Public Health (Nov 2011)

Unexpected decline in tuberculosis cases coincident with economic recession -- United States, 2009

  • Winston Carla A,
  • Navin Thomas R,
  • Becerra Jose E,
  • Chen Michael P,
  • Armstrong Lori R,
  • Jeffries Carla,
  • Yelk Woodruff Rachel S,
  • Wing Jessie,
  • Starks Angela M,
  • Hales Craig M,
  • Kammerer J Steve,
  • Mac Kenzie William R,
  • Mitruka Kiren,
  • Miner Mark C,
  • Price Sandy,
  • Scavotto Joseph,
  • Cronin Ann M,
  • Griffin Phillip,
  • LoBue Philip A,
  • Castro Kenneth G

DOI
https://doi.org/10.1186/1471-2458-11-846
Journal volume & issue
Vol. 11, no. 1
p. 846

Abstract

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Abstract Background Since 1953, through the cooperation of state and local health departments, the U.S. Centers for Disease Control and Prevention (CDC) has collected information on incident cases of tuberculosis (TB) disease in the United States. In 2009, TB case rates declined -11.4%, compared to an average annual -3.8% decline since 2000. The unexpectedly large decline raised concerns that TB cases may have gone unreported. To address the unexpected decline, we examined trends from multiple sources on TB treatment initiation, medication sales, and laboratory and genotyping data on culture-positive TB. Methods We analyzed 142,174 incident TB cases reported to the U. S. National Tuberculosis Surveillance System (NTSS) during January 1, 2000-December 31, 2009; TB control program data from 59 public health reporting areas; self-reported data from 50 CDC-funded public health laboratories; monthly electronic prescription claims for new TB therapy prescriptions; and complete genotyping results available for NTSS cases. Accounting for prior trends using regression and time-series analyses, we calculated the deviation between observed and expected TB cases in 2009 according to patient and clinical characteristics, and assessed at what point in time the deviation occurred. Results The overall deviation in TB cases in 2009 was -7.9%, with -994 fewer cases reported than expected (P Conclusions Our assessments show that the decline in reported TB was not an artifact of changes in surveillance methods; rather, similar declines were found through multiple data sources. While the steady decline of TB cases before 2009 suggests ongoing improvement in TB control, we were not able to identify any substantial change in TB control activities or TB transmission that would account for the abrupt decline in 2009. It is possible that other multiple causes coincident with economic recession in the United States, including decreased immigration and delayed access to medical care, could be related to TB declines. Our findings underscore important needs in addressing health disparities as we move towards TB elimination in the United States.