TB Notes Newsletter
No. 3, 2013
SURVEILLANCE, EPIDEMIOLOGY, AND OUTBREAK INVESTIGATIONS BRANCH UPDATES
Developing a Surveillance Definition for Binational Tuberculosis Cases
Successful treatment of persons with tuberculosis who cross international borders during their infectious or treatment periods requires significant collaborative efforts among TB programs in more than one country. Particularly with patients who go between the U.S. and Mexico, the relationship between border crossing and the impact on TB control in U.S. border states has been documented.1,2 TB patients who travel or move to another country require staff time and resources above and beyond what is typically provided for TB patients who receive all of their care and treatment in one country.2 However, owing to the lack of a uniformly applied surveillance definition for binational TB cases, there are currently no data that measure either the extent of the binational burden or the epidemiologic trends.
In 1999, the Tuberculosis Along the U.S.-Mexico Border Work Group, made up of staff from CDC and 17 state and local programs in Arizona, California, New Mexico, and Texas, proposed a binational TB case definition and recommended development of a registry for binational TB cases.2 More recently, the U.S.-Mexico Binational Commission has developed a set of guidelines for cross-border coordination of public health events, such as infectious disease outbreaks, which includes a proposed general definition for a binational case that can be applied to all notifiable diseases.3 While these proposed definitions may be useful for programmatic purposes, they may not necessarily meet the needs of TB surveillance in the United States.
The objective of this project is to develop a TB-specific surveillance definition that is easy to apply and interpret uniformly across reporting jurisdictions using routinely collected data that may or may not be currently reported to CDC. An effective and useful surveillance definition will be TB-specific as well as easy to apply and interpret, and will minimize inconvenience on TB programs by using information that is already being collected. In addition, the definition should be consistent with other binational definitions, and it should not detract from federal, state, or local TB control program activities.
Summary of Recent Activities
Estimating Binational TB Case Burden in Select Border Counties, California and Texas
During October 2012–April 2013, epidemiologists from CDC's DTBE interviewed key informants, including staff associated with binational treatment programs, at the state, regional, and county levels. They sought to describe systems of case management for binational cases and the collection and reporting of binational information. Data on binational patient characteristics were abstracted from medical or clinic records in four border counties to make an inventory of information currently being collected that could help in creating a standard surveillance definition for a binational TB case. Medical records for patients who met the following criteria were included in the review: 1) patient had a verified case of TB, 2) case was reported to the CDC National Tuberculosis Surveillance System in 2011, and 3) patient was born in the United States or Mexico.
Binational characteristics abstracted from the records included TB treatment in Mexico, contact investigation in Mexico, travel to Mexico during infectious period, travel to Mexico during treatment, contacts elicited in Mexico, and epidemiologically linked cases diagnosed in Mexico. This information was obtained from a combination of treatment forms, contact investigation forms, patient interview forms, and case manager notes. Across all four counties, an average of 17% of TB cases that were reviewed either received treatment in Mexico or had a contact investigation done in Mexico, and 42% had at least one of the binational characteristics specified above.
U.S.-Mexico Tuberculosis Summit
DTBE staff held a half-day summit during the 2013 National TB Conference. The purpose of the summit was to discuss key demographic, social, and risk factor data to be incorporated in a surveillance definition for a binational TB case. Invited speakers from federal, state, and local TB and border health programs presented their activities related to management and surveillance of binational TB cases and key data elements used to ascertain binational cases locally.
In addition to DTBE staff, summit attendees included program staff from Arizona, California, New Mexico, and Texas, members of CDC's Division of Global Migration and Quarantine, panel physicians (physicians who provide required medical examinations to persons applying for entry to the United States) from Mexico, and staff from Mexico's National Tuberculosis Control Program. Attendees agreed that it is important to develop and pilot a surveillance definition for binational TB cases.
Developing and Piloting a Surveillance Definition
Data elements discussed during the NTCA U.S.-Mexico TB Summit were summarized and used to create a draft surveillance definition for binational TB cases. A pilot project to implement the proposed definitions in at least six jurisdictions in areas along the U.S.-Mexico border, as well as at least one jurisdiction not located on the U.S.-Mexico border, is under development. Pilot sites will collect data on a standardized form and will send completed forms to CDC for data entry and analysis. An evaluation of the sensitivity and specificity of the proposed surveillance definition for binational TB cases will follow the pilot project.
There is a need for a national surveillance definition for binational TB cases in the United States that is TB-specific, easy to apply and interpret, and based on data that are already being routinely collected. The definition developed for surveillance purposes will not affect federal, state, or local TB control activities. The primary purpose of developing a surveillance definition is to quantify the burden and monitor trends in binational TB cases. Using the data to educate policy makers and partners in TB control will be helpful to promote investments in systems for prevention and control. For more information about the collaborative effort to develop a national surveillance definition for binational TB cases, please contact Rachel Yelk Woodruff by e-mail at firstname.lastname@example.org or by telephone at 404-639-6018.
Andy Heetderks, and Roque Miramontes
Div of TB Elimination
- Schneider E, Laserson KF, Wells CD, and Moore M. Tuberculosis along the United States-Mexico border, 1993-2001. Pan Am J Public Health 2004; 16:23–33.
- Centers for Disease Control and Prevention. Preventing and controlling tuberculosis along the U.S.-Mexico border: work group report. MMWR 2001;50(No. RR-1): 1–27.
- Technical guidelines for United States—Mexico coordination on public health events of mutual interest. Available at http://www.cdc.gov/USMexicoHealth/united-states-mexico-guidelines-cooperation.html. Accessed July 10 2013.