Guide to the Application of Genotyping to Tuberculosis Prevention
Developing a Tuberculosis Genotyping Program
Database Management and Quality Control
Genotyping programs rely on the collection and analysis of large
quantities of data. TB programs that are implementing genotyping
programs for the first time have to address database management
issues. Although a detailed discussion of the options for database
management is beyond the scope of this document, this section summarizes
Central databases for isolate tracking, laboratory results, and
epidemiologic data are essential. Because cluster investigations
are an epidemiologic activity, the TB program should maintain the
principal databases for isolates and contact investigations. Although
clustering occurs most frequently in relatively small geographic
areas (i.e., a single county or adjacent counties), genotyping clusters
can be widespread and are not bound by state lines. Including the
number for the Report of a Verified Case of Tuberculosis (RVCT)
or the state case number in all database entries will allow a comparison
of data from different jurisdictions.
In order for field workers to have access to needed information,
data must be abstracted from different databases and merged. The
information in these databases can enable TB programs to identify
easily patients with matching genotypes and epidemiologic links.
The TB program should establish a database management system that
includes and links at least three elements.
- TB surveillance data (e.g., data collected for the RVCT).
TB surveillance data contain demographic information, patientís
risk factors, and sputum and smear results.
- Laboratory results data. At a minimum, data will include
a) the patientís name, b) RVCT or state case number, c) patientís
status (e.g., isolate represents a verified case of TB, a false-positive
culture, or a duplicate isolate), d) patientís county of residence,
e) accession numbers of submitting and genotyping laboratories,
f) names of originating and submitting laboratories, g) specimen
source, h) dates of specimen collection and culture report, i)
drug-susceptibility pattern, j) genotyping laboratory report results,
and k) cluster designations. Because a suspicion of a false-positive
culture is often based on the presence of only a single positive
culture, this information should be captured in the database as
- Epidemiologic data. A database is essential for maintaining
information about relationships between and among every patient
with matching genotypes so that results can be analyzed effectively.
At a minimum, the database should include a) the patientís name;
b) RVCT or state case number; c) case report date; d) whether
patient has epidemiologic links with other clustered patients;
e) source patientís name; f) setting of transmission; and g) whether
the link was established by a contact investigation, a cluster
investigation, or another method.
Collecting data on certain process measures is essential to ensure
and improve the quality of the genotyping program. For example,
turnaround times should be monitored so that progress in reducing
turnaround can be documented. TB programs should decide what process
measures they will collect and evaluate. Programs should consider
collecting data to provide answers to the following questions:
- Of the isolates that met submission criteria, how many were
submitted or lost or are pending?
- How much time elapsed between the date of culture report and
the date of isolate submission?
- How much time elapsed between the date of isolate submission
and the date the TB program received the genotyping laboratory
Epidemiologic investigation process measures are equally important
and should include the following questions:
- How much time elapsed between the identification of a cluster
that required a cluster investigation and a record review or patient
- How many patient interviews were needed and how many were conducted?
- Why were needed interviews not conducted (e.g., patient lost,
died, moved, or refused)?
- How many attempts were made to contact a patient (i.e., times
and type of attempts)?
- How many epidemiologic links were identified and when (i.e.,
before or after genotyping results)?
Standard Forms for Data Collection
Standardized forms are required to ensure that data are collected
in the same way for every patient. A template for collecting cluster
investigation information in a standardized manner is posted on
the WebBoard at http://web-tb.forum.cdc.gov.
The form can be employed for cluster investigations in its present
format, or it can be modified to suit the specific needs of a TB
Released October 2008
Centers for Disease Control and Prevention
National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention
Division of Tuberculosis Elimination - http://www.cdc.gov/tb
Please send comments/suggestions/requests
CDC/Division of Tuberculosis Elimination
Communications, Education, and Behavioral Studies Branch
1600 Clifton Rd., NE - Mailstop E-10, Atlanta, GA 30333