SURVEILLANCE, EPIDEMIOLOGY, AND OUTBREAK INVESTIGATIONS BRANCH UPDATEShttp://www.cdc.gov/tb/publications/newsletters/notes/TBN_4_11/images/tbn411.pdf
The legacy of the Tuberculosis Epidemiologic Studies Consortium’s (TBESC) first decade is not only the body of scientific and epidemiologic research produced by its members, but also the awareness that TB research can improve the ability to perform TB control, according to Bob Horsburgh, MD, TBESC co-chair. This, the 19th Semiannual Meeting, was marked not only by scientific sessions to discuss current research, but also by a look-back at important findings over the lifetime of the consortium. Approximately 150 principal investigators, project coordinators, and other TBESC personnel attended the meeting July 20–21, 2011, in Chicago. Meeting participants focused on the steps needed to bring current projects to completion, and on lessons learned over the last 10 years. The Chicago meeting was the final meeting of the first TBESC; members discussed both the past 10 years, as well as the future of TB and LTBI research.
Day one’s scientific sessions featured presentations of current TBESC study results. One highlight of the first day’s presentation was new data from the study “Integration of Mycobacterium tuberculosis genotyping into routine TB program practice: Testing and refinement of a method to prioritize clusters for investigation.” This study was performed to determine the best way to prioritize investigation of two or more TB patients with identical genotypes, or clusters. Determining the best method of cluster prioritization is important in order to determine which clusters likely represent recent transmission and the potential for a larger outbreak, and which ones are unlikely to pose an increased risk for transmission. Wendy Cronin, PhD, reported that of 44 clusters randomly selected among three sites for investigation, 164 epidemiologically linked TB case pairs were identified. In 11 clusters, there were no identified epidemiological links between patients. Of identified epidemiologically linked pairs, 45% occurred in congregate settings, 20% in close social settings, 18% in nonresidential areas, and 17% in household settings. Next steps for the study include evaluating whether the time between cluster cases plays a role in the priority assigned to the cluster.
A study to assess the performance and agreement between the tuberculin skin test (TST) and interferon gamma release assays (IGRAs) in 2- to 14-year-old children immigrating from Vietnam, Mexico, and the Philippines found that 26% of children applying for immigration tested positive by TST, compared to only 6% testing positive by QuantiFERON Gold In-Tube (QFT). Meredith Howley, project coordinator for the study, reported that agreement between the two tests was 74%; positive results increased with age for both tests. Future analysis for this study includes evaluation of the association between the TB status of the family, and the child’s QFT and TST results.
At the end of day one of the conference, participants attended a welcome reception, as they had after the first day of previous TBESC meetings. However, the welcome reception for the final TBESC meeting featured the ukulele, played by Hawaii Field Medical Officer Dick Brostrom; the flute, played by CDC Medical Officer John Jereb; a trivia contest; and a mashed potato bar. A good time was had by all.
On the second day of the conference, presenters provided a retrospective of TBESC findings over the previous 10 years. Paul Colson, PhD, discussed “Improving LTBI Treatment Outcomes.” He stated that a TBESC research intervention to increase the knowledge of physicians in the importance of LTBI treatment was valuable in teaching them the risk of LTBI progression in HIV-infected persons, the interpretation of the TST, and the appropriateness of isoniazid (INH) in all age groups. Another study, performed at all TBESC sites, was designed to find factors associated with acceptance and completion of LTBI treatment. Phase Two of the study found that about 53% of all patients failed to complete treatment; factors associated with failure to complete treatment included a 9-month INH regimen, and being a healthcare worker. Phase Three of the study found that persons who reported that the clinic schedule was not inconvenient, or only slightly inconvenient, were more likely to accept LTBI treatment than persons who reported the schedule was a major inconvenience. Persons with stable housing were 1.7 times more likely to complete LTBI treatment than person who did not report stable housing.
Randall Reves, MD, presented TBESC findings pertaining to TB elimination in the foreign-born and U.S.-born African Americans. He reported that a TBESC study designed to identify missed TB prevention opportunities in the foreign born found that over 85% of foreign-born persons diagnosed in the first year after U.S. entry were diagnosed as a result of screening due to TB symptoms or immigration screening. Of those diagnosed in the first 3 months after U.S. entry, immigration screening was the most likely source of diagnosis. Conversely, in a TBESC study, “National Study of Determinants of Early Diagnosis, Prevention, and Treatment of TB in the African-American Community,” Dr. Reves stated that diagnosis of TB in African Americans occurred due to routine care, screening, or treatment for a comorbid condition, or as a result of a contact investigation.
Other highlights from the second day of the conference included updates from the Publications and Presentations Committee, the Translating Research into Practice Workgroup, and the External Relations Committee.
—Reported by Suzanne Beavers, MD, and Dolly Katz, PhDCDC - SEOIB Updates - TB Notes 4, 2011 - TB
Div of TB Elimination
Div of TB Elimination