COCA Conference Call – 6/19/07Summary of Clinical Guidance: Evaluation and Management of Persons Potentially Exposed to XDR TB on Two Recent Transatlantic Flights Division of Tuberculosis Elimination Centers for Disease Control and Prevention (CDC)
Situational Review • CDC is currently investigating a case of extensively drug resistant tuberculosis (XDR TB). The case involves a U.S. citizen with potentially infectious XDR TB who traveled to and from Europe on commercial flights between May 12 and May 24, and then re-entered the U.S. at the Canada-U.S. border via automobile. • Since May 25, the patient has been hospitalized in airborne isolation or wearing an appropriate mask, and is now receiving medical therapy for XDR TB.
CDC Letter to Healthcare Providers Dear Healthcare Professional, A person with recently diagnosed culture-confirmed, extensively drug-resistant pulmonary tuberculosis (XDR TB) traveled on the following two extended flights (more than 8 hours in duration) in May 2007: Date From To Airline / Flight# May 12/13 Atlanta, Georgia Paris, France Air France #385 // Delta #8517 May 24 Prague, Czech Republic Montreal, Canada Czech Air #104 XDR TB is defined as a subtype of multidrug resistant TB (MDR TB) (i.e., an isolate resistant to at least isoniazid and rifampin), with additional resistance to at least two of the most important second-line antibiotics (i.e., a fluoroquinolone and an injectable agent [amikacin, kanamycin, or capreomycin]). Since May 25, the patient has been hospitalized in airborne isolation or wearing an appropriate mask, and is now receiving medical therapy for XDR TB. He has remained relatively asymptomatic, and his sputum smear results were negative for acid fast bacilli (AFB), both before and after his travel; however, his sputum culture results are positive for XDR TB. This is the first investigation of a case of XDR TB during air travel. Due to the serious nature of this strain of TB disease, CDC is recommending that all U.S. residents and citizens on these two flights receive evaluation, testing, and follow-up for TB infection. We are requesting your assistance to perform TB evaluation and testing on any person identified as a contact on one of these flights. Access the XDR TB Contact Investigation Form (PDF - 83K) and enter the requested information. Please keep a copy of this completed form for your records, give a copy to the person tested, and also please contact your State or Local TB control office. For inquiries related to this investigation, please call your State or Local Health Department. For more information about XDR TB. We greatly appreciate your assistance on this important international XDR TB contact investigation.
Principles of TB Testing • It can take 8 to 10 weeks following exposure until the tuberculin skin test (TST) result or QuantiFERON®-TB Gold (QFT-G) becomes positive. • A baseline test should be followed-up in 8-10 weeks with subsequent retesting
Event-Specific Considerations • For purposes of a contact investigation, a TST result of ≥5 mm induration is positive for any contact. • Persons with a documented prior positive TST or QFT-G result, or those who have been previously diagnosed with TB disease, do not need to be retested via TST or QFT-G. • However, it is important to note that these persons should still undergo TB evaluation, which may include signs and symptoms screening and chest X-ray.
Management of Non-immunocompromised Contacts with Positive TST or QFT-G Results
Management of Immunocompromised Contacts with Positive TST or QFT-G Results
Notes for Algorithms 1) Management of contacts to XDR-TB patients is complex and largely based on expert opinion. Individual patient decisions may need to vary from these algorithms based on individual circumstances. Consultation with a TB expert, especially one with experience in managing MDR or XDR TB, is strongly recommended, especially for any contact suspected of having TB disease, who has a positive TST or QFT-G result or who is immuncompromised regardless of TST or QFT-G result. For purposes of this investigation, immunocompromised contacts are those in the highest risk category according to the Targeted Tuberculin Testing and Latent Tuberculosis Treatment guidelines. (http://www.cdc.gov/MMWR/preview/MMWRhtml/rr4906a1.htm)
Notes for Algorithms (cont.) 2) Resources for consultation:a) Local or state TB control program. http://www.cdc.gov/tb/pubs/tboffices.htmb) Tuberculosis Regional Training and Medical Consultation Centers http://www.cdc.gov/tb/rtmcc.htm 3) Use of TST or QFT-G is recommended (not both). Persons with a documented prior positive TST or QFT-G result do not need to be retested. However, it is important to note that these persons should still undergo TB evaluation, which may include signs and symptoms screening and chest X-ray.
Notes for Algorithms (cont.) 4) Per ATS/CDC/IDSA guidelinesDiagnostic Standards. http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5211a1.htmTB Treatment Guidelines. http://www.cdc.gov/tb/pubs/PDF/1376.pdf LTBI Guidelines. http://www.cdc.gov/MMWR/preview/MMWRhtml/rr4906a1.htmContact Investigation. http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5415a1.htmQuanitFERON-TB Gold® http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5415a4.htm5) Examples: work or residence in a homeless shelter or correctional facility, travel to, or residence in countries with TB incidence of at least 20 per 100,000
Notes for Algorithms (cont.) 6) If infected, immunocompromised persons are at a high risk to progress to active TB. It is impossible to definitively determine if a positive TST or QFT-G result occurred due a prior TB exposure. INH or rifampin are the only known effective LTBI treatment regimens, some clinicians may elect to treat immunocompromised contacts who have a positive TST or QFT-G result with INH even if the contact does not have a known prior TB exposure or history of spending time in an environment where TB exposure is a significant possibility. Other factors that may be considered in determining whether the positive TST or QFT-G is likely a result of infection from the patient on the flight include proximity to TB patient (seated within 2 rows of patient) and if TST or QFT-G converted from negative to positive 8–10 weeks post exposure.