National Center for Emerging and Zoonotic Infectious Diseases

Division of Global Migration and Quarantine

Karen J Marienau, MD, MPHCenters for Disease Control and Prevention

kqm5@cdc.gov

CDC 2011 Protocol for Flight-Related

Tuberculosis Contact Investigations

TB PEN WebinarAug 7, 2013

Overview

Background of flight-related tuberculosis (TB) contact investigations (CIs)

Changes to CDC protocol for flight-related tuberculosis contact investigations (TBCIs) that were implemented in July 2011

Preliminary results of TBCIs conducted under the CDC 2011 protocol in comparison to those conducted under the CDC 2008 protocol

BackgroundAirline TBCIs

World Health Organization (WHO) provided guidelines for flight-related TBCIs in 2006 (updated in 2008*)

Public health benefits of airline TBCIs are not well established

Airline TBCIs are time-consuming, costly, and compete for resources with other TB prevention and control efforts with well-established benefits

*http://www.who.int/tb/publications/2008/WHO_HTM_TB_2008.399_eng.pdf

BackgroundAirline TBCIs (cont.)

Two of 13 studiesa showed reliable evidence of Mycobacterium tuberculosis transmission

Two CDC reviewsb,c of TB CIs conducted in the US were inconclusive, but suggested risk of transmission was low

No documented cases have been reported of TB disease resulting from exposure during air travelaAbubakar, I. Tuberculosis and air travel: a systematic review and analysis of

policy. Lancet Infect Dis. 2010:10:176-83

bKornylo-Duong K,, et al. Three air travel-related contact investigations associated with infectious tuberculosis, 2007–2008. Travel Med Infect Dis (2010);8:120-8

cMarienau KJ, et al. Tuberculosis investigations associated with air travel: US CDC Jan 2007-June2008. Travel Med Infect Dis (2010);8:104-12

Flight-related TBCIs in the United States

Quarantine branch staff Determine whether the case meets protocol

criteria for conducting a TBCI Obtain passenger contact information from

airline and Customs and Border Protection Provide information to US state health

departments US health departments

Locate and evaluate passenger contacts according to national guidelines*

Report results to DGMQ (voluntary)*Guidelines for the Investigation of Contacts of Persons with Infectious Tuberculosis: Recommendations from the National Tuberculosis Controllers Association and CDC MMWR 2005; 54 (No. RR-15, 1-37)

Comparative Cost-Benefit Analysis

To evaluate the cost-benefit of TBCIs for preventing TB disease following exposure during air travel we:

Identified 3 potential alternatives to the CDC 2008 protocol for flight TBCI

Selected one potential alternative protocol to the 2008 CDC protocol for comparative risk and economic analyses

Comparative Cost-Benefit AnalysisCDC 2008 Protocol vs. CDC 2011 Protocol

Risk analyses: Epidemiology of TBCIs conducted from 2007 to 2009 to

predict numbers and clinical characteristics of index cases and number of passenger contacts

Outcomes data from TBCIs from Jan 2007 to Jun 2008* to predict passenger contact outcomes

Economic analyses: Estimate the immediate costs of TBCIs for health

department and DGMQ Return on Investment Model to estimate the long-term

impact of airline TBCIs related to reducing future cases of TB disease:

(Gain of investment – Cost of investment) / (Cost of investment)

*Marienau KJ, Burgess GW, Cramer EH, et al. Tuberculosis Investigations associated with air travel: US CDC Jan 2007-June2008. Travel Med Infect Dis 2010;8:104-12

Comparison of 2008 and 2011CDC TB Protocols for Flight-Related Tuberculosis

Contact Investigations

Criteria 2008 CDC Protocol 2011CDC Protocol

Diagnosis relative to flight date

Within 3 months of flight

Within 3 months of flight

Time since flight when CDC notified

Within 6 months of flight

Within 3 months of flight

Isolate: susceptible to isoniazid (INH) or rifampin (RIF)

Sputum smear +, chest radiograph (CXR) with/without cavitation; OR sputum smear - and CXR with cavitation

Sputum smear + ANDCXR with cavitation

Isolate: multidrug-resistant (resistant to INH and RIF)

All All

Results of Comparative Risk and Economic Analyses for CDC 2008 and

2011 Protocols

Risk of acquiring latent TB infection (LTBI) on a flight: 2008 vs. 2011 criteria 2008 criteria: risk range was 1.1% - 24% 2011 criteria: risk range was 1.4% - 19%

Economic impact– Immediate 2011 protocol would result in about half as

many TBCIs, and approximately 50% reduction in HD costs

Economic impact – Long term Return on investment comparable for the two

protocols

Risk and Economic Analyses Outcomes

Our analyses predicted that public health resources would be conserved with minimal negative effect on TB prevention and control if the 2008 CDC flight-related TBCI protocol was replaced by the 2011 CDC Protocol

The 2011 CDC protocol was implemented July 1, 2011, with endorsement by CDC’s Division of TB Elimination and the National TB Controllers Association

2011 CDC TB Air Travel Protocol Implemented July 1, 2011 Criteria for initiating a TBCI

Index case• diagnosed ≤ 3months after flight• Sputum smear positive AND cavitation on CXR OR• Multidrug-resistant isolate

Flight• ≥ 8 hours long (gate-to-gate)• ≤3 months of notification of index case to CDC

Considerations for doing a CI even if criteria not met Cavitation on CT scan but not on CXR, or no

CXR More than expected close household contacts

with positive screening tests Laryngeal TB

Comparison: 2008 Protocol Last 18 months and 2011 Protocol First18

Months

Numbers Jan 1, 2010-June 30, 2011* (2008

Protocol)

July 1, 2011-Dec. 31, 2012 (2011

Protocol)

TB Cases 119* 52

Passenger contacts (total) 3798* 1620

Passenger contacts (Assigned to US

health departments)

2790* 1096

*Excludes 5 cases, 51 flights, and 1549 passengers (911 passengers assigned to states)from contact investigations done for outbound flights because DGMQ stopped doing CIs on outbound flights in May 2011. Since then DGMQ notifies the country where flight arrived of the TB case, and they conduct a CI according to their national policy .

Preliminary data

Acknowledgments State and local TB control program staff National TB Controllers DTBE: Ken Castro, Tom Navin, Phil Lobue, Maryam

Haddad, Sundari Mase, John Jereb CDC Quarantine Station staff involved in

TBCIs Quarantine Branch staff involved in risk and

economic analyses of 2011 protocol: Elaine Cramer, Maggie Coleman, Nina Marano, Marty

Cetron Quarantine Branch staff that assisted with

data entry/analyses Chris Schembri , Jenna Kirschenman, and Faith Washburn

National Center for Emerging and Zoonotic Infectious Diseases

Division of Global Migration and Quarantine

The findings and conclusions in this presentation are those of the authors and do not necessarily represent the official position of the

Centers for Disease Control and Prevention

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