Contact tracing in international travel: A German national prospective study. Preliminary results and case example

Transcription

1 Contact tracing in international travel: A German national prospective study Preliminary results and case example Benedikt Greutélaers Robert Koch Institute, Surveillance Unit CAPSCA, Content Part 1: Background, methods and preliminary results Part 2: Case example: Measles on a long haul flight 2

2 Definition Contact tracing:. is an investigation procedure aimed at acquiring contact information in order to approach contacts that were potentially exposed to pathogens. Quelle: RAGIDA Technical Report, ECDC, Background More than 1.5 trillion passenger kilometers in EU 27 (Air, bus and train, 2007) So far no systematic investigation of contact tracing in Germany Findings are mostly based on anecdotal reports Source: www. wz-newsline.de 4

3 Background Article 18 IHR Recommendations with respect to persons, baggage, cargo etc. comprises: implement tracing of contacts of suspect or affected persons Article 23 IHR Health measures on arrival and departure: information concerning the traveller s destination so that the traveller may be contacted German IHR Implementation Act in force since Contact tracing (on Article 23 paragraph 1 letter a IHR): the air carrier has to make the data immediately available to the health department. Penalty up to 30,000 if data is not provided at all or not correctly, completely or in a timely manner 5 Background European projects on contact tracing Development of decision aids When to conduct contact tracing? Air transport RAGIDA (Risk assessment guidelines for diseases transmitted on aircraft) Diseases: TB, measles, meningococcal disease, SARS, viral haemorrhagic fevers, rubella* Ground transport REACT(Response to emerging infectious diseases: assessment and development of core capacities and tools)** Diseases: TB, measles, meningococcal disease * ( **( 7 tool,templateid=raw, property=publicationfile.pdf/wp_7_tool.pdf) 6

4 Aim of the study Collection of contemplated and carried out contact tracing in international travelers*: frequencies, decision basis and implementation details Basis for further / revised guidance * Only travelers to (not from) Germany will be included in the study. 7 Study questions 1. How often does the public health service receive information about potentially infectious international travelers, where contact tracing is considered? Active monthly surveillance (E mail query) 2. What is the decision basis for and against the implementation of contact tracing? Decision questionnaire (questionnaire 1) 8

5 Study questions 3. How often is contact tracing performed? Decision questionnaire (questionnaire 1) 4. How (methods of contact tracing, difficulties, etc.) and with what results (number of identified contacts, conducted interventions, etc.) was contact tracing performed? Detail questionnaire (questionnaire 2) Person questionnaire (questionnaire 3) 9 Methods Questionnaire based, prospective longitudinal study Participating institutions: Local public health authorities at designated points of entry Local public health authorities responsible for further large transportation hubs RKI Regional public health authorities German railway company 10

6 1. Active monthly surveillance (E mail query) No Contact tracing considered? Yes No further questionnaire 2. Decision questionnaire (questionnaire 1) Decision basis for / against contact tracing One questionnaire per event No Contact tracing conducted? Yes 11 No further questionnaire 3. Detail questionnaire (questionnaire 2) Details of the conducted contact tracing One questionnaire per contact tracing + Person questionnaire (questionnaire 3) Details of contact persons, including interventions etc. One questionnaire per contact person Preliminary results (May 2012 April 2013) Contact tracing considered: 15 Diseases: Means of transport: Decision aids used: 14x TB 1x Measles 13x Aircraft 1x Bus 1x Train 8x (e.g. RAGIDA, REACT) Contact tracing conducted: 4 (3x TB und 1x measles) 12

7 Preliminary results (since May 2012) Reasons against contact tracing: Reasons for contact tracing: Duration to obtain passenger list: No data of contacts available (passenger lists) Results of decision aids Low infectiousness High infectiousness Cooperation with airline Investigation at place of residence no longer available 7 days Contacts/ successfully traced (%): 60/408 (15 %) 13 Preliminary results (since May 2012) Measures taken (N=25): Main problems: Interview for risk assessment: 23x Yes Further measures: 5x 2x titer control (Measles) 1x booster vaccination (Measles) 2x Diagnostics + INH prophylaxis (TB) Availability and content of passenger lists Feedback on international contacts Expenditure of time 14

8 Interim conclusion Well accepted by participating health authorities Less incidents than expected Very few people successfully traced Measures: usually only information about exposure Main problems: Obtaining passenger lists with valid contact information Large expenditure of time in the absence of resources No uniform approach for contact tracing Lack of feedback on international contacts 15 Part 2 Case example: Measles on a long haul flight 16

9 Case example: background Measles : Incubation period 7 18 days Infectivity 5 days before to 4 days after onset of rash Literature: Measles transmission aboard aircrafts (up to eight rows of seats away from an index case, regardless of flight duration)* Possible (reasonable) measures*: Post exposure vaccination up to 3 days after exposure Human immunoglobulin up to 6 days after exposure Information aboutexposure duringincubation * Schenkel K, Amorosa R, Mücke I, Dias Ferrao V, Diercke M, Leitmeyer K, et al. Risk Assessment Guidelines for Infectious Diseases transmitted on Aircraft (RAGIDA) Stockholm, European Centre for Disease Control. 17 Case example: background Local health authority gets information about index patient 3 days after flight Symptoms (onflight): cough, fever, rash Receipt of passenger list after 20h Reasons for contact tracing: Infectiousness High number of suspected contacts (> 300) Duration of exposure No decision aid used 18

10 RAGIDA: measles * For practical reasons, contract tracing should start with the seating row of the index case and then proceed row by row in both directions, for as long as time allows. ** As defined by national guidelines 19 Case example: contact tracing Passenger list: 344 contact persons, excluding crew (103 Germans, 220 from 29 other states, 21 of unknown origin) Local health authority in the jurisdiction of the index patient informs authorities in the jurisdiction of presumed residence (as of passenger list) of contacts RKI informs via EWRS or IHR Focal Points 20

11 Case example: results International: feedback from 23/29 countries (content from acknowledgements to details of measures) 20/220 (9%) contacts successfully traced* National: Contacts Total Successfully traced Not traceable No information (31 %) 34 (33 %) 37 (36 %) * Contacts who have been reached and where measures have been taken (from information to post exposure prophylaxis etc.) 21 Case example: results Period between exposure and contact (N = 24): 4 14 days (median = 5 days) Measures taken: Interview for risk assessment (N=23): 21x Yes, 2x No Further measures (N=3): 2x titer control, 1x booster vaccination Follow up: Number of symptomatic infections (N=21): none Number of seroconversions (N=11): none 22

12 Case example: summary A total of 52/344 (15%) contacts successfully traced (national + international) 1 Contact was given a booster vaccination No detection of symptomatic disease or seroconversion after exposure 23 Case example: conclusion Contacting airline unproblematic (contact after 30 min reached) Passenger list received after 20 hours, with the name of the contacts. But, residence information problematic: Address of the contact" (with address in Germany) Addresses (partly Tel) from travel agency Not possible to assign Real contact address Number of contacts (%) 97 (94,2 %) 5 (5,8 %) 0 (0 %) Travel agents and online providers partly refuse to hand over customer data 24

13 Case example: conclusion Residence of contacts often in a jurisdiction other than presumed from passenger list Enormous coordination effort No clear regulation on responsibility for the coordination The question of proportionality was raised by participating institutions 25 Team at RKI: Dr. Christophe Bayer Dr. Maria Wadl Dr. Andreas Gilsdorf Dr. Tim Eckmanns E Mail: KoNa@rki.de Tel: / 3426 Fax: Thank you! Robert Koch Institute Department for Infectious Disease Epidemiology Surveillance Unit DGZ Ring 1, D Berlin Germany Source: www. spiegel.de Source: www. wz-newsline.de 26