Contact tracing of in-flight measles exposures: lessons from an outbreak investigation and case series, Australia, 2010

Abstract

Review of current contact tracing guidelines following in-flight exposure to an infectious measles case is required. Alternative strategies could include expanding routine contact tracing beyond the two rows on either side of the case's row or expansion on a case-by-case basis depending on cabin layout and case and contact movements in flight. Releasing information about the incident by press release or providing generic information to everyone on the flight using e-mail or text messaging information obtained from the relevant airline, may also be worthy of consideration. Disease importation, inadequately vaccinated young adults and health care-related transmission remain challenges for measles control in an elimination era.

A risk stratification approach to assessing for true cases of measles in a highly vaccinated population

“…The strength of this small case series is the completeness of the dataset and the use of the current national case definition. Outbreak papers often do not include epidemiological and clinical features for rejected notifications; 7,9,10,24,25 while previous Australian case series generally have poor 26,27 or unverified 20 documentation of vaccination status or do not state how it was determined 8,27 . Many used older versions of the national case definition with differing clinical features 8,20,28 or low proportions of cases confirmed by laboratory definitive evidence 28 .…”

“…During this elimination phase, outbreaks have been characterised by the introduction of overseas‐acquired infections into pockets of susceptible residents 7–10 . Residents who are overseas‐born, and thus may not have followed the Australian immunisation schedule, are particularly vulnerable 7,11 .…”

Measles transmission at an international airport — Taiwan, March–April 2018

“…Routine measles contact tracing of aircraft passengers based on seating proximity is not recommended in the European and Australian guidelines (ECDC, 2009;CDNA, 2019); if initiated, however, eight rows from the case is the minimum distance that should be considered for contact tracing (ECDC, 2009). When investigating measles cases in travelers, expanded strategies, including routinely releasing the itinerary of the index case during their infectious period to identify unknown contacts (Beard et al, 2011;Nelson et al, 2013), are recommended by TCDC to facilitate the identification of exposures and additional cases.…”

Geography, global pandemics & air travel: Faster, fuller, further & more frequent

“…Standard World Health Organization (WHO) guidance on potential transmission onboard airlines for TB, for example, suggests follow-up contact tracing on the row of an infected person, plus two rows ahead and behind [27]. However, there is growing evidence that this 'two row rule' may be ineffective [28][29][30][31].…”

“…Given the fragile nature of international public health [16,17], and concerns over inadequate though authoritative contact tracing advice [28][29][30][31], it is vitally important to acknowledge developments that are likely to further challenge this weak infrastructure. This piece examines three ongoing developments in air travel that are likely to adversely hamper pandemic preparedness in the forthcoming decades.…”