Disease outbreaks and other matters of airline medical interest

From Airfinity’s curated analysis of various health and media sources and from the ECDC (European Centre for Disease Prevention and Control) Weekly Communicable Disease Threats Report:

  • On December 4th, JN.1 was officially designated as a variant by the UKHSA. The variant is a sublineage of BA.2.86.1 and contains the L455S mutation in the spike protein, which is associated with very high immune escape but significantly attenuated infectivity. First detected in Luxembourg, JN.1 is believed to have evolved from the Pirola variant (BA.2.86), which itself stems from the Omicron sub-variant. According to the WHO, Pirola and its variants accounted for 17% of the Sars-CoV-2 sequences uploaded to the global database GISAID. By the beginning of December, more than half of these sequences were of JN.1.
  • In vitro data suggest that vaccines are still effective against JN.1 (UKHSA).
  • In Europe, SARS-CoV-2 continued to circulate at higher levels than seasonal influenza and respiratory syncytial virus (RSV). Countries have been reporting a mix of increasing and decreasing trends for SARS-CoV-2 activity.
  • ECDC: UKHSA have published an update on the recently reported human case of swine influenza virus A(H1N2) variant infection, detected in England. The person resides in an area where several pig farms are located. No human-to-human transmission has been detected so far. The occurrence of sporadic human cases following exposure to pigs is expected due to the high prevalence of swine influenza viruses in the pig population.
  • Seventeen countries from Asia, Europe and North America, have reported cases of atypical pneumonia amongst children.
  • Bangladesh has reported its highest Nipah virus burden for eight years, with the virus detected in breast milk for the first time.
  • The Philippines has reported a 5-fold increase in chikungunya incidence compared to the same period last year, while dengue incidence is declining.
  • Dengue and Chikungunya overviews:

For those less conversant with clinical topics here is a very good short introduction on Chik: https://www.who.int/health-topics/chikungunya#tab=tab_1 

Links to selected articles/publications of interest:

  • One very relevant document for airlines and airports - the 2nd Edition of the WHO aircraft disinsection methods and procedures manual:

https://iris.who.int/bitstream/handle/10665/374318/9789240080317-eng.pdf?sequence=1

The pre-departure method for a single flight sector replaces the previous “blocks-away” and “top of descent” methods and comprises aerosol spraying of the aircraft cabin after passenger

embarkation but before the overhead lockers are closed and the aircraft is pushed back for departure. And much more, of course.

With thanks to Dr Vincent Feuillie and Dr Michel Kleinert from Air France for drawing my attention to the publication of this landmark document, I’d like in turn to highlight to you this 350+-page report on cabin air quality and occupational health of air crew (Etat des connaissances sur les effets sur la santé liés à la profession de personnels navigants et sur la qualité de l’air dans les cabines d’avion) published a few weeks ago by the French Agency for Food, Environmental and Occupational Health & Safety, ANSES.

The drive for this comprehensive report came from formal a request from a French labour union federation for a scientific assessment concerning the symptoms reported by air crew and healthcare professionals grouped under the term “aerotoxic syndrome”, which have at times been associated with unusual odours or fumes in aircraft cabins.

The work undertaken was vast and included an extensive review of the scientific literature (until as recently as June 1st 2023), as well as of the grey literature and of health data from the French national occupational disease surveillance and prevention network. Various civil aviation stakeholders and international agencies and organizations were also consulted.

The conclusions of the assessment are in accordance with the US National Research Council (NRC) conclusions from 2002: there is a low level of evidence for the existence of a syndrome specifically linked to exposure to various polluting substances or breakdown products from aircraft engine or hydraulic fluid leaks.

ANSES stress that, though not questioning the symptoms described by individuals, there is no consensus to date around whether “aerotoxic syndrome” (a term coined in 1999) corresponds to an actual nosological entity (i.e. a syndrome or a disease), in that the reported symptoms are diverse and non-specific.

The ANSES report includes international data on prevention, identification, and recommended actions in case of a CAC (“cabin air contamination”) event. You can find IATA’s Cabin Air Quality Event (CAQE) FAQs here: https://www.iata.org/contentassets/ccbdc54681c24574bebf2db2b18197a5/faq-cabin-air-quality-event.pdf  and guidance on response here:

https://www.iata.org/contentassets/ccbdc54681c24574bebf2db2b18197a5/guidance-medical-response-cabin-air-events.pdf

Given the low level of evidence found, ANSES concludes that more studies are needed, and highlights four that are currently still ongoing:  AVISAN (Bensefa-Colas et Mullot 2019, Bossard 2017); SPACE, Etude de la Santé du Personnel navigant d’Air France; FAA & ASHRAE research on bleed air contamination; CAQ III.

Those of you who attended the IATA/IAMA Aviation Health Conference last September could see the presentation by Dr Joerg Hedtmann of the FUSE II study, which is expected to be published soon. The study was promoted by the German Institute for prevention and occupational medicine (IPA) and BG Verkehr institute for transportation, and it involved biological monitoring of aircrew after fume and odour events. The preliminary conclusions presented were that “[crew exposed to fume and smell events] show no relevant levels of potentially toxic substances in body fluids”; short term health effects were seen but no evidence of chronic disease was found; and “[…] there is a background exposure of the general public”.

The ANSES report also addressed irregular hours and ionising radiation – expect another sum-up for the MC Group next week.

Meanwhile, if you want to read the document in full (in French) you can download it here: https://www.anses.fr/fr/system/files/AIR2019SA0075Ra.pdf . For a short summary in English: https://www.anses.fr/en/content/health-flight-crew-members  

  • According to the IATA 2023 Global Passenger Survey (GPS) https://www.iata.org/en/publications/store/global-passenger-survey/ , in what concerns the accessibility of air transport to passengers with disabilities, more travellers than ever are requesting assistance and 80% of passengers who used special assistance services report that their expectations were met. However, 20% call for improved online accessibility for booking and reservations. IATA recommends developing a user-friendly gateway to the specific accessibility portion of airlines’ websites, emphasising the importance of passengers requesting assistance early, preferably while searching.

Season’s Greeting everyone!

Dr Rui Pombal
IATA Medical Advisor