From the ECDC Weekly Communicable Disease Threats Report, the US CDC, and the WHO:
- Marburg virus disease (MVD) outbreak in Tanzania: The MVD outbreak in Rwanda was declared over last month. On 20 January, Tanzania declared an MVD outbreak in Kagera region where a previous outbreak occurred in March 2023. This time so far 10 cases have been reported, of which two confirmed and eight probable. Response efforts are ongoing: https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON552
- Acute respiratory infections: There is high influenza activity in Europe as expected for this time of year, while SARS-CoV-2 activity is at very low level. It looks like influenza has peaked in the US as well earlier this month.
- Global outbreak of mpox: The global epidemiological situation of clade I and clade II mpox remains essentially unchanged with the virus circulating in multiple countries.
- Highly pathogenic avian influenza (HPAI) A(H5N1):
- Ohio is the US state with the most cases of H5N1 avian influenza in poultry, with some 3 million birds affected.
- Recent research has revealed signs of mammalian adaptation of viral strains circulating in cattle populations.
- Human infections with avian influenza viruses remain rare and sporadic, with no evidence of sustained human-to-human transmission so far. According to the US CDC, the risk to the general population remains low.
A selection of other articles of interest:
First large-scale epidemiological study on fume events
This article published earlier this month in Aerospace Medicine and Human Performance (commonly referred to as the “Blue Journal”) represents a groundbreaking retrospective cohort study on the medical consequences of fume events.
As highlighted by the authors, Michel Klerlein and Lena Dubiez, prior scientific and other literature on the medical effects of fume events primarily consisted of case reports or experimental studies involving a limited number of subjects. This new study marks a significant advancement by involving a robust dataset of 14,953 Air France crewmembers, including 2,577 individuals exposed to a fume event and 12,376 matched controls.
The research focused on comparing the incidence of new medical conditions or chronic symptoms in flight crews following exposure to fume events, according to whether they had been exposed or not and using hazard ratios to estimate the risk.
Though the study had some potential limitations—such as the data being recorded by several different doctors, potential underreporting (particularly by pilots), and possible confounders associated with the retrospective nature of data collection—it has significant methodological strengths:
- Data quality, completeness, and consistency: In France, there is mandatory occupational medical follow-up for crewmembers every two years. All the participants in the study were monitored by the same occupational medicine department. Since 2017, this department has systematically recorded all identified fume event exposures and distributed a digital questionnaire to all involved crewmembers.
- The study cohort included all the crewmembers who were actively working between 2017 and 2022. Each exposed crewmember identified was matched with at least one control non-exposed crewmember.
- All conditions and symptoms analyzed in the study were confirmed by a medical doctor and coded in a standardized manner. This approach is rare in epidemiological studies that predominantly involve baseline healthy worker populations.
- The study included a substantial number of fume events (357) and a large cohort of crewmembers. This provided the study with a high level of statistical power, enabling the detection of even small differences between the exposed and non-exposed groups.
The authors conclude that fume events in this study were not associated with significant clinical consequences for cabin and cockpit crew; the results do not support the proposal of an “aerotoxic syndrome” in association with exposure to fume events.
For more details: Klerlein M, Dubiez L. Medical consequences after a fume event in commercial airline crews. Aerosp Med Hum Perform. 2025; 96(1):12–17.
Dr Rui Pombal
IATA Medical Advisor