Key Points

Hepatitis A

• In 2023, 128 cases were reported in the region (+97% compared to 2022).

• The regional incidence rate was 1.6 cases per 100,000 inhabitants, slightly higher than the incidence rate in the rest of mainland France (1.1 per 100,000).

• The departments of Rhône and Isère accounted for more than 61% of cases.

• Children aged 5 to 14 were the age group most at risk.

• Travel to countries where the disease is endemic and contact with a case in the immediate environment were the main sources of exposure.

Invasive Meningococcal Disease (IMD)

• In 2023, 93 cases (including 9 deaths) were reported in the region (+55% compared to 2022).

• The regional incidence rate was 1.15 cases per 100,000 inhabitants, higher than the incidence rate in the rest of mainland France (0.82/100,000). Children under 4 years of age remained the age group at highest risk, followed by those aged 15–24; the average age of cases was higher than in 2022.

• Serogroups B and W accounted for 85% of cases (43% and 42%, respectively); IIM W cases showed a sharp increase compared to 2022 (number of cases x3.9).

Legionellosis

• In 2023, 335 cases were reported in the region (-10% compared to 2022).

• The regional incidence rate was 4.1 cases per 100,000 inhabitants, higher than the incidence rate in the rest of mainland France (3.1/100,000).

• The departments of Rhône, Isère, and Haute-Savoie accounted for nearly half of the cases, with the incidence rate in Haute-Savoie remaining the highest in the region (6.8 per 100,000).

• Older adults, particularly men, constituted the population most at risk. In 2023, the median age (70 years) and the case fatality rate (33 cases: 10.2%) were higher compared to the average of the past 5 years.

• Several clusters of cases linked to tourist facilities were identified in 2023.

Measles

• In 2023, 73 cases were reported in the region (+100% compared to 2022).

• The regional incidence rate was 0.9 cases per 100,000 inhabitants, higher than the incidence rate in the rest of mainland France (0.1/100,000).

• The Ardèche department accounted for more than 88% of the cases linked to an outbreak that occurred between September and November 2023 at a middle school. The index case responsible for this outbreak was unvaccinated and had traveled to an area in Asia where the virus was present.

Outbreaks of foodborne illness (TIAC)

• In 2022, 236 outbreaks of foodborne illness were reported in the region, affecting 1,623 people. An upward trend was observed compared to 2020 and 2021.

• The incidence rate was 2.9 outbreaks per 100,000 inhabitants, similar to that of the rest of mainland France (2.8/100,000).

• 40% of suspected meals were consumed at home, and 38% in commercial food service establishments.

• The most frequently implicated pathogens were: Staphylococcus aureus (23%), Salmonella (21%), and Bacillus cereus (16%).

Tuberculosis

• In 2022, 463 cases of tuberculosis were reported (+18% compared to 2021).

• The regional incidence rate of 5.6 cases per 100,000 inhabitants was higher than that of the rest of mainland France excluding the Île-de-France region (4.8/100,000).

• The departments of Isère, Loire, Puy-de-Dôme, Savoie, and Rhône had rates higher than the regional average.

• The majority of reported cases involved men under 45 years of age (63%) born abroad. Pulmonary forms were reported in more than 70% of cases.