Key Points

Measles

• 159 cases of measles (including 12 imported cases) among residents of Occitanie were reported, with no difference by sex. The male-to-female ratio was 0.92.
• The regional incidence rate (calculated excluding imported measles cases) was 2.4 cases per 100,000 inhabitants, higher than that of France as a whole (1.1).
• Children under 1 year of age were the most affected age group.
• Clusters of measles cases were more frequently observed in the departments of Aude and Tarn-et-Garonne.
• Among the cases, 90% were unvaccinated or had received only a single dose of the vaccine.
• A resurgence of measles cases has been observed since 2024 in both France and Occitanie.

Invasive meningococcal disease (IMD)

• 54 cases among residents of Occitanie were reported. The male-to-female sex ratio was 0.74.
• The regional incidence rate was 0.87 cases per 100,000 inhabitants, lower than that for France as a whole (0.92).
• The most common serogroups were serogroup B (48%) and W (28%); the others were serogroup Y (17%) or other serogroups or untyped cases (7%).
• Infants under 1 year of age and children aged 1 to 4 years were the most affected (serogroups B and W).
• No clusters of cases¹ or areas of excess incidence were identified in 2025.
• The increase in the number of cases observed since 2023 in France and in Occitanie may be linked to a decline in post-COVID-19 immunity as well as to the severity of the influenza epidemic in 2024–2025.

Leptospirosis

• Thirty-three cases among residents of Occitanie were reported in 2025, which was the second full year of surveillance under mandatory reporting (since August 2023). The male-to-female sex ratio was 2.8.
• The regional incidence rate was 0.53 cases per 100,000 inhabitants in 2025, similar to that of mainland France.
• The case descriptions confirm the known profile: predominantly male, aged 30–50 (although, exceptionally, several pediatric cases were reported), a summer surge, and potential severity.
• The clinical presentation and the hospitalization rate—particularly in intensive care—highlight the potential severity of this disease.
• Identified risk exposures included: contact with domestic or wild animals; the presence of rodents at home or at work; participation in freshwater activities, gardening or agricultural activities, high-risk occupational activities; or a recent return from travel.
• A comparison with CNR data suggests underreporting, as only 61% of cases confirmed by the CNR in 2024 in Occitanie were reported in the MSO surveillance system.
• The severity of the reported cases suggests possible underdiagnosis and underreporting of cases with milder forms of the disease.

Hepatitis A

• 167 cases among residents of Occitanie were reported, with a resurgence of hepatitis A cases at the regional and national levels in 2025. The male-to-female sex ratio was 1.1.
• Among the documented risk exposures, travel to countries where the disease is endemic represented the primary risk exposure. Abroad, numerous cases of acute hepatitis A have been reported among populations exposed to poor sanitary conditions in several Eastern European countries since January 2025.
• The regional incidence rate was 2.7 cases per 100,000 inhabitants, identical to that of France as a whole.
• Incidence rates were highest in the Pyrénées-Orientales, Tarn-et-Garonne, and Hérault departments.
• Children aged 5 to 14 were the most affected age group.
• Since 2023, there has been a gradual increase in the incidence rate at both the regional and national levels.

Listeriosis

• 54 cases of listeriosis among residents of Occitanie were reported in the region. The male-to-female ratio was 0.66.
• The incidence rate was 0.87 per 100,000 inhabitants (slightly higher than the rate of 0.78 for France as a whole).
• Incidence rates were highest in Lozère, Ariège, and Gers, although the number of cases in each of these departments was fewer than 5.
• The annual number of non-maternal-neonatal listeriosis cases showed a marked increase in Occitanie in 2019 and 2021, while it has been rising steadily across France. The number of maternal-neonatal cases remained stable over the period.

Tularemia

• In 2025, 25 cases of tularemia among residents of Occitanie were reported in the region.
• 52% of the cases were men. The male-to-female sex ratio was 0.52.
• The incidence rate was 0.40 per 100,000 inhabitants (higher than in mainland France (0.21)). The Gers department had the highest incidence rate (2.6 cases per 100,000 inhabitants, N=5).
• The most affected age group was 18–64 years old, with an incidence rate of 0.57 per 100,000 inhabitants.
• Regarding high-risk activities, 80% of cases reported contact with animals (including rodents and hares), 72% engaged in outdoor activities, and 64% had been in contact with soil.
• The increase in the number of cases could be partly explained by greater awareness among healthcare professionals regarding the diagnosis and reporting of this disease.