Although leptospirosis primarily presents as flu-like symptoms, it can also lead to severe forms of the disease that may be fatal. The disease is transmitted to humans through contact between broken skin or mucous membranes and the urine of infected animals, or through contact with environments (such as fresh water or damp soil) contaminated by this urine.

To take action and prevent the risk of epidemics, as well as to analyze how these diseases evolve over time, improve understanding, and adapt public health policies to the needs of the population, certain diseases must be reported by healthcare professionals; these are notifiable diseases (NDs). This system now includes 38 notifiable diseases, with the addition of leptospirosis as of August 24, 2023.

Why is leptospirosis included in the MDO?

In mainland France, including Corsica, the annual incidence has been estimated at approximately 1 case per 100,000 inhabitants since 2014, corresponding to about 600 to 700 cases reported annually by the National Reference Center and its partner laboratories across the country. This surveillance system has never been evaluated, and the comprehensiveness of this network is unknown, with a likely underestimation of the number of cases.

In the overseas departments, regions, and communities, leptospirosis is endemic, and the incidence is, depending on the territory, 10 to 70 times higher than in mainland France. Epidemic peaks occur during the rainy season or during unusual weather events such as cyclones.

Currently, there is a significant lack of information and knowledge regarding leptospirosis, particularly concerning the actual incidence of the disease, the emergence of new strains, the risk of transmission to humans from emerging animal reservoirs, etc.

Adding leptospirosis to the list of MDOs will enable:

• a better understanding of the epidemiology of leptospirosis and improved monitoring of morbidity and mortality;

• assess the burden of the disease;

• better characterize at-risk populations in order to target public health interventions by adapting them to local epidemiology.

The inclusion of leptospirosis as an MDO will also enable the identification of clusters of cases to implement appropriate management measures:

• issuing alerts to travelers and residents in hyperendemic areas following unusual weather events (e.g., cyclones, storms, monsoons, floods);

• closing access to waterways;

• implementation of measures to control reservoirs (e.g., rodent control, animal population control, management of effluents from industrial livestock farms, drainage of flooded areas).

Santé publique France’s Role in Monitoring MDOs

As part of regional and national surveillance, Santé publique France epidemiologists centralize all data, analyze it, and transmit it to public authorities along with recommendations on measures or actions to be implemented.

They provide scientific expertise to the Regional Health Agencies (ARS) for epidemiological investigations, particularly during outbreaks. Finally, they ensure that this information is communicated to stakeholders in the system, the medical and scientific community, and the general public.

In addition, the Ministry of Health, and more specifically the Directorate General of Health, receives health alerts and, as needed, participates in risk management decisions in coordination with the ARS. Surveillance data is transmitted by Santé publique France to the Ministry of Health, which uses it to define and adapt public health policies.

What steps can you take to protect yourself from leptospirosis?

Prevention measures rely on collective control efforts, such as rodent control, management of animal populations in rural areas, management of effluents from industrial livestock operations, drainage of flooded areas, and comprehensive waste management.

Preventing leptospirosis also relies on individual protective measures against contamination from animal urine.

• Wear appropriate protective gear when:

  • high-risk occupational activities (livestock farming, sewer workers, garbage collectors, farmers, working the land, etc.), including boots, gloves, thigh-high boots, protective clothing, and even splash-proof goggles if there is a risk of splashes;

  • whitewater sports such as canyoning and kayaking, including a protective wetsuit, boots, and gloves.

• Avoid swimming in murky or muddy water.

• Avoid walking barefoot or in open-toed sandals on muddy ground, in puddles, stagnant water, or ravines (especially in overseas departments).

• Protect wounds from contact with water using waterproof bandages.

After exposure to risk, you should:

• Wash with potable water and disinfect any wounds.

• If you develop a fever, see a doctor and mention the high-risk activity you engaged in.