Water alert in Nantes: sharp increase in hepatitis A cases

Water alert in Nantes: sharp increase in hepatitis A cases

An atypical increase

Since June 2025, at least 16 cases of hepatitis A have been recorded in Nantes. The ARS of Pays de la Loire speaks of an unusual increase. For comparison, the region had 6 cases in 2021, 7 in 2022, 12 in 2023 and 14 in 2024.

The key role of contaminated water

Hepatitis A is transmitted by the fecal-oral route: ingestion of contaminated water or food, or contact with contaminated surfaces. Water is a major vector because it is used to wash foods consumed raw and, in certain precarious households, hygienic conditions (toilets, hand washing) are insufficient.

  • Domestic water: Rinse fruits and vegetables with safe drinking water.
  • Hygiene: Wash your hands with soap and water before eating and after using the toilet.

European context

The local increase is part of a broader dynamic in Central Europe (Austria, Hungary, Slovakia, Czech Republic). In Nantes, the origins are varied: returns from travel, vulnerable populations and a few local outbreaks with identical strains identified since April.

Symptoms and risks

Nausea, abdominal pain, fatigue, jaundice. The infection is often mild, but can be serious in vulnerable people (mortality ≈ 1/1000). Not chronic but very contagious.

Prevention measures

  1. Strict hygiene: hands, work surfaces, utensils.
  2. Secure power supply: avoid shellfish and raw seafood.
  3. Targeted vaccination: travelers, children in communities, people in precarious situations or those suffering from liver diseases; after contact, vaccination within 14 days.
  4. Health surveillance: identification of transmission chains and prevention actions.

Also read

  • Indoor pollution: the air in homes under surveillance
  • Practical advice: choosing the right sunscreen

Things to remember: Water quality remains a major health issue. Hygiene, water filtration and targeted vaccination are the best protections.

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