Lassa fever looks a bit like Ebola fever, with fairly severe symptoms such as fever, vomiting, diarrhea, abdominal pain and bleeding. It can kill up to 20% of patients and becomes fatal 10 days after the first symptoms appear, especially if it is not treated.
It is found in Africa, in Nigeria in particular where there have already been around 800 cases and 150 deaths since the start of 2024. But it is also rife in Liberia, Benin, Guinea, and therefore especially in West Africa.
Contamination by contact or ingestion of contaminated food
Lassa fever is transmitted in two ways, as Marie Jaspard, infectious disease specialist at Saint-Antoine hospital in Paris, explains: “It is a disease that is transmitted by contact, like Ebola virus disease. You need fairly close contact, this is the classic mode of contamination. It is also possible to become contaminated via the famous rodents, small rats, “Mastomys”, which circulate in the villages. These animals make their excrement on food that dries on the ground, such as cassava that dries in front of homes. These rodents carrying the virus contaminate food which is then ingested by the population.“