Concern in France after the hospitalization of a man suffering from Lassa fever.
A man suffering from Lassa fever is hospitalized in France, at the Bégin military hospital in Saint-Mandé in Val-de-Marne according to information from BFM-TV. A rare case in France which is worrying since this disease is contagious and potentially fatal.
What is Lassa fever?
Lassa fever is caused by a virus of the arenavirus family, present in West Africa, mainly in Sierra Leone, Liberia, Guinea and Nigeria. It was discovered for the first time in 1969 in Lassa, Nigeria, hence its name. It is a common disease in West Africa.
The virus is originally spread by a type of rat (Mastomys) found in West, East and Central Africa. This rodent carries the virus in its urine and droppings. It then contaminates humans through contact with the urine or droppings of the infected rat and/or by inhalation of fine particles present in the air contaminated by urine or droppings. The disease can then spread to other people through direct contact with the blood, body fluids and secretions of an infected person (via saliva for example). “Lassa fever is not spread by casual contact such as hugs, handshakes or sitting next to someone” indicates the US Centers for Disease Control (CDC). Cases of sexual transmission have been described but the frequency of this mode of transmission is unknown.
What are the symptoms of Lassa fever?
80% of cases of Lassa fever are pauci-symptomatic, that is to say that the patient presents very few symptoms or symptoms that are not very suggestive. The first symptoms of the disease appear after an incubation period of approximately 10 days. They understand :
- a fever,
- a feeling of fatigue and weakness,
- headaches.
- abdominal pain
- diarrhea
In some people, the disease can cause more serious symptoms as :
- bleeding,
- difficulty breathing,
- vomitings,
- facial swelling,
- pain in the chest, back and abdomen, and shock.
People with Lassa fever appear not to be contagious until symptoms appear. The risk of contagion begins with the first signs of the disease and lasts around ten days or even up to 2 weeks.
A deadly virus, especially in pregnant women
Lassa fever like Ebola are hemorrhagic fevers transmitted by a virus but the first is much less fatal than the second. Only 1% of cases of Lassa fever are fatal in Africa compared to 70% for the Ebola virus. On the other hand, the disease is particularly severe in pregnant women with high maternal mortality in the last trimester and fetal mortality of 95%.
Ribavirin, treatment of choice for Lassa fever
Ribavirin is the antiviral drug used in the treatment of patients with Lassa fever. This medication is most effective when given as soon as the patient becomes ill, ideally within the first 6 days. There is no vaccine currently available against this disease.
- What you need to know about Lassa Fever, CDC GOV
- Lassa hemorrhagic fever, Public Health, 2012