In the Indian Ocean, between Madagascar and the coast of Mozambique sits the archipelago of Mayotte, a Department of France.


Health officials have reported (computer translated) an increase in autochthonous Rift Valley fever (RVF) cases in the past six weeks.

Since the first human case was detected on Dec. 11, 2018, health officials have reported 19 human cases. Most of the cases were located in the western part of the island.

Samples made on ruminants present around human cases were analyzed at CIRAD in Réunion
for the search for the RVF virus. The results identified several positive animals in different villages located in west and center of the island.

In addition, a positive IgM cattle has been reported in Mamoudzou. This is a cattle 2 years old belonging to a breeding of 8 cattle including 4 adults and 4 calves of 2 months. Biological control and investigations are underway.

ECDC reports the detection of autochthonous Rift Valley fever cases on Mayotte is not unexpected, but the occurrence of 19 cases within a short time period is of concern as current weather conditions (rainy season from November to March) are favorable for the vectors.

Rift Valley fever (RVF) is an illness that is primarily spread by direct contact with blood, fluids, or tissues of infected animals such as cattle, buffalo, sheep, goats, and camels. Less commonly, it can also be spread through mosquito bites.

Most people with RVF do not feel sick or have only mild illness. Symptoms of RVF include fever, weakness, back pain, dizziness, and weight loss. However, a small percentage (8%–10%) of people may have more serious illness, such as severe bleeding, swelling of the brain, or eye disease. Approximately 1% of people who get RVF die from the disease.