TY - JOUR

T1 - Rift Valley Fever

T2 - risk of persistence, spread and impact in Mayotte (France)

AU - Nielsen, Soren Saxmose

AU - Alvarez, Julio

AU - Bicout, Dominique Joseph

AU - Calistri, Paolo

AU - Depner, Klaus

AU - Drewe, Julian Ashley

AU - Garin-Bastuji, Bruno

AU - Rojas, Jose Luis Gonzales

AU - Schmidt, Christian Gortezar

AU - Michel, Virginie

AU - Chueca, Miguel Angel Miranda

AU - Roberts, Helen Clare

AU - Sihvonen, Liisa Helena

AU - Stahl, Karl

AU - Velarde, Antonio

AU - Viltrop, Arvo

AU - Winckler, Christoph

AU - Cetre-Sossah, Catherine

AU - Chevalier, Veronique

AU - de Vos, Clazien

AU - Gubbins, Simon

AU - Antoniou, Sotiria-Eleni

AU - Broglia, Alessandro

AU - Dhollander, Sofie

AU - Van der Stede, Yves

PY - 2020

Y1 - 2020

N2 - Rift Valley fever (RVF ) is a vector‐borne disease transmitted by different mosquito species, especially Aedes and Culex genus, to animals and humans. In November 2018, RVF re‐emerged in Mayotte (France) after 11 years. Up to the end of October 2019, 126 outbreaks in animals and 143 human cases were reported. RVF mortality was 0.01%, and the number of abortions reported in polymerase chain reaction (PCR )‐positive ruminants was fivefold greater than the previous 7 years. Milk loss production in 2019 compared to 2015–2018 was estimated to be 18%, corresponding to an economic loss of around €191,000 in all of Mayotte. The tropical climate in Mayotte provides conditions for the presence of mosquitoes during the whole year, and illegal introductions of animals represent a continuous risk of (re)introduction of RVF . The probability of RVF virus (RVFV ) persisting in Mayotte for 5 or more years was estimated to be < 10% but could be much lower if vertical transmission in vectors does not occur. Persistence of RVF by vertical transmission in Mayotte and Réunion appears to be of minor relevance compared to other pathways of re‐introduction (i.e. animal movement). However, there is a high uncertainty since there is limited information about the vertical transmission of some of the major species of vectors of RVFV in Mayotte and Réunion. The only identified pathways for the risk of spread of RVF from Mayotte to other countries were by infected vectors transported in airplanes or by wind currents. For the former, the risk of introduction of RVF to continental France was estimated to 4 × 10−6 epidemic per year (median value; 95% CI : 2 × 10−8; 0.0007), and 0.001 epidemic per year to Réunion (95% CI : 4 × 10−6; 0.16). For the latter pathway, mosquitoes dispersing on the wind from Mayotte between January and April 2019 could have reached the Comoros Islands, Madagascar, Mozambique and, possibly, Tanzania. However, these countries are already endemic for RVF , and an incursion of RVFV ‐infected mosquitoes would have negligible impact.

AB - Rift Valley fever (RVF ) is a vector‐borne disease transmitted by different mosquito species, especially Aedes and Culex genus, to animals and humans. In November 2018, RVF re‐emerged in Mayotte (France) after 11 years. Up to the end of October 2019, 126 outbreaks in animals and 143 human cases were reported. RVF mortality was 0.01%, and the number of abortions reported in polymerase chain reaction (PCR )‐positive ruminants was fivefold greater than the previous 7 years. Milk loss production in 2019 compared to 2015–2018 was estimated to be 18%, corresponding to an economic loss of around €191,000 in all of Mayotte. The tropical climate in Mayotte provides conditions for the presence of mosquitoes during the whole year, and illegal introductions of animals represent a continuous risk of (re)introduction of RVF . The probability of RVF virus (RVFV ) persisting in Mayotte for 5 or more years was estimated to be < 10% but could be much lower if vertical transmission in vectors does not occur. Persistence of RVF by vertical transmission in Mayotte and Réunion appears to be of minor relevance compared to other pathways of re‐introduction (i.e. animal movement). However, there is a high uncertainty since there is limited information about the vertical transmission of some of the major species of vectors of RVFV in Mayotte and Réunion. The only identified pathways for the risk of spread of RVF from Mayotte to other countries were by infected vectors transported in airplanes or by wind currents. For the former, the risk of introduction of RVF to continental France was estimated to 4 × 10−6 epidemic per year (median value; 95% CI : 2 × 10−8; 0.0007), and 0.001 epidemic per year to Réunion (95% CI : 4 × 10−6; 0.16). For the latter pathway, mosquitoes dispersing on the wind from Mayotte between January and April 2019 could have reached the Comoros Islands, Madagascar, Mozambique and, possibly, Tanzania. However, these countries are already endemic for RVF , and an incursion of RVFV ‐infected mosquitoes would have negligible impact.

KW - Rift Valley Fever

KW - vector-borne

KW - spread

KW - impact

KW - ruminants

KW - Mayotte

U2 - 10.2903/j.efsa.2020.6093

DO - 10.2903/j.efsa.2020.6093

M3 - Journal article

C2 - 32874301

VL - 18

JO - E F S A Journal

JF - E F S A Journal

SN - 1831-4732

IS - 4

M1 - e06093

ER -