Detection in and circulation of Bluetongue virus among domestic ruminants in Madagascar.
So far, no published data was available concerning the circulation of Bluetongue virus (BTV) in Madagascar. During a survey on Rift Valley Fever, we were able to detect a virus belonging to BTV. Therefore, we conducted a study aiming at characterizing molecularly the BTV isolated and assess the importance of circulation of BTV in Madagascar. A total of 4393 sera from ruminants selected randomly by stratification and sampled in 30 districts of Madagascar were tested for BTV. Moreover, 175 cattle were followed during 11 months. Phylogenetic analyses were performed from virus isolated from unfed pools of mosquitoes. Overall, the estimated mean seroprevalence of infection at the national level was 95.9% (95% CI: [95.2-96.5]) in cattle and 83.7% (95% CI: [81.4-85.9]) in small ruminants. Estimation of incidence rate was 54 per 100 cattle-years assuming that the incidence rate is constant all year along. Phylogenetic analyses revealed that BTV detected belong to serotype 2. In conclusion, our results showed that BTV is endemic in Madagascar and highly prevalent among cattle. In our study we did not work on the vector involved in transmission of BTV in cattle. Thus, research should be conducted to better describe epidemiology of BTV in Madagascar including vectors and assess economic impact of the disease associated to BTV infections.
Virology Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar. Electronic address: soafy@pasteur.mg.
Soa Fy
SF
Andriamandimby
Anses-Laboratoire Santé Animal-UMR 1161, Maisons-Alfort, France. Electronic address: cyril.viarouge@anses.fr.
Cyril
C
Viarouge
Virology Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar. Electronic address: jpierre@pasteur.mg.
Jean-Pierre
JP
Ravalohery
Virology Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar. Electronic address: jean-marc.reynes@inserm.fr.
Jean-Marc
JM
Reynes
Anses-Laboratoire Santé Animal-UMR 1161, Maisons-Alfort, France. Electronic address: corinne.sailleau@anses.fr.
Corinne
C
Sailleau
Medical Entomology Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar. Electronic address: lucinambi@pasteur.mg.
Michael Luciano
ML
Tantely
Medical Entomology Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar. Electronic address: nohal_elissa@yahoo.com.
Nohal
N
Elissa
CIRAD, UMR 15 CMAEE, Sainte-Clotilde, La Réunion, France; INRA, UMR 1309 CMAEE, Montpellier, France. Electronic address: eric.cardinale@cirad.fr.
Eric
E
Cardinale
Virology Unit, Institut Pasteur de Dakar, Dakar, Senegal. Electronic address: asall@pasteur.sn.
Amadou Alpha
AA
Sall
Anses-Laboratoire Santé Animal-UMR 1161, Maisons-Alfort, France. Electronic address: szientara@vet-alfort.fr.
Stephan
S
Zientara
Virology Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar. Electronic address: jmheraud@pasteur.mg.
Jean-Michel
JM
Heraud
D000818:Animals; D001483:Base Sequence; D001819:Bluetongue / Q000453:epidemiology* / Q000821:virology; D001820:Bluetongue virus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000821:virology; D019353:Endemic Diseases; D005260:Female; D008270:Madagascar / Q000453:epidemiology; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D012295:Rift Valley Fever / Q000453:epidemiology* / Q000821:virology; D012418:Ruminants / Q000821:virology*; D017422:Sequence Analysis, DNA / Q000662:veterinary; D016036:Seroepidemiologic Studies
Bluetongue virus; Bovidae; Madagascar