The Re-Emergence of Rift Valley Fever in Mananjary District, Madagascar in 2021: A Call for Action

Aina Nirina Harimanana (1) , Soa Fy Andriamandimby (1) , Dany Bakoly Ranoaritiana (2) , Laurence Randrianasolo (1) , Judickaelle Irinantenaina (1) , Nirina Nantenaina Ranoelison (1) , Jean Théophile Rafisandrantatsoa (1) , Miamina Fidy Ankasitrahana (2) , Antso Hasina Raherinandrasana (2, 3) , Manuela Vololoniaina Andriamahatana (2) , Michael Luciano Tantely (1) , Romain Girod (1) , Philippe Dussart (1) , Vincent Lacoste (1) , Rindra Vatosoa Randremanana (1)

1 Institut Pasteur de Madagascar
2 Ministère de la Santé Publique - Ministry of Public Health [Antananarivo, Madagascar]
3 Université d'Antananarivo

An epizootic of rift valley fever (RVF) was suspected on 21 February 2021 in various districts of Madagascar, with a lab confirmation on 1 April 2021. A cross-sectional survey aiming to detect cases of RVF in humans and to study the circulation of rift valley fever virus (RVFV) in animals was conducted from 22 April to 4 May 2021 in the district of Mananjary. Blood samples from cattle and humans were tested using serological and molecular techniques. In cattle, the circulation of RVFV was confirmed between 5 February and 4 May 2021. The positivity rates of anti-RVFV IgG and IgM were 60% and 40%, respectively. In humans, the circulation of RVFV was observed from 1 April to 5 May 2021. The positivity rate of RVFV was estimated to be 11.7% by combining the results of the molecular and serological approaches. Of the 103 individuals who agreed to participate in the survey, 3 were determined to be positive by RT-PCR, and 10 had anti-RVFV IgM. Among them, one was positive for both. Given that previous studies have reported the circulation of RVFV during inter-epidemic periods and the occurrence of outbreaks due to imported RVFV in Madagascar, our findings suggest the importance of strengthening RVF surveillance from a “One Health” perspective by conducting syndromic and risk-based surveillance at the national and regional levels.

Mots clés: cattle; disease outbreaks; humans; Madagascar; One Health approach; rift valley fever

Domaines: Sciences du Vivant [q-bio]

Aina Nirina Harimanana, Soa Fy Andriamandimby, Dany Bakoly Ranoaritiana, Laurence Randrianasolo, Judickaelle Irinantenaina, et al.. The Re-Emergence of Rift Valley Fever in Mananjary District, Madagascar in 2021: A Call for Action. Pathogens, 2024, 13 (3), pp.257. ⟨10.3390/pathogens13030257⟩. ⟨hal-04553469⟩