Absence of Rift Valley Fever Virus in Wild Small Mammals, Madagascar

Olive, Marie-Marie; Razafindralambo, Nadia; Barivelo, Tony Andrianaivo; Rafisandratantsoa, Jean-Théophile; Soarimalala, Voahangy; Rollin, Pierre E.; Heraud, Jean‐Michel; Reynes, Jean-Marc

doi:10.3201/eid1906.121074

Cited by 15 publications

(10 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A total of 585 rodents belonging to seven species were sampled (Olive et al 2013). Partial L amplification was positive in pools of organs from two species-the roof rat (R. rattus), the widely distributed species of the family Muridae introduced in Madagascar, and the Major's tufted-tailed rat (E. majori), a Malagasy endemic species of the family Nesomyidae.…”

Section: Resultsmentioning

confidence: 99%

“…During a survey looking for hemorrhagic fever viruses associated with wild terrestrial small mammals in Madagascar (Olive et al 2013), animals were captured in the Anjozorobe-Angavo forest corridor (Anjozorobe district) (18°18¢41.9 † S, 48°00¢57.6 † E, 70 km north from Antananarivo, the capital city) over four 3-week trapping sessions conducted in October, 2008, March and October, 2009, and March, 2010 (Fig. 1).…”

Section: Sample Collectionmentioning

confidence: 99%

See 1 more Smart Citation

Anjozorobe Hantavirus, a New Genetic Variant of Thailand Virus Detected in Rodents from Madagascar

Reynes

Lacoste

et al. 2014

Vector-Borne and Zoonotic Diseases

Self Cite

View full text Add to dashboard Cite

Until now, there was only serological evidence that hantaviruses were circulating in rodents and infecting humans from Madagascar. To assess the presence of a hantavirus on the island, between October, 2008, and March, 2010, we sampled 585 rodents belonging to seven species in the Anjozorobe-Angavo forest corridor, 70 km north from the capital city Antananarivo. A hantavirus was detected from organs of the ubiquist roof rat (Rattus rattus) and of the endemic Major's tufted-tailed rat (Eliurus majori). Amazingly, sequence analysis of the S (small), M (medium), and L (large) coding DNA sequence of this virus showed that the Anjozorobe strain (proposed name) was a new genetic variant of Thailand virus (THAIV) that comprises other variants found in Southeast Asia. Because THAIV is suspected of causing hemorrhagic fever with renal syndrome in humans, ongoing studies are addressing the risk of infection by this new variant in the Malagasy population.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Sample Collectionmentioning

confidence: 99%

Anjozorobe Hantavirus, a New Genetic Variant of Thailand Virus Detected in Rodents from Madagascar

Reynes

Lacoste

et al. 2014

Vector-Borne and Zoonotic Diseases

Self Cite

View full text Add to dashboard Cite

show abstract

“…Several mechanisms are likely involved in the persistence of RVFV: vertical transmission in mosquitoes, the existence of wild mammal reservoir populations, the maintenance of low level transmission associated with ruminant movements243536. While the existence of wild terrestrial mammals as reservoir of RVF in Madagascar is unlikely37, the vertical transmission has still to be considered. Indeed, vertical transmission has been described in Aedes subgenus Neomelaniconion mosquitoes38 which is present in all Malagasy eco-regions2939.…”

Section: Discussionmentioning

confidence: 99%

Reconstruction of Rift Valley fever transmission dynamics in Madagascar: estimation of force of infection from seroprevalence surveys using Bayesian modelling

Olive

Grosbois²,

Tran³

et al. 2017

Sci Rep

Self Cite

View full text Add to dashboard Cite

The force of infection (FOI) is one of the key parameters describing the dynamics of transmission of vector-borne diseases. Following the occurrence of two major outbreaks of Rift Valley fever (RVF) in Madagascar in 1990–91 and 2008–09, recent studies suggest that the pattern of RVF virus (RVFV) transmission differed among the four main eco-regions (East, Highlands, North-West and South-West). Using Bayesian hierarchical models fitted to serological data from cattle of known age collected during two surveys (2008 and 2014), we estimated RVF FOI and described its variations over time and space in Madagascar. We show that the patterns of RVFV transmission strongly differed among the eco-regions. In the North-West and Highlands regions, these patterns were synchronous with a high intensity in mid-2007/mid-2008. In the East and South-West, the peaks of transmission were later, between mid-2008 and mid-2010. In the warm and humid northwestern eco-region favorable to mosquito populations, RVFV is probably transmitted all year-long at low-level during inter-epizootic period allowing its maintenance and being regularly introduced in the Highlands through ruminant trade. The RVF surveillance of animals of the northwestern region could be used as an early warning indicator of an increased risk of RVF outbreak in Madagascar.

show abstract

“…We defined two indexes for the risk of RVFV infection in humans: (i) We created an index of local RVFV transmission risk, defined by the product of local predicted seroprevalence rate in cattle and cattle density. This index was built to capture the risk associated with the primary RVFV epidemiological cycle involving mosquitoes and domestic ruminants, in the absence of known wild hosts for RVFV in Madagascar (41,42). Humans are not involved in this cycle.…”

Section: Methodsmentioning

confidence: 99%

Drivers of Rift Valley fever epidemics in Madagascar

Lancelot

Béral

Rakotoharinome

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Rift Valley fever (RVF) is a vector-borne viral disease widespread in Africa. The primary cycle involves mosquitoes and wild and domestic ruminant hosts. Humans are usually contaminated after contact with infected ruminants. As many environmental, agricultural, epidemiological, and anthropogenic factors are implicated in RVF spread, the multidisciplinary One Health approach was needed to identify the drivers of RVF epidemics in Madagascar. We examined the environmental patterns associated with these epidemics, comparing human and ruminant serological data with environmental and cattle-trade data. In contrast to East Africa, environmental drivers did not trigger the epidemics: They only modulated local Rift Valley fever virus (RVFV) transmission in ruminants. Instead, RVFV was introduced through ruminant trade and subsequent movement of cattle between trade hubs caused its long-distance spread within the country. Contact with cattle brought in from infected districts was associated with higher infection risk in slaughterhouse workers. The finding that anthropogenic rather than environmental factors are the main drivers of RVF infection in humans can be used to design better prevention and early detection in the case of RVF resurgence in the region.vector-borne infection | zoonosis | El Niño | cattle trade | One Health

show abstract

Absence of Rift Valley Fever Virus in Wild Small Mammals, Madagascar

Cited by 15 publications

References 5 publications

Anjozorobe Hantavirus, a New Genetic Variant of Thailand Virus Detected in Rodents from Madagascar

Anjozorobe Hantavirus, a New Genetic Variant of Thailand Virus Detected in Rodents from Madagascar

Reconstruction of Rift Valley fever transmission dynamics in Madagascar: estimation of force of infection from seroprevalence surveys using Bayesian modelling

Drivers of Rift Valley fever epidemics in Madagascar

Contact Info

Product

Resources

About