Anjozorobe hantavirus, a new genetic variant of Thailand virus detected in rodents from Madagascar

Abstract

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.

FIG. 1.

Study site in Madagascar—the Anorana camp, in the north of the forest corridor of Anjozorobe-Angavo.

FIG. 2.

Phylogenetic tree based on the complete nucleoprotein coding sequences from the Anjozorobe virus (indicated by ●), from the 22 hantavirus species associated with rodents and listed by the International Committee on Taxonomy of Viruses, from strains related to Thailand virus, and from Sangassou hantavirus recently described in Africa. Bootstrap percentages ≥70% (from 1000 resamplings) are indicated at each node. Scale bar indicates nucleotide substitution per site.

FIG. 3.

Phylogenetic tree based on the partial nucleoprotein coding sequences (nucleotides 364–882) from the Anjozorobe virus (indicated by ●), from the 22 hantavirus species associated with rodents and listed by the International Committee on Taxonomy of Viruses, from strains related to Thailand virus, and from the Sangassou hantavirus recently described in Africa. Bootstrap percentages ≥70% (from 1000 resamplings) are indicated at each node. Scale bar indicates nucleotide substitution per site.

FIG. 4.

Phylogenetic tree based on the complete glycoproteins coding sequences from the Anjozorobe virus (indicated by ●), from 18 of the 22 hantavirus species associated with rodents and listed by the International Committee on Taxonomy of Viruses, from strains related to the Thailand virus, and from the Sangassou hantavirus recently described in Africa. Bootstrap percentages ≥70% (from 1000 resamplings) are indicated at each node. Scale bar indicates nucleotide substitution per site.