Itaya virus, a Novel Orthobunyavirus Associated with Human Febrile Illness, Peru

Abstract

Our genetic analyses of uncharacterized bunyaviruses isolated in Peru identified a possible reassortant virus containing small and large gene segment sequences closely related to the Caraparu virus and a medium gene segment sequence potentially derived from an unidentified group C orthobunyavirus. Neutralization tests confirmed serologic distinction among the newly identified virus and the prototype and Caraparu strains. This virus, named Itaya, was isolated in 1999 and 2006 from febrile patients in the cities of Iquitos and Yurimaguas in Peru. The geographic distance between the 2 cases suggests that the Itaya virus could be widely distributed throughout the Amazon basin in northeastern Peru. Identification of a new Orthobunyavirus species that causes febrile disease in humans reinforces the need to expand viral disease surveillance in tropical regions of South America.

Keywords: Amazon; Caraparu virus; Itaya; Orthobunyavirus; Peru; arboviruses; bunyavirus; febrile surveillance; human pathogen; vector-borne infections; viruses.

Figure 1

Geographic distribution of the confirmed Itaya virus human cases (arrows) identified as part of the febrile disease surveillance project in Loreto, Peru during 1999 and 2006

Figure 2

Neighbor-joining phylogenetic tree of group C orthobunyaviruses constructed by using MEGA5 (23) on the basis of the small gene segments of published virus sequences and Itaya virus strains isolated in Peru in 1999 and 2006 (boldface). The Itaya strain segments show a close relationship to Caraparu virus. Virus strains are labeled by code designation. Numbers indicate bootstrap values for the clades to the right. Bootstrap values were obtained based on 1,000 replicates. Scale bar indicates nucleotide substitutions per site.

Figure 3

Neighbor-joining phylogenetic tree of group C orthobunyaviruses constructed by using MEGA5 (23) on the basis of the large gene segments of published virus sequences and Itaya virus strains isolated in Peru in 1999 and 2006 (boldface). The Itaya strain segments show a close relationship to Caraparu virus. Virus strains are labeled by code designation. Numbers indicate bootstrap values for the clades to the right. Bootstrap values were obtained based on 1,000 replicates. Scale bar indicates nucleotide substitutions per site.

Figure 4

Neighbor-joining phylogenetic tree of group C orthobunyaviruses constructed by using MEGA5 (23) on the basis of the large gene segments of published virus sequences and Itaya virus strains isolated in Peru in 1999 and 2006 (boldface). The Itaya strain segments show a more distant relationship to Caraparu virus than for the small and large segments, indicating that Itaya virus is a novel reassortant strain. Virus strains are labeled by code designation. Numbers indicate bootstrap values for the clades to the right. Bootstrap values were obtained based on 1,000 replicates. Scale bar indicates nucleotide substitutions per site.