Role of migratory birds in spreading Crimean-Congo hemorrhagic fever, Turkey

Abstract

We investigated migratory birds' role in spreading Crimean-Congo hemorrhagic fever virus (CCHFV) through attached ticks. We detected CCHFV RNA in ticks on migratory birds in Turkey. Two isolates showed similarity with CCHFV genotype 4, suggesting a role for ticks in CCHFV epidemics in Turkey and spread of CCHFV by birds.

Keywords: CCHF; Crimean-Congo hemorrhagic fever; Turkey; birds; epidemiology; migration; ticks.

Figure 1

Phylogenetic tree of nucleotide sequences of CCHFV. Phylogenetic tree based on the 260 bp of the small segment of the CCHFV genome. The multiple sequence alignment was obtained by using MEGA 5.1 (http://www.megasoftware.net), and the phylogenetic tree was constructed by the maximum-likelihood method using 1,000 bootstrap replicates of the sequence data. The tree is drawn to scale with branch length in the same unit as those of the evolutionary distance used to infer the phylogenetic tree. The phylogenetic tree includes the 7 genotypes described by Mild et al. (8). Bootstrap confidence limits (>50) are shown at each node. The geographic origin is given for each sequence. The CCHFV Samsun Turkey described in this report is shown by the diamond. Scale bar indicates number of nucleotide substitutions per site. CCHFV, Crimean-Congo hemorrhagic fever; S., South; C., Central.

Figure 2

Migration patterns of birds carrying ticks with Crimean-Congo hemorrhagic fever virus. A) Great reed warbler (Acrocephalus arundinaceus) eastern migration routes (red lines), breeding grounds (yellow) and wintering areas (purple). Bodies of water are blue, and nonbreeding/nonwintering areas are light green.. B) European robin (Erithacus rubecula) eastern migration routes (red lines), resident grounds (green), breeding grounds (yellow), and wintering areas (purple). Bodies of water are blue, and nonbreeding/nonwintering areas are light green.