Fatal Case of Crimean-Congo Hemorrhagic Fever Caused by Reassortant Virus, Spain, 2018

Abstract

In August 2018, a fatal autochthonous case of Crimean-Congo hemorrhagic fever was confirmed in western Spain. The complete sequence of the viral genome revealed circulation of a new virus because the genotype differs from that of the virus responsible for another case in 2016. Practitioners should be alert to possible new cases.

Keywords: Crimean Congo hemorrhagic fever virus; Hyalomma; RT-PCR; Spain; molecular epidemiology; phylogenetic analyses; reassortant; tick-borne illness; ticks; vector-borne infections; viruses; zoonoses.

Figure 1

Regions where human infections with Crimean-Congo hemorrhagic fever virus (CCHFV) or infected ticks have been found in Spain. 1, CCHFV hyperendemic focus; 2, human infected by a tick bite in 2016 (Ávila); 3, human infected by a tick bite in 2018 (Badajoz). Red circle indicates area where infected ticks were detected during a surveillance study in 2016.

Figure 2

Bayesian phylogenetic trees showing genetic relationships among Crimean-Congo hemorrhagic fever (CCHFV) viruses based on complete small (A), medium (B), and large (C) segment sequences. In the medium segment, the hypervariable mucin-like domain was excluded. We used CIPRES Science gateway (http://www.phylo.org) to implement Bayesian analyses. Black dots indicate nodes with posterior probabilities >0.95; boldface indicates CCHFV strain Badajoz 2018 from Spain; arrowheads indicate other isolates from Spain. Other sequences are named by GenBank accession number, strain, geographic origin, and sampling year. Sequences from this study are included in EMBL/GenBank databases. Roman numerals indicate genotypes, named according to (4) with the equivalent clade nomenclature according to (5) indicated by brackets: I, West Africa (Africa 1); II, Central Africa (Africa 2); III, South and West Africa (Africa 3); IV, Middle East/Asia, divided in 2 groups corresponding to groups Asia 1 and Asia 2; V, Europe/Turkey (Europe 1); VI, Greece (Europe 2). Italics indicate the proposed new lineage, Africa 4. Scale bars indicate time in years.