Causative agent of Pogosta disease isolated from blood and skin lesions

Abstract

Pogosta disease is a mosquito-borne viral disease in Finland, which is clinically manifested by rash and arthritis; larger outbreaks occur in 7-year intervals. The causative agent of the disease has been suspected of being closely related to Sindbis virus (SINV). We isolated SINV from five patients with acute Pogosta disease during an outbreak in fall 2002 in Finland. One virus strain was recovered from a whole blood sample and four other strains from skin lesions. The etiology of Pogosta disease was confirmed by these first Finnish SINV strains, which also represent the first human SINV isolates from Europe. Phylogenetic analysis indicates that the Finnish SINV strains are closely related to the viral agents that were previously isolated from mosquitoes and that are related clinically similar diseases in nearby geographic areas.

Figure 1

Sindbis virus isolates around the world. Each dot represents either one strain (isolated from insect or vertebrate) or several strains isolated from specific Diptera genus (e.g., Culex or Aedes) at the same time and place. The strains included in the phylogenetic analyses are indicated with arrows. The enlarged map presents the new Sindbis virus isolates introduced in this study.

Figure 2

Phylogenetic tree is based on the nucleotide sequences of 1,178–1,281 bp from nsP3 and nsP4 region, nucleotides 5,258-6,510; the genome position is given according to the published sequence of the strain AR339 (HRsp variant) (2). The tree was constructed by using Neighbor-joining algorithms (NEIGHBOR). 5,000 bootstrap replicates were calculated. Only those bootstrap support values that exceed 50% are shown. The following sequences available in GenBank were included into the comparison: AR339 (HRsp variant); Egypt (J02363, J02364, J02365, J02366, J02367), Girdwood S.A.; South-Africa (U38304), MRE16; Malaysia (AF492770), Ockelbo (Edsbyn 82); Sweden (M69205), S.A.AR86; South-Africa (U38305), SW6562; Australia (AF429428), YN87448; China (AF103734) and XJ-160; China (AF103728).