Molecular Epidemiology and Clinical Features of Human T Cell Lymphotropic Virus Type 1 Infection in Spain

Abstract

Human T cell lymphotropic virus type 1 (HTLV-1) infection in Spain is rare and mainly affects immigrants from endemic regions and native Spaniards with a prior history of sexual intercourse with persons from endemic countries. Herein, we report the main clinical and virological features of cases reported in Spain. All individuals with HTLV-1 infection recorded at the national registry since 1989 were examined. Phylogenetic analysis was performed based on the long terminal repeat (LTR) region. A total of 229 HTLV-1 cases had been reported up to December 2012. The mean age was 41 years old and 61% were female. Their country of origin was Latin America in 59%, Africa in 15%, and Spain in 20%. Transmission had occurred following sexual contact in 41%, parenteral exposure in 12%, and vertically in 9%. HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) was diagnosed in 27 cases and adult T cell leukemia/lymphoma (ATLL) in 17 subjects. HTLV-1 subtype could be obtained for 45 patients; all but one belonged to the Cosmopolitan subtype a. One Nigerian pregnant woman harbored HTLV-1 subtype b. Within the Cosmopolitan subtype a, two individuals (from Bolivia and Peru, respectively) belonged to the Japanese subgroup B, another two (from Senegal and Mauritania) to the North African subgroup D, and 39 to the Transcontinental subgroup A. Of note, one divergent HTLV-1 strain from an Ethiopian branched off from all five known Cosmopolitan subtype 1a subgroups. Divergent HTLV-1 strains have been introduced and currently circulate in Spain. The relatively large proportion of symptomatic cases (19%) suggests that HTLV-1 infection is underdiagnosed in Spain.

Clinical Presentation of Individuals With Human T-Cell Leukemia Virus Type-1 Infection in Spain

“…Screening in Spanish blood banks mostly identified asymptomatic Latin American carriers, whereas classic HTLV-1-associated conditions such as TSP/HAM and ATL unexpectedly unveiled a disproportionately high number of HTLV-1 infections among Spaniards and Africans. In native Spaniards, late HTLV-1 diagnoses could largely be due to poor clinical suspicion in persons that had acquired the virus locally after sexual contacts with Latin Americans [14, 15]. This finding supports that HTLV-1 should no longer be neglected, and testing should be promoted at clinics for sexually transmitted infections [16].…”

Strongyloidiasis in Southern Alicante (Spain): Comparative Retrospective Study of Autochthonous and Imported Cases

“…Besides, Latin American countries are endemic for HIV and HTLV-1 virus. HTLV-1 infection is a well-known factor for strongyloidiasis hyperinfection syndrome [ 32 ]. However, information about HTLV-1 serostatus of our patients was limited as serology was not routinely requested.…”

Molecular epidemiology, genetic variability and evolution of HTLV-1 with special emphasis on African genotypes

“…The proportion of the different HTLV-1 genotypes and subgroups is presented for each African country. This figure incorporates the information from papers of molecular epidemiology available on PubMed [20, 21, 23–27, 30, 41, 44–46, 55, 68, 135–144]. It also incorporates results from two manuscripts in preparation (Cassar et al and Filippone et al), notably concerning the situation in Benin, Sierra Leone, Western Sahara, and Madagascar, where no data were available to our knowledge.…”

“…3) [19–21]. More recently, the E/a-Per subgroup, comprising 2 strains from Black Peruvian, was defined [22]; based on partial segment of LTR, a F subgroup has also been identified, especially in an Ethiopian patient [23]. Lastly, we have added in 2006, a Senegalese subgroup (a-Sen), which has also been named “Trans-Saharan” or clade W within the HTLV-1aD subgroup [24–26].…”