New insights into prevalence, genetic diversity, and proviral load of human T-cell leukemia virus types 1 and 2 in pregnant women in Gabon in equatorial central Africa.
Human T-cell leukemia virus type 1 (HTLV-1) is highly endemic in areas of central Africa; mother-to-child transmission and sexual transmission are considered to be the predominant routes. To determine the prevalence and subtypes of HTLV-1/2 in pregnant women in Gabon, we conducted an epidemiological survey in the five main cities of the country. In 907 samples, the HTLV-1 seroprevalence was 2.1%, which is lower than that previously reported. Only one case of HTLV-2 infection was found. The HTLV-1 seroprevalence increased with age and differed between regions (P </= 0.05), with the highest prevalence (5%) in the southeastern region. A wide range of HTLV-1 proviral loads was observed among the infected women. The level of the proviral load was correlated with a high HTLV-1 antibody titer (P </= 0.02). Sequencing of HTLV-1 env and long terminal repeat fragments showed that all but one strain belonged to the central African subtype B; the outlier was of cosmopolitan subtype A. The new strains of subtype B exhibited wide genetic diversity, but there was no evidence of clustering of specific genomes within geographical regions of the country. Some strains were closely related to simian T-cell leukemia virus type 1 strains of great apes, suggesting that in these areas some HTLV-1 strains could arise from relatively recent interspecies transmission. The sole HTLV-2 strain belonged to subtype B. In this study we showed that the prevalence of HTLV-1 in the southeast is one of the highest in the world for pregnant women.
Etenna
Sonia Lekana-Douki
SL
Département de Rétrovirologie, Centre International de Recherches Médicales, BP 769 Franceville, Gabon.
Caron
Mélanie
M
Besson
Guillaume
G
Makuwa
Maria
M
Gessain
Antoine
A
Mahé
Antoine
A
Kazanji
Mirdad
M
D000293:Adolescent; D000328:Adult; D016000:Cluster Analysis; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D005260:Female; D005681:Gabon / Q000453:epidemiology; D014644:Genetic Variation; D005838:Genotype; D015491:HTLV-II Infections / Q000453:epidemiology* / Q000821:virology; D015368:Human T-lymphotropic virus 1 / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D015367:Human T-lymphotropic virus 2 / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000453:epidemiology* / Q000821:virology; D008969:Molecular Sequence Data; D010802:Phylogeny; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious; D011533:Proviruses / Q000235:genetics / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D016036:Seroepidemiologic Studies; D014505:Urban Population; D019562:Viral Load
D004279:DNA, Viral