Epidemiology of HTLV-I in Gabon (Western Equatorial Africa)

In 1986 a survey to determine the distribution of HTLV-I infection was conducted in Gabon in a representative sample of adults and children. Five samples were taken in adults and 2 samples in children living in urban and rural areas. Samples were taken by the cluster sampling technique, i.e., clusters of randomly selected households. Sera were tested for IgG antibodies to HTLV-I by ELISA. ELISA-positive sera were retested by Western blot. The study comprised 1,874 adults and 684 children, all apparently healthy. In the adults the crude prevalence rates of anti-HTLV-I antibodies ranged from 5.0% in urban areas to 10.5% in the southern province. In rural areas, the age-adjusted prevalence rate (9.1%) was significantly higher than in urban areas (5.0%) (p less than 0.01). In children there was no significant difference between urban (2.4%) and rural (2.0%) prevalence rates. Prevalence increased with age but was not related to sex. This survey shows that HTLV-I infection is common in Gabon but varies considerably by region.