Screening for prolonged incubation of HTLV-I infection in British and Jamaican relatives of British patients with tropical spastic paraparesis [see comments]

ABSTRACT

OBJECTIVE -- To compare the prevalence of antibody to and proviral DNA of the retrovirus HTLV-I in relatives of 11 British patients with tropical spastic paraparesis who migrated from Jamaica before they developed symptoms, and to examine factors possibly related to transmission of HTLV-I. DESIGN -- Migrant family study. Antibody state was determined by several methods and confirmed by western blotting; the polymerase chain reaction was used to detect proviral DNA. SETTING -- Britain and Jamaica. SUBJECTS -- All available first degree relatives those born and still resident in Jamaica (group 1); those born in Jamaica who migrated to Britian (group 2); and index patients' children who were born and resident in Britian (group 3). All had been breast fed and none had had blood transfusions. RESULTS -- Of the 66 living relatives, 60 were traced. Seroprevalence among those born in Jamaica (irrespective of current residence) was 22 percent (10/46; 95 percent confidence limits 9 to 34 percent) compared with zero among British born offspring (0/14) and was higher in group 2 at 33 percent (7/21; 12 to 55 percent) than in group 1 at greatest mean age.) Proviral DNA was not detected in any subject negative for HTLV-I antibody, making prolonged viral incubation in those negative for the antibody unlikely. CONCLUSION -- In this sample factors related to place of birth and early residence were more important in transmission of HTLV-I than naternal or age effects. In areas with a low to moderate prevalence policies of preventing mothers who are carriers of the virus from breast feeding would be premature (AU)