title: Screening for prolonged incubation of HTLV-I infection in British and Jamaican relatives of British patients with tropical spastic paraparesis.
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 had migrated from Jamaica before they developed symptoms, and to examine factors possibly related to transmission of HTLV-I.
  
  
  METHODS
  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.
  
  
  METHODS
  Britain and Jamaica.
  
  
  METHODS
  All available first degree relatives: those born and still resident in Jamaica (group 1); those born in Jamaica who migrated to Britain (group 2); and index patients' children who were born and resident in Britain (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% (10/46; 95% confidence limits 9 to 34%) compared with zero among British born offspring (0/14) and was higher in group 2 at 33% (7/21; 12 to 55%) than in group 1 at 12% (3/25; 0 to 25%). (Patients in group 1 had the 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.
  
  
  CONCLUSIONS
  In this sample factors related to place of birth and early residence were more important in transmission of HTLV-I than maternal 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.
authors.affiliation: Department of Medicine, Northwick Park Hospital, Harrow.
authors.forename: J K
authors.initials: JK
authors.lastname: Cruickshank
authors.forename: J H
authors.initials: JH
authors.lastname: Richardson
authors.forename: O S
authors.initials: OS
authors.lastname: Morgan
authors.forename: J
authors.initials: J
authors.lastname: Porter
authors.forename: P
authors.initials: P
authors.lastname: Klenerman
authors.forename: J
authors.initials: J
authors.lastname: Knight
authors.forename: A L
authors.initials: AL
authors.lastname: Newell
authors.forename: P
authors.initials: P
authors.lastname: Rudge
authors.forename: A G
authors.initials: AG
authors.lastname: Dalgleish
mesh_terms: D001483:Base Sequence; D002353:Carrier State; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D015481:HTLV-I Antibodies / Q000032:analysis; D015490:HTLV-I Infections / Q000453:epidemiology* / Q000235:genetics; D006801:Humans; D007563:Jamaica / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D015493:Paraparesis, Tropical Spastic / Q000453:epidemiology* / Q000635:transmission; D010375:Pedigree; D016133:Polymerase Chain Reaction; D015995:Prevalence; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D004279:DNA, Viral; D015481:HTLV-I Antibodies