The prevalence and clinical associations of HTLV-1 infection in a remote Indigenous community.
OBJECTIVE
Hospital and laboratory data indicate that human T-lymphotropic virus type 1 (HTLV-1) is endemic to central Australia, but no community-based studies of its prevalence or disease burden have been reported. We determined the prevalence rates of HTLV-1 infection and of HTLV-1-associated diseases in a remote Indigenous community.


METHODS
A remote Northern Territory community.


METHODS
All residents were asked to complete a health survey and offered a limited clinical examination, together with serological tests for HTLV-1 and Strongyloides, and HTLV-1 proviral load (PVL) assessment.


METHODS
HTLV-1 seropositivity rates; HTLV-1 PVL (copies/105 peripheral blood leucocytes [PBL]); presentation with HTLV-1-related clinical disease.


RESULTS
HTLV-1 serostatus was determined for 97 of 138 residents (70%). The prevalence of HTLV-1 infection was significantly higher among adults (30 of 74 people tested) than children (1 of 23; P = 0.001). Nine of 30 HTLV-1-positive adults had a clinical syndrome that was potentially attributable to HTLV-1 infection (chronic lung disease, seven; symptomatic strongyloidiasis, two). The median HTLV-1 PVL was significantly higher for adults with chronic lung disease than for those who were asymptomatic (chronic lung disease, 649 copies/105 PBL [IQR, 162-2220]; asymptomatic adults, 40 copies/105 PBL [IQR, 0.9-229]; P = 0.017). Ten of 72 adults tested were seropositive for Strongyloides (six of 28 HTLV-1-positive participants and four of 44 HTLV-1-negative participants; P = 0.17), as were three of 15 children tested; the three children were HTLV-1-negative.


CONCLUSIONS
The prevalence of HTLV-1 infection and the rate of disease potentially attributable to HTLV-1 were high among adults in this remote community.
Northern Territory Rural Clinical School, Flinders University, Alice Springs, NT lloyd.einsiedel@nt.gov.au.
Lloyd J
LJ
Einsiedel
Baker IDI Heart and Diabetes Institute, Alice Springs, NT.
Hai
H
Pham
Flinders Centre for Epidemiology and Biostatistics, Flinders University, Adelaide, SA.
Richard J
RJ
Woodman
Baker IDI Heart and Diabetes Institute, Alice Springs, NT.
Clinton
C
Pepperill
Poche Centre for Indigenous Health, Flinders University, Alice Springs, NT.
Kerry A
KA
Taylor
D000328:Adult; D000368:Aged; D002648:Child; D015897:Comorbidity; D005260:Female; D015490:HTLV-I Infections / Q000208:ethnology*; D015368:Human T-lymphotropic virus 1 / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015876:Northern Territory / Q000453:epidemiology; D010865:Pilot Projects; D015995:Prevalence; D019562:Viral Load; D000095283:Australian Aboriginal and Torres Strait Islander Peoples