Prevalence of antibody to human T cell leukaemia/lymphoma virus in women attending antenatal clinic in southeast London: retrospective studyBMJ 2000; 320 doi: http://dx.doi.org/10.1136/bmj.320.7227.92 (Published 08 January 2000) Cite this as: BMJ 2000;320:92
- Matthew Donati, specialist registrar in virologya,
- Habib Seyedzadeh, grade 1 medical laboratory scientific officera,
- Teresa Leung, grade 2 medical laboratory scientific officera,
- Maggie Blott, consultant obstetrician and gynaecologistb,
- Mark Zuckerman, consultant virologist ()a
- a Public Health Laboratory and Medical Microbiology, Department of Virology, Guy's, King's and St Thomas's School of Medicine, King's College Hospital (Dulwich), London SE22 8QF
- b Department of Obstetrics and Gynaecology, King's Healthcare Trust, London SE5 9RS
- Correspondence to: M Zuckerman
- Accepted 7 October 1999
Infection with human T cell leukaemia/lymphoma virus (HTLV) type I occurs mainly in Japan, central and west Africa, and the Caribbean basin. Infection confers a lifetime risk of 2-4% for adult T cell leukaemia or lymphoma and 0.2-5% for tropical spastic paraparesis. However, the incubation period for these conditions after naturally acquired infection may be several decades.1 The virus is transmitted via infected lymphocytes, and in areas of high prevalence breast feeding is an important route of transmission, particularly if continued for over six months.2
We determined the prevalence of HTLV antibody in women who had attended antenatal clinics at King's Healthcare NHS Trust, southeast London, to assess whether antenatal screening should be considered locally.
Subjects, methods, and results
With the approval of the local ethics committee, we tested sera that had been collected routinely at antenatal clinics between January 1994 and December 1996 for HTLV antibody. The samples were anonymised for patient's name and hospital number, but data on ethnicity, age, and partner's ethnicity were retained.
We initially pooled sera from five separate samples in a single assay well and used an enzyme linked immunoassay for HTLV antibody (Murex Biotech, Dartford, product code GE80/81). When the assay was reactive for a pool, we tested each sample using the same assay. Reactivity was then confirmed with a passive particle agglutination test (Serodia HTLV-I, Fujirebio, Tokyo, Japan), and we used an immunoblot assay to discriminate between HTLV types (Inno-Lia, HTLV I/II antibody assay, Innogenetics NV, Belgium).
We tested 8656 samples altogether and identified 110 reactive pools. These pools yielded 34 samples positive for HTLV antibody (0.39%, 95% confidence interval 0.26% to 0.52%)—32 with HTLV type I (0.37%), one with HTLV type II (0.01%), and one that was untypable. One sample gave an indeterminate antibody result. The table shows the overall results.
We found the seroprevalence of antibody to human T cell leukaemia/lymphoma virus was 0.39% among pregnant women in southeast London over a 36 month period. This result probably reflects the ethnic composition of the local residents of Lambeth, Lewisham, and Southwark, about 18% of whom are black (1991 census data).
The policy of not screening for HTLV antibody in pregnant women and in blood and organ donors is partly based on its perceived low prevalence and the low lifetime risk of associated disease. Although the cost of antenatal screening could be limited by selecting those women thought to be at high risk, this would require knowledge of the ethnicity details of current and previous sexual partners in order to be comprehensive. Such information might be difficult to obtain. In our study HTLV infection was not limited to women who described themselves as black African or black Caribbean, a finding that was also reported in the West Midlands.3 Three white women were infected, of whom two were born in Britain and one in Jamaica, and all three had black Caribbean partners. We also found HTLV antibody in 10 women born in Britain who described themselves as either black African of black Caribbean.
The prevalence of HTLV antibody was similar to that reported for HIV in the same population at the same time.4 With appropriate counselling, screening for HTLV should be accepted in the same light as testing for HIV, which has recently been recommended as part of the routine antenatal screening programme.5 However, unlike HIV infection, infection with HTLV is less likely to become clinically apparent, and the factors conferring a high risk of developing associ- ated disease have not been defined. In the mean- time, antenatal screening could help limit vertical transmission.
We thank Dr Jennifer Tosswill, Virus Reference Laboratory, Central Public Health Laboratory, London, for further analysis of three samples sent for confirmation of antibody status; Natalie Ives for the statistical analysis of the data; and the staff in the department of virology at Dulwich Public Health Laboratory for their help with this study.
Contributors: MD helped with writing the paper, preparing samples for testing, and analysing the results. HS performed much of the sample testing and helped with analysing the results. TL helped with constructing the database of participants' details and analysing the results. MB helped with designing the study and drafting the article. MZ designed the study, helped with analysing data and revising the article, and is the guarantor for the study. Pam Dobson, computer liaison midwife at King's Healthcare Trust, provided the demographic data for the antenatal clinic attendees. All authors reviewed the manuscript.
Funding nternal sources only.
Competing interests None declared.