HTLV infection in England _ Wales

HTLV infection in England & Wales Reports received by the end of January 2005 Overview What is HTLV infection and what does it cause? Background: HTLV in England & Wales Surveillance for HTLV diagnoses: 1987-2001 Enhanced surveillance for HTLV diagnoses: 2002-2003 Summary of results What is HTLV infection? • HTLV stands for human T cell lymphotropic virus • It is a retrovirus that infects T lymphocytes • There are two molecularly distinct types: HTLV-I and HTLV-II • HTLV-I and -II are transmitted through breast feeding, sexual contact, blood transfusion, and injecting drug use • HTLV-I is endemic in the Caribbean, Japan, South America, and parts of Africa • HTLV-II is found among some native American groups and, more rarely, in Africa. In Europe, HTLV-II is particularly associated with injecting drug use What does HTLV infection cause? • While HTLV infection is lifelong, fewer than 5% of those infected develop related disease • First symptoms occur several years, maybe decades, after initial infection • Clinically, HTLV-I may cause: - adult T cell lymphoma (ATLL) – an aggressive, drug resistant malignancy, with a median survival of less than 12 months (post diagnosis) - HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP) – a chronic progressive inflammatory neurological disease that leads to a reduction in mobility and general limb function • There is some evidence that HTLV-II infection contributes to cases of neurological and lymphoproliferative disorders HTLV in England and Wales (E&W) • E&W maintains strong historical links with HTLV endemic areas, particularly the Caribbean • The black Caribbean population of E&W is over half a million people. (Office for National Statistics, Census, April 2001) HTLV seroprevalence studies in E&W In 1989, a study found a seroprevalence of 3.4% among Caribbean immigrants (Mowbray J, Mawson S, Chawira A, et al (1989) J. Med. Virol. 29: 289-295) A seroprevalence study of different accessible sub-populations showed HTLV prevalence of 0.05 per 1000 among almost 100,000 blood donors (Brennan M, Rununga J, Barabara JAJ, et al (1993) BMJ 307: 1235-1239) Of almost 100,000 Guthrie card samples tested in the North Thames neonatal screening laboratory, there was a seroprevalence of 17 per 1,000 among infants whose mothers were born in the Caribbean (Ades AE, Parker S, Walker J et al (2000) BMJ 320: 1497-1501) Reports of HTLV infection in E&W: the trend over time 120 100 100 Number of diagnoses 88 80 60 60 40 20 0 13 51 36 30 38 56 45 35 48 50 71 65 57 83 66 1987 1988 1989 1990 1991 1992 1993 Year of diagnosis 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 HTLV surveillance 1987-2001 [See Payne LJC, Tosswill JHC, Taylor GP, et al. In the shadow of HIV – HTLV infection in England & Wales 1987-2001. Communicable Disease and Public Health 2004; 7(3): 200-206] • Case ascertainment through the review of referral forms made to two national reference laboratories, with additional clinical details requested from referring centres as appropriate • Information on ATLL and HAM/TSP patients collected through HERN network HTLV testing Confirmation of HTLV infection is by Western Blot, which in most cases will discriminate between HTLV-I and II Indeterminate serology is investigated using PCR HTLV infection reports: 1987-2001 [See Payne LJC, Tosswill JHC, Taylor GP, et al. In the shadow of HIV – HTLV infection in England & Wales 1987-2001. Communicable Disease and Public Health 2004; 7(3): 200-206] Period of diagnosis Number of reports Av. no. of reports per year Median age at diagnosis (Interquartile range) 1987 – 1991 190 38 56 (45-81) 1992 – 1996 1997 – 2001 222 44 57 (47-63) 309 62 58 (44-67) F:M ratio Number (%) reports with ethnicity/origin indicated Of which: 2:1 105 (55%) 97 2:1 123 (55%) 107 2:1 134 (43%) 108 Caribbean African S Am’n/Japanese/Mid Eastern 5 2 1 7 4 5 13 4 9 European Methods: an enhanced surveillance system Laboratory Reports 2002 onwards NB. Some data analyses only include patients for whom a clinician report was received as this has extra information Sexually Transmitted and Blood Borne Virus Laboratory, Colindale Dulwich Reference Laboratory, Kings College Hospital Clincian Reports from National Blood Service, reports of HTLV positive blood donors HTLV Surveillance Database Communicable Disease Surveillance Centre, London Clinican Reports from attending clinicians of HTLV positive individuals, identified by laboratory receiving request for HTLV test • Additional variables collected: country of probable infection, country of birth, reason for test, further clinical details Diagnoses of HTLV infection in E&W: 2002-2004 • 271 new diagnoses of HTLV infection between 2002 - 2004 • Sub type - 252 (93%) were HTLV-I positive - 12 were HTLV-II positive - 1 was HTLV-I & II positive - 6 were untyped • Sex - 99 (37%) were male and 169 (62%) female • Median age at diagnosis - males: 54 years (IQR: 40–67 years) - females: 51 years (IQR: 42–64 years) HTLV diagnoses in 2002-2004: region of diagnosis • 67% of hospitals/laboratories requesting HTLV testing were in London, and 12% in the West Midlands 10 1 13 7 2 32 9 13 1 - probably reflects the underlying distribution of the Black Caribbean population in E&W, as well as the location of reference laboratories and specialist referral centres for HTLV 182 HTLV diagnoses in 2002 - 2004*: ethnic group 1% 4% 7% 6% Black Caribbean White Black African Other/mixed Black other Not reported 27% 55% *From clinician reports only (n=195) HTLV diagnoses in 2002 - 2004*: probable route of infection 60 55 Male Female Number of new diagnoses 50 45 40 35 30 25 20 15 10 5 0 Heterosexual sex Mother to child Mother to child Injecting drug transmission transmission or use heterosexual sex Blood transfusion 37 29 26 23 13 14 15 8 2 Sex between men Other 21 Not known *From clinician reports only (n=195) Probable route of infection HTLV diagnoses in 2002 - 2004*: probable country of infection and country of birth Region/country of birth UK UK Caribbean Africa Europe & other regions Not known Total Caribbean Africa Europe & other regions Not known Total 52 2 2 59 11 3 57 61 11 *From clinician reports only (n=195) Probable region/country of infection 2 14 17 3 8 2 20 10 56 70 78 14 10 23 195 HTLV diagnoses in 2002 - 2004*: reason for test 7% 7% 2% 39% Symptoms 6% Blood donor Blood relative positive Partner diagnosed with HTLV Other Not reported 39% *From clinician reports only (n=195) HTLV diagnoses in 2002 - 2004*: clinical presentation at diagnosis Clinical presentation at diagnosis Not reported Other neurology HAM/TSP Other malignancy ATLL Non-HTLV related Asymptomatic 0 5 12 14 18 Note: three patients reported with HAM/TSP and other neurology are included in the HAM/TSP figure. Two patients - one with reported ATLL and non-HTLV related diagnosis and another reported with ATLL and other neurology - are included in ATLL figure. Another patient reported with nonHTLV related diagnosis and other neurology is included in the other neurology figure. 35 23 88 20 40 60 80 100 Number of diagnoses *From clinician reports only (n=195) HTLV diagnoses in 2002 - 2004*: ATLL and HAM/TSP • 35 patients diagnosed with ATLL • 13 male and 22 female • Median age at diagnosis: 56 years (interquartile range: 45-68) • 28 black Caribbean, three black African, one white, one other/mixed ethnicity and two ethnicity not reported • 13 have lymphoma; 10 acute ATLL; 2 smouldering ATLL; 3 chronic ATLL; seven type not reported • Eight death reports • 14 patients diagnosed with HAM/TSP • Six male and eight female • Median age at diagnosis: 51 years (interquartile range: 41-65) • Eight black Caribbean, three white, three black African • One death report *From clinician reports (n=195) Summary • Introduction of blood donor HTLV testing increased the number of new HTLV diagnoses made in England & Wales • Over half HTLV diagnoses were made in people of black Caribbean ethnicity, with nearly a third in people of white ethnicity • Most people were infected through heterosexual intercourse, motherto-child transmission or either • HTLV-I transmission is occurring within the UK • More people with asymptomatic HTLV infection are being identified since the introduction of the testing of blood donations and contact tracing, but there are still a significant number of people presenting with disease Acknowledgements We would like to acknowledge the contribution of all the virologists and clinicians who have reported to the HTLV surveillance system.