Download presentation
Presentation is loading. Please wait.
Published byLaurence Hutchinson Modified over 9 years ago
1
HIV and STI Department - Centre for Infections Surveillance of recently acquired HIV infections among newly diagnosed individuals in the UK S. Lattimore, G. Murphy, R. Smith, J. Tosswill, D. Pillay, O.N. Gill & V. Delpech On behalf of the HIV Incidence Advisory and Working Group Dr Samuel Lattimore
2
HIV and STI Department - Centre for Infections Aim of RITA RITA “Incorporate RITA as part of the routine public health monitoring of all newly diagnosed HIV infections in England and Wales”
3
HIV and STI Department - Centre for Infections The system in England Study period, 16 months between Feb 2009 to May 2010 Estimated 7950 newly diagnosed infections during this time frame, from ~200 laboratories 4116 aliquots from diagnostic samples were submitted to the national reference laboratory 2480 linked to national epidemiological database (as of 1 st July 2010) Representing 2099 individuals Epidemiologically representative sample Prevention groupSample received Est. number of new dx MSM8862834.7 Heterosexual9513497.3 IDU39145.3 Uncatergorised2231473.3 Total20997950.6
4
HIV and STI Department - Centre for Infections Performance AxSYM avidity - guanidine as chaotrope Low avidity index (AI) indicates recent infection (<80%) >90% returned within 5 working days Results cascaded to the clinic via diagnostic laboratory
5
HIV and STI Department - Centre for Infections Reclassification of low avidity specimens 2099 samples, 280 low AI CD4 <200 within 90 days of dx Excluded: 20 AIDS diagnosis within 90 days dx Excluded: 7 HIV positive test result more than 180 days previously Excluded: 40 24 seen in the annual census of individuals accessing HIV treatment and care 6 never received treatment 10 on ARV when sample drawn 8 ARV reported after sample date 9 30 1 5 5 0 1 51 excluded
6
HIV and STI Department - Centre for Infections AI 167 Uncategorised: 223IDU: 39Heterosexuals: 951MSM: 889 Individuals: 2099 Duplicate samples: 381 Linked: 2480 Unlinked: 1636 Aliquots received: 4116 Samples not received: ? New dx 7950 LS 888R 63 AI 719 AI 88 AI 863 AI 2 AI 37 AI 22 AI 198 LS 743R 143 LS 38R 1LS 198R 21
7
HIV and STI Department - Centre for Infections Recent infections by prevention group, England Feb 2009 – May 2010 as of end June 2010 Prevention groupRecent Samples received % recentPopulation MSM14388616.12834.7 Heterosexual Men203226.21306.6 Women436296.82644.0 IDU1392.6145.3 Uncategorised212239.41473.3
8
HIV and STI Department - Centre for Infections Similar proportion of recent infections across all age groups Recent infections among MSM England, Feb 2009 – May 2010 as of end June 2010
9
HIV and STI Department - Centre for Infections Recent infections among heterosexuals England, Feb 2009 – May 2010 as of end June 2010 Female: Highest in youngest age group Antenatal testing Decreasing with age Peaking again in 50+ Male: Later peak Decreasing with age Differential service access Exact permutation t.test, P = 0.083
10
HIV and STI Department - Centre for Infections Conclusions Experience from England demonstrates national surveillance of recent infections is possible in industrialised countries Application of Laboratory tests for recent information require surveillance information Estimated costs of 5000 specimens, between 77,000 - £138,000 Among MSM 1 in 6 recently infected Similar proportion of recent infections across age groups Among heterosexuals 1 in 16 recently infected Recent infections highest among 15-24 for women, 25-34 for men UK acquired Collect HIV test interval data from clinics to estimate HIV incidence in clinic attendees.
11
HIV and STI Department - Centre for Infections www.hpa.org.uk/HIV Key word STARHS or RITA
12
HIV and STI Department - Centre for Infections Acknowledgements National surveillance team Brian Rice, Ruth Smith, Meaghan Kall, Celia Penman, Sonia Ribero, Ragani Raghu & Vicky Gilbart National HIV survey team Alison Brown, Zheng Yin, Tom Hartney, Cuong Chau National virus reference lab Gary Murphy, Deenan Pillay, John Parry, Jennifer Tosswill, Elaine McKinney, Grace Mensah, Caroline Motamed And a very special thank you to Ruth Smith!
13
HIV and STI Department - Centre for Infections SPARE SLIDES
14
HIV and STI Department - Centre for Infections Factors independently associated with RHI after exclusion All Samples: 229 recent infections Male (180; 2.1) Infected in the UK (114; aOR 2.4) White ethnicity (142; aOR 1.8) Born in the UK (93; 2.8) MSM (143; aOR 2.9) MSM: 143 RHI Infected in the UK (84; aOR 1.4) White ethnicity (113; aOR 2.0) UK born (74; aOR 2.4) No association with age at dx HET: 63 RHI Infected in the UK (29; aOR 2.7) White ethnicity (21; aOR 1.6) UK born (29; aOR 3.1) Diagnosed in London (40; aOR 3.2) Age 15-24 (14; aOR 2.2)
15
HIV and STI Department - Centre for Infections Proportion of RHI by age group MSM No association between age and RHI Similar proportion RHI across age groups Hets Highest 15-24, decreasing to 35-49 (p<0.001) More than double the proportion of recent infections among 50+ cf 35-49 22 14 55 26 54 15 12 8
16
HIV and STI Department - Centre for Infections Is there a difference by sex among heterosexuals? Exact permutation t.test, P = 0.083 Women Men
17
HIV and STI Department - Centre for Infections Ongoing work Testing patterns in age Ascertaining country of infection Combine with UK resistance database to explore subtype issues, and transmitted drug resistance False long-standing infections relies on quantity and quality of surveillance data, especially self-reported testing history Use RITA as a basis for estimating HIV incidence Require knowledge of testing bias, representativeness and population estimates, repeat test pattern Are we testing the right specimens? Should AIDS /low CD4 specimens be called misclassified or should they just be excluded Are we wrongly increasing the false recent rate by wrongly including specimens?
18
HIV and STI Department - Centre for Infections
19
RITA platform Investigate the maturity of the anti-HIV antibody response by assessing its avidity. Avidity index based upon the rational that avidity increases progressively with time from infection, thus low avidity indicates primary infection Avidity index applied to other infections including toxoplasmosis, rubella, CMV, HCV, HBV and human herpes virus AI for HIV described by Barbara Suligoi et al 2002 Based on an automated AxSYM HIV-1/2gO assay (Abbott)
20
HIV and STI Department - Centre for Infections Sensitivity and Specificity
21
HIV and STI Department - Centre for Infections Why determine recent HIV infections (RHI) Monitoring current burden, or prevalence of HIV infection in populations is a blunt tool for understanding: Trends in transmission Impact of behaviour change Impact of public health interventions Identifying RHI allows us to track patterns in HIV transmission Reveal groups at greatest risk of HIV infections and Tailor of health promotion initiatives to meet their needs Highlight programmes most effective at reducing transmission May be used to strengthen partner notification programmes, & target discussions on risk behaviour to recent timeframe.
22
HIV and STI Department - Centre for Infections CD4 count at diagnosis among laboratory determined recent and long-standing infections CD4 count significantly higher in laboratory determined recent infections (p<0.001) 10% RITA recent have CD4 count <200 Median 529 344580 400450 275 R: Recent LS: Long standing
23
HIV and STI Department - Centre for Infections Detecting recent HIV infections CD4 count at diagnosis AIDS diagnoses Previous positive HIV test S T A H R S erological esting lgorithms ecent IV eroconversion R I T A ecent nfection esting lgorithm SOURCE: Murphy G, Parry JV. Assays for the detection of recent infections with human immunodeficiency virus type 1. Euro.Surveill. 2008;13(36):18966.
24
HIV and STI Department - Centre for Infections Factors driving new diagnoses New HIV Diagnoses Changes in population Size (MSM) Testing Improved reporting Migration and travel Transmission (incidence)
25
HIV and STI Department - Centre for Infections Proportion recent by risk group
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.