B4 Blood-borne viruses
Key Points 2005
Hepatitis B Virus
Overview
- In 2005 there were 22 new hepatitis B virus (HBV) diagnoses among persons for whom injecting drug use was indicated as a risk factor (Table B4.1).
Five Year Trends — 2001 to 2005
- The overall number of new diagnoses of HBV declined between 2001 and 2004 from 357 to 341, but rose in 2005 to 372. This rise was not reflected in figures for new hepatitis B infected injecting drug users (IDU’s) which show a decline between 2001 and 2003, from 69 to 22, a figure which has remained the same in 2004 and 2005 (Table B4.1).
Geographical Profile
- Reports of new hepatitis B cases in IDU’s were received from 6 health board areas. Of the 22 reports, 41% were resident in NHS Greater Glasgow (9 reports), 14% in each of NHS Ayrshire and Arran, NHS Lanarkshire and NHS Lothian (3 reports in each) and 9% in each of NHS Argyll and Clyde and NHS Grampian (2 reports in each) (Table B4.1).
Hepatitis C Virus
Hepatitis C data has been revised by Health Protection Scotland therefore information referring to data prior to 2004 in this publication will differ from that previously published (see Background Information section for further detail).
Overview
- In 2005 886 IDU’s were diagnosed with hepatitis C virus (HCV). IDU’s accounted for 55% of the 1,600 HCV cases diagnosed in 2005 (Table B4.2).
- The total number of IDU’s known to be infected with the hepatitis C virus is 12,296, accounting for 90% of the 13,668 HCV reports in Scotland for which the possible/probably route of transmission was known. This is over 9 times the number of HIV diagnoses amongst IDU’s. There have been a further 6,495 reports in Scotland where the route of transmission is not known, some of which would be expected to be IDUs (Tables B4.2 and B4.4).
- 70% of the IDU’s with a diagnosis of HCV were male (Table B4.3).
- 50% of IDU’s were recorded as aged under 30 years when diagnosed with HCV. 4% were recorded as aged under 20 years on diagnosis (Table B4.3).
Blood-borne viruses
Five Year Trends — 2001 to 2005
- Between 2001 and 2005 there has been a small decrease in the total number of HCV cases reported, from 1,682 to 1,600. There was a larger decrease in the number of IDU HCV cases reported from 1,136 in 2001 to 886 in 2005. However, there was an increase in the number of cases of HCV reported where the probable/possible route of transmission was not known, from 472 in 2001 to 612 in 2005, some of which would be expected to be IDUs (Table B4.2).
Geographical Profile
- Of the 12,296 reports of HCV infected IDU’s 39% were from NHS Greater Glasgow, a further 15% were from NHS Lothian and 14% were from NHS Grampian (Table B4.2).
Human Immunodeficiency Virus and AIDS
Overview
- In 2005 there were 25 new cases of HIV infection among IDU’s (Table B4.4).
- 10 of the new cases were aged 30 to 34 years and the median age was 32 years (Table B4.6).
- 23 of the new cases were males (Table B4.6).
- The cumulative total (to 31 December 2005) of HIV infected reports in IDU’s is 1,330. IDU’s accounted for 29% of the cumulative total of 4,623 HIV infection reports for Scotland (Table B4.4).
- 4 new AIDS cases were registered in 2005, bringing the cumulative total number of cases registered to 435 (Table B4.4).
Five Year Trends —2001 to 2005
- The number of new HIV infections amongst the IDU population declined from 2001 to 2002 (from 21 to 10. Between 2002 and 2005 numbers have risen, with the largest year on year rise occurring between 2004 and 2005 (from 15 reports to 25 reports) (Table B4.4).
- The number of AIDS cases registered has declined from 16 cases in 2001 to 4 cases in 2005 (Table B4.4).
- There has been a decline over the last five years in the number of HIV infected IDU’s in clinical care, from 417 in 2001 to 384 in 2005 (Table B4.7).
Geographical Profile
- Of the 25 new HIV reports in 2005, just under a third were in NHS Lothian (9 reports) and a fifth were in NHS Dumfries and Galloway (5 reports). NHS Tayside and NHS Greater Glasgow each reported 3 new infections, NHS Lanarkshire and NHS Grampian each reported 2 new infections and NHS Borders reported 1 new case (Table B4.5).
- Of the cumulative total of infections 52% of cases were in NHS Lothian (686 of 1,330 reports). A further 22% were in NHS Tayside and 14% in NHS Greater Glasgow (Table B4.5).
Background information
Hepatitis B Virus
Health Protection Scotland (HPS) receives notification of positive hepatitis B Virus (HBV) tests from all laboratories located in the 15 NHS Board areas. At present no standard exists for the reporting of HBV infection and the amount of information provided by the different laboratories varies significantly. Information on risk factors, clinical history and status of HBV markers is frequently missing, thus it is difficult to determine whether cases are acute or chronic and to estimate the true incidence and prevalence of the virus. HPS are currently working towards developing an enhanced surveillance system for HBV in order to improve the quality of data that they receive.
Hepatitis C Virus
HPS, in association with Scotland’s principal HCV testing laboratories (the West of Scotland Specialist Virus Centre at Gartnavel General Hospital, Glasgow, the East of Scotland Specialist Virus Centre at the Edinburgh Royal Infirmary, the Department of Microbiology at Ninewells Hospital, Dundee, and the Department of Microbiology at Aberdeen Royal Infirmary) collates information on all cases of HCV diagnosed in Scotland. There is no dedicated HCV request form and information is limited to what is available on standard virological test request forms that accompany blood specimens.
Revised data — A comprehensive review of all records of diagnoses, received by HPS from HCV testing laboratories, was undertaken in 2005. This established that 6% of records of persons diagnosed HCV positive to December 2003 were duplicates (previously published in HPS weekly reports and included in this publication in previous years); most duplicates applied to the period 2000-2003 and the NHS board area most affected was Grampian where 18% of records had been duplicated. New procedures to reduce the chances of recording duplicate diagnoses have been introduced though HPS, for the purposes of patient confidentiality, only holds the following limited identifiers on individuals: gender, initial of forename, soundex code of surname, date of birth and postcode district of residence.
Human Immunodeficiency Virus
Voluntary case reporting of HIV and AIDS forms the basis for surveillance in Scotland; this provides information only on diagnosed infections. Data collected by HPS includes limited patient identifiers (initials, soundex code of surname, date of birth, gender and first part of postcode), risk exposure. Follow-up information such as all AIDS indicator diseases present at the time of the AIDS diagnosis, immunological (CD4 count which is testing to assess the immunological status and thus the stage of HIV disease has reached) monitoring and antiretroviral treatment are linked to cases where relevant. The number of individuals undergoing CD4 count monitoring is a good indicator of the number receiving clinical care.
Further information
Information about HPS data collection and research and statistics on blood-borne viruses are available at: http://www.hps.scot.nhs.uk/bbvsti/index.aspx
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