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HIV/AIDS

Definition of indicator

Incidence of a) HIV-infected and b) AIDS cases, in a calendar year. A case of HIV infection and AIDS are defined following the European AIDS and HIV surveillance case definitions.

Calculation (numerator, denominator)

The rates are calculated as the number of newly diagnosed cases (of HIVand AIDS) per million inhabitants, based on the number of reported cases reported by national surveillance systems (as reported to the European Centre for the Epidemiological Monitoring of HIV and AIDS). Rates are calculated in year x for the year x-1 to account for delayed reporting.

Additional underlying concepts

National case definitions are applied and have been harmonised to a large extend. The indicators are calculated by the European Centre for the Epidemiological Monitoring of HIV and AIDS (EuroHIV, www.eurohiv.org). For the calculation EuroHIV considers the characteristics of country specific surveillance systems.

European AIDS and HIV surveillance case definitions

HIV infection

A case of HIV infection is defined as an individual with HIV infection confirmed by laboratory according to country definitions and requirements, diagnosed at any clinical stage including AIDS, and not previously reported in that country. For children aged under 18 months at diagnosis, at least one direct detection HIV test (non-antibody based) is also required. Adult/adolescent cases are defined as those aged 13 years and over, and paediatric cases as those under 13 years.

AIDS

Cases are reported according to a uniform AIDS case definition originally published in 1982[1] and revised in 1985[2,3] 1987[4,5] and, for adults and adolescents (13 years and over), in 1993[6,7]. The 1993 European AIDS surveillance case definition differs from the definition used in the USA in that it does not include CD4 lymphocyte count criteria. For children (less then 13 years), the case definition used in Europe[8] is essentially the same as that used in the USA.

Relevant dimensions (subgroups)

Country (also region), calendar year, sex, age at diagnosis, transmission group (Grouping:, Injecting drug user, Haemophiliac/Transfusion recipient, Heterosexual contact, Mother-tochild, Nosocomial infection, Other/Undetermined; only for men: Men who have sex with men)

Preferred data sources

EuroHIV – the European Centre for the Epidemiological Monitoring of HIV/AIDS – collects data on HIV/AIDS from the 53 Member States of the WHO European Region, the analyses of which are published in reports “HIV/AIDS Surveillance in Europe” and are presented on the EuroHIV website (http://www.eurohiv.org/reports/index_reports_eng.htm). The EuroHIV databases are not available online.

Rationale

HIV remains one of the most important communicable diseases in Europe. It is an infection associated with serious morbidity, high costs of treatment and care, significant mortality and shortened life expectancy. In western and central Europe, 720 000 persons are living with HIV/AIDS and, each year, over 20 000 individuals are becoming infected; in eastern Europe, 1.5 million persons are living with HIV/AIDS and more than 200 000 persons have been infected in 2005.

Data availability, quality and periodicity

EuroHIV is the primary dataholder in Europe, gathering data from national surveillance systems. National data, stratified by age and sex is available from 50 countries. It is not available from IT, ES and Monaco.

Data collection and management

Data on HIV and AIDS cases are reported to EuroHIV in a standard format. Individual data are reported without personal identifiers and elimination of duplicate reports between countries is therefore not possible. Since linkage between HIV and AIDS databases is not possible in all countries, two separate databases are maintained at European level (ENAADS, EHIDS: see below). New complete databases are provided at each update to allow validation and inclusion of follow-up data on previously reported cases.

AIDS

Anonymous, individual data on all cases reported in each of the 53 countries of the WHO European Region are reported annually to EuroHIV since the beginning of the epidemic, according to a standard data file specification. After validation, these data are merged to form the European Non-Aggregate AIDS Data Set (ENAADS).

HIV infection

Reporting of cases of newly diagnosed HIV infections started at different times in European countries and is now implemented in most of them (Annex Table 1). Anonymous, individual data on all reported cases are sent annually to EuroHIV, according to a standard data file specification, by countries able to provide individual data. After validation, these data are merged into the European HIV Infection Data Set (EHIDS). From other countries, aggregate data (by sex, age group, transmission group and half-year of report) on new cases reported are provided annually, with no updating of previously reported data.

Specific information on the HIV/AIDS surveillance systems in the countries have been published by EuroHIV. No national HIV data are reported from Italy, Monaco and Spain. Regional data from Italy and Spain (representing approximately a third of the population in each country) are available. Thus, the number of new cases of HIV will be underestimated in western Europe; The information on national surveillance systems has been collected in a survey conducted in the year 2006. The report is available online.

http://www.eurohiv.org/reports/eurohiv_2006_survey_report/eurohiv_2006_survey_report.pdf

WHO-HFA: Data from EuroHIV is reported

OECD: Data from EuroHIV is reported

Eurostat does not provide data on infectious diseases any more as the ECDC is considered responsible for reporting on infectious diseases in Europe. ECDC has not yet established an own database.

References

- EuroHIV (European Centre for the Epidemiological Monitoring of HIV and AIDS) European AIDS and HIV surveillance case definitions

1 Centers for Disease Control. Update on acquired immune deficiency syndrome (AIDS) – United States. MMWR 1982; 31: 507-514.

2 Centers for Disease Control. Revision of the case definition of acquired immunodeficiency syndrome for national reporting – United States. MMWR 1985; 34: 373-375

3 World Health Organization. WHO/CDC case definition for AIDS. Wkly Epidemiol Rec 1986; 61: 69-72.

4 Centers for Disease Control. Revision of the CDC surveillance case definition for acquired immunodeficiency syndrome. MMWR 1987; 36: No.1S.

5 World Health Organization. 1987 revision of CDC/WHO case definition for AIDS. Wkly Epidemiol Rec 1988; 63: 1-7

6 Ancelle-Park R. Expanded European AIDS case definition. Lancet 1993; 341: 441.

7 European Centre for the Epidemiological Monitoring of AIDS. 1993 revision of the European AIDS surveillance case definition. AIDS Surveillance in Europe, Quarterly Report 1993; No. 37: 23-28.

8 European Centre for the Epidemiological Monitoring of AIDS. European case definition for AIDS surveillance in children - revision 1995. HIV/AIDS Surveillance in Europe, Quarterly Report 1995; No. 48: 46-53.WHO-HFA, OECD, Eurostat

- HIV/AIDS Surveillance in Europe: End-year report 2006 No.75

- The EUPHIX (European Union Public Health Information & Knowledge System, www.euphix.org); the Health Status chapter dedicates a topic on HIV/AIDS among Diseases, disorders, injuries / Infectious diseases

Work to do

- The WP Indicators should decide which sub-indicator should be used for the ECHI-Shortlist. ECHIM recommends the HIV/AIDS rates per million inhabitants. If the WP follows the recommendation, the transmission subgroups can be deleted in the relevant dimensions section.

Suggestion: The main subgroups should not be given as core indicators ?

- Suggestion: ECHIM recommends to use the data from the primary dataholder, EuroHIV.

- should the text in the box Additional underlying concepts be moved to the box definition?

More indicator information will follow in due time.