Concept: Human Immunodeficiency Virus (HIV) - Method of Identification
Last Updated: 2023-02-09
1. Brownell et al. (2012)
In the deliverable How are Manitoba's Children Doing? by Brownell et al. (2012), a Manitoba Health report on the provincial count of new cases of HIV by age and sex distribution between 2000 and 2009 was examined (Manitoba Health - Public Health and Primary Health Care Division, 2010). For youths aged 15 to 19 years, 23 cases of HIV for females were identified and six for males. For youths less than 15 years of age, there were seven new cases for females and one case for males. According to this provincial report, between 2000 and 2009, the incident of new cases of HIV was four times greater for female youths. In 2010, there were two new cases of HIV for females aged 15 to 19 years of age and one for males. For those less than 15, only one new case was identified in females and none for males.
Because the percent of youths with a reported case of HIV in Manitoba is relatively low, it precludes presentation by region or income quintile. For more information read the section HIV in Brownell et al. (2012) .
2. Lix et al. (2012)
In the deliverable A Systematic Investigation of Manitoba's Provincial Laboratory Data by Lix et al. (2012), the Cadham Provincial Laboratory (CPL) data from 1992/93 to 2008/09 was used to identify the frequency of records for HIV tests with a linkable PHIN; that is, a PHIN that can link the CPL data to the administrative records at the MCHP Population Health Repository. Prior to 2006/07, the PHINs in the CPL data were not linkable to the administrative data. In 2006/07, only a small amount of tests were linkable and this number increased significantly in 2007/08 and in 2008/09. Thus, record linkage is not possible prior to 2007/08 in Manitoba.
Data from the CPL Serology Section was used to identify the CPL number of tests and the frequency of positive laboratory-confirmed cases in Manitoba. As an initial screening test, CPL uses an ELISA (enzyme-linked immunosorbent assay) on serum to detect antibodies for HIV and all positive ELISA test results are confirmed by a western blot (Manitoba Health - Communicable Disease Control Branch, 2010). In Manitoba, CPL is responsible for all confirmatory HIV antibody testing.
Table 1 reports the AUXCD5 codes used to identify HIV in the Serology Section of CPL. For more information on CPL, see the CADHAM Provincial Laboratory (CPL) - Overview of Services and Data concept.
NOTE: Individuals infected with HIV usually develop detectable antibodies within two weeks to three months after initial infection (antibodies detected by ELISA and western blot). However for some, this detection window might be more prolonged (Manitoba Health - Communicable Disease Control Branch, 2010).
Table 1 - HIV: Serology Section
STARTDT 1 STOPDT 2 AUXCD5 DESCR40 11/25/1993 01/01/2099 HIV ANTI-HIV1/HIV2 01/01/1990 05/01/2006 HIV1C HIV1 CONFIRM 01/01/1990 05/01/2006 HIV2C HIV2 CONFIRM 10/23/2007 01/01/2099 HIVA ANTI-HIV1/HIV2 01/01/1990 01/01/2099 HIVAG HIV1 ANTIGEN DETECTION 04/02/1998 01/01/2099 HIVDN HIV-DNA 04/30/2003 01/01/2099 HIVGT HIV-1 DRUG RESISTANCE 01/01/1990 05/01/2006 HIVIF HIV1 IFA 12/21/2006 01/01/2099 HIVN ANTI-HIV1/HIV2 09/24/1996 01/01/2099 HIVQR HIV QUANTITATIVE RNA - PCR 02/01/2008 01/01/2099 HIVRT ANTIBODY TO HIV (RAPID TEST) 05/01/2006 01/01/2099 HIVVL HIV VIRAL LOAD 01/01/1990 01/01/2099 HVCC HIV1/HIV2 CROSSREACT/CONFIRM 05/07/2009 01/01/2099 HVCOM COMBO ANTI-HIV-1/O/2 AND HIV-1 P24 01/01/1990 12/03/1993 HVCS HIV1/HIV2 SCREEN 05/03/1993 05/01/2006 HVCS2 HIV1-HIV2 SUPPLEMENTARY SCREEN TEST 03/20/1997 05/01/2006 HVRNA HIV QUANTITATIVE RNA-PCR 12/21/2006 01/01/2099 ROHIV ANTI-HIV1/HIV2
1 - The date that the code was created in the file.
2 - The date that the code became inactive.
Comparison of Lab Data to Hospital Discharge Abstracts and Medical Services Data
Incident HIV cases identified from the hospital abstracts data and medical services data were compared to the CPL data for the fiscal years 2007/08 and 2008/09. ICD-9-CM codes 042 and ICD-10-CA codes B20-B24 were used to identify the diagnoses of HIV. In the two-year period, a total of 203 new cases of HIV were identified in the hospital abstracts and medical services/physician claims data. Of these cases, 33.0% had a positive HIV test result in the CPL data 30 days before or after the diagnosis date. When a 180-day period was used, 45.8% had a positive test in the CPL data, indicating a moderate agreement between positive test results and diagnoses for HIV in hospital abstracts and medical services/physician claims data. For more information on how HIV was investigated in the CPL data, read the section titled Case Study #1: Record Linkage for HIV Tests in Lix et al. (2012).
3. Fransoo et al. (2019)
In the deliverable The 2019 RHA Indicators Atlas by Fransoo et al. (2019), they investigated the prevalence of HIV in the population.
DATA SOURCE: - The Cadham Provincial Laboratory (CPL) - Laboratory Management Information System (LIMS) data from August 31, 2009 to December 31, 2017 was used to identify records with a positive HIV laboratory test results. The lab data is considered the "gold standard" for identifying cases of HIV.
METHOD: - The method for determining a positive HIV laboratory test in the RESULTS file of the CPL - LIMS data was established in partnership with the CPL. This involved analyzing the values from two variables in the RESULTS file: ANALYSIS and FORMATTED_ENTRY. The following algorithm was applied to identify positive HIV test results:Specific Inclusion Criteria:Findings in this Researchif analysis = 'HIV_DRUGRES_REF' then hiv_positive = '1';Specific Exclusion Criteria:
if analysis = 'HIV_VL' and formatted_entry ^in: ( 'Invalid', 'Ottawa result', 'nlhrs', 'Specimen inhibitory' ) then hiv_positive = '1';
if analysis = 'HIV' and formatted_entry = 'Positive' then hiv_positive = '1';
if analysis = 'HIV_COMBO' and formatted_entry in ( 'Positive', 'Screen Test Positive' ) then hiv_positive = '1';
if analysis = 'HIV_PRO_REF' and formatted_entry = 'Detected' then hiv_positive = '1';- remove "Target Not Detected" HIV_VL tests performed before 18 months
- keep only those records that were reported to Manitoba Health (e.g. records with an invalid scrambled PHIN are removed) to reduce duplicate tests and remove 'child' tests.For more information on the HIV prevalence findings from this research, please see section 4.12 Human Immunodeficiency Virus (HIV) Prevalence