About the Cohort

The following section provides descriptive statistics of baseline information that has been collected and compiled for all the participants enrolled into the cohort. It contributes to an on-going effort to provide updated information on the evolution of the CCC population.

This data is provided for information purposes only and should not be copied or used without obtaining permission from the CCC.


The Canadian Co-infection Cohort Study (CCC; CTN222) is a prospective multi-centre study recruiting co-infected patients from existing HIV clinic populations at 18 centres across five Canadian provinces. The cohort was initiated in 2003 in Montreal, Quebec, and then was expanded to other urban and semi-urban centres in 2007. As of April 2015, 1498 participants were enrolled. In 2010, the annual number of newly enrolled participants decreased while recruitment was temporarily put on hold pending grant renewal. Recruitment resumed and remains active since early 2011. Recently 2 new sites (Saskatoon, SK and Quebec City, QC) have been initiated and are enrolling patients.

Figure 1: Geographical Distribution of Participants Enrolled in the Canadian Co-infected Cohort (CCC) by Centre, 2003-2015 (N = 1498).

Figure 2a: CCC Participant Enrollment by Year, 2003-2015.

Figure 2b: CCC Participant Enrollment by Province, 2003-2015.


The population of the CCC is predominantly male (at least 65%, Figure 3), with a majority of the participants reporting heterosexual orientation (72%); 18% are men-having-sex-with-men (MSM). 76% of participants self-identified as being white; however, a unique feature of the CCC is its large proportion of Aboriginal participants (16% in 2015).

Past injection drug use is very common (81%) and 35% are current injection drug users.

Over time, the two main transmission modes for both HIV and HCV in newly enrolled participants remained injection drug use (IDU) and sexual transmission.

Figure 3: Distribution of Participants Enrolled in the CCC by Gender, 2003-2015.

Figure 4: Distribution of Participants Enrolled in the CCC by Self-Reported Mode of HIV Infection, 2003-2015.

Figure 5: Distribution of Participants Enrolled in the CCC by Self-Reported Mode of HCV Infection, 2003-2015.

Figure 6: Distribution of Participants Enrolled in the CCC by Self-Reported Ethnicity, 2003-2015.

Figure 7: Distribution of Participants Enrolled in the CCC by Self-Reported Sexual Orientation, 2003-2015.

Figure 8: Distribution of Participants Enrolled in the CCC by Self-Reported History of Injection Drug Use, 2003-2015.


Figure 9: HIV Therapeutic Status at Enrollment, 2003-2015.

As of April 2015, 83% of the participants are on cART while a small proportion of participants (11%) remain HIV treatment naive.

Figure 10 (below) illustrates the therapeutic status according to CD4 cell count. At enrollment, the proportion of treatment naïve participants with CD4 value below 200 cells/µL is relatively small (5%).

Figure 10: Distribution of CD4 Measurements by HIV Therapeutic Status at Enrollment, 2003-2013.

Figure 11: Distribution of Viral Loads by HIV Therapeutic Status at Enrollment, 2003-2013.

Among the participants currently treated, the majority possess an undetectable viral load (73%).

Figure 12: Distribution of HCV genotype, 2003-2015.

The largest proportion of participants are HCV genotype 1 (73%).

Figure 13: Distribution of HCV PCR status at enrollment, 2003-2015.

The majority of HCV participants with serologic evidence of HCV exposure remain chronically infected with HCV at the time of CCC entry.

Figure 14: HCV Therapeutic Status Distribution at Enrollment, 2003-2015.

Figure 14 illustrates the increasing number of participants initiating HCV therapy in the CCC. The proportion of treatment-naive participants has decreased over time and currently amounts to approximately 67%.

Figure 15: Distribution of HCV therapy Outcome at Last Study Visit, 2003-2015.

A large proportion of participants treated for HCV had a sustained virological response (40%).

Figure 16: APRI Status of Participants at Enrollment, 2003-2015.

The aspartate aminotransferase (AST) to platelet ratio index (APRI) is used as a non-invasive surrogate for liver fibrosis and defined as: [100 X (AST/upper limit of normal)/platelet count (109/L). An APRI score ≥ 1.5 is considered equivalent to significant fibrosis (corresponding to a biopsy score >F2).

Figure 17: History of ESLD and AIDS Diagnosis at Enrollment, 2003-2015.

ESLD includes liver cirrhosis, ascites, hepatic encephalopathy, bleeding esophageal varices, spontaneous bacterial peritonitis and hepatocellular carcinoma.

AIDS diagnoses were defined according to the Centres for Disease Control classification.

Figure 18: Distribution of Causes of Death Among CCC Participants, 2003-2015.

The widespread use of highly active antiretroviral therapy (cART) for the treatment of patients with HIV in developed countries has led to a dramatic decrease in AIDS-related mortality. Among patients co-infected with HCV, liver disease has emerged as a leading cause of death. This is shown to be true in our cohort where the main cause of death was end-stage liver disease (19%) followed by drug overdose (16%). All deaths in the CCC were reported following the “Coding of Death in HIV” (CoDe) system (www.cphiv.dk/CoDe/tabid/55/Default.aspx) then the underlying cause of death was determined according to the International Classification of Diseases, Tenth Revision rules (ICD-10).

Table 1: Socio-Demographic Characteristics of Participants at Enrollment, 2003-2015.

Table 2: Clinical Characteristics of Participants at Enrollment, 2003-2015.

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