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INFECTIOUS DISEASE SURVEILLANCE
in Canadian Federal Penitentiaries 2005-2006

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Part II: Results

Chapter 5: Sexually Transmitted Infections (STI)

Aggregate IDSS STI Data

The IDSS provides the number of cases diagnosed with genital chlamydia, gonorrhea, syphilis, and ‘other STI’ (which includes herpes simplex, genital warts, and any other non-specific STI such as urethritis). For syphilis cases the aggregate data did not include staging information therefore we are unable to distinguish infectious cases from later non-infectious stages. The overall frequency of cases reported and the corresponding case prevalence rates for STI by gender are shown in Table 5.1. Cases disaggregated by Region and gender are in Appendix D (Tables D.1.i (chlamydia), D.2.i (gonorrhea) and D.3.i (syphilis)). The trends in STI prevalence rates over time are displayed in Figure 5.1 and described in the following disease-specific subsections.

 

Table 5.1: Reported STI Cases and Prevalence (Percentage), Inmates, IDSS, 2000 - 2006
STI (n/%) 2000 2001 2002 2003 2004 2005 2006

Source: IDSS Aggregate Surveillance Data, CSC 2010
1 – Other STI includes herpes simplex, genital warts, and any other non-specific STI such as urethritis

Chlamydia 21 (0.17%) 23 (0.18%) 53 (0.43%) 58 (0.48%) 53 (0.40%) 92 (0.75%) 95 (0.72%)
Male 19 (0.16%) 21 (0.17%) 49 (0.41%) 55 (0.46%) 48 (0.38%) 87 (0.74%) 87 (0.68%)
Female 2 (0.64%) 2 (0.60%) 4 (1.31%) 3 (0.89%) 5 (1.23%) 5 (1.29%) 8 (1.80%)
Gonorrhea 11 (0.09%) 13 (0.10%) 20 (0.16%) 7 (0.06%) 11 (0.08%) 11 (0.09%) 20 (0.15%)
Male 11 (0.09%) 11 (0.09%) 19 (0.16%) 6 (0.05%) 7 (0.06%) 10 (0.08%) 19 (0.15%)
Female 0 (0.00%) 2 (0.60%) 1 (0.33%) 1 (0.30%) 4 (0.98%) 1 (0.26%) 1 (0.22%)
Syphilis 0 (0.00%) 0 (0.00%) 3 (0.02%) 4 (0.03%) 10 (0.08%) 6 (0.05%) 16 (0.12%)
Male 0 (0.00%) 0 (0.00%) 3 (0.03%) 3 (0.03%) 9 (0.07%) 6 (0.05%) 14 (0.11%)
Female 0 (0.00%) 0 (0.00%) 0 (0.00%) 1 (0.30%) 1 (0.25%) 0 (0.0%) 2 (0.45%)
Other STI1 60 (0.49%) 35 (0.28%) 53 (0.43%) 85 (0.70%) 91 (0.69%) 66 (0.54%) 61 (0.46%)
Male 20 (0.17%) 10 (0.08%) 45 (0.38%) 71 (0.60%) 69 (0.54%) 50 (0.42%) 35 (0.27%)
Female 40 (12.74%) 25 (7.53%) 8 (2.61%) 14 (4.14%) 22 (5.41%) 16 (4.13%) 26 (5.84%)

Enhanced Surveillance: Web-IDSS STI Data Results

Questions on previous tests for STI, test results, and treatment were asked among New Admissions and captured by the enhanced surveillance system (Web-IDSS). The number of tests and test results for general population inmates were also captured by the Web-IDSS. Note that general population cases cannot be interpreted as seroconversion because these offenders might not have tested on admission.

The overall Web-IDSS results for both new admissions and general population offenders are shown in Table 5.2 and are discussed in the disease-specific subsections below. Disaggregated results are shown in Appendix D. Results by region and gender can be found in Tables D.1.ii (chlamydia), D.2.ii (gonorrhea) and D.3.ii (syphilis). Results by origin are in Tables D.1.iii (chlamydia), D.2.iii (gonorrhea) and D.3.iii (syphilis).

Chlamydia

Aggregate IDSS chlamydia Data

The number of chlamydia cases reported through the IDSS was 92 in 2005 and 95 in 2006. Over time, the prevalence rates have generally increased from a low of 0.17% in 2000 to a high of 0.75% in 2005, with a small decrease to 0.72% in 2006 (Figure 5.1). The rates of infection among women are consistently higher than those among men (Table 5.1). Table D.1.i in Appendix D shows that the highest prevalence rates of chlamydia infection for both men and women in 2005-2006 were in the Prairies Region (for women, 2.38% and 3.42% respectively; for men, 1.77%, and 2.14% respectively). The Prairies Region has consistently accounted for the highest burden of chlamydia reported in CSC from 2000-2006.

 

Figure 5.1: STI Prevalence in Canadian Federal Penitentiaries,
Inmates, IDSS, 2000 – 2006 Figure 5.1: STI Prevalence in Canadian Federal Penitentiaries, Inmates, IDSS, 2000 – 2006

Source: IDSS Aggregate Surveillance Data, CSC 2010

 

Enhanced Surveillance: Web-IDSS chlamydia Data Results

Overall, 19.0% of new admissions reported a previous chlamydia test (Table 5.2). A higher proportion of females reported a previous chlamydia test on admission at 47.7 % compared to males at 17.4% (see Appendix D, Table D.1.ii). Of those tested, females had higher previous test positivity at 29.9% compared to 21.7% for males. However, reported previous treatment uptake was higher among males (79.3%) compared to females (75.0%).

Overall, there were 2,068 chlamydia tests among New Admissions. Adjusting for the proportion of new admissions in Web-IDSS (59%) and assuming that all chlamydia tests are captured, the lowest estimate of testing uptake among new admissions for 2005-2006 is 21% (Table 5.2). Overall unadjusted testing uptake on admission for chlamydia among new admissions recorded in Web-IDSS was 35.4% (Appendix D, Table D.1.ii, and Table D.1.iii). Testing uptake was higher among females at 64.6% compared to males at 33.8%.

Of the 2,068 chlamydia screening tests recorded in Web-IDSS, results were available for only 1,301 (63%). A total of 72 chlamydia cases were detected among new admissions which translates to a test positivity of 5.5% and was higher among males at 5.7% compared to 3.2% among females. Combining self-reported previous chlamydia and infection diagnosed on admission, a “lifetime prevalence” of chlamydia infection can be calculated. Overall, an estimated 5.0% of males and 15.3% of females, on admission, have had (or have) chlamydia infection.

 

Table 5.2: STI History, Testing and Outcome among New Admissions and
General Population Inmates, Web-IDSS, 2005 - 2006
  CHLAMYDIA GONORRHEA SYPHILIS1

* - Testing uptake rate adjusted by 59% of all new admissions (assuming all tests are captured in Web-IDSS) represents a lowest estimate
1 – Syphilis case is any positive serology. For the purposes of this report a syphilis case is
any positive serology for VDRL, RPR, MHA, FTA.
2 – Newly diagnosed cases divided by the number with a known result
Source: Web-IDSS Enhanced Surveillance Data, CSC 2010

NEW ADMISSIONS (n=5,840)
Testing / Clinical History
Previous Test 1,107 1,020 1,248
Previous Test Uptake 19.0% 17.5% 21.4%
Previous Positive 253 127 36
Previous Test Positivity 22.9% 12.5% 2.9%
Previous Treated 198 101 17
Proportion Previously Treated 78.3% 79.5% 47.2%
Testing on Admission
Testing Uptake [n (%)]* 2,068 (21%) 2,003 (20%) 3,580 (36%)
Positive Case on Admission 72 11 5
Test Positivity on Admission2 5.5% 0.9% 0.2%
 Lifetime Prevalence among New Admissions 5.6% 2.4% 0.7%
GENERAL POPULATION (n=3,773)
Testing Throughout Incarceration
Testing Uptake [n (%)]* 1,159 (31%) 1,079 (29%) 1,906
Testing Uptake among General Population 30.7% 28.6% 50.5%
Positive Result among General Population 31 5 6
Test Positivity among General Population 3.8% 0.7% 0.4%
Population Prevalence Estimate 0.8% 0.1% 0.2%

 

These results differed by region (see Appendix D, Table D.1.ii). Among males, the highest proportion with a previous chlamydia test reported on admission was in the Prairies at 29.5% and lowest in Ontario at 5.6%. Previous test positivity among males was highest in Pacific at 41.8% and lowest in Quebec at 14.7%. Testing for chlamydia on admission among males was highest in Prairies at 61.3% and lowest in Pacific at 7.0%. Test positivity on admission was highest in Prairies at 8.0% and lowest in Ontario and Pacific at 0.0%. Lifetime prevalence was highest in Prairies at 10.7% and lowest in Ontario at 1.2%.

Among females, the highest proportion with a previous chlamydia test reported on admission was in Quebec at 55.6% and lowest in Pacific at 32.4% (excluding Ontario, which has too few records to draw conclusions). Previous test positivity among females was highest in Prairies at 34.9% and lowest in Quebec at 16.0%. Testing on admission for chlamydia among females was highest in Quebec at 77.8% and lowest in Pacific at 14.7%. Test positivity is difficult to interpret regionally since it is based on small numbers; however the lifetime prevalence was highest in Prairies at 17.8% and lowest in Pacific at 8.8%.

The results for chlamydia among New Admission also differed by origin (see Appendix D, Table D.1.iii). Ignoring the unknown category, new admissions of Aboriginal origin reported the highest proportion with a previous chlamydia test at 30.9% and Foreign-born offenders had the lowest rate at 11.3%. Previous test positivity was also highest among the Aboriginal group (28.0%). Testing uptake (52.2%), test positivity (6.9%), and lifetime prevalence (11.2%) were all highest among the Aboriginal group.

With respect to general population inmates, there were 1,159 inmates (30.7%) tested for chlamydia in 2005-2006 according to Web-IDSS data (Table 5.2) for whom results are available for 824 (71%). Thirty-one of these individuals had a positive test result and the overall test positivity was 3.8%. Test positivity was higher among males at 3.8%, compared to females at 3.0%. Test positivity by region for males was highest in Prairies at 6.8% and lowest in Atlantic at 1.7% (Appendix D, Table D.1.ii). Test positivity by region for females was variable as it was based upon a small number of tests. The results for test positivity by origin were highest for Canadian-born Aboriginal inmates at 6.0% and lowest for Canadian-born non-Aboriginal inmates at 3.1% (ignoring the Unknown category, see Appendix D, Table D.1.iii). chlamydia testing uptake was also highest for the Aboriginal group at 38.5% and lowest for Foreign-born inmates at 23.5%.

Overall, there were 103 chlamydia cases reported in Web-IDSS, or 55% of the 187 reported in 2005-2006 by IDSS. There were 97 among males (56% of the 174 in IDSS) and 5 among females (38% of the 13 in IDSS).

Gonorrhea

Aggregate IDSS gonorrhea Data

Gonorrhea prevalence from IDSS was 0.08% in 2005 and 0.15% in 2006. Since 2000, the number of cases has been small, ranging from 7-20, thus the rate is statistically unstable. Table 5.1 indicates that the rates among women were higher than the rates among men for every year since 2001 (0.22% vs 0.15% in 2006). Prairie Region accounted for almost all of the gonorrhea reported in CSC 2005-2006 (Appendix D, Table D.2.i).

Enhanced Surveillance: Web-IDSS gonorrhea Data Results

Overall, 17.5% of new admissions reported a previous gonorrhea test (Table 5.2). A higher proportion of females reported a previous gonorrhea test on admission at 45.5 % compared to males at 16.0% (see Appendix D, Table D.2.ii). Of those tested, females had higher previous test positivity at 15.0% compared to 12.0% for males. However, reported previous treatment uptake was higher among males (83.0%) compared to females (61.9%).

Overall, there were 2,003 gonorrhea tests among new admissions. Adjusting for the proportion of new admissions in Web-IDSS (59%) and assuming that all gonorrhea tests are captured, the lowest estimate of testing uptake among new admissions for 2005-2006 is 20% (Table 5.2). Overall unadjusted testing uptake on admission for gonorrhea among new admissions recorded in Web-IDSS overall was 34.3% (Appendix D, Table D.2.ii, and Table D.2.iii). Testing uptake was higher among females at 64.3% compared to males at 32.6%.

Of the 2,003 gonorrhea screening tests recorded in Web-IDSS, results were available for only 1,198 (60%). A total of 11 gonorrhea cases were detected among new admissions which translates to a test positivity of 0.9% and was higher among females at 2.1% compared to 0.8% among males. Combining self-reported previous gonorrhea and infection diagnosed on admission, a “lifetime prevalence” of gonorrhea infection can be calculated. Overall, an estimated 2.1% of males and 7.5% of females, on admission, have had (or have) gonorrhea infection.

These results differed by region (see Appendix D, Table D.2.ii). Among males, the highest proportion with a previous gonorrhea test reported on admission was in Quebec at 27.2% and lowest in Ontario at 5.5%. Previous test positivity among males was highest in Pacific at 30.9% and lowest in Atlantic at 6.1%. Testing for gonorrhea on admission among males was highest in Quebec at 61.4% and lowest in Pacific at 7.2%. Test positivity on admission was highest in Prairies at 1.5%. Lifetime prevalence was highest in Pacific at 4.1% and lowest in Atlantic at 0.7%.

Among females, the highest proportion with a previous gonorrhea test reported on admission was in Quebec at 53.3% and lowest in Pacific at 32.4% (excluding Ontario, which has too few records to draw conclusions). Previous test positivity among females was highest in Prairies at 18.8% and lowest in Pacific at 0.0%. Testing on admission for gonorrhea among females was highest in Quebec at 77.8% and lowest in Pacific at 14.7%. Test positivity is difficult to interpret regionally since it is based on small numbers; however lifetime prevalence was highest in Quebec at 11.1% and lowest in Pacific at 0.0%.

The results for gonorrhea among New Admission also differed by origin (see Appendix D, Table D.2.iii). Ignoring the unknown category, New Admissions of Canadian-born Aboriginal origin reported the highest proportion with a previous gonorrhea test at 29.1% and Foreign-born offenders had the lowest rate at 10.5%. Previous test positivity was highest among the Aboriginal and Foreign-born groups at 14.3%. Testing uptake on admission and lifetime prevalence were highest among the Aboriginal group at 50.2% and 4.4% while test positivity on admission was highest in the Canadian-born non-Aboriginal group (1.0%).

With respect to general population inmates, there were 1,079 inmates (28.6%) tested for gonorrhea in 2005-2006 according to Web-IDSS data (Table 5.2) for whom results are available for 738 (68%). Five of these individuals had a positive test result and the overall test positivity was 0.7% while the estimated population prevalence was 0.1%. Indeed, all 5 cases were reported from the Prairies Region where test positivity was 2.0% and population prevalence 0.5% (Appendix D, Table D.2.ii). Gonorrhea testing uptake was highest among Canadian-born Aboriginal inmates at 35.5% as was test positivity at 0.5% (Appendix D, Table D.2.iii). Testing uptake and population prevalence were lowest for Foreign-born inmates at 19.6% and o.o%.

Overall, there were 16 gonorrhea cases reported in Web-IDSS, or 52% of the 31 reported in 2005-2006 by IDSS. There were 14 among males (48% of the 29 in IDSS) and two among females (100% of the two in IDSS).

Syphilis

Aggregate IDSS syphilis Data

There were 6 syphilis cases in 2005 and 16 in 2006 reported in IDSS (Table 5.1). In 2005 there were no cases of syphilis in females and in 2006 there were two female syphilis cases. The majority of cases reported in 2005 were from Quebec and Ontario, whereas in 2006 the majority of the cases were from Ontario and Pacific (Appendix D, Table D.3.i). The syphilis case rates have generally increased from 0.0% in 2000 and 2001 to 0.12% in 2006. The rates are difficult to compare by gender and region as they are based upon small numbers and are therefore statistically unstable.

Enhanced Surveillance: Web-IDSS syphilis Data Results

Overall, 21.4% of New Admissions reported a previous syphilis test (Table 5.2). A higher proportion of females reported a previous syphilis test on admission at 39.0% compared to males at 20.4% (see Appendix D, Table D.3.ii). Of those tested, females had higher previous test positivity at 5.0% compared to 2.6% for males. Reported previous treatment uptake was similar between females (50.0%) and males (48.3%).

Overall, there were 3,580 syphilis tests among New Admissions. Adjusting for the proportion of New Admissions in Web-IDSS (59%) and assuming that all syphilis tests are captured, the lowest estimate of testing uptake among New Admissions for 2005-2006 is 36% (Table 5.2). Overall unadjusted testing uptake on admission for syphilis among New Admissions recorded in Web-IDSS was 61.3% and was higher among females at 78.2% compared to males at 60.4%.

Of the 3,580 syphilis screening tests recorded in Web-IDSS, results were available for only 2,286 (59%). A total of 5 syphilis cases were detected among New Admissions which translates to a test positivity of 0.2% which was higher among females at 1.1% compared to 0.4% among males. Combining self-reported previous syphilis and infection diagnosed on admission, a “lifetime prevalence” of syphilis infection can be calculated. Overall, an estimated 0.60% of males and 2.3% of females, on admission, have had (or have) syphilis infection.

These results differed by region (see Appendix D, Table D.3.ii). Among males, the highest proportion with a previous syphilis test reported on admission was in Quebec at 30.1% and lowest in Atlantic at 11.5%. Previous test positivity among males was highest in Pacific at 9.0% and lowest in Quebec at 0.7%. Testing for syphilis on admission among males was highest in Quebec at 87.4% and lowest in Atlantic at 32.9%. Test positivity on admission was highest in Pacific at 1.1% although three of four syphilis cases on admission were detected in Ontario Region. Lifetime prevalence was highest in Pacific at 1.7% and lowest in Quebec and Atlantic at 0.2%.

Among females, the highest proportion with a previous syphilis test reported on admission was in Quebec at 46.7% and lowest in Pacific at 23.5% (excluding Ontario, which has too few records to draw conclusions). Previous test positivity among females was highest in Prairies at 5.4% and lowest in Atlantic and Pacific at 0.0%. Testing on admission for syphilis among females was highest in Quebec at 91.1% and lowest in Pacific at 35.3% (excluding Ontario). Diagnostic yield is difficult to interpret regionally since it is based on small numbers. Lifetime prevalence was highest in Prairies at 2.87%.

The results for syphilis among New Admission also differed by origin (see Appendix D, Table D.3.iii). Ignoring the unknown category, New Admissions of Aboriginal origin reported the highest proportion with a previous syphilis test at 29.4% while Foreign-born offenders had the lowest rate at 14.5%. Previous test positivity was also highest among the Aboriginal group (4.4%). Testing uptake (68.1%) and lifetime prevalence (1.5%) were also highest among the Aboriginal group, whereas test positivity was highest amongst Foreign-born inmates at 1.2%.

With respect to general population inmates, there were 1906 inmates (50.5%) tested for syphilis in 2005-2006 according to Web-IDSS data (Table 5.2) for whom results are available for 1,423 (75%). Six of these individuals had a positive test result and the overall test positivity was 0.4%. Test positivity was higher among females at 1.1%, compared to males at 0.4%. Test positivity by Region for males was highest in Atlantic at 1.1% and lowest in Ontario at 0.0% (Appendix D, Table D.3.ii). Test positivity by region for females was variable as it was based upon a small number of tests. The results for test positivity by origin were highest for Canadian-born non-Aboriginal inmates at 0.4% and lowest for Foreign-born inmates at 0.0% (ignoring the Unknown category, see Appendix D, Table D.3.iii). Syphilis testing uptake was highest for the Aboriginal group at 53.9% and lowest for Foreign-born inmates at 50%.

Overall, there were 11 syphilis cases reported in Web-IDSS, or 50% of the 22 reported in 2005-2006 by IDSS. There were 9 among males (45% of the 20 in IDSS) and two among females (100% of the two in IDSS).

Other STI

Aggregate IDSS “Other STI” Data

For the IDSS, “Other STI” is a catch-all category which includes Human Papillomavirus (HPV), herpes-simplex virus (HSV), non-specific urethritis, and other STI not included in the previous categories. The prevalence of other STI reported through the IDSS system was 0.54% in 2005 and 0.46% in 2006 (Table 5.1). In absolute numbers, the number of cases reported has stayed relatively stable, from 2000 (n=60) to 2006 (n=61), although there has been some variability in the number of cases per year over this time period. As was observed with the other STI, the rate among women was higher than that among men.

Enhanced Surveillance: Web-IDSS HPV / HSV Data Results

Data for Human Papilloma Virus (HPV) are strongly delineated by gender with 33% of females reporting a previous HPV / Pap Test and only 3.0% of males reporting a test for HPV. Among those tested, almost half (42%) of females and a quarter (25%) of males reported a previous positive test. Of those positive, 77% of males and 59% of females reported previous treatment.

One half of female New Admissions (49%) reported a Pap Test and two were reported positive (test positivity 1.3%). Very few (less than 3%) of males reported an HPV test on admission. Combining self-reported previous HPV and infection diagnosed on admission, the lifetime prevalence of HPV among females was 15% and among males 0.8%. While based on small number of tests, there were 7 cases of HPV reported among general population inmates, all among males.

Data for Herpes Simplex Virus (HSV) are also delineated along gender lines. Among females on admission,19% report a previous test and of those 24% were positive and most (64%) report treatment. Among males, only 5% report a previous test for HSV and among those, 15% were positive; 55% report previous treatment for HSV. While 23% of females report a test for HSV on admission compared to only 3% of males, all three newly diagnosed cases of HSV were among males. Combining self-reported previous HSV and infection diagnosed on admission, the lifetime prevalence of HSV among females was 5% and among males 0.8%. While based on small number of tests, there were 11 cases of HSV reported among general population inmates, 10 of which were among males.

 

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