an overview of sexually transmitted infections in canada

CIDPCCIDPC Division of Community Acquired Infections 04/21/23 1

An Overview of Sexually Transmitted Infections in Canada

Thomas Wong, MD MPH FRCPCCommunity Acquired Infections DivisionHealth Canada(613) 941-7539


Sexually Transmitted Infections (STIs) in Canada

Chlamydia Gonorrhea Syphilis HSV HPV


Chlamydia

Most prevalent bacterial STI in Canada

Disproportionately affects adolescents and young adults

Females account for over 2/3 of reported chlamydia cases PID, chronic pelvic pain, ectopic

pregnancy, infertility


Reported Chlamydia Rates in Canada, by sex*

0.0

50.0

100.0

150.0

200.0

250.0

300.0

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

Year

Rat

e pe

r 10

0,00

0

MaleFemaleTotal

•Data for 2002 are preliminary and changes are anticipated•Source: Sexual Health and STI Division, Health Canada 2004


Reported Male Genital Chlamydia Rates in Canada, by age group*


0.0

100.0

200.0

300.0

400.0

500.0

600.0

700.0

Year

Ra

te p

er

10

0,0

00

15-19

20-24

25-29

30-39

40-59


Reported Female Genital Chlamydia Rates in Canada, by age group*


0.0200.0400.0600.0800.0

1000.01200.01400.01600.0

Year

Rat

e pe

r 10

0,00

0 15-19

20-24

25-29

30-39

40-59


Chlamydia

Reported rate had been declining until the last few years

Recent rate increase may be due in part to increased screening since the availability of new non-invasive NAAT (eg. PCR, LCR) – but not the whole story


Chlamydia:Factors favouring control

Effective, single-dose treatment

Non-invasive urine testing


Chlamydia:Hurdles and Challenges

Lack of chlamydia awareness/knowledge

Majority of infections are asymptomatic 80% of females 50% of males

“Hidden Epidemic” – lack of awareness and symptoms results in a lack of adequate screening, diagnosis, treatment and reporting.


Chlamydia Prevention and Control: Strategies

Increase Awareness – Sexual Health Education Canadian Sexual Health Education

Guidelines

Targeted Prevention and Promotion

Take advantage of non-invasive testing and one-dose treatment


Gonorrhea

Second most commonly reported bacterial STI in Canada

Males account for almost 2/3 of nationally reported cases

Other STI often present with gonorrhea – especially chlamydia


Reported Gonorrhea Rates in Canada, by sex*


0

5

10

15

20

25

30

35

40

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

Year

Rat

e pe

r 10

0,00

0

male

female

total


Reported Male Gonorrhea Rates in Canada, by age group*


0

20

40

60

80

100

120

140

160

Year

Ra

te p

er

10

0,0

00

15-19

20-24

25-29

30-39

40-59


Reported Female Gonorrhea Rates in Canada, by age group*


0

20

40

60

80

100

120

140

160

180

200

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

Year

Ra

te p

er

10

0,0

00 15-19

20-24

25-29

30-39

40-59


Gonorrhea in Canada

Gonorrhea rates in Canada had been declining until the last few years

Rates have risen by more than 50% over past 5 yrs


Gonorrhea:Hurdles and Challenges

Lack of symptoms (asymptomatic): Up to 80% of females 10-20% of males

Even more likely to be asymptomatic if infected at rectal or pharyngeal sites


Gonorrhea:Hurdles and Challenges

Antimicrobial resistance

Quinolone resistance increasing in Canada < 1% in the early 90’s = 1% late 90’s 2.4% rate for 2001

Reduced capacity in tracking resistance because of increasing NAAT use


Gonorrhea:Factors favouring control

Effective, single-dose treatment

Non-invasive urine testing – continually improving and more available


Gonorrhea Prevention and Control: Strategies

Increase Awareness – Sexual Health Education Canadian Sexual Health Education

Guidelines

Targeted Prevention and Promotion

Take advantage of non-invasive testing and one-dose treatment


Syphilis


Syphilis

The least common of the 3 bacterial STIs

The elimination of syphilis was seen as an imminent goal as recently as 1996

BUT – increasing national rates since 1997


Reported Syphilis Rates in Canada, by sex*


0

0.5

1

1.5

2

2.5

3

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

Year

Rat

e pe

r 10

0,00

0

male

female

total


Reported Male Syphilis Rates in Canada, by age group*


0

1

2

3

4

5

6

7

8

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

Year

Rat

e pe

r 10

0,00

0 15-19

20-24

25-29

30-39

40-59


Reported Female Syphilis Rates in Canada, by age group*

Data for 2002 are preliminary and changes are anticipatedSource: Sexual Health and STI Division, Health Canada 2004

0.00.51.01.52.02.53.0

Year

Rate

per

100,0

00

15-1920-2425-2930-3940-59


Reported Syphilis Diagnoses in the UK, by sex

Source: Public Health Laboratory Service, 2003

0

200

400

600

800

Year

Num

ber

of D

iagn

oses

(E

ngla

nd, W

hale

s &

Nor

ther

n Ir

elan

d)

Male

Female

Total


Reported Primary and Secondary syphilis rates in Canada and the United States*

0123456789

19

94

19

95

19

96

19

97

19

98

19

99

20

00

20

01

20

02

Canada U.S.

U.S. Source: Sexually Transmitted Disease Surveillance, 2002, CDC

* Data for 2001 and 2002 are preliminary and changes are anticipated

Rat

e p

er 1

00,0

00

Year


Syphilis Control:Factors favouring elimination

T. pallidum slow growth rate

Long incubation period

Effective treatment with benzathine penicillin

Lack of penicillin resistance


Syphilis Control:Hurdles and Challenges

Regional Outbreaks Vancouver: heterosexual, sex-trade, MSM Yukon: heterosexual Calgary: MSM Winnipeg: heterosexual Toronto: MSM Ottawa: MSM Montreal: MSM


Syphilis Control:Hurdles and Challenges

Lack of availability of treatment – Benzathine Penicillin G

Increasing Trend of Risky Sexual Behaviour

Lack of Awareness


Syphilis Prevention and Control: Strategies

Intensify targeted prevention and health promotion

Cyberprevention Enhance surveillance Enhance efforts for case finding and

management Rapid outbreak response


Reportable Bacterial STI

National rates of Chlamydia, Gonorrhea and Syphilis all rising

WHY? Safe-sex burnout HAART and post-exposure prophylaxis Younger generation did not witness AIDS

devastation Internet facilitating high risk partnering


Genital Herpes (HSV)

Not reportable at the federal level Prevalence in Canada not well

known (therefore a priority) Caused by HSV types 1 and 2 Infection is life-long Predominantly asymptomatic Asymptomatic viral shedding leads

to transmission


Neonatal Herpes

Most serious direct consequence of genital HSV infection

Not reportable at Federal level (passively reported in many prov/terr – information collected is limited and case definitions vary)

Incidence per 100,000 live births: United States : 20-50 cases United Kingdom & Australia : 2-3 cases Canada : 5.9 cases


Neonatal Herpes Surveillance

Partnership between Canadian Paediatric Society (CPS) and Center for Infectious Diseases Prevention and Control of Health Canada


Neonatal Herpes Surveillance

Two phase project:

Phase I: surveillance of neonatal herpes Canadian pediatricians report every new

observed neonatal case Maternal HSV infection Neonatal morbidity and lab results Immediate sequelae in neonatal period

Phase II: follow-up of neonatal cases 3 year follow up of neonatal cases RE longer term

sequelae of neonatal infection


Human Papillomavirus (HPV)

Estimated to be the most common STI

Not reportable at federal level

High risk types (oncogenic) Genital cancers (cervical, anal, penile)

Low risk types (non-oncogenic) Genital warts


HPV Infection: Natural History

Often transient

Peak prevalence: ages 20-24

More likely to persist in women > 30 years


Oncogenic HPV Prevalence in Ontario and Newfoundland Women*

0

5

10

15

20

25

<25 25-34 35-44 45+

Pre

vale

nce

(%)

Ontario Newfoundland

Source: Sellors JW et al. CMAJ (2000);163:503-508Ratnam S et al. Cancer Epidemiol Biomarkers Prev (2000);9:945-951

* HPV Hybrid capture assay


HPV and Cervical Cancer:New Horizons

HPV-DNA testing Primary screening Triage

HPV Vaccine

Liquid Based Cytology Implications for HPV testing and testing

for other STIs

Awareness of HPV – Cervical Cancer link


STI Testing Issues

Culture vs. NAAT (PCR, LCR)

NAAT: Urine vs. Swab

Order of Swabs/Pap Test

Menstruation and testing

New and emerging tests


OtherOther STIsSTIs

HIVHIVEnhance transmission of

Risky Sex

Risky Sex


STI & HIV Synergy

STI increases HIV transmission & acquisition

STI morbidity can be worse, and infection more difficult to treat, for HIV-infected individuals

Rise in syphilis indicative of unsafe sexual practices; implications for rates of HIV

STI incidence in HIV-infected individuals Can use as marker of unsafe sexual

behaviors in HIV-positive population


Conclusion Reportable STIs continue to rise

Behavioural surveillance gap exists – hindering targeted awareness, prevention and promotion

Lack of data on viral STIs, however efforts to address viral STIs are underway


Acknowledgements

Provincial and Territorial Partners Toronto Public Health Department AIDS Committee of Ottawa National Microbiology Lab Lai King Ng Janice Mann Rhonda Kropp Maureen Perrin

an overview of sexually transmitted infections in canada

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