Sexually Transmitted Infections

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Sexually Transmitted Infections
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Definition

• Diseases transmitted from one person to another
  through heterosexual or homosexual intercourse
• OR
• Through intimate touch with the sex organs, mouth
  or rectum of an infected person

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• STIs divided into two groups
• 1) Sexually transmitted
• Exclusively transmitted by sexual contact
• Chancroid
• Chlamydia
• Gonorrhea
• Syphilis

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• 2) Sexually Transmissible
• Can be transmitted sexually, but have other modes
  of transmission

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STI Infections

• Transmission
• 1. Direct sexual contact
• Chancroid
• Chlamydia
• Gonorrhea
• Syphilis
• HPV
• Herpes

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• 2. Auto-innoculation
• Chlamydia
• Gonorrhea
• Herpes

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• 3. Direct contact during LD
• Chlamyida
• Gonorrhea
• HPV
• Herpes

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• 4. Placental transfer
• Syphilis
• Body fluid exchange
• Hepatitis B
• AIDS

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• Susceptibility
• 1. Universal
• Chancroid
• Chlamydia
• Gonorrhea
• Primary syphilis
• Secondary syphilis
• Herpes
• AIDS

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• 2. Resistance conferred by infection
• Tertiary syphilis
• Hepatitis B
• 3. Resistance acquired by passive immunization
  (post-exposure)
• Hepatitis B

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• 4. Resistance acquired by active immunization
  (pre-exposure)
• Hepatitis B
• 5. Not known
• HPV

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• Communicability
• 1. While lesions present
• Chancroid
• HPV
• Herpes

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• 2. Unknown/variable (likely until treated)
• Chlamydia
• Syphilis
• Primary
• Secondary
• 3. Until treated
• Gonorrhea

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• 4. Lifetime
• Hepatitis B (all HbsAg carriers are
  communicable)
• AIDS

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• Incubation Period
• 1. Short
• Chancroid (3-5 days)
• Chlamydia (5-14 days)
• Gonorrhea (2-7 days)
• Herpes (2-12 days)

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• 2. Moderate
• Syphilis (10-90 days)
• 3. Long
• HPV (2-3 mo., as long as 20 mo.)
• AIDS (1-3 mo for antibodies 1-10 yr for
  symptoms)
• HepB (45-180 days)

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• Detection
• 1. Physical examination
• Always
• For each disease, need to know clinical
  presentation

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• 2. Culture
• Chancroid
• Chlamydia
• Gonorrhea
• Herpes

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• 3. Direct antigen test
• Chlamydia
• Gonorrhea
• Primary syphilis
• 4. Stain/smear
• Gonorrhea

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• 5. Blood work
• Syphilis
• AIDS
• HepB
• 6. Biopsy
• HPV
• Herpes

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• Manifestations
• 1. Local lesions
• Chancroid
• Primary syphilis
• HPV
• Herpes

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• 2. Infection of GI tract
• Chlamydia
• Gonorrhea
• 3. Infection of rectum
• Chlamydia
• Gonorrhea
• HPV
• Herpes

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• 4. Oral infections
• Chlamydia
• Gonorrhea
• HPV
• Herpes
• 5. Infection of reproductive tract (including
  PID)
• Chlamydia
• Gonorrhea

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• 6. Systemic infections
• Gonorrhea (disseminated gonococcal infection)
• Secondary syphilis
• Tertiary syphilis
• HepB
• AIDS

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• Fetal Manifestations
• 1. Conjunctivitis
• Chlamydia
• Gonorrhea
• 2. Oral infections
• Chlamydia
• Gonorrhea
• HPV

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• 3. Pneumonitis
• Chlamydia
• 4. Anomalies
• Syphilis

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• 5. Multiple generalized effects r/t infection
• Herpes (late manifestation, usually 1 week after
  delivery)
• Syphilis
• HepB
• AIDS

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Impact on Population Health

• 1) Significant cost to the health care system
• 2) Significant personal social costs

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• 3) Small segment of population may carry
  disproportionate burden of risk
• Young
• Those with more than 6 sex partners (cumulative)
• Poor homeless
• Women
• Those living where access to preventive services
  is difficult

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Epidemiology of STI in Canada

• Chlamydia
• Most commonly diagnosed communicable disease in
  Canada
• More frequently diagnosed in women than in men

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• Unacceptable high rates in women under age 25
• Associated risk of PID and future fertility
  problems

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• Regional variations in incidence

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• Gonorrhea
• Epidemiological contrast to Chlamydia
• Dramatic decrease in infection rates since 1981
• Slight increase since 1998

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• Infection rates higher in males overall
• However, infection rates higher in females during
  adolescence

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• Regional patterns of infection are similar to
  chlamydia

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• Syphilis
• Like gonorrhea, infection rates are higher in
  males than in females

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• Still an excess of cases in females aged 15-24

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• Regional patterns of disease also vary

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Prevention of STIs

• Specific preventive activities related to this
  formula and to Primary Secondary prevention
  tend to overlap because
• Secondary prevention depends on effective Primary
  Prevention
• Primary prevention depends on effective Secondary
  prevention

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Primary Prevention

• Reducing Probability of Transmission
• 1) Use of barrier methods
• 2) Reduction in use of high risk sexual practices
• 3) Vaccines

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• 4) Reproductive Health Education
• 5) Changing social values
• 6) Community development

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• Reducing Contact Between Infected
  Uninfected Persons
• 1) Reducing of sex partners
• 2) Delaying initiation of sexual activity
• 3) Deliberate appraisal of new sex partners

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• Harm Reduction
• First priority is to limit the harmful
  consequences of the health risk in question
• Examples
• Sexual activity
• Injection drug use
• Illicit tattooing

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• Recognition that abstinence may not be a
  realistic or desirable goal for everyone
• Main principles
• 1. Pragmatism
• Acceptance that risky behaviours are unlikely to
  disappear entirely

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• 2. Humanism
• No moral judgements
• 3. Focus on harms
• Risky behaviour is secondary to the harms it
  might produce

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• 4. Hierarchy of goals
• Focus on the most pressing needs first

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Secondary Prevention

• 1) Prompt diagnosis treatment of known cases
• Always screen for multiple STIs
• 2) Contact Tracing
• Make no assumptions about who is doing what with
  whom
• Confidentiality

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• 3) Monitoring/surveillance/screening of known
  high risk populations
• Young people
• Sex trade workers
• 4) Reporting to appropriate authorities

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National STI Prevention Goals

• A goal without a deadline is only a wish.
• Canada established several goals for the
  reduction of STIs in Canada in 1997

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• For chlamydia in general
• By the year 2000, rate to be less than 80/100,000
• Actual rate in 2000 151.1/100,000
• By the year 2010, rate to be less than 50/100,000

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• For chlamydia in females
• By the year 2000, rate for females 15-14 to be
  less than 500/100,000
• Actual rate for females 15-19 714.4/100,000
• Actual rate for females 20-24 818.7/100,000
• By the year 2010, rate for females 15-24 to be
  less than 200/100,000

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• For infectious syphilis
• By the year 2000, rate to be less than
  0.5/100,000
• Actual rate 0.6/100,000
• By the year 2010, endemic infectious syphilis to
  be eliminated

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• For congenital syphilis
• By the year 2000, congenital syphilis to be
  totally prevented

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• Congenital syphilis in Canada since 1992
• 1992 4 cases
• 1993 4 cases
• 1994 3 cases
• 1995 2 cases
• 1996 1 case
• 1997 2 cases
• 1998 2 cases
• 1999 0 cases

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• For gonorrhea
• By the year 2010, endemically acquired gonorrhea
  to be eliminated
• For PID ectopic pregnancies
• By the year 2010, rates for PID ectopic
  pregnancies to be reduced to 50 of that recorded
  in 1996

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• Wide variation in infection rates in different
  regions of the country
• Related to isolation, inadequate access to
  services

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Challenges

• 1. Antibiotic resistance
• 2. Asymptomatic infections
• 3. Co-existing infections
• 4. Long latent periods

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• 5. Importation of cases
• 6. Lack of uniform reporting systems
• 7. Synergistic effects of host agent
• 8. Synergistic effects of host environment