Chlamydia trachomatis infections

Reporting Obligations

Individuals with suspect or confirmed cases must be reported to the Thunder Bay District Health Unit by the next working day by fax, phone or mail.

  • Fax: (807) 625-4866
  • Phone: 625-5976 or toll-free at 1-888-294-6630, ext. 5976
  • Mail: 999 Balmoral Street, Thunder Bay, ON P7B 6E7



Aetiologic Agent:

Chlamydia trachomatis is an obligate intracellular bacterium causing genital infections and other forms of infections including chlamydial conjunctivitis, chlamydial pneumonia, and Lymphogranuloma venereum (LGV).

Clinical Presentation:

Chlamydia infection is often asymptomatic including pharyngeal and rectal infections. If symptoms are present in rectal infections, individuals often display rectal pain (proctitis) with or without discharge. Pharyngeal infections also may occur, with individuals displaying pharyngitis.

Males may present with urethral discharge, dysuria and frequency, non-specific urethral symptoms such as redness, itching, and swelling. More than 50% of infected males are asymptomatic.

Females may present with cervical infection that includes the following signs and symptoms: a mucopurulent endocervical discharge with edema, mucopurulent endocervical discharge with edema, dysuria, dyspareunia, erythema, and easily induced endocervical bleeding. Up to 70% of sexually active females with chlamydia infection are asymptomatic.

Complications and sequelae include salpingitis pelvic inflammatory disease with subsequent risk of infertility, epididymo-orchitis (males), Reiter syndrome (males), ectopic pregnancy, and chronic pelvic pain.

Can present as chlamydial pneumonia and conjunctivitis (Ophthalmia neonatorum) in infants.

Modes of Transmission:

Sexual contact via oral, vaginal, cervical, urethral or anal routes; in children, exposure to infected genitals (consider the possibility of sexual abuse in these cases); newborns: during delivery from infected mother.

Incubation Period:

From time of exposure to onset of symptoms is 2-3 weeks, but can be as long as 6 weeks.

Period of Communicability:

Unknown; may extend for months or longer if untreated, especially in asymptomatic persons; re-infections are common; effective treatment ends infectivity. In the absence of treatment, infection persists for many months.


Risk Factors/Susceptibility

Transmission is more efficient male-to-female than female-to-male. No acquired immunity has been demonstrated, although strain specific immunity probably exists. Risk factors include:

  • Sexual contact with a Chlamydia-infected person
  • A new sexual partner or more than two sexual partners in the past year
  • Previous sexually transmitted infections
  • Judgment impaired by alcohol/drugs
  • Vulnerable populations (e.g., injection drug users, incarcerated individuals, sex trade workers, street-involved youth, etc.)
  • The 15 to 24 year old age group


Diagnosis & Laboratory Testing

Chlamydia trachomatis detected in an appropriate clinical specimen (e.g., urogenital tract, rectal specimen). Refer to the Canadian Guidelines on Sexually Transmitted Infections Chlamydial infections chapter and the Public Health Ontario: STI Testing Quick Reference Chart. (PDF)

Testing Information & Requisition


Treatment & Case Management

Treatment is determined as per attending health care provider. Refer to the Canadian Guidelines on Sexually Transmitted Infections Chlamydial infections chapter for treatment information.

Provide education about and promote safer sex practices. Repeat testing is recommended 6 months post-treatment, as re-infection risk is high.


Patient Information

Patient Fact Sheet



1. Ministry of Health and Long Term Care, Infectious Diseases Protocol - Appendix 1 (2022) Chlamydia trachomatis infections.


Additional Resources

Public Health Agency of Canada. “Canadian Guidelines on Sexually Transmitted Infections, evergreen edition.”

Public Health Ontario. Bacterial STI Testing: Quick Reference, 2019.  (PDF)

Planned Parenthood. "Chlamydia." "Chlamydia."

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