The window period is the time period between when a person comes in contact with a sexually transmitted infection and when a false negative result may occur in an STI screen. The window period can vary for the different STIs. Sexual partners may have a false negative test result in this period. Follow up testing should be discussed.
Partner notification (sometimes called contact tracing) is an integral part of the management and control of STIs. The look-back period is the time during which the index case may have been infectious and transmitted infection. Testing and treatment of sexual partners is important to prevent reinfection and onward transmission. Patients who have been diagnosed with an STI in primary care, should be encouraged to inform their sexual partners and of the need for testing. For complex cases that might require more expert help with partner notification, referral to a GUM clinic should be considered.
STI: Chlamydia trachomatis
Look back period:
For males with urethral symptoms: all contacts since symptom onset and in the 4 weeks prior to the symptoms.
For females, asymptomatic males/females or males with symptoms at other sites (rectal, throat or eye): all contacts in prior 6 months.
Window Period: 2 weeks
Consider empiric partner treatment: Yes
STI: Lymphogranuloma Venereum (LGV is an invasive serovar of chlamydia)
Look back period: Refer LGV cases to a GUM clinic.
Window Period: Refer LGV cases to a GUM clinic.
Empiric treatment: Refer LGV cases to a GUM clinic.
STI: Gonorrhoea (Neisseria Gonorrhoea)
Look back period: Males with urethral symptoms: all partners in past 2 weeks or last partner if longer than 2 weeks. All others including asymptomatic infection: 3 months.
Window Period: 2 weeks
Consider empiric partner treatment: Yes
STI: Trichomoniasis (Trichomonas Vaginalis)
Look back period: Sexual partners in the preceding 4 weeks prior to presentation
Window Period: 4 weeks
Consider empiric partner treatment: Yes
STI: HIV
Look back period: Refer to GUM/HIV clinic
Window Period: 45 days
Consider empiric partner treatment: Refer to GUM/HIV clinic (Be mindful of new sexual partners who may require PEP)
STI: Anogenital Warts (Human Papilloma Virus)
Look back period: N/A
Window Period: N/A
Empiric partner treatment: N/A
STI: Syphilis (Treponema pallidum)
Look back period: Refer syphilis cases to GUM clinic.
Window Period: 12 weeks
Empiric partner treatment: Refer to GUM clinic
STI: Genital Herpes (Herpes Simplex Virus)
Look back period: N/A
Window Period: N/A
Empiric partner treatment: No
Herpes simplex virus persists following primary infection. Defining lookback and window periods is not possible, as primary infection may have occurred in the remote past.
STI: Pelvic Inflammatory Disease
Look back period: Screen current male partners and refer to look back period if specific organism identified.
Window Period: Dependent on organism.
Empiric partner treatment: N/A
STI: Mycoplasma Genitalium
Look back period: Refer to GUM clinic
Window Period: Refer to GUM clinic
Empiric partner treatment: Refer to GUM clinic