Chlamydia and Gonorrhea (2021)

Summary of recommendations for clinicians and policy-makers 

This guideline on screening for chlamydia and gonorrhea applies to sexually active individuals (defined as ever having oral, vaginal or anal intercourse) under the age of 30 not specifically seeking care for a possible STI and not known to belong to a high-risk group.  

Key Recommendation 

• We recommend opportunistic screening of sexually active individuals under 30 years of age who are not known to belong to a high-risk group, annually, for chlamydia and gonorrhea at primary care visits, using a self- or clinician-collected sample (Conditional recommendation; very low-certainty evidence).  

Providers should refer to relevant national, provincial, or local guidance for screening of individuals known to belong to specific high-risk groups. 

Methodology and Evidence 

A systematic review was carried out to examine the benefits and harms of screening, as well as patient values and preferences as related to the potential outcomes of screening. The available evidence on the benefits of screening for chlamydia is uncertain, largely due to it’s low applicability to how opportunistic screening is delivered in Canada, for example: 

• Four RCTs offered screening (regardless of uptake) by mailed invitation or through public education and screening encouragement rather than via direct discussion between clinicians and patients, and one cluster RCT provided clinic-level interventions (packages to help encourage clinicians to offer screening) rather than direct clinician engagement, yielding low clinician participation and offers of screening.  

• Three trials evaluated only those accepting screening (acceptors of screening), and 1 trial evaluated an offer to screen among those pre-selected due to an interest in screening (offer to screen, pre-selected), which is indirect to the varied screening interest and acceptance among Canadian primary care patients.  

• Overall, evidence suggests that pelvic inflammatory disease may be reduced through the routine offering of chlamydia screening in Canadian primary care. No studies were identified that examined the benefits of screening for gonorrhea for those at general risk. 

• Eleven studies were identified on the harms of screening for chlamydia suggesting that some individuals undergoing screening may experience psychosocial harms (e.g., anxiety, shame and stigma) although this evidence was very uncertain and likely impacts a small proportion of those eligible for screening. No studies examined harms of screening for gonorrhea. 

• Fourteen studies examining patient values and preferences, as well as Task Force patient engagement activities suggested that patients prioritize the benefits over the harms of screening, even when provided with the evidence and its uncertainty.  

• Considering the potentially important benefit of screening relative to harms and patient values and preferences in favour of screening, the task force recommends opportunistic screening for chlamydia and gonorrhea in primary care for individuals under 30 years of age.  

• This recommendation is conditional based on very low certainty evidence. 

Rationale 

• The recommendation to screen individuals under 30 years of age is based on almost all of the underlying evidence coming from studies of individuals under 30 years of age.  
• Additionally, the rates of chlamydia and gonorrhea are increasing among those aged 25-29 years in Canada, with rates and total cases similar to those aged 15-19 years.  
• The recommendation to also screen males is based on the properties of sexual networks (given the roles of males in the transmission of these infections) and potential to reduce chlamydia and gonorrhea infection and its negative consequences in females (who carry the burden of health complications associated with chlamydia and gonorrhea infections).  
• The recommendation to also screen for gonorrhea was made despite the lack of available evidence, given that many gonorrhea cases are asymptomatic , up to 40% of those with gonorrhea may have concurrent chlamydia and current Canadian clinical and laboratory practice is to combine testing for gonorrhea with chlamydia using a single sample. 

Additional Documents

ECRI Evaluation Scores

ECRI Guidelines Trust scores guidelines based on their adherence to the National Academy of Medicine Standards for Trustworthy Guidelines. Find the ECRI evaluation scores for this guideline here.