NICE vs BASHH: Management of Chlamydia (2025) - A Clinical Guideline Comparison
This document provides a comparative summary of the key recommendations for the management of uncomplicated genital chlamydia infection in the UK, as outlined by the National Institute for Health and Care Excellence (NICE) and the British Association for Sexual Health and HIV (BASHH). Both guidelines are authoritative; NICE provides a public health-focused, primary-care-friendly approach, while BASHH offers a more detailed, specialist-level guide. Understanding the nuances between them is essential for clinicians to deliver effective, standardised care across different healthcare settings.
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Diagnosis and Assessment
The approach to diagnosis is largely consistent, reflecting the established standard of care, but with subtle differences in emphasis.
NICE (NG109 & Public Health Guideline [PH21])
- Population Focus: Strong emphasis on opportunistic screening for asymptomatic individuals under 25 years in a variety of settings (GP surgeries, pharmacies, contraception clinics).
- Testing Method: Recommends Nucleic Acid Amplification Tests (NAATs) on first-void urine (FVU) specimens from men and self-taken vulvovaginal swabs from women. Provider-taken swabs are an alternative.
- Assessment: Focuses on identifying risk factors (e.g., age, new partner) to guide screening. Less detail on clinical examination findings for symptomatic patients.
BASHH (2023 Update)
- Population Focus: While supporting screening, the guideline is more focused on the management of both symptomatic and asymptomatic patients presenting to sexual health services.
- Testing Method: Also strongly recommends NAATs. Provides more detailed guidance on sample types, including the use of rectal and pharyngeal swabs in patients with a history of receptive anal or oral sex, regardless of symptoms.
- Assessment: Includes comprehensive guidance on clinical history and examination for symptomatic patients. Stresses the importance of testing at all potentially exposed sites (urogenital, rectal, pharyngeal).
Key Difference: BASHH provides more explicit and routine recommendations for extragenital (rectal and pharyngeal) testing based on sexual history, whereas NICE's primary focus is urogenital screening and infection.
First-Line Treatment
Both guidelines agree on the first-line antibiotic regimens, but differ in their preferred choice and practical administration advice.
NICE
- Preferred Regimen: Doxycycline 100 mg twice daily for 7 days.
- Alternative: Azithromycin 1 g single dose (if doxycycline is contraindicated or not tolerated).
- Rationale: Positions doxycycline as superior based on higher microbiological cure rates, particularly for rectal infections.
BASHH
- Preferred Regimen: Also recommends Doxycycline 100 mg twice daily for 7 days as the first-line treatment for uncomplicated anogenital infection.
- Alternative: Azithromycin 1 g single dose is an alternative, but the guideline notes a slightly lower efficacy and potential for macrolide resistance selection.
- Practical Point: Provides more detailed advice on managing side effects and ensuring adherence to a 7-day course.
Key Difference & Practical Takeaway: There is now a strong consensus that doxycycline is the preferred first-line treatment over azithromycin for uncomplicated chlamydia. This represents a significant shift from historical practice and is a critical update for clinicians.
Special Situations and Complex Cases
This is where the specialist nature of the BASHH guideline becomes most apparent, offering more granularity.
Pregnancy and Breastfeeding
- NICE: Recommends Azithromycin 1 g single dose. Doxycycline is contraindicated.
- BASHH: Also recommends Azithromycin 1 g single dose. Provides additional detail on the evidence for its safety and recommends a test-of-cure (TOC) 6 weeks after treatment (or at the next prenatal visit) due to the serious consequences of untreated infection.
Rectal Infection
- NICE: Acknowledges that doxycycline is more effective than azithromycin for rectal chlamydia.
- BASHH: States definitively that doxycycline is the treatment of choice for rectal chlamydia. Explicitly recommends against azithromycin as first-line due to higher failure rates. Strongly advises TOC for rectal infections, especially if azithromycin was used.
Pharyngeal Infection
- NICE: Does not provide specific treatment recommendations for pharyngeal infection.
- BASHH: Recommends Doxycycline 100 mg twice daily for 7 days. Notes that azithromycin has lower efficacy for pharyngeal infection and that spontaneous clearance can occur, making TOC interpretation complex.
Key Difference: BASHH offers comprehensive, evidence-based guidance for extragenital infections, including clear treatment hierarchies and TOC recommendations, which are largely absent from the NICE guideline.
Practical Clinical Flow and Partner Management
Test of Cure (TOC)
- NICE: Advises against routine TOC unless there is a risk of re-infection, non-adherence, persistent symptoms, or in pregnancy.
- BASHH: Aligns with NICE for uncomplicated urogenital cases. However, recommends TOC in specific scenarios: pregnancy, rectal infection (particularly if treated with azithromycin), when non-standard regimens are used, and in immunocompromised patients.
Partner Notification (PN)
- Both guidelines emphasise the critical importance of PN.
- NICE: Recommends treating sexual partners from the last 3 months, or the most recent partner if contact was over 3 months ago. Supports the use of PN strategies like patient referral, provider referral, and expedited partner therapy (EPT).
- BASHH: Provides more detailed and structured algorithms for PN. Recommends offering treatment to all partners within the 6 months preceding diagnosis (a longer window than NICE's 3 months), or the most recent partner beyond that.
Frequently Asked Questions (FAQs) for Clinicians
1. Which guideline should I follow in primary care?
Answer: The NICE guideline (NG109) is designed to be practical for primary care. Its recommendations on screening, first-line treatment with doxycycline, and simplified TOC and PN criteria are well-suited for a GP or pharmacy setting. For standard cases, following NICE is appropriate.
2. When should I refer to or consult the BASHH guideline?
Answer: Use the BASHH guideline for complex cases: patients with rectal or pharyngeal infection, treatment failure, persistent symptoms, pregnancy, or complex comorbidities. It is the definitive resource for management in a sexual health clinic setting.
3. A patient is allergic to doxycycline. What now?
Answer: Both guidelines agree that Azithromycin 1 g stat is the alternative. BASHH adds that for a confirmed rectal infection treated with azithromycin, a TOC is strongly recommended due to the higher risk of treatment failure.
4. Is there a role for Azithromycin 1g stat anymore?
Answer: Yes, but its role is narrower. It remains first-line in pregnancy and breastfeeding, and is an alternative for urogenital infection when doxycycline is truly contraindicated. It is no longer considered equivalent to doxycycline for rectal infection.
5. How should I manage an asymptomatic patient with a positive pharyngeal chlamydia result?
Answer: This is a specialist area covered best by BASHH. Treatment with doxycycline for 7 days is recommended. The need for TOC is debated due to high spontaneous clearance rates; follow-up may be based on clinical judgement and repeat risk assessment.
Source Links
- NICE Guideline NG109 (2025 update expected): NICE NG109 (Covers broader STI prevention).
- NICE Public Health Guideline [PH21] (2017): NICE PH21 (Focuses on chlamydia screening).
- BASHH Chlamydia Guideline (2023): BASHH Chlamydia guideline (2023)
Summary and Key Takeaways
- Unified First-Line Treatment: Doxycycline for 7 days is now the preferred first-line treatment for uncomplicated anogenital chlamydia in both guidelines, superseding azithromycin.
- Guideline Synergy: NICE provides an excellent framework for public health and primary care. BASHH offers the necessary depth for specialist management of complex cases and extragenital infections.
- Critical Difference: BASHH provides essential, detailed guidance on the management of rectal and pharyngeal chlamydia, including the clear superiority of doxycycline and specific TOC advice.
- Practical Flow: For a typical case in primary care: Test with NAAT -> Treat with Doxycycline 100mg BD for 7 days -> Advise no sex for 7 days after treatment start -> Arrange PN for partners from the last 3 months -> No routine TOC needed unless specific risk factors.