What changed recently

The 2026 edition expands to 129 statements, 46 of them on questions the 2021 guidelines never addressed, including a conditional recommendation for point-of-care ultrasound to guide resuscitation and new guidance on active fluid removal once initial resuscitation is complete. Of the 38 questions carried over from 2021, only three recommendations actually reversed direction.

The October 2025 antiviral update reframed treatment decisions around preventing hospitalisation rather than death, given higher population immunity. It keeps a strong recommendation for nirmatrelvir/ritonavir in adults at high risk of progression but now suggests against routine antiviral treatment in mild to moderate COVID-19 without risk factors.

Version 13.0 restructured the guidelines into two parts, added a new consolidated Substance Use section covering alcohol, opioid use and chemsex, and extensively rewrote the obesity guidance to cover pharmacotherapy and bariatric surgery. Recommended first-line ART regimens for treatment-naive adults were left unchanged from v12.1, and the lipodystrophy section was retired.

The September 2025 revision added a dedicated chapter on cardiovascular and metabolic complications as people with HIV approach normal life expectancy, and retired the standalone statin primary-prevention section in favour of the ACC/AHA multisociety dyslipidaemia guidance. It also revised laboratory monitoring intervals, added subsections on starting ART in early infection and in hospitalised patients, and expanded cost guidance around long-acting injectables.

Version 8 added two new antibiotic-stewardship recommendations drawn from a meta-analysis of antibiotic use in COVID-19: withhold empirical antibiotics in non-severe COVID-19 when bacterial co-infection is clinically unlikely (strong), and likewise suggest withholding them in severe COVID-19 with low suspicion of co-infection (conditional).

The 2024 WHO update extended scope from severe influenza to non-severe disease and added recommendations on baloxavir marboxil, favipiravir and umifenovir. It advises against oseltamivir in non-severe influenza, conditionally supports early baloxavir only for non-severe patients at high risk of progression, and keeps oseltamivir as a conditional option for severe influenza.

The 2023 ESC edition upgraded antibiotic prophylaxis before invasive dental procedures in high-risk patients to a Class I recommendation, added a revised diagnostic algorithm built around multimodality imaging, and endorsed switching stabilised, uncomplicated patients to outpatient parenteral or oral antibiotic therapy. It also formalised management by a multidisciplinary Endocarditis Team based at heart valve centres.

The 2021 CDC guidelines replaced dual therapy for uncomplicated gonorrhoea (ceftriaxone 250 mg plus azithromycin) with a single 500 mg intramuscular dose of ceftriaxone, reflecting declining cephalosporin susceptibility and stewardship concerns about azithromycin. Doxycycline for seven days became the preferred chlamydia regimen and is added only when chlamydial co-infection has not been excluded.

The 2021 WHO guidelines moved away from purely syndromic care: where quality-assured molecular assays are available, treatment should be directed by laboratory diagnosis, while resource-limited settings use a modified syndromic algorithm. Treatment recommendations across the five common STI syndromes were also rewritten to account for rising antimicrobial resistance, especially in Neisseria gonorrhoeae.

The 2018 IDSA update was the first revision since before the 2009 H1N1 pandemic. It moved diagnosis toward rapid molecular assays instead of antigen-based rapid tests, incorporated peramivir as a parenteral antiviral option, broadened the recognised risk factors for severe disease, and clarified that antiviral treatment is optional rather than automatic for low-risk outpatients presenting within two days of onset.

The 2016 IDSA/SHEA guidelines replaced the broad 2007 blueprint for what a stewardship programme should look like with GRADE-rated recommendations for specific interventions, notably preauthorisation and/or prospective audit with feedback as core activities. They also added syndrome-specific strategies, antibiotic time-outs, allergy delabelling and use of rapid diagnostics and procalcitonin to shorten therapy.

The 2015 AHA statement dropped adjunctive gentamicin from native-valve Staphylococcus aureus endocarditis regimens, since combination therapy added nephrotoxicity without clear benefit, leaving six weeks of single-agent anti-staphylococcal therapy. It also updated the epidemiology to reflect the rise of healthcare-associated and staphylococcal disease and reinforced early echocardiography plus at least three separately drawn blood culture sets.