Season's Greetings, and watch out for the Mycoplasma

Like the World Cup and the Olympics, epidemic peaks of Mycoplasma pneumoniae infections come around every four years. The last epidemic season in the UK was 2019/20 and the UK Health Security Agency UKHSA, Dec 2023 sent out a briefing last week warning that bang on cue we are currently seeing a rapid increase in cases and the data suggest we are entering a new epidemic winter of Mycoplasma. Given the reduction in exposure and natural immunity during the pandemic it is possible that cases could be both more numerous and severe than in previous outbreaks, and the UKHSA have advised we need to consider it in the differential diagnosis of respiratory infections. Other European countries have recently reported a significant increase in cases and France and Denmark have declared epidemics. 

So, as we enter into the ‘bleak midwinter’, what do we need to know? 

• Just remind me, what is Mycoplasma pneumoniae?
  • Mycoplasma pneumoniae (M.pneumoniae) is a bacterial pathogen which is atypical because it lacks a cell wall, meaning that it is inherently resistant to beta-lactam antibiotics e.g. penicillin
• Who does it tend to affect?
  • It most commonly affects children and young adults, and it is transmitted by close contact with an infected individual, so outbreaks are often seen in close community settings such as schools, colleges, nursing homes and therefore possibly (please not, and where’s that mask?!) health centres
• And what happens if you catch it?
  • M.pneumoniae causes a broad range of respiratory infections ranging from mild URTIs with cough and fever to severe community acquired pneumonia; most infections though are mild and self-limiting
  • It usually presents in primary care with an unresolving persistent cough, low grade fever, headache, hoarseness, rash and occasionally ear infections
  • Symptoms typically come on gradually over a few days with a typical URTI (sore throat, fever, hoarseness, cough) and as it spreads to the lower airways cough develops (often dry) which can become persistent and severe
  • Children under 5 are more likely to present with coryza and wheeze
• How do we diagnose it, does it need a test?
  • No, it is a clinical diagnosis and testing in primary care is not necessary; it is not detected by standard bacterial culture so sputum samples are not needed
  • Infections are monitored by the UKHSA and diagnosed by PCR through their surveillance programme; we do not need to report suspected cases
• So, how should we manage it?
  • We should continue to manage suspected cases of community acquired pneumonia according to usual NICE guidance NG138
    • If we make a clinical diagnosis of pneumonia we should offer antibiotics and start treatment as soon as possible
    • The antibiotic choice depends on the clinical severity, the risk of complications due to immune suppression or severe lung disease and current surveillance data including for M.pneumoniae
  • The UKHSA state that we should continue to treat low severity community acquired pneumonia (based on clinical judgement and a CRB65 score of zero) with amoxicillin 500mg tds for 5 days first line, even though this will obviously be ineffective if it is indeed M.pneumoniae
  • However, if the patient is penicillin allergic or if we suspect M.pneumoniae infection (e.g. based on surveillance data, local exposure or clinically) then doxycycline (200mg first day, then 100mg for the next 4 days) or clarithromycin (500mg bd for 5 days) or erythromycin in pregnancy (500mg qds for 5 days)
  • For patients with moderate severity pneumonia (based on clinical judgement and guided by a CRB65 score of 1 or 2) who are managed in primary care then the addition of a macrolide or doxycycline to amoxicillin is recommended; consider hospital assessment for these patients, especially if the score is 2, and if managed in the community safety net carefully with follow up
  • For patients with severe pneumonia (based on clinical judgement and guided by a CRB65 score of ≥ 3) arrange urgent admission
  • Note that the CRB65 score is not validated in children and young people; use clinical judgement guided by vital signs to assess severity

On behalf of all the team here at NB Medical we wish you, your families and your practice teams a very happy holiday season and all the very best for 2024. You did an amazing job delivering incredible care to your patients in 2023. We have no idea what 2024 will bring for UK primary care, but you can rest assured that with our rolling programme of courses, webinars, blogs, podcasts, modules and NB On Call we shall be there to support you all the way!