Respiratory Infections

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Respiratory Infections

Mycoplasma Pneumoniae

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Causative Agent

Mycoplasma pneumoniae is among the smallest free-living organisms that are able to replicate on cell free media.

Clinical Description

Mycoplasma pneumoniae infection is a cause of mild pneumonia and a wide spectrum of other respiratory symptoms such as bronchitis, bronchiolitis and pharyngitis. Lacking a cell wall, mycoplasmas are resistant to penicillins although antibiotic treatment is not usually required.


Spread is slow because of limited communicability and long case-to-case intervals, although epidemics may last 1-2 years in larger communities.

Surveillance in Scotland

Since M. pneumoniae is not a notifiable disease, HPS information, depends wholly on laboratory reports of infection. The combination of mild presenting symptoms and the predominance of infection in older children in young adults means that laboratory reports are likely to substantially under-estimate the true extent of infection.

Trends in Scotland (1995-2000)

There were substantial outbreaks of mycoplasma infection in Scotland in both 1995 and in 1998. Since epidemics generally occur in four yearly cycles, the next significant outbreak is not expected until the winter of 2001 at the earliest.

Incidence and Risk

M. pneumoniae infections are endemic in larger urban areas. Epidemic increases are observed at 4 - 7 year intervals and predominantly affect older children and young adults. High incidences have also been seen in military populations. Asthmatic children, as well as other individuals with pre-existing respiratory disease, may be at higher risk of developing pneumonia.


Since M. pneumoniae infections are almost exclusively mild, preventative measures are not normally recommended as necessary.

Graph of Mycoplasma pneumoniae lab reports 5 week rolling averages 1994-2001