Investigation of ear, nose, eye, mouth and throat for infection.
Otitis externa: In general, infection of the external auditory canal resembles infection of skin and soft tissue elsewhere. However, there are some notable differences. The canal is narrow and, as a result, foreign materials and fluid that enter can become trapped, causing irritation and maceration of the superficial tissues. Otitis externa can be subdivided into categories: acute localised; acute diffuse; chronic; and invasive (‘malignant’). However, except for invasive, they are rarely differentiated as such in clinical practice.
Otitis media: Otitis media covers a broad spectrum of disease, which includes acute otitis media and chronic suppurative otitis media, both these conditions are covered in more detail below. Although uncommon in adults, the causative organisms and treatment of otitis media are the same as in children. As uptake of the pneumococcal vaccination has become more widespread the causative organisms for this condition have changed.
An external ear swab is not useful in the investigation of otitis media unless there is perforation of the eardrum. Tympanocentesis, to sample middle ear effusion, is rarely justified.
Infections of the eye can be caused by a variety of microorganisms. Swabs from eyes may be contaminated with skin microflora, but any organism may be considered for further investigation if clinically indicated.
Exogenous organisms may be introduced to the eye via hands, fomites (eg, contact lenses), traumatic injury involving a foreign body, following surgery, or simply by spread from adjacent sites. Haematogenous spread from a focus elsewhere in the body can also occur.
Nasal swabs are not a suitable sample type for the identification of sinusitis or Bordetella pertussis and should only be used for carriage detection.
Although nose swabs are not the ideal specimen for the examination of nasal discharge, they are sometimes received.
Nasal colonisation with Staphylococcus aureus increases the risk of staphylococcal infections at other sites of the body such as postoperative wounds and dialysis access sites. It is also associated with recurrent skin infections and nosocomial infections in nurseries and hospital wards. S. aureus is a major cause of morbidity and mortality in haemodialysis patients as most patients carry the organism in their anterior nares.
Eradication of nasal carriage of S. aureus may be beneficial in certain clinical conditions such as recurrent furunculosis. Systemic, in addition to topical, treatment is appropriate for nasally colonised patients who have infection elsewhere.
Infections of the oral mucosa usually present as acute conditions. Usually these arise from the colonising oral flora but can also result from a flare-up of a chronic low-grade infection.
Oral mucosal infections are typically associated with biofilms formed on the inanimate surfaces present in the oral cavity such as the teeth and dentures. Infections of the gingiva (gingivitis, including acute ulcerative gingivitis) and periodontal tissues (periodontitis) are the most common forms of oral infection.
Upper respiratory tract infections are classified according to the type of inflammation they cause. As with many infections, the primary challenge in these conditions lies in identifying the causative pathogen and determining the extent of disease progression. There are several types of inflammation of the upper respiratory tract, and they are as follows:
- Use aseptic technique
- Refer to Bacteriology e-Swab user guide
Pink top or orange top Copan e-Swab
Limitations & restrictions
- If processing is delayed, refrigeration is preferable to storage at ambient temperature
- Collect specimens before antimicrobial therapy where possible
- Bacterial investigation: 4 days
- Fungal investigation: 7 days
Microbiology Lab, James Cook University Hospital, Marton Road, TS4 3BW
Please see Bacteriology e-Swab user guide