Bacteria and viruses are microscopic organisms that can cause infectious diseases. Bacteria are single-celled organisms while viruses are smaller and can only replicate inside of living cells. Both bacteria and viruses can be found on and inside the human body. When someone feels sick, their symptoms are often caused by an infection from bacteria or a virus. To determine the specific cause, healthcare providers will collect samples from the infected site to test for different bacteria and viruses in a laboratory.

There are various methods used for collecting bacterial and viral specimens depending on the type of infection being tested for. Some common collection techniques include:

Nasal/Throat Swabs - To test for respiratory infections like influenza, respiratory syncytial virus (RSV), or Streptococcus, healthcare providers will insert a sterile cotton, Dacron, or polyester swab into the nose or throat to collect cells and secretions. This involves gently rubbing the swab along the nasal walls or posterior pharynx and tonsillar areas.

Sputum Sample - For infections in the lungs like pneumonia, clinicians may request a sputum sample. This involves coughing up mucus and phlegm from deep in the lungs and respiratory tract into a sterile container. Sputum plugs containing pus are ideal specimens.

Blood Sample - Blood is often tested to detect viral infections like hepatitis, HIV, or bacterial bloodstream infections. Several milliliters of blood are collected via a sterile needle inserted into a vein, usually in the arm.

Urine Sample - Urine can be analyzed to check for certain Bacterial And Viral Specimen Collection infections that cause a urinary tract infection (UTI). A clean-catch, mid-stream urine sample of at least 10-20mL is collected in a sterile cup.

Stool Sample - Stool analyses can uncover gastrointestinal infections by bacterial pathogens like Salmonella, Shigella, Campylobacter, or viruses such as norovirus or rotavirus that cause diarrhea. A small stool sample is collected in a wide-mouthed sterile container without touch contaminants.

Skin/Wound Swabs - For skin and soft tissue infections, the provider will swab lesions, wounds, or abscesses using sterile Dacron or rayon-tipped applicators moistened with saline. This picks up cells and microbes from the infected site.

Proper Bacterial and Viral Specimen Collection, Transportation and Storage

Once the appropriate clinical samples are obtained, it is imperative they are transported and held under the proper conditions to maintain the viability of any bacteria or viruses present, as well as the integrity of the sample itself.

Most specimens should be delivered to the lab as soon as possible, ideally within 2 hours of collection. If this window may be exceeded, samples may need to be refrigerated - especially important for urine, nasopharyngeal/throat swabs, and stool. Never freeze specimens unless instructed.

Some pathogens are particularly fragile and deteriorate quickly at room temperature. Examples include Neisseria gonorrhoeae from urethral swabs and Bordetella pertussis from nasopharyngeal swabs. These should be placed immediately into transport media.

Certain clinical samples like blood cultures must be maintained at a constant temperature of 35-37°C during shipment to promote bacterial/fungal growth. Transport boxes fitted with warming devices keep cultures at this optimal heat range.

Following standardized procedures and using supplied collection/transport containers labeled with patient data ensures samples arrive intact and suitable for analysis. This accurate tracking is essential for correlating lab results with the correct individual. Strict adherence to protocols maximizes the ability to arrive at the right diagnosis from microbiological testing.