What clinical details should I provide?Please note that faeces culture is a highly specialised series of tests that involves screening a sample for a number of bacterial pathogens causing gastroenteritis. Therefore our laboratory requires clinical information to select the appropriate tests. Please include as much information as possible regarding: Show
What volume of sample should I collect?The department requires a minimum of 5ml of faeces collected into a 30ml sterile universal or blue top with 'spoon' for processing. Please note also that samples should be fresh (ideally sent up to the laboratory within 2-3 hours of being passed). If faeces contaminated with urine then M, C & S, parasitology and clostridium difficile investigations can be tested but this may affect the result. What does faeces culture include?Culture for enteric pathogens includes: campylobacter species, salmonella species and E. coli O:157 in all cases of non-hospital acquired diarrhoea. The department also screens for shigella species in all patients with a history of foreign travel. We also screen for vibrio cholerae in patients with a history of travel to cholera endemic areas AND if the patient has a liquid stool. We screen for Vibrio parahaemolyticus in patients with a history of shellfish consumption or participation in water related activities. Lastly, the department also cultures for Yersinia enterocolitica in patients with symptoms suggestive of yersiniosis (especially young or elderly patients with mesenteric lymphadenitis, pseudoappendicitis, terminal Ileitis). What happens if I don’t provide suitable clinical information?Samples will not be cultured unless appropriate clinical information is provided. The microbiology department deals with a large volume of samples; therefore it is vital that sufficient clinical details are provided to establish the cause of diarrhoea as being unrelated to C. difficile. Which samples are cultured regardless of clinical information?All GP samples and the following wards/ departments will receive faeces culture (If requested) regardless of clinical Information. Emergency department, MAU, ICU, SAU, CDU, all paediatric wards, all outpatient wards/ clinics wards 305 and 304. The microbiology department wil also check samples from other inpatient wards where culture has been requested, for admission dates. Samples from patients who have been in hospital for less than 3 days will also be cultured. Travel associated diarrhoeaWhat clinical details should I provide? Travel to foreign countries may result in infectious diarrhoea being attributed to more unusual pathogens not seen (or seen rarely) in the UK. Faeces foreign travel investigation includes additional culture methods and additional microscopyfor faecal parasites. It is vital that if a patient has been abroad to provide as much information as possible such as:
If a High Risk pathogen is suspected, please indicate so we can process the sample using the correct safety procedures. Which parasites will the department screen for? In the laboratory, provided the relevant clinical details are given, we will look for Helminths (worms) e.g. Ascaris, hookworm, tapeworm, liver flukes and other Helminths. We will also look for Protozoan parasites e.g. Giardia, Cryptosporidia, Entamoeba and others. What happens if I don’t provide suitable clinical information? Please note that samples will not be examined for ova, cyst’s and parasites unless appropriate clinical information is provided. The microbiology department deals with a large volume of samples; therefore it is vital that in these cases, sufficient clinical details are provided to establish the cause of diarrhoea as being unrelated to C. difficile. Clostridum difficile testingWhen will the sample be tested? The microbiology department currently processes faeces samples for C. difficile investigations on a 7 day basis. Monday - Friday: 2 runs are performed in the day (am and pm). Samples must reach pathology reception by 9am at the latest for the morning run and 12.30pm for the afternoon run. Saturday - Sunday: 1 run is performed each day. Samples must reach pathology reception by 9am at the latest.
C. difficiie is an opportunistic anaerobic spore forming bacteria present in the intestines. It can produce toxins which results in infection. Some strains do not produce toxins but the bacteria being present can mean that the patient has the potential to excrete it and have an increased risk of developing the infection and diarrhoea. This method will differentiate between patients who have active C. difficile infection and those that could be at risk of becoming infected (excretors). This new method aims to provide more effective and consistent diagnosis across the NHS.
The 2 stages include:
Test ordering ICM users will now see the test as: Faeces (C. difficile screen only) The is no change for other electronic users. IF an electronic ordering system is not available please request 'C. diff screen'. What volume of specimen is required and when should it be taken?A minimum of ¼ of a pot of faeces of Bristol stool type 6 or 7 must be submitted for testing. Samples must be sent immediately (within 2 hours) to the lab (a delay in transport can result in a significant loss of any toxin that may be present in the sample). Samples that cannot be processed within two hours must be refrigerated (up to two days). Please consult Infection Control for guidance as to when to submit samples per episode of diarrhoea. What is the department’s policy on not testing samples?
* Samples may be processed but only after clearance from a consultant microbiologist or the Infection Control Team. VirologyWhat are the indications for testing a sample for enteric viruses? Most people with viral gastroenteritis have only mild symptoms, and the condition improves within a few days without the need for treatment. However in certain cases, for example; if the symptoms are severe, persistent or recurrent and if the patient is especially vulnerable due to age or immune status, or in outbreaks of diarrhoea it may be clinically useful to isolate the causative agent What type of viral investigations are carried out routinely? The microbiology department only carries out in-house testing for rotavirus in paediatric patients (<5 years). Norovirus testing is also carried out in outbreaks of diarrhoea and vomiting after notification by the Infection control team only. How do I go about requesting virology investigations on individual patients that are not under 5 or part of an outbreak of diarrhoea and vomiting? Any requests for testing of patient samples, which do not meet the above criteria, must be approved by a consultant microbiologist. This can be done by contacting the on-call Consultant microbiologist through switchboard 01332 340171. Please have the patient’s details ready. Any samples submitted for virology thereafter must state on the request form that testing has been approved by a consultant microbiologist. What happens if I don’t get approval from a consultant microbiologist? Please note that samples will not be examined for enteric viruses unless approved by a consultant microbiologist. The microbiology department deals with a large volume of samples and aside from Rotavirus, samples have to be referred for viral investigation. What urine specimen tends to be the most concentrated?A first voided specimen is the most concentrated and is the preferred specimen for pregnancy testing, bacterial cultures and microscopic examinations.
Which of the following is an acceptable sample for laboratory testing?Most often, all that is required is a blood sample. However, samples of urine, saliva, sputum, feces, semen, and other bodily fluids and tissues also can be tested.
Which of the following patient information should be included in the requisition form in addition to the patient's complete name DOB medical record number?a. In addition to having an accurate patient diagnosis (narrative and/or ICD-10) indicating the medical necessity for testing, each requisition form must also include complete patient demographic information including the patient's full legal name, date of birth (DOB), gender, and current insurance information.
Which specimen should be transported at 37 degrees Celsius?Cryoglobulin is a common and simple clinical immunology laboratory test that requires the blood samples to be transported to the laboratory, without cooling, at 37°C (1, 5, 6).
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