Listeriosis other diagnostic studies: Difference between revisions
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==Other Laboratory Studies== | ==Other Laboratory Studies== | ||
===CSF analysis=== | |||
**[[Pleocytosis]] | **[[Pleocytosis]] | ||
**More than 25 [[lymphocytes]] in [[CSF]] [[Differential blood count (patient information)|differential count]], without [[antibiotic]] therapy. | **More than 25 [[lymphocytes]] in [[CSF]] [[Differential blood count (patient information)|differential count]], without [[antibiotic]] therapy. | ||
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*'''[[Stool cultures]]''' for ''Listeria'' are not indicated in systemic [[listeriosis]] patients, since routine culture media for enteric [[pathogens]] are not appropriate for the growth of ''Listeria''. However, in cases of outbreaks of [[listeriosis]] or individual patients with suspected ''listerial'' [[gastroenteritis]], special selected media can be used. The special culture media may be suggested by a local [[microbiology]] laboratory, a state health department or the [[CDC]]. | *'''[[Stool cultures]]''' for ''Listeria'' are not indicated in systemic [[listeriosis]] patients, since routine culture media for enteric [[pathogens]] are not appropriate for the growth of ''Listeria''. However, in cases of outbreaks of [[listeriosis]] or individual patients with suspected ''listerial'' [[gastroenteritis]], special selected media can be used. The special culture media may be suggested by a local [[microbiology]] laboratory, a state health department or the [[CDC]]. | ||
===Serodiagnosis=== | |||
Diagnosis of [[listeriosis]] with [[antibodies]] for ''listeriolysin O'' have proven useful for diagnosis of [[infected]] patients with noninvasive disease<ref>{{Cite book | last1 = Mandell | first1 = Gerald L. | last2 = Bennett | first2 = John E. (John Eugene) | last3 = Dolin | first3 = Raphael. | title = Mandell, Douglas, and Bennett's principles and practice of infectious disease | date = 2010 | publisher = Churchill Livingstone/Elsevier | location = Philadelphia, PA | isbn = 0-443-06839-9 | pages = }}</ref>. | |||
===Imaging studies=== | |||
Although both MRI and CT scan may be used to help in the diagnosis of ''Listeria monocytogenes'' lesions, the MRI is a more [[sensitivity|sensitive]] method to detect ''listerial'' lesions in the cerebellum, brainstem and cortex.<ref name="pmid8507761">{{cite journal| author=Armstrong RW, Fung PC| title=Brainstem encephalitis (rhombencephalitis) due to Listeria monocytogenes: case report and review. | journal=Clin Infect Dis | year= 1993 | volume= 16 | issue= 5 | pages= 689-702 | pmid=8507761 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=8507761 }} </ref> On an [[MRI]], in the [[cerebral]] [[parenchyma]] there may be identified high-signal lesions on T2-weighted images and enhancing lesions on T1-weighted images, following administration of IV contrast. | |||
Since MRI evidence of brainstem involvement, coupled with proper clinical setting, is strongly suggestive of infection by ''Lysteria'', it is recommended the use of contrast [[MRI]] in all patients presenting with ''listerial'' [[meningitis]], ''listerial'' [[bacteremia]], [[CNS]] signs and symptoms or suspicion of intracranial [[listeriosis]]. | Since MRI evidence of brainstem involvement, coupled with proper clinical setting, is strongly suggestive of infection by ''Lysteria'', it is recommended the use of contrast [[MRI]] in all patients presenting with ''listerial'' [[meningitis]], ''listerial'' [[bacteremia]], [[CNS]] signs and symptoms or suspicion of intracranial [[listeriosis]]. | ||
Revision as of 16:23, 22 July 2014
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
The diagnosis of infection by Listeria monocytogenes may be suspected from the clinical findings, however due to the similarities with other infectious diseases, it can be mistaken with those. Therefore, the diagnosis should be established by culture of the organism from blood and CSF. In many reported cases, despite the presence of the disease, CSF cultures were negative, in which cases, blood cultures should orient the diagnosis, since these are more commonly positive than the first ones.[1]
Other Laboratory Studies
CSF analysis
- Pleocytosis
- More than 25 lymphocytes in CSF differential count, without antibiotic therapy.
- Moderately elevated CSF protein concentration with reduced CSF glucose concentration.[2]
- Gram stain of the CSF has very low sensitivity and even when organisms are seen, they may be misidentified. [3] Therefore, Listeria monocytogenes should always be considered when similar organisms are growing in blood or CSF cultures. The presumptive diagnosis of viral meningitis should also be carefully considered in immunocompromised, chronically ill, or elderly patients, presenting with acute meningitis and a negative Gram stain. Due to the fact that rhombencephalitis patients CSF examination often reveals only mild abnormalities, its diagnosis is often delayed.
- A Polymerase chain reaction assay has been developed for the hly gene detection, which encodes for the listeriolysin O, in CSF cultures. However, despite more specific and more sensitive, it is not commercially available yet.
- Stool cultures for Listeria are not indicated in systemic listeriosis patients, since routine culture media for enteric pathogens are not appropriate for the growth of Listeria. However, in cases of outbreaks of listeriosis or individual patients with suspected listerial gastroenteritis, special selected media can be used. The special culture media may be suggested by a local microbiology laboratory, a state health department or the CDC.
Serodiagnosis
Diagnosis of listeriosis with antibodies for listeriolysin O have proven useful for diagnosis of infected patients with noninvasive disease[4].
Imaging studies
Although both MRI and CT scan may be used to help in the diagnosis of Listeria monocytogenes lesions, the MRI is a more sensitive method to detect listerial lesions in the cerebellum, brainstem and cortex.[1] On an MRI, in the cerebral parenchyma there may be identified high-signal lesions on T2-weighted images and enhancing lesions on T1-weighted images, following administration of IV contrast. Since MRI evidence of brainstem involvement, coupled with proper clinical setting, is strongly suggestive of infection by Lysteria, it is recommended the use of contrast MRI in all patients presenting with listerial meningitis, listerial bacteremia, CNS signs and symptoms or suspicion of intracranial listeriosis.
References
- ↑ 1.0 1.1 Armstrong RW, Fung PC (1993). "Brainstem encephalitis (rhombencephalitis) due to Listeria monocytogenes: case report and review". Clin Infect Dis. 16 (5): 689–702. PMID 8507761.
- ↑ Mylonakis E, Hohmann EL, Calderwood SB (1998). "Central nervous system infection with Listeria monocytogenes. 33 years' experience at a general hospital and review of 776 episodes from the literature". Medicine (Baltimore). 77 (5): 313–36. PMID 9772921.
- ↑ Lavetter A, Leedom JM, Mathies AW, Ivler D, Wehrle PF (1971). "Meningitis due to Listeria monocytogenes. A review of 25 cases". N Engl J Med. 285 (11): 598–603. doi:10.1056/NEJM197109092851103. PMID 4998254.
- ↑ Mandell, Gerald L.; Bennett, John E. (John Eugene); Dolin, Raphael. (2010). Mandell, Douglas, and Bennett's principles and practice of infectious disease. Philadelphia, PA: Churchill Livingstone/Elsevier. ISBN 0-443-06839-9.