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Query: UMLS:C0085437 (bacterial meningitis)
 4,038 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fungal meningitis tends to be a subacute or chronic process; however, it may be just as lethal as bacterial meningitis if untreated. There are many similarities between the pathogenic fungi. Most of the fungi are aerosolized and inhaled, and initiate a primary pulmonary infection which is usually self-limited. Hematogenous dissemination may follow the initial infection, with subsequent involvement of the CNS. Rarely, trauma or local extension provides the route to CNS infection. The host is frequently, although not always, immunosuppressed. The hyphae of molds generally cause focal disease with hemorrhagic necrosis secondary to vascular thrombosis. The yeasts tend to cause a more diffuse process with the base of the brain being primarily affected, such that hydrocephalus is seen as a frequent complication of chronic disease. Diagnosis may be difficult, as the CSF may be normal, with negative smears and sterile cultures, although more often there is at least one abnormality indicating disease. Serologies (if available, depending on the fungus) may point towards the proper diagnosis, as may a careful travel history. Currently, amphotericin B is still the drug of choice in most situations; however, the newer azole antifungal agents offer great promise, especially in the treatment of cryptococcal meningitis. The precise role of such agents will remain unclear until appropriate large-scale studies of their effectiveness have been completed. The treatment of the unusual CNS mycoses will continue to be based on clinical experience, and reports of the use of new azoles in these diseases need to be critically evaluated.
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PMID:Fungal meningitis. 227 99

Meningitis is the most common serious manifestation of infection of the central nervous system. Inflammatory involvement of the subarachnoid space with meningeal irritation leads to the classical triad of headache, fever, and meningism, and to a pleocytosis of the cerebrospinal fluid (CSF). Meningitis is clinically categorized into an acute and chronic disease based on the acuity of symptoms. Acute meningitis develops over hours to days, while in chronic meningitis symptoms evolve over days or even weeks. Aseptic meningitis, in which no bacterial pathogen can be isolated by routine cultures, can mimic bacterial meningitis, but the disease has a much more favorable prognosis. Many cases of aseptic meningitis are caused by viruses, primarily enteroviruses, but bacteria and noninfectious etiologies also cause meningitis with negative cultures. Symptoms of meningeal inflammation with CSF pleocytosis that persist for more than 4 weeks define the chronic meningitis syndrome. The diagnosis is based on the patient history, clinical evidence of meningitis, CSF examination, and often imaging studies. The differential diagnosis is broad, and the predominant CSF cell type can provide clues as to the underlying disease. Empiric therapy is primarily based on the age of the patient, with modifications if there are positive findings on CSF gram stain or if the patient presents with special risk factors. In patients with chronic meningitis, a definite diagnosis is often not available or delayed for days, in which case empiric therapy may have to be initiated. It is important to cover the treatable causes of meningitis, for which the outcome is poor if treatment is delayed.
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PMID:[Meningitis (I)--differential diagnosis; aseptic and chronic meningitis]. 1059 75

The laboratory diagnosis of CNS infection is essential for optimal therapy. Acute infection requires rapid turn-around testing with high predictive values, that is, the ability of a test to accurately identify those patients who do or do not have disease caused by a specific etiology. The Gram's stain, fungal stains of direct smears, antigen testing for C. neoformans, and culture of bacteria, fungi, mycobacteria, and some viruses are important tests for the diagnosis of acute infection. The laboratory diagnosis of chronic infection necessitates discussion between the clinician and laboratory technician to allow triaging of testing. Antigen tests for bacteria, fungi, and viruses; antibody tests for multiple microorganisms; and PCR testing for bacteria, M. tuberculosis, and many viruses are all important in limited clinical situations. All testing for acute or chronic disease depends on sufficient specimen that is transported to the laboratory in a manner that will not compromise viability or chemical integrity. Sterile containers that maintain moisture content, exclude oxygen for anaerobic requests, and are stored at proper temperatures (22 degrees C room, 4 degrees C refrigeration, or -20 degrees C freezer depending on pathogen and test) are mandatory. Many laboratory issues addressing the diagnosis of CNS infection are changing or evolving. Most important is the recognition that bacterial antigen testing for the diagnosis of acute bacterial meningitis rarely impacts patient management and is not routinely needed, CSF shunt infections differ from usual meningeal infections and require rapid diagnosis, and TB meningitis remains a difficult disease to diagnosis but may be confirmed first by PCR testing of CSF. In addition, Whipple's disease of the CNS can be confirmed using PCR with CSF; CJD has a marker protein, referred to as 14-3-3 antigen, that can be detected in CSF, and the diagnosis of fungal CNS disease requires careful interpretation of direct smears, antigen and antibody testing, and culture. Most difficult to diagnose among the CNS infections are viral meningitis and encephalitis. The appearance of new etiologies, such as West Nile virus, and the common use of PCR for the herpes viruses and enteroviruses represent important advances. Evolving methods for the laboratory diagnosis of CNS infection represent significant improvements over previous testing; however, the array of tests available demands more attention for appropriate selection, is significantly more expensive, and requires new skills for performance and interpretation. The responsibility for proper use of laboratory testing lies both with the clinician and laboratory technician.
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PMID:Laboratory diagnosis of central nervous system infections. 1178 Feb 67