Changes

*'''Immunoblot analysis (Western blot) of serum and CSF''': senstivity around 90%, specificity 48-89%.(EPM4)  Cultured merozoites are used to detect antibodies versus ''S.neurona''-specific proteins.  The CSF test has over 90% specificity and sensitivity(86 in Furr).  The blood brain barrier is not prevent the passage of antibodies, thus the CSF concentration of a specific antibody will be directly related to its serum concnetration (87 in Furr).  This permeability is likely responsible for many of the weakly false-positive CSF immunoblot tests.  Blood contamination during CSF collection or bleeding within the CNS due to trauma or infection might also cause false positives.  The CSF titre will be greatly increased during CNS infection as there will be local production of the antibody.  One of the difficulties in interpreting immunoblot results is that many horses develop antibodies against ''S.neurona'' in the absence of neurological disease.(EPM4)  For this reason, testing CSF may be preferable to serum despite the impact that minor blood contamination may have on CSF results.(IVIS 4)False negative results may arise if horses fail to respond to the specific proteins recognised by the immunoblot.  Such cases are rare, so a negative immunoblot result tends to exclude the diagnosis of EPM.(Merck)  Cases that originally test negative should be re-tesed 14-21 days later.  In most instances, owing to a substantial incubation period, detectable levels of IgG are present prior to the emergence of clinical signs.(Furr)  

*'''Immunoblot analysis (Western blot) of serum and CSF''': senstivity around 90%, specificity 48-89%.(EPM4)  Cultured merozoites are used to detect antibodies versus ''S.neurona''-specific proteins.  The CSF test has over 90% specificity and sensitivity(86 in Furr).  The blood brain barrier is not prevent the passage of antibodies, thus the CSF concentration of a specific antibody will be directly related to its serum concnetration (87 in Furr).  This permeability is likely responsible for many of the weakly false-positive CSF immunoblot tests.  Blood contamination during CSF collection or bleeding within the CNS due to trauma or infection might also cause false positives.  The CSF titre will be greatly increased during CNS infection as there will be local production of the antibody.  One of the difficulties in interpreting immunoblot results is that many horses develop antibodies against ''S.neurona'' in the absence of neurological disease.(EPM4)  For this reason, testing CSF may be preferable to serum despite the impact that minor blood contamination may have on CSF results.(IVIS 4)False negative results may arise if horses fail to respond to the specific proteins recognised by the immunoblot.  Such cases are rare, so a negative immunoblot result tends to exclude the diagnosis of EPM.(Merck)  Cases that originally test negative should be re-tesed 14-21 days later.  In most instances, owing to a substantial incubation period, detectable levels of IgG are present prior to the emergence of clinical signs.(Furr)  

*'''Whole organism indirect fluorescent antibody test (IFAT)''': sensitivity around 90%, specificity 97-100%.(EPM4)  Serum titres of more than 1:100 and CSF titres of more than 1:5 indicate an active infection. The IFAT is considered to have slightly improved diagnostic efficiency than the immunoblot test(92 in furr) but is unable to distinguish between ''S.neurona'' and other related nonpathogenic organsims such as ''S.fayeri''(94 in Furr).  This can lead to false positive results.  Compared with the immunblot test, CSF blood contamination has an insignificant effect on the IFAT.(11 in IVIS 4)  An IFAT for ''N.hughesi'' is also available from the Universty of California.(Furr)

*'''Whole organism indirect fluorescent antibody test (IFAT)''': sensitivity around 90%, specificity 97-100%.(EPM4)  Serum titres of more than 1:100 and CSF titres of more than 1:5 indicate an active infection. The IFAT is considered to have slightly improved diagnostic efficiency than the immunoblot test(92 in furr) but is unable to distinguish between ''S.neurona'' and other related nonpathogenic organsims such as ''S.fayeri''(94 in Furr).  This can lead to false positive results.  Compared with the immunblot test, CSF blood contamination has an insignificant effect on the IFAT.(11 in IVIS 4)  An IFAT for ''N.hughesi'' is also available from the Universty of California.(Furr)

*'''ELISA for antibodies to the snSAG-1 protein''': based on an immunodominant surfae antigen of S.neurona (SAG-1).(IVIS 4)  Serum titres more than 1:100 suggest an active infection.  False negatives are possible as not all ''S.neurona'' isolates produce the specific protein.(58 in Furr).  SAG-5 is an alternative surface antigen of ''S.neurona'' strains, which is mutually exclusive to SAG-1.(15 in IVIS 4) Therefore, the ELISA may only be of use where strains of ''S.neurona'' expressing SAG-1 predominate.(IVIS 4)

*'''ELISA for antibodies to the snSAG-1 protein''': based on an immunodominant surface antigen of ''S.neurona'' (SAG-1).(IVIS 4)  Serum titres more than 1:100 suggest an active infection.  False negatives are possible as not all ''S.neurona'' isolates produce the specific protein.(58 in Furr).  SAG-5 is an alternative surface antigen of ''S.neurona'' strains, which is mutually exclusive to SAG-1.(15 in IVIS 4) Therefore, the ELISA may only be of use where strains of ''S.neurona'' expressing SAG-1 predominate.(IVIS 4)

===Other tests===

===Other tests===