Making the diagnosis
The Diagnosis is a clinical one - refer Burruscano
Since the introduction of ELISA and associated
serological testing for IgG and IgM in the 1980's we have come to accept such
results as a gold standard for the proof of any contracted infection.
For Lyme disease, Mycoplasma and Chlamydia Pn we can
unfortunately have positive PCR's and negative immunological findings. Such a
scenario of course is abysmal if we are relying on the latter as a proof of
diagnosis. As a reminder the polymerase chain reaction detects the absolute
DNA sequencing of the organism you are looking for dependent upon proper
validation of the primers. Further the spirochaete is not always or easily
found in blood - the usual sample used. Recall the methods used to demonstrate
Strep Viridans etc. It is not recommended that an ELISA screening test be
because it may be negative when the western blot is positive.
In the US the western blot is considered reliable
only when performed by laboratories dedicated to that testing. Many smaller
labs report negatives subsequently found to be positive at these "more
competent" labs. There is even some controversy at the CDC Atlanta about
testing and interpretation of the Western Blot.
In the US some 50 percent of Chronic Lyme sufferers
are both serologically and PCR negative for the disease. For this reason it is
a clinical diagnosis based on exposure, reaction at the time and manifesting
symptoms or syndrome. This is possibly easier in the US as they have a
migratory monoarthritic form of the disease predominantly.
In concluding a diagnosis one should use the
terminology - Burrascano again
or “highly likely”
of course an EM history and positive serology or PCR would be