Girlie said...
“ So who knows I suspect bart bigtime bt had neg testing to henslae and quint. Bt there are more strains“
And high false negatives with coinfection testing
i write this a lot as it seems to be under appreciated how poor testing for chronic bartonella infections is - or is just plain confusing to a lot of people.
the problem is sensitivity ( high false negative rate )
best test on the market for bartonella by a long shot is the Galaxy's latest digital droplet PCR method
they work very hard to get the sensitivity up:
-3 blood draws on different days
-culture the samples in special media for around 1 week
-run digital droplet pcr on the culture thousands of times and statistically combine the results
even after all that effort, way more than a standard PCR or ELISA test, in their published paper they are still only able to claim a 49% sensitivity - in other words they still miss more positive cases that they detect.
regular PCR or regular ELISA ( serology ) tests are thought to be in the region of 20% sensitive
in the light of this - a person concluding they DO NOT have bartonella based on a ANY of the above tests is very hard to support logically.
so its important to recognise the asymmetry in the meaning of test results - driven by the large asymmetry in the sensitivity and specificity of the tests themselves.
eg
a positive result in a test that has a 90+% specificity can sensibly be used as evidence to support a diagnosis (though there is still a 1/10 chance it is wrong)
whereas a negative result in a test with 50% sensitivity does not mean anything at all ....