Experts disagree on Lyme diagnosis

Re: Lyme disease diagnostics need improving, Letters, Aug. 4

While we applaud the Canadian Lyme Foundation’s advocacy for sick patients, we would like to state, for the record, that far from being reluctant to discuss the limitations of testing in early Lyme disease, we have been informing physicians for many years that diagnosis and treatment in early Lyme disease should be based on clinical findings.

The two-step testing protocol has been found to be 87 per cent to 97 per cent sensitive in identifying Lyme disease in individuals with previously untreated later stage Lyme disease.

It is also highly specific, meaning that a negative test has a very high likelihood of being a true negative.

This is in contrast to those from certain U.S. laboratories that have been shown to report Lyme disease in up to 57 per cent of healthy (not infected) individual’s blood samples.

In addition, the BC Centre for Disease Control laboratories recognize that British Columbians can be infected while travelling out-of-province and testing for non-indigenous strains of Borrelia is available.

These strains are not as yet found in B.C., but we are looking for them.

The assertion that chronic Lyme disease is caused by persistent infection, with organisms (Borrelia) that have survived antibiotic therapy and tricked the body’s immune system is disputed by the vast majority of infectious disease specialists.

Basing a diagnosis of chronic infection with Borrelia on a history of debilitating physical symptoms and a positive outof-province laboratory test, in the presence of multiple negative tests from the BCCDC, is not supported by the evidence.

It risks misdiagnosing many individuals and exposing them to harmful long-term antibiotic therapy, which has shown no benefit in a number of randomized control trials.

Yes, better testing and treatment options are needed, but what David Cubberly of the Canadian Lyme Foundation is advocating is not the answer to the problem.

P.R.W. KENDALL Provincial health officer,

B.C. Ministry of Health

DAVID PATRICK Professor and director, School of Population and Public Health Faculty of Medicine, UBC

BONNIE HENRY Deputy provincial health officer, B.C. Ministry of Health

MUHAMMAD MORSHED Program head, Zoonotic and Emerging Pathogens B.C. Public Health Microbiology & Reference Laboratory BC Centre for Disease Control