Lyme disease takes flight

In addition the usual suspects, now birds have been found to carry Lyme disease. Don Trethewey, retired Kamloops biologist, alerted me to the latest risk as reported in Entomology Today.


Blood samples of birds studied in California revealed that some species carried the bacteria that causes Lyme disease. Alarmingly, they were common birds found in suburban environments such as American robins, dark-eyed juncos and golden-crowned sparrows. Some of the ticks on the birds were also infected.

“Lyme disease was known to be carried by white-footed mice, wood rats, western gray squirrels, and other small mammals, but fewer studies have looked at the role of birds as reservoirs,” says the journal.

Birds are so effective as carriers that the bacterium wasn’t even regional. Instead, it was a bacterium that causes a Lyme-like disease in central and southern Europe.

“The fact that we found this particular bacterium for the first time in birds in California is notable because of the ease with which birds can distribute spirochetes to different regions.”

We like to think of the ticks as the culprits in Lyme disease, but not all ticks carry the bacterium. Of the ticks taken from the birds in the California study, only 25 per cent were infected. It’s a complex chain. Uninfected ticks bite hosts that carry the bacterium and they become infected. In turn, the ticks bite other birds or mammals and the chain of infection grows.

Not all species of ticks carry the bacterium, either because they are resistant or they have not been exposed. In North America, it’s the black-legged ticks in the west and the similarly named black-legged deer tick in the east.

In the U.S., there are approximately 300,000 cases each year with the large majority occurring in the east.

In Canada, it’s hard to say. Green party Leader Elizabeth May hopes to change that with her bill passed in the Parliament last June. It calls on the government to develop a Lyme disease strategy including a national program to track rates of infections, develop guidelines for preventing infections, and diagnose and treat them when they occur.

While May’s proposal gained all-party support, one group suggested that she was politicizing a general fear of Lyme disease.

The Association of Medical Microbiology and Infectious Diseases Canada was concerned that the bill plays on a general fear of Lyme Disease.  Many suffer from chronic symptoms that haven’t been properly diagnosed.

The lack of tracking and diagnosis leads to further anguish because sufferers are not taken seriously. Some organizations say the existence of chronic Lyme disease is based on pseudo-science, while others claim it is a real and debilitating condition.

No wonder there’s confusion. The bite from an infected tick can cause a bull’s-eye rash to appear – – or not. Within a few weeks, a myriad of hellish symptoms appear such as pain in muscles, joints, tendons; heart palpitations and dizziness. Acute neurological problems may emerge: facial palsy with the loss of muscle tone on one or both sides of the face, meningitis with severe headaches, neck stiffness, and sensitivity to light, memory loss, sleep disturbances, and mood changes.

Now a spooked Canadians have one more thing to worry about as they watch their favourite birds of spring arrive.


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