Animal Health Diagnostic Center

Sign in | Register

Lab Links  

Where you get what you need ... not just what you ask for.


Locating Lyme Disease

Tick

Cornell's Lyme Multiplex assay reveals infection history

Romping through summer fields seems like a harmless pleasure for dogs, horses, and humans alike. But just one bite from the wrong tick can rob an animal of that pastime. The bacteria Borrelia burgdorferi live in certain species of ticks, and can infect animals the ticks bite with Lyme disease.

Lyme disease can cause a slew of debilitating symptoms from arthritis to outright lameness, cardiac complications, kidney disease, and neurological symptoms from chronic pain and weakness to paralysis. It’s important to diagnose the disease early because it becomes progressively harder to treat as the bacteria hide in the joints and organs of their hosts.

“The bacteria that cause Lyme disease are particularly difficult to detect,” explained Dr. Bettina Wagner, associate professor in the Department Of Population Medicine and Diagnostic Sciences and director of serology at the Animal Health Diagnostic Center (AHDC) at Cornell. “After infection they tend to hide where they can’t be detected. They bury in the joints of dogs, causing arthritis or lameness, or in severe cases kidney disease, the so-called ‘Lyme nephritis’. In humans and horses they can also enter the central nervous system, causing pain, paralysis, or behavioral alterations. By the time such clinical signs appear, the bacteria are not in circulation anymore and cannot be detected by tests that target the pathogen directly.”

Fortunately for hosts, infection with the bacteria causes the immune system to produce antibodies, protective proteins in the blood, specially tailored to identify, bind and fight specific pathogens such as harmful bacteria. Diagnosticians can test blood samples to see whether an animal made antibodies in response to B. burgdorferi bacteria. If the antibodies are detectable, the animal is likely infected.

“The Lyme Multiplex assay has been offered through the AHDC at Cornell since 2011,” said Wagner, “The new test exceeds its predecessor in accuracy, specificity, and analytical sensitivity. It is fully quantitative which is important to make treatment decisions and to follow-up on treatment success.”

The Lyme Multiplex assay for horses and dogs was developed by Wagner and her colleagues at Cornell.  It detects antibodies to three different antigens of B. burgdorferi simultaneously in one test.

Multiplex technology has been around for the last decade, but the Animal Health Diagnostic Center (AHDC) is the first veterinary diagnostic laboratory that used it for Lyme disease testing. Different kinds of antibodies can be found in the body at different stages of infection.  The new test can distinguish and measure these differences, giving more information about the disease.

“With the Lyme Multiplex assay, we can not only distinguish between infection and vaccination, but also between early and chronic infection stages,” Wagner noted. “That was not possible before the Lyme Multiplex Assay was available.  Previously, we were able to say whether an animal was infected, but not when it was infected, or how far the infection has developed.”

The test and information it provides helps veterinarians to make advanced decisions about treatment. Antibiotic treatment of Lyme disease is much more effective during the early infection stages. As longer the infection persists, as more difficult it gets to treat or cure. If veterinarians decide to treat an animal for Lyme disease, they usually conduct Lyme Multiplex follow-up testing to see if the treatment was successful.

“We look at the improvement of clinical signs and for a clear decline of antibodies in the blood,” Wagner said. “If the treatment starts late in the chronic stage, we sometimes don’t see that decline. This generally means that the treatment wasn’t successful. The veterinarian can then modify the treatment to improve the patient’s condition. With the information the Lyme Multiplex assay gives us before and after treatment, we can measure its success and better manage Lyme disease in animals.”