LYME DISEASE

Lyme disease

Lyme disease

Introduction

Lyme disease, sometimes referred to as Lyme infection, is a bacterial illness, transmitted to humans by the bite of deer ticks (Ixodes ticks) carrying a bacterium known as Borrelia burgdorferi. The disease has been reported in the Northeast, Mid-Atlantic, North Central, and Pacific coastal regions of the United States (see map) and in Europe, where it was first described almost 100 years ago. It is most prevalent in the northeastern states of the United States, with about half of all cases clustered in New York and Connecticut. (Taylor R, Simpson I 2005)

What is the history of Lyme disease?

Interestingly, the disease only became apparent in 1975 when mothers of a group of children who lived near each other in Lyme, Connecticut, made researchers aware that their children had all been diagnosed with rheumatoid arthritis. This unusual grouping of illness that appeared "rheumatoid" eventually led researchers to the identification of the bacterial cause of the children's condition, what was then called "Lyme disease" in 1982? Ticks are carriers of the Lyme bacterium in their stomachs. The ticks then are vectors that can transmit the bacterium to humans with a tick bite. The number of cases of the disease in an area depends on the number of ticks present and how often the ticks are infected with the bacteria. In certain areas of New York, where Lyme disease is common, over half of the ticks are infected. Lyme disease has been reported most often in the northeastern United States, but it has been reported in all 50 states, as well as China, Europe, Japan, Australia, and parts of the former Soviet Union. In the United States, it is primarily contracted in the Northeast from the state of Maine to Maryland, in the Midwest in Minnesota and Wisconsin, and in the West in Oregon and Northern California.

Ticks are small and can be hard to see. Immature ticks, or nymphs, are about the size of a poppy seed. Adult ticks are about the size of a sesame seed. (Taylor R, Simpson I 2005)

Explanation

It's important to know and watch for symptoms of Lyme disease because ticks are hard to find and it's easy to overlook a tick bite — in fact, many people who get Lyme disease don't remember being bitten. The good news is that most tick bites don't result in Lyme disease.

Signs and Symptoms Lyme disease can affect different body systems, such as the nervous system, joints, skin, and heart. The symptoms of Lyme disease are often described as happening in three stages (although not everyone experiences all of these stages): (Taylor R, Simpson I 2005)

lymedisease_illustration

1. Often, the first sign of infection is a circular rash. This rash appears within 1-2 weeks of infection but may develop up to 30 days after the tick bite. The rash often has a characteristic "bull's-eye" appearance, with a central red spot surrounded by clear skin that is ringed by an expanding red rash. It may also appear as an expanding ring of solid ...