| Since its identification nearly 30 years ago, Lyme disease has continued to spread, and there have been increasing numbers of cases in the northeastern and north central US, Europe, also in China. The Lyme disease agent, Borrelia burgdorferi, causes infection by migration through tissues, adhesion to host cells, and evasion of immune clearance. Both innate and adaptive immune responses, especially macrophage- and antibody-mediated killing, are required for optimal control of the infection and spirochetal eradication. Ecological conditions favorable to the disease, and the challenge of prevention, predict that Lyme disease will be a continuing public health concern. In the late 20th century, Lyme disease, or Lyme borreliosis, was recognized as an important emerging infection. It is now the most commonly reported arthropod-borne illness in the US, Europe and in Asia. For example, since surveillance for Lyme disease was begun in the US by the Centers for Disease Control and Prevention, the number of reported cases has increased steadily, and in the year 2000, more than 18,000 cases were reported. Personal protection measures, including protective clothing, repellents or acaricides, tick checks, and landscape modifications in or near residential areas, may be helpful. However, these measures are difficult to perform regularly throughout the summer. In the 1990s, recombinant OspA vaccines were developed and shown to be safe and effective for the prevention of Lyme disease in the US. Although one of the vaccines was licensed commercially, its acceptance by the public and by physicians was also limited, and it was withdrawn by the manufacturer in 2002. Some of the reasons why its acceptance was limited included the low risk of Lyme disease in most parts of the country, the need for booster injections every year or every other year, and the relatively high cost of this preventive approach compared with antibiotic treatment of early infection. In addition, there was a theoretical, though never proven, concern that in rare cases, vaccination might trigger autoimmune arthritis. For now, control of Lyme disease depends primarily on public and physician education about personal protection measures, signs and symptoms of the disease, and appropriate antibiotic therapy. However, if the risk of the infection continues to increase or if public perceptions change, vaccine development may again become a priority. Experience gained in the last ten years has proven the feasibility of vaccination for the prevention of this complex, tick-transmitted infection. As a new emerging infectious disease, we know a little about its Epidemiology, Causative organism, Clinical manifestations, Diagnosis, Treatment, Prevention and prophylaxis. Especially, Jilin province is Lyme disease's nature landscape. The number of reported cases has increased steadily in Jilin province in recent years. Therefore, it is important to research the disease in Diagnosis, Treatment, Prevention and prophylaxis. As described previously, outer surface protein A (OspA) of Borrelia burgdorferi is very important and useful for developing vaccine and diagnosis reagent. However, the variation of OspA gene in difference places' isolate of Borrelia burgdorferi is very noted. Therefore, recombinant OspA vaccines, which were developed and shown to be safe and effective for the prevention of Lyme disease in the US, are not effective for the prevention of it in China. In our research, the objectives are to investigate the variation of OspA gene in Jilin's isolate of Borrelia burgdorferi, which is the foundation of developing the vaccine, suited our conditions. We collected the ticks, which tested to be Ixodes Persulcatus in Mount Changbai, Fusong County and Chaoyang county .The seven Borrelias have been isolated from these Ixode ticks, the dominant species of tick in north China. All Borrelia isolates were grown in BSK medium at 32°C. Extraction of DNA was performed as described previously. PCR technique was used to amplify the OspA gene f...
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