OspA L03 Group2: Difference between revisions

First recognized in 1957, [http://en.wikipedia.org/wiki/Lyme_disease Lyme disease] has been estimated to affect between 20 and 100 cases per 100,000 individuals in the United States (Rupprecht, 2008). The peak infection rates of this disease occur approximately between the months of May and August in North America (Onrust, 2000). The causative agent for this disease is a bacterial vector of [http://www.ucmp.berkeley.edu/bacteria/spirochetes.html spirochetes], called [http://en.wikipedia.org/wiki/Borrelia_burgdorferi Borrelia burgdorferi], which were found in the gut of the [http://en.wikipedia.org/wiki/Ixodes Ixodes] tick (Burgdorfer, 1982). The bacteria spread through the bite of the tick forming severe skin lesions. Other health complications include chronic [http://en.wikipedia.org/wiki/Arthritis arthritis], and neurologic and cardiac abnormalities (Burgdorferi, 1982). From 10-12 weeks of infestation, other symptoms like [http://en.wikipedia.org/wiki/Erythema_chronicum_migrans erythema chronicum migrans] begin to appear as well(Burgdorferi, 1982). Studies were first conducted through New Zealand white rabbits (Burgdorferi, 1982) through the use of [http://en.wikipedia.org/wiki/Immunofluorescence indirect immunofluorescence].  

These spirochetes however do not enter the host through salivary secretions into the blood stream. The host becomes infected because the tick's blood meal enters the gut where the spirochetes are located, and therefore some of the blood that returns to the bitten area is infected with this bacteria. This results in the transmission into the host's blood stream (Onrust, 2000). Once the bacteria is in the blood stream, the immune system may, or may not destroy this [http://en.wikipedia.org/wiki/Pathogen pathogen], depending on the presence of a [http://en.wikipedia.org/wiki/Vaccine vaccine]. The type of proteins on the surface of the borrelia detected by the host's immune system determines the fate of the survival of this disease. One of the main outer surface proteins, OspA, plays a major role in the ability of the immune system to destroy these [http://en.wikipedia.org/wiki/Antigen antigens] (Ding, 2000).

OspA is the least variable protein located on the outer surface of the borrelia bacteria <ref name=Ding >PMID: 11183781</ref>.  This results in fewer [http://en.wikipedia.org/wiki/Mutations mutations] to occur allowing the same [http://en.wikipedia.org/wiki/Vaccine vaccine] to stay in use for a longer time.  Individuals who were bit by an infected tick and received the ospA vaccine were able to produce anti-opsA antibodies. These antibodies enter the tick through its blood meal into the gut where spirochetes are found and are destroyed by the antibody’s detection of opsA. Therefore, before the spirochete enters the host, it will be inactivated and Lyme Disease may be prevented (Marks, 2011).

Recent studies however have shown that neurological complications may appear in patients with this vaccination. This occurs because the down regulation of OspA from the vaccine would not be an abundant amount to activate the immune system for defense (Marks, 2011). This may then cause a wide range of adverse events such as headaches and acute neuroborreliosis(Marks, 2011).