People have developed a red bulls-eye rash around a tick bite followed by weeks of fatigue and a fever.Lyme disease effects are comparable among males and females. A wide range of age groups is affected, though the number of cases is highest among 10- to 19-year-olds. For unknown reasons, Lyme disease is seven times more common among Asians. South America
In South America, tick-borne disease recognition and occurrence is rising. In Brazil, a Lyme-like disease known as Baggio–Yoshinari syndrome was identified, caused by microorganisms that do not belong to the B. burgdorferi sensu lato complex and transmitted by ticks of the Amblyomma and Rhipicephalus genera. The first reported case of BYS in Brazil was made in 1992 in Cotia, São Paulo. History
The evolutionary history of Borrelia burgdorferi genetics has been the subject of recent studies. One study has found that prior to the reforestation that accompanied post-colonial farm abandonment in New England and the wholesale migration into the mid-west that occurred during the early 19th century, Lyme disease was present for thousands of years in America and had spread along with its tick hosts from the Northeast to the Midwest.John Josselyn, who visited New England in 1638 and again from 1663 to 1670, wrote "there be infinite numbers of ticks hanging upon the bushes in summertime that will cleave to mans garments and creep into his breeches, eating themselves in a short time into the very flesh of a man. I have seen the stockings of those that have gone through the woods covered with them.
Laboratory testing
Tests for antibodies in the blood by ELISA and Western blot is the most widely used method for Lyme diagnosis. A two-tiered protocol is recommended by the Centers for Disease Control and Prevention (CDC): the sensitive ELISA test is performed first, and if it is positive or equivocal, then the more specific Western blot is run. The immune system takes some time to produce antibodies in quantity. After Lyme infection onset, antibodies of types IgM and IgG usually can first be detected respectively at 2–4 weeks and 4–6 weeks, and peak at 6–8 weeks. When an EM rash first appears, detectable antibodies may not be present. Therefore, it is recommended that testing not be performed and diagnosis be based on the presence of the EM rash. Up to 30 days after suspected Lyme infection onset, infection can be confirmed by detection of IgM or IgG antibodies; after that, it is recommended that only IgG antibodies be considered. A positive IgM and negative IgG test result after the first month of infection is generally indicative of a false-positive result. The number of IgM antibodies usually collapses 4–6 months after infection, while IgG antibodies can remain detectable for years.Other tests may be used in neuroborreliosis cases. In Europe, neuroborreliosis is usually caused by Borrelia garinii and almost always involves lymphocytic pleocytosis, i.e. the densities of lymphocytes (infection-fighting cells) and protein in the cerebrospinal fluid (CSF) typically rise to characteristically abnormal levels, while glucose level remains normal.