# Predictive Model of Lyme Disease Epidemic Process Using Machine Learning Approach
## 2 Background
### Lyme Disease Epidemiology
A polymorphism characterizes the disease in the clinical course [13]. The most common and early symptom of Lyme disease is erythema migrants. It occurs around the tick bite site, is characterized by a red or bluish-red macular skin lesion, and increases over several days or weeks. _B. afzedii_ causes erythema migrants with central clearing in 60% of cases. _B. burgdorferi sl_ and _B. garini_ usually result in homogeneous erythema migrants. Without treatment, erythema migrants may persist for weeks or sometimes months [14]. Skin manifestations also include Borreliosis lymphocyte, which is characterized by a painless bluish-red nodule, is rare and occurs predominantly in children, and acroder-matitis, chronic atrophic, which presents as a chronic, slowly progressive red or bluish skin lesion that may become atrophic over time [11]. Lesions of the nervous system are manifested by radiculoneuritis and lymphocytic pleocytosis of the cerebrospinal fluid in adults and facial paralysis in children. Sensory disturbances and paresis can manifest Lyme radiculitis. In Lyme disease, joint lesions in oligo- or mono-arthritis can also be observed three to six months after infection, often involving the knee joint. Left untreated, symptoms include intermittent or persistent joint swelling and pain over several months to several years [11]. A severe complication is Lyme cardiis. Acute cardiac injury, characterized by varying degrees of atrioventricular conduction defects, may occur during early disseminated infection. Rarely does acute myopericarditis or cardiomyopathy occur. Lyme cardiitis usually resolves independently, but if left untreated, it can be fatal. Antibacterial drugs form the basis of treatment. With late-started or inadequate therapy, the disease progresses, acquires a chronic course, manifested by damage to the joints, skin, heart, and nervous system, and often leads to disability. Lyme disease is the most common vector-borne disease in the Northern Hemisphere. Globally, Lyme disease has been reported in more than 80 countries, and there has been an increase in the number of cases of Lyme disease and an expansion of the territories in which it is registered [15; 16]. Comparison of the incidence of Lyme disease in different countries is not always correct due to different systems of epidemiological surveillance. In some countries, Lyme disease is subject to mandatory reporting. The incidence is estimated based on epidemiological studies or incidence estimates in neighboring comparator countries. In addition, not only do reporting procedures vary across countries, but also differences in case definitions and diagnostic procedures [14; 17; 18]. Lyme borreliosis is found throughout Europe and Asia. The highest reported incidence is in Central Europe and Scandinavia, especially in Germany, Austria, Slovenia, the Baltic Sea coast of Sweden, and some Estonian and Finnish islands, where reported incidence rates exceed 100 cases per 100,000 persons [15; 19]. The paper [17] states that the reported incidence of Lyme disease in Europe is about 22.6 cases per 100,000 inhabitants per year, with a wide range depending on the analyzed geographical area. In the United States, the high incidence is noted in the Northeastern and Mid-Atlantic states and the states of the upper Midwest, where 14 states account for more than 90% of Lyme disease cases. The incidence ranges from 25 to 100 per 100,000 population [20]. The registered incidence is lower than the actual one. The paper [21] provides examples of the estimated incidence for 2018, based on the results of modeling: incidence-USA 473,000/year, Germany 471,000/year, France 434,000/year and UK 132,000/year; prevalence--2.4 million in the US, 2.4 million in Germany, 2.2 million in France and 667,000 in the UK; the total number of infections is 10.1 million in the US, 10.0 million in Germany, 9.3 million in France and 2.8 million in the UK.