由tick传播引起的莱姆病的发病率Borrelia Burgdorferi细菌现在已经达到了美国的流行比例。估计每年有40万例病例，由于气候变化和tick矢量的栖息地扩大，数量增加。早期症状包括皮疹，发烧和关节疼痛。通过及时诊断和抗生素治疗，大多数患者康复。

但是，治疗至少失败10-20％的患者，，，，who develop persistent symptoms including chronic pain, cognitive dysfunction, and debilitating fatigue. This is known as post-treatment Lyme disease (PTLD). These symptoms are often severe, frequently leading to profound personal, educational, and monetary losses.

Using six sets of assumptions we estimate that by 2020 there will be between 81,713 to 1,944,189 individuals with PTLD in the US.

Until now, estimates of the number of people in the US living with PTLD were not available. This manuscript provides the framework for a mathematical modeling technique that can be used to estimate the prevalence of PTLD in the US. We apply our technique to three incidence scenarios and two failure rates to estimate the cumulative prevalence of PTLD in the years 2016 and 2020.

Using six sets of assumptions we estimate that by 2020 there will be between 81,713 to 1,944,189 individuals with PTLD in the US. The 95% confidence intervals suggest that incident rates could even reach as high as 2.3 million cases. All results indicate the prevalence of PTLD is rising over time. The approach we present provides a framework for updating prevalence estimates in future years and when more precise input data become available.

Our PTLD estimates are calculated using mathematical modeling and simulation, counting survivors of cases originating from 1980 until two index dates, 2016 and 2020. This framework incorporates multiple data types from several sources. We first propose three possible trajectories for the annual incidence of Lyme disease, and model the growth of the epidemic during the years the disease has been documented in the US. These trajectories were based on previously published information about Lyme disease incidence rates, originating from two sources.

一位来源是基于公共卫生监测，当时医疗临床医生向地方和州卫生当局报告莱姆病病例。该方法估计到2005年每年34,449例。第二个来源是由美国CDC流行病学家获得的，并基于对莱姆病测试实验室结果或健康保险索赔的研究。这些来源计算了每年有300,000多个事件案件by 2005.

这两个数字之间的差异表明，卫生当局报告的大量报告与基于社区的报告一致，这些报告表明大量病例，并体现了当前莱姆病知识库中的短缺。实际发病率可能更高。

根据这两个年度发病率的数字，我们对莱姆病流行的三种情况进行了建模：从1980年的0例线性生长到2005年的34,449，然后在此后的34,449处保持稳定（图1中的情况A）；从1980年的0个病例到2005年的329,000例线性增长，然后保持稳定为329,000（场景B）；或从1980年的0例线性增长到2005年的329,000例，并继续线性增长（方案C）。

计算累积PTLD病例的第二个重要输入度量是治疗失败率，在某些研究中，该病例的估计最高为40％。我们选择将其定义为10％或20％。这两个故障率加上三个发生率的情况，导致了六个数学模拟。

All simulations accounted for age and gender distributions of Lyme disease diagnosis, as well as life expectancy. For example, if a five-year-old girl diagnosed in 1983 with Lyme disease was among the 10-20% with PTLD, she might still be alive and counted in 2020. However, a 55-year old man diagnosed at the same time might not be.

我们的患病率估计表明，由于莱姆病的影响，可能有数百万的人因慢性病和残疾而苦苦挣扎。此外，他们和他们的家人在经济上受到影响，因为他们通常无法工作或完成教育，并且被迫自己承担医疗费用。

据估计，仅治疗急性莱姆病的成本over $1 billion per year在美国。治疗这种慢性病的成本尚未确定，但预计会很高。我们的研究是对PTLD负担的更多了解的第一步，并加强了大大扩展研究的需求，从而可以更好地治疗这些患者。