A seroepidemiological investigation of Lyme disease in Qiongzhong County, Hainan Province in 2019-2020

Abstract

Background: The incidence and prevalence of Lyme disease are expanding and rising, respectively, which constitutes a worldwide public health problem. The present study aimed to investigate the prevalence of Lyme disease (LD) in Qiongzhong County, Hainan, and to determine the LD infection level in the local population, so as to provide evidence for further local LD surveillance as well as effective prevention and treatment measures.

Methods: A total of 252 serum samples were collected from cases with suspected LD in Qiongzhong County, including 159 and 93 cases with joint and neurological symptoms, respectively. The serum samples were preliminarily screened for LD antibodies by indirect immunofluorescent assay (IFA). Western Blot (WB) was used to confirm the diagnosis of IFA positive serum samples.

Results: Of the 252 serum samples, 39 tested positive by indirect immunofluorescence, translating to a positive rate of 15.48%. Of these 39 positive serum samples, western blot testing confirmed 28 to be positive for LD antibodies, representing a positive rate of 11.11%. LD spirochete infection was found in individuals of different ages, with the positive rate being highest among those aged ≤20 and ≥81 years old (22.22% in both groups). The positive rate of LD antibody detection in men was 16.89%, which was higher than the rate of 13.46% seen in women; however, the difference was not statistically significant. The positive rate of LD antibody detection using the 2-step testing method was 10.06% in patients with joint symptoms, which was slightly lower than the positive rate among individuals with neurological symptoms.

Conclusions: Our results confirm the presence of LD among the population of Qiongzhong County, Hainan. LD surveillance should be carried out to actively prevent and treat LD in the locality. Local doctors should also consider the possibility of LD when diagnosing and treating patients with arthritis and neurological diseases.

Keywords: Lyme disease (LD); joint; neurological; seroepidemiological investigation.