Lyme disease (LD), or Lyme borreliosis, is caused by a bacterial infection from
Borrelia burgdorferi sensu lato (
B. burgdorferi s.l.). This vector-borne zoonotic disease is primarily spread by ticks from the genus
Ixodes. The typical clinical manifestation of early infection is erythema migrans (EM) rash at the site, which occurs in >80% of patients in both Europe and the United States
[1]. LD symptoms may range from asymptomatic to severe and develop into encephalitis and arthritis without prompt treatment. Other non-specific symptoms include fever, malaise, and myalgia; hence they are often misdiagnosed or left untreated. Currently, LD is prevalent in the United States and Europe
[1], but diagnosing LD has become challenging as clinical manifestations vary between
B. burgdorferi genospecies and disease progression differs between patients
[2][3][4]. For example, rheumatological manifestations of LD are common in North America, while neurological manifestations are customary in Europe. In addition, acrodermatitis chronica atrophicans and lymphocytomas, usually caused by
Borrelia afzelii or
Borrelia garinii, are common in Europe and Asia but extremely rare in the United States
[5][6]. In the United States, the new species
Borrelia mayonii was recognized in the Upper Midwest region
[7].
The global impact of LD has recently expanded to previously undetected regions and countries due to the booming international tourism in endemic nations, where the disease is under-reported by local healthcare practitioners
[8]. For instance, LD cases have been documented among tourists in Brazil, Canada, Australia, and Japan
[9][10][11][12][13]. The LD reservoir and vector hosts have migrated from their native habitats following the effect of climate change in the north, thus allowing
B. burgdorferi to expand its territory northward by 250–500 km in the next 30 years
[14]. Several studies have reported increasing LD incidences in various parts of Canada, Europe, and Asia, particularly China
[14][15][16][17][18].
Malaysia has a tropical climate and abundant wildlife in local forests, making it an ideal breeding ground for ticks.
Ixodes granulatus, a vector for the Borrelia pathogen, has been recorded in numerous areas throughout Peninsular Malaysia, but local LD occurrence is not well-reported
[19][20][21][22][23][24]. In addition,
Borrelia yangtzensis was isolated from
I. granulatus ticks discovered on rodents in Selangor’s recreational forests (18.1%) and Sarawak’s oil palm plantations (72.2%)
[21][25]. Clinical case reports from Japan and China have associated these new
Borrelia genospecies with LD
[26][27]. Moreover, unpublished data from the Acarology Unit, IMR, have reported that 47.4% of
Borrelia spp. was isolated from ticks collected from four coastal locations in Selangor, and 73.3% of ticks from recreational forests in Malaysia carried Rickettsia and Borrelia. Therefore, the risk of Borrelia infection in the Malaysian population remains high despite the small number of confirmed LD infections, owing to underdiagnosis or a lack of sensitive detection tools.
Several seroprevalence studies in Malaysia reported that 153 serum samples from patients exhibiting various infectious disease symptoms showed that 16.3% of IgM and 3.3% of IgG were reactive to the complete antigen of
B. afzelii. Meanwhile, 8.1% of serum samples among the aborigines in Peninsular Malaysia were reactive to
B. burgdorferi s.l. genospecies
[28]. These findings indicate the occurrence of co-infections and mixed infections in LD patients, such as leptospirosis, tick typhus, and melioidosis.
The LD diagnostic test comprises a two-tier serology test recommended by the Food and Drug Administration (FDA). Alternative detection assays with various sensitivities are employed in private laboratories as a confirmation tool for this disease. Currently, the direct detection test for LD is not easily accessible to the public. Therefore, the existing direct detection methods of LD and the potential of aptamer technology integrated with a biosensor for Borrelia detection in various samples to enhance the sensitivity of detection tools is discussed.