Evidence for Seroprevalence in Human Localized Cutaneous Leishmaniasis Caused byLeishmania donovaniin Sri Lanka

Abstract

Visceral leishmaniasis (VL) is considered as a major health threat in the Indian subcontinent. Leishmania donovani, a usually visceralizing species, causes cutaneous leishmaniasis (CL) in Sri Lanka. However, visceralizing potential of the local L. donovani is not yet fully understood. This project studied the seroprevalence of local CL by using an in-house ELISA. An IgG-based ELISA using crude Leishmania antigen (Ag) was developed and validated. A total of 50 laboratory confirmed cases of locally acquired CL were examined using the newly developed ELISA. According to the optimized ELISA, seroprevalence of anti-Leishmania IgG antibodies in the study group was 34.0% (n = 17/50). Majority of seropositive individuals were males (n = 13/17), representing 76%. Nearly half of the seropositive individuals were young adults (20–40 years, n = 9/17, 53%). Higher proportions of single lesions, large lesions, and nodular lesions were associated with a seroconversion. A proportion of local L. donovani infections leading to CL have the ability to raise an antibody response in the host. This may indicate early systemic involvement as one possibility. Study of a large number of patients with adequate follow-up would be useful.

First Serological Study Revealing High Humoral Response and Evidence for Antigenic Heterogeneity in Leishmania donovani Induced CL in Sri Lanka

“…ELISA was carried out using a previously optimized protocol [ 20 , 26 , 27 ]. A ninety-six- (96-) well ELISA plate (Sterilin or Greiner) was coated with 100 μ l (containing at least 1 μ g protein) of crude protein extract and incubated overnight at 4°C.…”

“…Serological assays are increasingly used in detecting asymptomatic and clinical infections with leishmaniasis [ 16 – 18 ]. However, previous local studies have demonstrated regional variations in epidemiology and poor response of a limited number of local leishmanial infections to standard rK39 assay, indicating the possibility of antigenic variation and the need for an in-house tool for serological assessment of local infections [ 19 , 20 ]. Furthermore, the availability of such a tool is important for the detection of microscopy negative cases.…”

Leishmaniasis in Sri Lanka: The need for effective targeting of island-specific issues through strategic implementation of global management plans for disease detection and control

“…52 Moreover, the date when VL emerged may be less recent than previously thought due to its asymptomatic nature. 53 Historically, most epidemiological studies and case reports have relied on diagnostic methods that enable detection of active infections only, yet two recent studies reported zero prevalence of apparent asymptomatic VL. 31,53 This highlights that at present it is possible to acquire accurate and detailed information on asymptomatic carriers of leishmaniasis in some locations but that this capacity is still generally lacking throughout Sri Lanka.…”

Literature review and a preliminary study on leishmaniasis to inform community awareness campaigns in Sri Lanka

“…9 In 2008, leishmaniasis was made a notifiable disease in Sri Lanka. 10 Establishment of more dangerous forms (VL, MCL) 11 , the presence of locally acquired mucosal leishmaniasis 12 and a humoral response associated with CL 13 have been reported recently. Furthermore, an array of problems are presented with the standard treatment, sodium stibogluconate.…”