Leishmania donovani Infection with Atypical Cutaneous Manifestations, Himachal Pradesh, India, 2014–2018

Abstract

L eishmaniasis is a complex disease with cutaneous, mucocutaneous, or visceral manifestations depending on the parasite species and host immunity. Despite continued elimination efforts, leishmaniasis continues to afflict known and newer endemic regions, where 0.5-0.9 million new cases of visceral leishmaniasis (VL) and 0.6-1.0 million new cases of cutaneous leishmaniasis (CL) occur every year (1). An increase in VL and CL cases from newer foci and atypical disease manifestation pose a challenge to leishmaniasis control programs (2-7). Unlike the known species-specific disease phenotype, parasite variants can cause atypical disease, so that Leishmania species generally associated with VL can cause CL and vice versa. In India, VL caused by L. donovani parasites in the northeastern region and CL caused by L. tropica in the western Thar Desert represent the prevalent forms of the disease (2). Himachal Pradesh is a more recently leishmaniasis-endemic state in northwest where VL and CL coexist; CL incidence is higher than VL incidence and most cases are attributable to L. donovani instead of L. tropica infection (8,9). Sharma et al. conducted limited molecular analysis of a few CL cases and reported preliminary findings (8). For an in-depth study on the involvement of L. donovani parasites in CL cases, we conducted a comprehensive molecular analysis of CL cases in Himachal Pradesh. The Study During 2014-2018, an increase in CL cases occurred in Himachal Pradesh; case reports came from different tehsils (i.e., townships) in Kinnaur, Shimla, and Kullu and the previously nonendemic districts of Mandi and Solan (Appendix Table 1, Figure 1, https://wwwnc.cdc.gov/EID/article/26/8/19-1761-App1.pdf). We confirmed 60 CL cases indigenous to the state with detailed patient information, demonstration of the presence of Leishman-Donovan bodies and CL-specific histopathologic changes in skin lesional specimens, and PCR detection of parasitic infection (Appendix). We conducted PCR and restriction fragmentlength polymorphism (RFLP) analysis of parasite species-specific internal transcribed spacer 1 (ITS1) sequences by using appropriate standard controls. We detected the expected ≈320-bp product with a HaeIII RFLP pattern specific to L. donovani complex in all patient biopsy specimens, indicating L. donovani, L. infantum, or both as the causative agent of infection (Appendix Figure 4) (10). BLAST analysis (https://blast.ncbi.nlm.nih. gov/Blast.cgi) of 44 ITS1 test sequences showed all the samples to be closest to L. donovani, having maximum identity to L. donovani isolates from Bhutan (GenBank accession nos. JQ730001-2) and possibly L. infantum. None of the CL cases were consistent with L. tropica infection, unlike in a previous report (8). To distinguish whether HP isolates were L. donovani, L. infantum, or both and to infer genetic and geographic relatedness between

Typical and atypical cutaneous leishmaniasis in Himachal Pradesh (India)

“…The countries like Kenya, Iraq, Sri Lanka, Yemen [ 14 , 15 , 16 , 17 ] have also reported L. donovani as causative parasite for CL. In our study we found three species of Leishmania , (with L. donovani as predominant), suggesting that in Himachal Pradesh there is existence of typical as well as atypical CL and the problem is quite wide spread in five districts (Shimla, Kinnaur, Kullu, Mandi and Solan) [ 26 ]. The L. donovani -infantum complex suspected by Sharma et al (2005) has been confirmed as L. donovani by the present study as well as by Thakur et al al (2020).…”

“…L. donovani is the established causative agent of VL in Bihar (India) but the strain is L. donovani zymodeme MON2 [ 22 , 23 , 27 ]. A recent study undertaken in Himachal Pradesh provided evidence that the L. donovani parasite isolated from the cases of CL is similar to L. donovani zymodeme MON37 but distinct from L. donovani zymodeme MON2 causing VL [ 26 ] and termed it as atypical CL. However, further studies on whole genome sequencing are required to confirm the preponderance of exclusively L. donovani zymodeme MON 37 strain from CL cases in Himachal Pradesh.…”

An Insight Into Systemic Immune Response in Leishmania donovani Mediated Atypical Cutaneous Leishmaniasis in the New Endemic State of Himachal Pradesh, India

“…major as the causative agent in India, Nepal, and Bangladesh (6)(7)(8). More recently, the disease is emerging as an unusual cutaneous manifestation caused by L. donovani in the newer endemic sites in Sri Lanka, Nepal, and India (9)(10)(11). The emergence of such atypical CL poses a newer challenge to the ongoing disease-control program and thus needs to be studied to understand the atypical disease etiology.…”

“…The emergence of such atypical CL poses a newer challenge to the ongoing disease-control program and thus needs to be studied to understand the atypical disease etiology. So far, there are few reports on genetic analysis of parasite isolates from atypical CL cases endemic in Sri Lanka, Nepal, and the states of Kerala and Himachal Pradesh (HP) in India, identified as L. donovani genetic variants distinct from the classical VL L. donovani isolates (9)(10)(11)(12).…”

“…Thus, the manifestation of L. donovani-mediated atypical CL (LdCL) needs to be urgently explored from an immunological perspective with the potential to explain the unusual disease phenotype. In the present work, we investigated systemic immune-cytokine expression profile and parasite-specific immunoglobulin G (IgG) and IgG subclasses expression patterns in LdCL patients from the endemic state of HP (11).…”