Trends in Parasitology
OpinionLeishmania donovani causing cutaneous leishmaniasis in Sri Lanka: a wolf in sheep's clothing?
Section snippets
Leishmaniasis: a global perspective
The leishmaniases are a group of vector-borne parasitic diseases that are counted among the least studied and most neglected of tropical diseases 1, 2, and come under Category 1: emerging or uncontrolled diseases, according to World Health Organization/Tropical Disease Research (WHO/TDR) classification of infectious diseases (see http://www.who.int/tdrold/publications/publications/swg_leish.htm). The astounding degree of neglect of this disease for so many years is due largely to the poor
Leishmaniasis in Sri Lanka: then and now
Leishmaniasis used to be considered as an exotic disease in Sri Lanka, linked with foreign travel and seen particularly among returnees from the Middle East or African region [11]. Local transmission was considered nonexistent, although the disease was prevalent in parts of other South Asian countries such as India, Bangladesh and Nepal, where it remains a major public health problem, with case burden as high as 21 cases per 10,000 population [10]. In Sri Lanka, the first autochthonous case of
Clinical management
The classical presentations of Sri Lankan CL are non-tender, non-itchy papules, scaling nodules or ulcers (Figure 3) affecting exposed areas of body, mainly on the extensor surfaces of limbs and the face 14, 15, 16. The lag period between the appearance of symptoms and the time of presentation of the patient at a health care centre (that enable diagnosis and treatment) can vary from a few months to a few years [14]. This latency is likely to be due to the lack of knowledge and awareness among
Causative agent
The aetiological agent of CL was isolated and propagated in the Department of Parasitology, UCFM 20, 21, 22 and confirmed as L. donovani, MON-37 both by isoenzyme characterization [23] and molecular typing methods [24]. This zymodeme has been previously reported to cause human VL in countries such as India (G. Moreno, PhD thesis, University of Montpellier, 1989), Kenya [25], Israel (L.F. Schnur et al. Abstract)1
Vector studies in Sri Lanka
Information regarding the vector of leishmaniasis in Sri Lanka dates back to 1938 [31], although the quantity of information published since then is rather limited. The presence of Phlebotomus argentipes, the established vector of the visceral form of leishmaniasis caused by L. donovani in the Indian subcontinent, has been well documented in Sri Lanka 32, 33, 34, 35. The studies carried out so far support the anthropophagic nature of the local vector 34, 35 and the environmental conditions that
Prevention and control
There are no organized efforts yet in place for the control of this disease in Sri Lanka, although the case numbers have increased since the year 2001 and the cases have been reported from almost all districts of the country 14, 15, 16 (Table 1 and Figure 2). Because notification of leishmaniasis cases to the central disease monitoring unit of the country was not a mandatory requirement within the national health sector until September 2008, the true disease burden is not known. Furthermore,
The future of leishmaniasis in Sri Lanka
The facts accrued point towards the possibility of the cutaneous form of the disease spreading further in Sri Lanka, and, more dangerously, of it mutating into a more-virulent form, with serious consequences. A recent report of a fatal case of VL [19], and hospital records that indicate two other autochthonous visceral cases and a patient with extensive mucosal tissue destruction during the period 2007–2008 could be considered as further proof for the potential of the prevalent species to
Conflicts of interest
The authors declare no conflicts of interest.
Acknowledgements
I thank Yamuna Siriwardane, Randeewari Gunaratna, Charani Abayaweera and Chandima Weligamage, Faculty of Medicine, Colombo, for their invaluable help in preparation of the figures and table. Helpful comments and suggestions on the manuscript made by Professor Jean Pierre Dedet, National Reference Centre for Leishmania, Montpellier, France is also gratefully acknowledged. Financial support for local studies on leishmaniasis was provided by the National Science Foundation of Sri Lanka.
References (36)
Leishmaniasis and poverty
Trends Parasitol.
(2006)Leishmaniasis: current situation and new perspectives
Comp. Immunol. Microbiol. Infect. Dis.
(2004)Cutaneous leishmaniasis in the Southern Sri Lanka
Trans. R. Soc. Trop. Med. Hyg.
(2007)Sri Lankan cutaneous leishmaniasis is caused by Leishmania donovani zymodeme MON-37
Trans. R. Soc. Trop. Med. Hyg.
(2003)Leishmania donovani causing visceral or cutaneous leishmaniasis in Europe: Cyprus evidence is an alarm call
Lancet Infect. Dis.
(2008)Identification of Leishmania donovani as a cause of cutaneous leishmaniasis in Sudan
Trans. R. Soc. Trop. Med. Hyg.
(2008)Leishmania species, drug unresponsiveness and visceral leishmaniasis in Bihar
India. Trans. R. Soc. Trop. Med. Hyg.
(2001)Visceral leishmaniasis: what are the needs for diagnosis, treatment and control?
Nat Rev. Microbiol.
(2007)Leishmaniasis: new approaches to disease control
Br. Med. J.
(2003)Leishmania/HIV co-infections in the second decade
Indian J. Med. Res.
(2006)
Spread of vector-borne diseases and neglect of leishmaniasis
Europe. Emerg. Infect. Dis.
Evolution, classification and geographical distribution
Taxonomy of Leishmania. Use of isoenzymes. Suggestions for a new classification
Ann. Parasitol. Hum. Comp.
Leishmaniasis
Can visceral leishmaniasis be eliminated from Asia?
J Vector Borne Dis.
Cutaneous leishmaniasis in Sri Lanka: an imported disease linked to the Middle East and African employment boom
Trop. Geogr. Med.
Locally acquired cutaneous leishmaniasis in Sri Lanka
J. Trop. Med. Hyg.
Cutaneous leishmaniasis: an emerging health risk in Sri Lanka
Ceylon Med. J.
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An intraspecies Leishmania donovani hybrid from the Indian subcontinent is associated with an atypical phenotype of cutaneous disease
2022, iScienceCitation Excerpt :The atypical disease phenotype trend associated with novel Leishmania variants is reported in known and newer endemic regions of the world (Thakur et al., 2018, 2020; Siriwardana et al., 2019). In Sri Lanka, the atypical CL and the rare coexisting VL form, are caused by variants of L. donovani Mon-37 based on genetic characterization of L. donovani clinical isolates (Siriwardana et al., 2007; Karunaweera, 2009; Ranasinghe et al., 2012; Zhang et al., 2014; Kariyawasam et al., 2017; Lypaczewski et al., 2018; Samarasinghe et al., 2018). Whole genome based studies of the CL L. donovani isolates in comparison to VL isolates revealed discrete chromosomal and gene copy-number variations and single nucleotide polymorphisms (SNPs) as underlying genetic alterations giving rise to these atypical L. donovani variants (Zhang et al., 2014; Lypaczewski et al., 2018; Samarasinghe et al., 2018).
Cutaneous Leishmaniasis Due to Leishmania aethiopica
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