Contribution of molecular diagnosis to the management of cutaneous leishmaniasis in travellers

Imported cases of cutaneous leishmaniasis in Cuba, 2017: role of human movement

Background

Leishmaniasis is a vector-borne disease caused by several species from genus Leishmania. An increase in the number of cases related to human movement has been informed in the last years. Due to the increase of suspicious leishmaniasis cases arriving in Cuba during 2017, a general analysis is presented herein.

Methods

Clinical samples were collected from 5 patients suspicious of leishmaniasis, received from January to December 2017 at the Institute of Tropical Medicine Pedro Kourí, Cuba. Skin lesion samples were analyzed using different diagnostic assays: direct smear, histological examination, and molecular analysis for species identification. Epidemiological and demographic data were requested from each case and analyzed. Treatment and follow up of patient was also performed.

Results

Five cases were confirmed as Leishmania infection according to microscopic observation and molecular methods results. PCR-18S, PCR-N/RFLP and PCR-F/RFLP identified the following species: L. panamensis (2 cases), L. braziliensis (1 case), L.panamensis/L.guyanensis (1 case), L. mexicana complex (1 case). In treated patients, drugs were well tolerated, cure were documented and no relapse have been currently reported (3 years later).

Conclusions

Clinical characteristics, demographic data, and epidemiological features of infection for each case evidence the potential risk related with travel to endemic areas of leishmaniasis.

Keyworks

Cutaneous leishmaniasis, Epidemiology, Imported cases.

Non-Endemic Leishmaniases Reported Globally in Humans between 2000 and 2021—A Comprehensive Review

Leishmaniases are human and animal parasitic diseases transmitted by phlebotomine sand flies. Globalization is an important driver of the burden and in the current dynamics of these diseases. A systematic review of articles published between 2000 and 2021 was conducted using the PubMed search engine to identify the epidemiology and clinical management of imported human leishmaniases as a fundamental step to better manage individual cases and traveler and migrant health from a global perspective. A total of 275 articles were selected, representing 10,341 human imported cases. Identified drivers of changing patterns in epidemiology include conflict and war, as well as host factors, such as immunosuppression, natural and iatrogenic. Leishmania species diversity associated with different clinical presentations implies diagnostic and treatment strategies often complex to select and apply, especially in non-endemic settings. Thus, diagnostic and management algorithms for medical clinical decision support are proposed. Increased surveillance of non-endemic cases, whether in vulnerable populations such as refugees/migrants and immunocompromised individuals or travelers, could improve individual health and mitigate the public health risk of introducing Leishmania species into new areas.

Imported leishmaniasis cases in Cuba (2006-2016): what have we learned

BACKGROUND

Leishmaniasis is a neglected parasitic disease caused by Leishmania spp., which is not endemic in Cuba. However, several factors (such as human activities, climate changes, and tourism) have led to an increase in the number of leishmaniasis cases in all regions, raising diagnosis and surveillance issues. We aim to present the retrospective analysis of 16 human cases suspicious of leishmaniasis, which were received during 2006-2016 for diagnosis at the Department of Parasitology from the Institute of Tropical Medicine Pedro Kourí, Cuba.

METHODS

Clinical samples were collected and analyzed via different diagnostic assays, including direct smear, cultivation, histological analysis, and molecular analysis. Epidemiology and background of infection, clinical features, sex and age from each patient was recorded.

RESULTS

From the 16 suspicious cases, 5 cases were confirmed for Leishmania infection, based on at least two positive results using different methods: PCR-based diagnosis [18S rRNA (5/5), hsp20 gene (4/5), hsp70 gene (3/5)], histopathology evaluation (2/3), parasite cultivation (2/3), or direct smears (2/3). L. braziliensis and L. mexicana were identified as the involving species in two cases, according to hsp70 PCR-RFLP protocols. Demographic and clinical features, as well as treatment and follow up, are described for every case.

CONCLUSIONS

The combination of parasitological and molecular methods allowed proper diagnosis of imported leishmaniasis cases in Cuba. The utility and advantages of molecular diagnosis assays in non-endemic countries like Cuba are discussed.

A case report of isolated lymphadenopathy revealing localized leishmanial lymphadenopathy in an asthenic 25-year-old man

BACKGROUND

Visceral leishmaniasis (VL) is endemic in large areas of the tropics, the subtropics, and the Mediterranean basin. Besides classical VL presentation, exceptional cases of a limited form of VL have been reported. Here we describe the challenges of diagnosis and management of this intriguing entity.

CASE SUMMARY

A 25-year-old French Caucasian man presented with marked asthenia that had lasted 6 months and was strictly isolated except for a 2-cm left cervical lymphadenopathy. The rest of the clinical examination and extensive biological exploration were unremarkable.Histological examination of the cervical lymphadenopathy showed a reactive lymphoid hyperplasia with granulomatous organization associated with small particles in the cytoplasm of epithelioid histiocytes and giant cells evocative of Leishman-Donovan bodies. Polymerase chain reaction (PCR) performed on the tissue confirmed the presence of Leishmania donovani/infantum DNA. Direct examination of a bone marrow aspiration, together with blood and bone marrow PCR, did not find other evidence for VL. Serology for leishmaniasis was unreactive. Extensive work-up for other causes of granulomatous lymphadenitis was negative. A diagnosis of localized leishmanial lymphadenopathy was made. Intravenous liposomal amphotericin B (20 mg/kg in five infusions) was initiated and well tolerated. Asthenia disappeared promptly and the patient fully recovered.

CONCLUSION

Localized lymph node enlargement because of leishmanial infection should be included in the differential diagnosis of lymphadenopathy of unknown origin in patients who stayed or visited, even a long time ago and for a short period, endemic areas for leishmaniasis such as the Mediterranean basin. Fine-needle aspiration cytology and/or PCR for Leishmania sp of the lymphadenopathy might contribute to the diagnosis. A low-dose liposomal amphotericin B treatment might be effective, and deserves further study.

Species typing in dermal leishmaniasis

Leishmania is an infectious protozoan parasite related to African and American trypanosomes. All Leishmania species that are pathogenic to humans can cause dermal disease. When one is confronted with cutaneous leishmaniasis, identification of the causative species is relevant in both clinical and epidemiological studies, case management, and control. This review gives an overview of the currently existing and most used assays for species discrimination, with a critical appraisal of the limitations of each technique. The consensus taxonomy for the genus is outlined, including debatable species designations. Finally, a numerical literature analysis is presented that describes which methods are most used in various countries and regions in the world, and for which purposes.