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Biological Warfare Hazard/Migration Induced Public Health Risk – Leishmaniasis (flesh-eating bacteria)

2016/12/12

LEISHMANIASIS: INTER-LABORATORY COMPARATIVE STUDY OF GENOTYPING PERFORMANCE
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Published Date: 2016-12-10 13:33:23
Subject: PRO/AH/EDR> Leishmaniasis: inter-lab comparative study of genotyping performance
Archive Number: 20161210.4689632

Date: Wednesday, 8 December 2016
Source: Eurosurveillance, Volume 21, Issue 49 [edited]

Comparison of _Leishmania_ typing results obtained from 16 European clinical laboratories in 2014
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Van der Auwera G, Bart A, Chicharro C, Cortes S, et al.

Summary
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Leishmaniasis is endemic in southern Europe, and in other European countries cases are diagnosed in travellers who have visited affected areas both within the continent and beyond. Prompt and accurate diagnosis poses a challenge in clinical practice in Europe. Different methods exist for identification of the infecting _Leishmania_ species. Sixteen clinical laboratories in 10 European countries, plus Israel and Turkey, conducted a study to assess their genotyping performance. DNA from 21 promastigote cultures of 13 species was analysed blindly by the routinely used typing method. Five different molecular targets were used, which were analysed with PCR-based methods. Different levels of identification were achieved, and either the _Leishmania_ subgenus, species complex, or actual species were reported. The overall error rate of strains placed in the wrong complex or species was 8.5 percent. Various reasons for incorrect typing were identified. The study shows there is considerable room for improvement and standardisation of _Leishmania_ typing. The use of well validated standard operating procedures is recommended, covering testing, interpretation, and reporting guidelines. Application of the internal transcribed spacer 1 of the rDNA array should be restricted to Old World samples, while the heat-shock protein 70 gene and the mini-exon can be applied globally.

Conclusions
———–
There is considerable room for improvement of current _Leishmania_ typing strategies, and inter-laboratory comparisons such as the one we conducted can contribute to enhance typing quality. Whichever the clinical need for determining the subgenus, complex, or species, and whichever the technology used in a particular setting, typing should be based on a well-defined and validated SOP designed by an expert in _Leishmania_ taxonomy. This SOP should cover not only testing, but also analysis and interpretation procedures, and a clear description of how species should be named and reported, taking into account the limitations of each marker and technique, and the problem of resolving closely related species or occasional inter-species hybrids. Validation should be performed on a sufficient amount of reference isolates from various geographic origins to cover each species’ variability. When using sequencing, sequence errors should be avoided, and a well-validated sequence reference set is recommended over BLAST analysis using GenBank, which lacks quality control. In cases where treatment is species- or complex-dependent, clinicians should be made aware of the limitations of the technology used whenever results are reported, especially when closely related species are involved. The use of real-time PCR assays developed for specific complexes or species could speed up typing and facilitate interpretation of results, but currently no globally applicable methods are available. As previously recommended and also apparent from this analysis, hsp70 and the mini-exon currently offer the best _Leishmania_ typing tools world-wide, and the use of ITS1 should be restricted to the Old World. Setting up similar evaluations outside Europe, in institutes in endemic as well as non-endemic countries, would shed additional light on the quality of _Leishmania_ typing across the globe.

Authors: G Van der Auwera [1], A Bart [2], C Chicharro [3], S Cortes [4, L Davidsson [5], T Di Muccio [6], J Dujardin [1, 7], I Felger [8, 9], MG Paglia [10], F Grimm [11], G Harms [12], CL Jaffe [13], M Manser [14], C Ravel [15], F Robert-Gangneux [16], J Roelfsema [17], S Töz [18], JJ Verweij [19], PL Chiodini [20, 21]

Author affiliations:
1. Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
2. Academic Medical Center, Amsterdam, The Netherlands
3. Instituto de Salud Carlos III, Madrid, Spain
4. Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, UNL, Lisbon, Portugal
5. The Public Health Agency of Sweden, Stockholm, Sweden
6. Istituto Superiore di Sanità, Rome, Italy
7. Biomedical Sciences, Antwerp University, Antwerp, Belgium
8. Swiss Tropical and Public Health Institute, Basel, Switzerland
9. University of Basel, Basel, Switzerland
10. National Institute for Infectious Diseases (INMI) Lazzaro Spallanzani, Rome, Italy
11. Institute of Parasitology, University of Zürich, Zürich, Switzerland
12. Institute of Tropical Medicine and International Health, Charité-Universitätsmedizin Berlin, Berlin, Germany
13. Hebrew University, Hadassah Medical Centre, Jerusalem, Israel
14. United Kingdom National External Quality Assessment Service, London, United Kingdom
15. University of Montpellier, Montpellier, France
16. Centre Hospitalier Universitaire de Rennes, Rennes, France
17. National Institute for Public Health and the Environment, RIVM, Bilthoven, The Netherlands
18. Ege University, Faculty of Medicine, Department of Parasitology, Izmir, Turkey
19. St. Elisabeth Hospital, Tilburg, The Netherlands
20. Hospital for Tropical Diseases, London, United Kingdom
21. London School of Hygiene and Tropical Medicine, London, United Kingdom

Correspondence: Gert Van der Auwera <gvdauwera@itg.be>

Communicated by:
ProMED-mail from HealthMap Alerts
<promed@promedmail.org>

[Genotyping of _Leishmania_ parasites is important in understanding transmission and reservoir hosts. The important recommendation of this work is that techniques and reagents have to be standardized. We could add that expertise follows volume and perhaps centers only performing a few typings should submit samples to a center with a larger volume and thus more expertise. The full paper including methodologies and list of references is available from Eurosurveillance, which is open source. – Mod.EP]

See Also

Leishmaniasis – USA: new guidelines, IDSA 20161124.4651450
Leishmaniasis, visceral – Brazil: (MG) children 20161029.4593491
Leishmaniasis, visceral – Nepal: (MO) 20161002.4531103
Leishmaniasis, visceral – South Sudan: (UN) 20160910.4479134
Leishmaniasis, cutaneous – Syria (03): (HL) 20160821.4430681
Leishmaniasis, cutaneous – Pakistan (05): (TA) 20160717.4350532
Leishmaniasis, cutaneous – Palestinian Auth: (WE) 20160528.4250881
Leishmaniasis, cutaneous – Pakistan (04): (NW) EpiCore responses 20160521.4236192
Leishmaniasis, cutaneous – Colombia: (NS) alert 20160429.4192208
Leishmaniasis, cutaneous – Iraq: (DA) Yazidi refugees 20160415.4161067
Leishmaniasis, cutaneous – Libya: (TR) 20160414.4160311
Leishmaniasis – Colombia: (TO) RFI 20160403.4136205
Leishmaniasis, canine – France 20160220.4033101
Leishmaniasis – Uruguay: (SA) canine, alert 20160122.3952222

2015
—-
Leishmaniasis, cutaneous – Israel (02): (Jerusalem) wildlife reservoir 20151223.3887577
Leishmaniasis, cutaneous – Sri Lanka: RFI 20151219.3873987
Leishmaniasis, visceral – Uganda: (Karamoja) 20151218.3871038
Leishmaniasis – Syria (03) 20151210.3853674
Leishmaniasis, visceral – Brazil (02): (SP) 20151205.3841901
Leishmaniasis, visceral – Sudan: (ND) IDP camp 20151128.3824888
Leishmaniasis, visceral – South Sudan (02): corr 20151126.3820915
Leishmaniasis, visceral – East Africa 20151123.3812985
Leishmaniasis, cutaneous – Ghana: (TV) new subspecies 20151107.3773819
Leishmaniasis – India: miltefosine resistance 20151025.3742346
Leishmaniasis, visceral – Brazil: (MS) 20151024.3740484
Leishmaniasis, cutaneous – Libya: (TR) 20151012.3710620
Leishmaniasis – Argentina (05): (ER) canine 20151008.3701288
Leishmaniasis – Honduras: (CR) 20151003.3688613
Leishmaniasis – Colombia: (HU) canine 20150918.3653741
Leishmaniasis – Argentina (03): (CN) 20150905.3626183
Leishmaniasis – Bolivia (TR) 20150823.3596714
Leishmaniasis, visceral – Nepal: The Terai 20150714.3510795
Leishmaniasis, cutaneous – French Guiana 20150530.3396947
Leishmaniasis – Argentina: (ER) companion animals 20150527.3388356
Leishmaniasis, cutaneous – Israel 20150516.3365512
Leishmaniasis, visceral – Thailand: L. martiniquensis 20150417.3304444
Leishmaniasis – Syria: (RA) ISIS-held area 20150403.3275924
Leishmaniasis – Uruguay: (SA) canine, OIE 20150305.3208769
………………………………………….sb/ep/je/ml

Source:
A ProMED-mail post
ProMED-mail is a program of the International Society for Infectious Diseases


Note

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Biological Warfare Agents

Some of these diseases are Category B Bioterrorism agents, such as brucellosis, HIV/AIDS, leishmaniasis and TB, they have prolonged and variable incubation periods. Clinical manifestations of these diseases may appear long after the return from travel to, or residing in, an infected area, so that the link with the travel destination and location where the infection was acquired may not be readily apparent.

The Centers for Disease Control calculates that there are somewhere between 1 million and 2 million new cases a year throughout the world. “In South Sudan, visceral leishmaniasis killed 10 times as many people as died in the Ebola outbreak of 2014-15—but it was silent, no one has covered this,” says Hotez. (Add leishmaniasis to the list of Syria’s woes.)

Disease information from World Health Organization, Leishmaniasis (Fact sheet N°375)

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Category B bioterrorism pathogens are the second highest priority organisms/biological agents. They are moderately easy to disseminate, result in moderate morbidity rates and low mortality rates and require specific enhancements for diagnostic capacity and enhanced disease surveillance.

Category C bioterrorism agents are the third highest priority organisms/biological agents, and are emerging pathogens that might be engineered for mass dissemination because of their availability, ease of production and dissemination, high mortality rate, or the ability to cause a major health impact.

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