Welcome to the Jungle! Dr Aileen Oon, 2017 Microbiology Registrar

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James Hancock
5 years ago
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1 Welcome to the Jungle! Dr Aileen Oon, 2017 Microbiology Registrar

2 AA 55M presented with sores on left olecranon and umbilical area Umbilical sores present for 3 weeks Left olecranon lesions for 1 week Now erythematous tracking up medial arm No recorded fevers but reported night sweats Also had lower limb lesions which had healed spontaneously

3 PMHx Renal calculi Laparotomy and appendectomy Nil regular medications

4 SHx Non- smoker Occasional EtOH Ex-fire brigade Travelled to Costa Rica for 3 weeks to visit son Spent time in the jungle Sustained cut to leg and wound took long time to heal

5 Costa Rica

6 O/E Lesion on left olecranon with surrounding erythema and tracking erythema medial arm 2 periumbilical lesions with crusting Given IV cefazolin and discharged on cephalexin

8 An astute ID physician gives phone advice to ED Biopsy of wound Mycobacterial and fungal culture/pcr Malaria thick and thin smear, ICT Zika serology Rickettsial serology HIV serology

9 Results Rickettsial and Zika serology negative Mycobacterial PCR on tissue negative HIV serology negative Swab MCS of lesions no growth

10 Leishmania PCR positive! Likely L.braziliensis

12 Leishmania Protozoa Obligate intracellular parasites Transmitted by bites from infected female sandflies (Phlebotomus Old World; Lutzomyia New World) 2 subgenera Viannia Leishmania

14 Old World vs New World Old world oriental sore Middle East, Mediterranean, Africa, India and Asia L.major, L.tropica, L.donovani and L.infantum New world Widespread in Latin America L.braziliensis, L.mexicana, L.panamensis

15 What s in a name? Cutaneous, diffuse cutaneous, mucocutaneous or visceral disease (kala azar)

18 In Australia No localised transmission Cases in dogs imported from endemic countries (L. infantum) Australian phlebotomine sandflies don t bite humans Zelonia australiensis affecting kangaroos

19 Cutaneous Leishmaniasis In New World vector usually Lutzomyia spp Papule forms at initial bite site developing into papulonodule which has central ulceration Amastigote containing macrophages dominate in acute infection Granulomatous response Lesions heal slowly Recovery associated with high level of resistance to reinfection with homologous spp

20 L.braziliensis regional lymphadenopathy can precede cutaneous lesions by 1-12wks When skin ulcer develops the lymphadenopathy and systemic symptoms subside Malekpour et al NEJM 2010

21 Diagnosis Can be made on clinical grounds in endemic countries Definitive Dx Detection of amastigotes in clinical specimens Promastigotes in culture Sampling of cutaneous lesions Clean with 70% EtOH and debris removed Scrape base of ulcer or edge of lesion Submit tissue for histology Giemsa stain

24 PCR PCR more sensitive cf direct microscopy, histology and culture Limited availability No standardisation and lack of multicentered studies for validation Targets rrna ITS, 7SL RNA gene, HSP 70 gene, cytochrome b gene Multiple targets needed due to gene polymorphism Jara et al JCM 2013

25 Culture Collect tissue aseptically Mince tissue prior to culture Novy, MacNeal, Nicolle s medium, Schneider s Drosophila medium supplemented with 30% foetal bovine serum Incubate up to 4wks Promastigotes can be detected on wet mounts Manual clinical micro 2015

26 Serology Only available for research or epidemiologic purposes Not useful for diagnosis Available at CDC

27 Treatment Simple cutaneous lesions heal spontaneously Cryotherapy, heat, photodynamic therapy, surgical excision, chemotherapy Azoles, amphotericin B, miltefosine, pentavalent antimonials Visceral leishmaniasis fatal if not treated No human vaccine available

28 Pentavalent antimony Intramuscular Sb overall cure rate 76% 20 day course Young age, non immune persons (e.g tourists), geographic location correlate with Rx failure Toxic and poorly tolerated

29 Miltefosine 50mg 3 times daily for 28 days Exact mechanism of action unknown?interacts with phospholipids and steroids in cell membrane Inhibition of cytochrome c oxidase FDA approved for 3 spp L.braziliensis, L.panamensis, L.guyanensis

30 Prevention Personal protective measure Clothing DEET based insect repellants Vector control in endemic countries Sandfly resistance to insecticides

31 Outcome AA was seen in the outpatient ID clinic No evidence of mucosal involvement Commenced on 28 day course of oral miltefosine Cutaneous lesions improving

32 Take home messages Suspect in pts with non healing wounds who have travelled through endemic areas Difficult to culture Utility in PCR but not validated Don t get bitten by sandflies

33 Acknowledgements Dr John Burston (ID consultant)

34 QUESTIONS?

Laboratory diagnosis of Blood and tissue flagellates

Laboratory diagnosis of Blood and tissue flagellates (Leishmania and trypanosma) Sarah Alharbi Clinical Laboratory department Collage of Applied Medical Sciences King Saud University Leishmania and trypanosma: