Welcome to the

Jungle! Dr Aileen Oon, 2017

Microbiology Registrar

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

PMHx Renal calculi

Laparotomy and appendectomy

Nil regular medications

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

Costa Rica

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

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

Results Rickettsial and Zika serology negative

Mycobacterial PCR on tissue negative

HIV serology negative

Swab MCS of lesions no growth

Leishmania PCR positive!

Likely L.braziliensis

Leishmania Protozoa

Obligate intracellular

parasites

Transmitted by bites from

infected female sandflies

(Phlebotomus – Old World;

Lutzomyia – New World)

2 subgenera

Viannia

Leishmania

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

What’s in a name? Cutaneous, diffuse cutaneous, mucocutaneous or visceral

disease (kala azar)

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

www.uts.edu.au

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

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

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

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

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

Serology Only available for research or epidemiologic purposes

Not useful for diagnosis

Available at CDC

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

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

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

Prevention Personal protective measure

Clothing

DEET based insect repellants

Vector control in endemic countries

Sandfly resistance to insecticides

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

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

Acknowledgements Dr John Burston (ID consultant)

QUESTIONS?