Current Strategies in Diagnosis & Treatment

of Leishmaniasis

Dr. Sayan ChakrabortyJR-3, Dept. of Tropical Medicine,School of Tropical Medicine, KolkataEmail: dr.sayan@gmail.com

Epidemiology

• Neglected tropical disease• Incidence: 2 million/year• Population exposed: 350 million• Types: VL; PKDL; CL; MCL• Endemic areas: VL: Indian subcontinent, East Africa, South America

(Brazil), Mediterranean region, Middle east, Central Asia, China

PKDL: Indian subcontinent CL: Middle east, Pakistan, Brazil, Columbia, AlgeriaMCL: New world only (South America)

Leishmania Parasite

Transmission• Routes: Bite of infected Sandfly Injection drug users Congenitally Blood transfusion Organ transplant Lab accidents Contact with active lesions of CL

• Vectors: Phlebotomus Lutzomyia

Transmission

Reservoirs

L. donovani Humans

L. infantum Dogs, wild foxes, crab-eating foxes, jackals, wolves, racoon dogs

L. major Great gerbill, Fat Sand Jird (Africa)

L. ethiopica Hyraxes

L. guyanensisL. panamensis

Sloths

L. amazonensis Spiny rat

L. mexicana Climbing rat

L. laisoni Paca

L. naiffi Armadillo

Leishmania Life Cycle

Pathogenesis VL: Disease of mononuclear phagocytic system• Affects spleen, L.n. & bone marrow (rarely intestine, lung, skin)• Granulomata by proliferation of activated macrophages• ↑ IL-1, IL-6, IL-8, IL-12, IL-15, IFN-γ, TNF-α

CL: • Localised self healing lesions: epidermal & dermal infiltrate of

histiocytes with amastigotes, lymphocytes & plasma cells• Non-healing forms: diffuse granuloma with amastigote laden

macrophages (no lymphocytes in DCL)• Leishmania recidivans: hypersensitive tuberculoid granuloma

with Langhans giant cells with small nos. of lymphocytes and plasma cells

Clinical Features - VLMost severe form; aka Kala-azar, Dum dum Fever, Black fever• Incubation period: Avg 2-6 months (10 days to 2 years)• Symptoms: Fever, fatigue, weakness, loss of appetite & weight,

dragging sensation in left upper abdomen• Signs: Hepatosplenomegaly, lymphadenopathy, Pallor,

tachycardia & bipedal edema s/o CHF; Hyperpigmentation• Complications: mainly due to pancytopenia Anemia: normochromic normocytic; due to chronic disease,

bone marrow suppression, bleeding, hypersplenism Infections: pneumonia, diarrhoea, otitis media, TB Bleeding: due to thrombocytopenia & altered hepatic

coagulation factors; epistaxis, gum bleeding, purpura, menorrhagia

CHF due to severe anemia

Special clinical forms - VL Asymptomatic & Sub-clinical Infections: 8.9 : 1 in India Post Kala-Azar Dermal Leishmaniasis:• Chronic rash due to L. donovani in Asia & East Africa (rarely seen in HIV/VL co-infection by L. infantum treated with Sb5+)• Usually occurs months to years after treatment of VL with Sb5+ (uncommon with Ampho B)• Hypopigmented maculae over papulae to nodules; starts from face then expands to other parts (Grades I, II, III)

Clinical Features - CL

• aka Delhi boil, Oriental sore, Baghdad boil, Tropical sore, Aleppo boil, Chiclero’s ulcer, Bouton de Biskra or Uta• Sandfly bite → Papule → Painless red nodule → Central

necrosis f/b fall of crust → Ulcer with indurated edge• Morphology:Wet sore with healing granuloma: L.mexicana, L.

guyanensis, L. brazilensis, L. majorDry & squamous lesion: L. tropica, L. peruvianaFlat plaques or hyperkeratotic lesions: Old world CLNodular with little inflammation: L. infantum, L. aethiopica

Clinical Features - CLNo systemic symptoms or signsLymphangitic dissemination: mainly in L. guyanensis, L.

panamensis, L. braziliensis & L. major • Lymphangitic cord palpable with small painless nodules

containing parasites

D/D: Sporotrichosis, Nocardiosis, M. marinum, Anthrax, Tularemia

Evolution: Chronic, spontaneous cure in months to years with disfiguring scars (Chiclero’s ulcer in external ear) and discoloration of skin

Special clinical forms - CLDCL: Severe form of CL; • Caused by L. aethiopica, L. amazonensis, L. mexicana; Resistant to therapy• Multiple, slowly progressive, relapsing & remitting nodules or plaques without ulceration, very rich in parasites• In HIV/Leishmania co-infection: may be caused by L. braziliensis, L. major, L. infantum, L. donovani• D/D: Lepromatous leprosy due to leonine facies

Special clinical forms - CLLeishmania Recidivans:• Chronic form due to L. tropica & L. braziliensis• Usually located on face• Central healing surrounded by peripheral constantly enlarging

active part (1-2 years after acute lesion)• Mimics lupus vulgaris; Small no. of parasites present• Exaggerated cell mediated response

Clinical Features - MCL• Aka Espundia; caused by L. braziliensis & other new world spp• Primary cutaneous lesion → Variable time of latency → Mucosal

lesions (local spread or metastatic)• Nasal congestion, epistaxis → Ulceration & perforation of nasal

septum → Tapir nose• Mucosa of palate (Escomel cross) and lips involved later; tongue

spared. Palatal perforation may occur; Painless• Laryngeal extension → Dysphonia, metallic cough, obstruction

causing acute dyspnea• In advanced stage, nose & lips may totally disappear; nasal & oral cavity connect into a single hole• D/D: Paracoccoidomycosis & Malignancy

Leishmaniasis & HIV• 2-5.6% of VL patients may be HIV +ve in India (NVBDCP)• Re-inforce each other in detrimental manner; impair response

to ART (which can cause PKDL)• Co-infected patients are highly infectious to sandflies• Viscerotropic & Dermotropic distinction less valid in co-

infection• Atypical presentations in patients with CD4 < 200/uL;

cutaneous, mucosal, GI or pulmonary disease; parasite may be present in lung, pleura, whole of GIT & skin.

• Lower frequency of splenomegaly; Higher frequency & degree of pancytopenia

• Due to high parasite load, aspirates are more sensitive in detecting parasites than in immunocompetent.

Leishmaniasis & HIV … Contd

• Sensitivity of serological tests like rK39 ↓• Latex agglutination test: high sensitivity in detecting Ag in

the urine of co-infected patients • VL is now an AIDS defining illness (WHO); So ART should

be started irrespective of CD4 count. • 79 to 97% of co-infected patients will relapse (NVBDCP)• ART should be started 7-10 days after initiating t/t of VL

(NVBDCP)• Inf Ampho B total dose 40 mg/kg (4 mg/kg on days 1-5,

10, 17, 24, 31, 38) and repeat same dose on relapse

Leishmaniasis & HIV … Contd• Secondary Prophylaxis:1. Amphotericin B lipid complex 3–5 mg/kg/dose every 3 weeks for 12 months2. Liposomal amphotericin B 3–5 mg/kg/dose every 3–4 weeks3. Pentavalent antimonials 20 mg Sb5+/kg/dose every 3–4 weeks and Pentamidine 4 mg/kg/dose [300 mg for an adult] every 3–4 weeks

• Prophylaxis could be suspended, provided that the CD4+ count is maintained at > 200 cells/μl for > 6 months

Diagnosis - VLClinical diagnosis: suspect in a patient with • fever > 2 weeks• splenomegaly &/or• weight loss

who lives in or has returned from an endemic area

Routine blood work: isolated or combined presence of• Anaemia• Leukopenia• Thrombocytopenia• Polyclonal hypergammaglobulinaemia

reinforces clinical suspicion

Diagnosis - VLParasitological diagnosis: Amastigote form by microscopy of

tissue aspirates → classical confirmatory test• Sensitivity of aspirates: Spleen (93–99%); Bone marrow (53–86%);

Lymph node (53–65%)• Stain: Giemsa, Wright’s or Leishman

• Culture of Promastigote: Novy-MacNeal-Nicolle (NNN),United States Army Medical Research Unit (USAMRU),Modified Tobie,‘Sloppy Evans’Semi-solid Locke blood–agar.

Diagnosis - VL• Contraindications for Splenic aspiration to be excluded:

(NVBDCP)1. Hg level is not < 3.0 g/dL 2. No bleeding tendency & not jaundiced3. Not at an advanced stage of pregnancy4. Prothrombin time is not > 5 seconds longer than control or

platelet count is not < 40,000/mm35. Patient (in case of children) cannot lie still6. The spleen palpable at least 3 cm below the costal margin

on expiration7. Vital signs (BP and pulse) are not prohibitive for performing

the procedure

Diagnosis - VL Immunological diagnosis: • IFAT: Indirect Fluorescence Antibody testing• ELISA• Counter-current Immuno-electrophoresis• Indirect hemagglutination • Immunoblot techniques• Easy to use in fields:

o Direct agglutination testo rK39 ICTo Dot-ELISAo Fast agglutination screening test 2 Limitations: 1. Relapse of VL cannot be diagnosed (Ab persists many years)2. Asymptomatic individuals harbour Ab in endemic areas

rK39 Strip test• Rapid diagnostic test; Immunochromatographic test• > 90% specificity and sensitivity• Results read in 10 minutes in field• Detects antibodies in blood (even in urine- not validated)• Test line coated with rK39 antigen – 39-amino acid repeat that is

part of kinesin-related protein in L.chagasi• Control line region: Chicken anti-protein A.• The membrane coated with dye conjugate (protein A colloidal

gold conjugate)• False positives: in Hepatitis and TB.• False negatives: in HIV• RDT positive for years after t/t of VL. Not useful in the diagnosis

of relapse.

Diagnosis - VLAntigen-detection tests: • Latex agglutination test for heat-stable, low-relative molecular-

mass carbohydrate Ag in urine• Good specificity but low-to-moderate sensitivity in East Africa

and on the Indian subcontinent• More appropriate for HIV/Leishmania co-infection

DNA PCR (Qualitative or Quantitative):• In blood, tissue aspirates, urine, buccal swabs• Most sensitive and specific• Positive in asymptomatic individuals of endemic areas• Restricted to referral hospitals and research centres

Diagnosis - PKDL• Diagnosis is mainly clinical; with h/o VL or stay in endemic

area• Confirmed by finding parasites in skin biopsy or scraping of

skin slit; higher detection when taken from nodular lesions than papular or macular lesions.

• Skin biopsies: histopathology, immunohistochemistry, culture, PCR (also in slit skin specimens; more sensitive)

• Serological tests (direct agglutination test, ELISA and the rK39 rapid diagnostic test) usually positive; limited value, positive result may be due to Ab persisting after a past VL.

• Serology helpful when other diseases (e.g. leprosy) are considered in the D/D or previous h/o VL is uncertain

Diagnosis - CLParasitological diagnosis:• Sample obtained by scraping/ slit skin smear/ FNA/ Bx• Culture on NNN medium for species identification

DNA PCR: improves diagnostic sensitivity & allows species identification

Immunological diagnosis:• Usually no detectable antibody response in L. major or L.

tropica infections

Diagnosis - MCL

• Suspect MCL in patients with typical mucosal lesions and a h/o CL• Difficult to get samples for parasitological

diagnosis (bleed on contact & difficult to administer anesthesia) • Scarce parasites in mucosal lesions (strong local

immune reaction)• Positive serology (IFAT or ELISA) increase clinical

suspicion.• DNA PCR – more sensitive tool

Treatment of VL - WHO

Treatment of VL - WHO

Treatment of VL - NVBDCP

Treatment of VL in East Africa

Treatment of VL – Middle east, Mediterranean, South America

Treatment outcomes in VL

Treatment of PKDL - WHO

Treatment of PKDL - NVBDCP

Treatment outcomes in PKDL

Treatment of Old World CL

Treatment of Old World CL

• Local Therapy:

Treatment of Old World CL

Treatment of DCL

Treatment of New World CL

Treatment of New World CL

Treatment of New World CL

Treatment of MCL

Precautions• Pentavalent Antimonials: Anorexia, N & V, abdominal pain,

metallic taste, arthralgia, myalgia, acute pancreatitis (in HIV), hepatitis, QT prolongation (then to VT)

• Amphotericin B: fever with chill and rigor, thrombophlebitis, myocarditis, hypokalemia, AKI

• Paromomycin: Nephrotoxic, Ototoxic to fetus• Pentamidine: IDDM, Hypoglycemia, Unexplained shock• Miltefosine: D & V, hepatotoxicity, renal insufficiency, teratogenicContraindications:• Women during pregnancy & lactation• Married women of child-bearing age who refuse to give an undertaking

of refraining from pregnancy during the treatment period and two/three months after completion of treatment

• HIV positive serology• Infants < 2 years

During Pregnancy

• Amphotericin B deoxycholate and lipid formulations are the best therapeutic options• Pentavalent antimonials: spontaneous abortion,

preterm deliveries and hepatic encephalopathy in the mother and vertical transmission (C).• Paromomycin: Ototoxicity in the fetus is the

main concern.• Pentamidine is contraindicated during the first

trimester• Miltefosine is potentially embryotoxic and

teratogenic

Prevention & Control

2nd gen VACCINE• Leish-111f + MPL-SE, reached clinical trials. • Being evaluated for the immunotherapy of PKDL in the Sudan,

in phase- 1–2 trials in Peru and in a phase-1 trial in India.

Canine leishmaniasis vaccines: in Brazil

Immunochemotherapy and therapeutic vaccines:• Convit vaccine: autoclaved L. mexicana mixed with BCG• Mayrink vaccine: killed L. amazonensis vaccine

along with/without chemotherapy

Prevention & Control

Sandfly control:• Destruction of breeding sites• Insecticide residual spraying (IRS): DDT/Synthetic pyrethroids• Insecticide treated materials: ITNs

Reservoir Control: Test-and-Treat

Case Detection & Management: Active and passive surveillance (mainly of PKDL & HIV-VL co-infection)

Recent Publications

Recent Publications

Road to Kala Azar Elimination

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