Classification of Leishmania parasites

Kingdom : ProtistaPhylum : SarcomastigophoraClass : Zoomastigophora Order : KinetoplastidaFamily : Trypanosomatidae Genous : LeishmaniaSubg. : Leishmania Viania (Suprapylarian) (Peripylarian)

Leishmaniaiasis

Leishmaniasis is the collective name for a number of diseases caused by protozoan

flagellates of genous leishmania , which have diverse clinical manifestations

Causative agent

Parasitic protozoa of the genus leishmania ,transmitted to human by sandflies.

Over 20 species and subspecies infect humans, each causing a different spectrum of symptoms.

Morphology of leishmania parasites

*in vertebrate hosts * in sandfly vectors

Amastigote Promastigote (Leishman body) (Leptomonad)

Vector of Leishmania Phlebotomus(sandfly )

Larvae of sandfly

Vectors of Cutaneous Leishmaniasis in the world

Human are infected via bite of sandflies ( subfamily phlebotominae)-tiny sand-coloured blood-feeding flies that:- breed in dark,damp places, forest area, caves,or the burrows of small rodents

-are relatively weak flyers, with a range of only 50 metres from their breeding sites -are most active in the evening and at night - Their numbers are related to natural factors such as rainfull, and may increase with global warming.

A ) IN Old World: are phlebotomus sp.;P. sergenti & P.papatasi(mainly vectors in Iran) and other vectors are P. prrfiliewi, P. caucasicus, P. perniciosus

B)In New World: are Lutzomyia sp.

Promastigote(leptomonad) form

Vertebrate hosts

Amastigote form

Leishmania organism.

Life cycle of species of Leishmania

Different clinical form of Leishmaniaiasis

A) Visceral leishmaniasis

B) Cutaneous leishmaniasis

C) Muco-cutaneous leishmaniasis

Distribution of Leishmaniaiasis in the world

-Endemic in 88 countries -Population at risk: 350 millions-Annual incidence: estimated at-Overall prevalence: 12 millions people- More than 90% of C.L. cases occur in; Iran, Algeria Afghanistan,,

Brazil, Peru, Saudi Arabia and Syria - More than 90% of V.L. Cases occur in 5 countries ; Bangladesh,

India , Nepal, Sudan, and Brazil - -The DALY burden is 2,357,000-Annual death due to V.L. is 59,000 cases

*DALYS-Disability Adjusted Life Years (due to premature death and disability)

72 are developing countries 13 are among the least developed

countries 1-1.5 millions cases of

C.L 500,000 cases of V.L.

1,410,000 male

946,000 female

35,000 male

24,000 female

Disturbing increase in the number of C.L. cases in several area

In Brazil : 1998; 21,800 cases, 2003; 60,000 cases

In Afghanistan : 1994; 14,200 cases, 2002; 67,500 cases

In Syria : 1998; 3900 cases, 2002; 6,275 cases

Related factors:

- Economic development - Behavioural and enviromental changes including : development of new settlements, deforestatio, massive migration from rural to urban area, fast and unplaned urbanization,………

Geographical distribution

Different clinical form of Cutaneous Leishmaniaiasis

1) Old world C.L.

2) New world C.L.

AnthroponoticC.L.(L.tropica))Dry sore or Urban C.L(.

Zoonotic C.L.( L.major))Wet sore or Rural C.L(.

Diffuse or Disseminated C.L.) L. aethiopica(

Cutaneous L.(L. mexicana Complex) ) Chiclero ulcer(

Muco-cutaneous L.( L. braziliensis) ) spoundia or Pian bois or Uta (

Clinical Features of cutaneous leishmaniasis• The factors determining the form of disease include;

leishmania species, geographic location, and immune response of the host.

•   Cutaneous leishmaniasis is characterized by one or more cutaneous lesions on areas where sandflies have fed. 

• Persons who have cutaneous leishmaniasis have one or more sores on their skin.  The sores can change in size and appearance over time.  They often end up looking somewhat like a volcano, with a raised edge and central crater.

•   A scab covers some sores.  The sores can be painless or painful.  Some people have swollen glands near the sores (for example, in the armpit if the sores are on the arm or hand).

Urban C. leishmaniasis (Dry sore)

Lesions of Z.C.L.( Wet sore)

Reservior hosts of Z.C.L

Rhombomys opimus and other wild rodents as reservior host of Z.C.L.

Different form of C. leishmaniasis

Epidemiology of common form of Leishmaniasis in IranA) Anthroponotic Cutaneous Leishmaniasis:-It is common in man and endemic cities.-Cuasative agent: L.tropica; smaller than L.major-Transmition ways: 1) man to man by sand fly vector 2)contact infection (inoculable & oinoculable)

3)Mechanical transmitionfrom an open ulcer( by stable fly:Stomoxys)

-Reservior host: Mainly; man occasionally dog

P. sergenti

Epidemiology of common form of Leishmaniasis in Iran B) Zoonotic Cutaneous Leishmaniasis: - Rural Oriental sore is a zoonosis with human infections

occuring only sporadically. - Causative agent : is L. major- Reservior host: the principal reservior host in Iran is :

the gerbil Rhobomys opimusm, a ground-dwelling rodent.Secondary reservior are Meriones lybicus

erythrourus,Tatera indica, Nesokia indica and Meriones hurrianea.

- The principal vector in Iran is Phlebotomus papatasi, other vectors are P.caucasicus, P.ansarii,P.m ongolensis

Geographical varieties of Cuasative agent visceral leishmaniasis (L.donovani complex) ( Dum Dum fever , Kala-azar )

1) Indian kala-azar L.donovani donovani

2) Mediterranean kala-azar L.(d.) infantum

3) African kala-azar L.(d.) archibaldy

4) American kala-azar L.(d.) chagasi

Clinical Features of visceral leishmaniasis

• Persons who have visceral leishmaniasis usually have fever, weight loss, and an enlarged spleen and liver (usually the spleen is bigger than the liver).

•   Some patients have swollen glands. • Certain blood tests are abnormal.  For example, patients

usually have low blood counts, including a low red blood cell count (anemia), low white blood cell count, and low platelet count. 

• Some patients develop post kala-azar dermal leishmaniasis.  Visceral leishmaniasis is becoming an important opportunistic infection in areas where it coexists with HIV.

Clinical Features of visceral leishmaniasis

Epidemiology of Visceral Leishmaniasis in Iran

Mediterranean Kala-azar:

- Causative agent is L. infantum

- Reservior host: involving canine such as Dog, Jackal and other wild carnivorouses.

- The probably main vector in Iran is Phlebotomus major, other vectors are P.keshishiani, P.wenyoni,…….

- Age distribution: the disease occure in children from 1 to 4 years of age.

Distribution of Leishmaniaiasisin the Iran

- Incidence rate of C.L. is: 0.28 (thousands)

- The most cases related to Isfahan and Bushehr provinces : 1.66 (thousands)

-The least cases related to Mazandaran province : 0.22 (thousands)

-Annually 20,000 cases of C.L.is repoted from different regions of Iran(1989, Azmoodae)

A.C.L foci

Z.C.L. foci

V.L. foci

كا

مختلف فرمهاي نونهاي كاايران در ليشمانيور

Laboratory Diagnosis

Examination of Giemsa-stained slides of the relevant tissue is still the technique most commonly used to detect the parasite

Diagnostic findingsMicroscopy

• Isolation of the organism in culture (diphasic NNN medium)

• Inoculation in experimental animals (hamsters) constitutes another method of parasitilogic confirmation of the diagnosis, and in addition can provide material for further investigations (e.g., isoenzyme analysis).

•   Antibody detection can prove useful in visceral leishmaniasis but is of limited value in cutaneous disease, where most patients do not develop a significant antibody response. 

• Other diagnostic techniques exist that allow parasite detection and/or species identification using biochemical (isoenzymes), immunologic (immunoassays), and molecular (PCR) approaches.  Such techniques, however, are not readily available in general diagnostic laboratories.

Microscopy finding

           

                                                                

 

AB

Treatment

•Physicians may consult CDC to obtain information on how to treat leishmaniasis.  The drug sodium stibogluconate is available under an Investigational New Drug protocol from the CDC Drug Service.  Also, see recommendations in The Medical Letter (Drugs for Parasitic Infections).

Number cases of Cutaneous Leishmaniasis in Abarkooh city from 1376 to 1383

255

192

390

180

83114 95

290

0

50

100

150

200

250

300

350

400

1376 1377 1378 1379 1380 1381 1382 1383

Number cases of Cutaneous Leishmaniasis in Ardakan city from 1376 to 1383

191

417

992

213 204164

166

100

0

100

200

300

400

500

600

700

800

900

1000

1376 1377 1378 1379 1380 1381 1382 1383

Number cases of Cutaneous Leishmaniasis in Bafgh city from 1376 to 1383

7 2 1 7 3 1

268261

0

50

100

150

200

250

300

1376 1377 1378 1379 1380 1381 1382 1383

Number cases of Cutaneous Leishmaniasis in Taft city from 1376 to 1383

72

11

39

5

19

4

11

33

0

10

20

30

40

50

60

70

80

1376 1377 1378 1379 1380 1381 1382 1383

Number cases of Cutaneous Leishmaniasis in Khatam city from 1376 to 1383

0 0 0 0

44 40

167

238

0

50

100

150

200

250

1376 1377 1378 1379 1380 1381 1382 1383

Number cases of Cutaneous Leishmaniasis in Meyboad city from 1376 to 1383

1021

143

22

31 30

44

16

0

20

40

60

80

100

120

140

160

1376 1377 1378 1379 1380 1381 1382 1383

Number cases of Cutaneous Leishmaniasis in Yazd city from 1376 to 1383

218

443467

266 244

209

241

180

0

50

100

150

200

250

300

350

400

450

500

1376 1377 1378 1379 1380 1381 1382 1383

Numbf er cases oCutaneous Leishmaniasis in Yazd province from 1376 to 1383

1076

1295

2174

760 642570

1027 1133

0

500

1000

1500

2000

2500

1376 1377 1378 1379 1380 1381 1382 1383

f

02

468

101214

161820

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frequency distribution of C.L cases according to month during 2001-2003

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Frequency distribution of C.L cases according to sex

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Frequency distribution of C.L cases according to place type

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Life cycle of Leishmania sp.