4. CLASSIFICATION
Leshmania parasitic for humanutas have been classified
into three main groups as follows:
A. Visceral Leishmaniasis
L .donovani complex
B. Mucocutaneous Leishmaniasis
L. brazilensis complex
C. Cutaneous Leishmaniasis
L. tropica
L. mexicana
5. Geographical distribution
- Endemic in many places in India, China, Africa, South
Europe, South America and Russia.
- In India it is especially common in Assam and Bengal
.It is also endemic in Bihar, Orissa, Madras, and the
eastern part of U.P as far as Lucknow.
Habitat : Inside the vertebrate host (man) the
parasite is always intracellular, occuring in the
amastigote form. It is essentially a parasite of the R.E
System.
8. Pathogenecity
Incubation Period: It generally varies from 3-6 months
but it may exceed one and sometimes two years.
Clinical Features:
- Infection with L. donovani produces the disease
Kala- azar or visceral Leishmaniasis, characterised by
the following:
9. Contd…
Pyrexia: is often an early symptoms and it may be
continuous or remittent in type, become intermittent
at a later stage.
Splenic enlargement: It is one of the
most striking (very good looking) features and the
organs progressively enlarges.
- With the progress of the disease, it extends several
inches below the costal margin, often filling up the
entire abdomen
10. Contd…
Hepatomegaly: The liver is also enlarge
but not as much as spleen.
Lymphadenopathy: may be observed
in Africa and Chinese form. Recently it has been
detected in some cases India also.
11. Contd…
General Health:
- There is no malaise or apathy(lack of emotion) and
the patient may be unaware of the high fever.
- Epistaxis (haemorrage from nose), may be presenting
symptoms.
- In a fully developed case, emaciation and anaemia
become noticeable.
12. Contd…
Skin:The skin over the entire body is dry, rough,
and harsh(rough) and is often pigmented (darkened)
- The hair tends to be brittle (hard but easily broken)
and falls out.
If left untreated 75-95% patients die with in the period
of 2 years.
Death in kala-azar is always due to some complication
such as amoebic or bacillary dysentry, pneumonia
,pulmonary tuberculosis etc.
13. Mode of Transmission
The” natural “ transmission of L. donovani from man
to man is carried out by a certain species of sandfly of
the Genera Phlebotomus and Lutzomyia.
Indian vector- Phlebotomus argentipes
Mediterranean vector- Phlebotomus perniciosus
Chinese vector- phlebotomus chinesis
14. Contd…
Other method of transmission:
These include
- Congenital Infection of a child in
utero.
- Transmission by blood
transfusion.
- Possible transmission during
coitus,
