Leishmaniasis

Question 1

Short notes about Leishmaniasis

Answer 1

Leishmaniasis are a group of protozoal diseases caused by the parasite genus leishmania. • Transmitted to man by the bite of female phlebotomine sandfly.
• The agent Exist in two forms: amastigote (human) & flagellated promastigote (Sandfly)

Question 2

Agent factors

Answer 2

1. L. Donovani- Kala. Azar (Visceral L ): N. Africa, middle east, S. America, India, China (sporadic). endemic infection in Mediterranean basin, East Africa
2. L. Tropica- Oriental sore (Cutaneous L): Occurs in dry, Semi- desert rural areas of north & west Africa, central & south America.
3. I. Brazilensis- Espundia (Muco-cutaneous L): South & central America, Brazil.
   In Libya Both visceral & cutaneous leishmaniasis Localised outbreaks is occurred in north western parts of the country adjoining Tunisia: Zawia, Gharian, Musrata, Murguib etc.

Question 3

Reservoir of Infection & vector:

Answer 3

Reservoir of Infection
Rodents (main reservoir of infection in Libya). Canines ( Dogs , Jackal , Hyenas ): Mediterranean Kala- Azar J Human (Indian kala- Azar)

Vector: female phlebotomine sandfly.

Question 4

Host Factors

Answer 4

Age: Can occur at any age.
Sex: Males > females
Population movement: tourists, migrants between endemic & non-endemic.
Immunity: Recovery from Kala azar & Oriental sore gives a lasting immunity (L. Donovani does not protect against L. Tropica )
Occupation: People who work in farming practices, forestry, mining, fishing.

Question 5

Environmental factors :

Answer 5

Season: end of summer.
Altitude : not occur in altitudes over 2000 feet.
Rural areas: where conditions for the breeding of sand-flies readily.

Question 6

Mode of transmission

Answer 6

• Major vectors of transmission are:
1. Phlebotomous major & P. Perniciosus for Kala -Azar
2. P. Paptasii & P. Sergenti for Oriental sore in Libya
3. Female sandfly which bites & transmits Infection.

• After Infective blood meal, the sandfly becomes infected in 6-9 days (Extrinsic incubation period)
• Blood transfusion (Kala -Azar)
• Contamination of the bitten wound

Question 7

Diagnosis

Answer 7

Is established by demonstrating LD (Leishman-Donovan) bodies in splenic smears, and bone marrow smears.

Question 8

Control measures

Answer 8

1. Personal prophylaxis : health education is an important
2. Control of sand fly
3. Control of reservoir

Question 9

Personal prophylaxis

Answer 9

• Covering of cutaneous lesions
• Avoidance of being bitten by sensible clothing
• Use of insect repellent
• Bed nets
• Avoid sleeping on floor
• Dwellings away from forest

Question 10

Control of sand fly :

Answer 10

• Elimination of sand fly breeding places e.g cracks & cervices near human dwellings.
• Removal of shrubs & vegetations which provide shelter to sand flies.
• Spraying of houses and animal shelters with DDT (dichloro-diphenyl trichloroethane).

Question 11

Control of reservoir:

Answer 11

• Mass survey in endemic areas to detect cases early.
• Cases: treated by (sodium stibogluconate).
• Infected & stray dogs should be Identified & Destroyed.
• General sanitation & Improvement of housing (control of rodents).