1. Visceral leishmaniasis
Caused by an obligate intracellular protozoan parasite
Most common infectious agent is Leishmania donovani
Less common parasites- L. infantum and L. chagasi

2. World Distribution

3. Epidemiology Prevalence Estimated 500,000 cases each year world wide
Second largest parasitic killer in the world
Found in rural areas rather than urban areas
World Distribution
Found in more than 60 countries
Found in tropics, subtropics, and Southern Europe

4. Transmission Transferred via female phlebotomine sand flies
Amastigotes become Promastogotes inside the stomach of the fly
Regurgitated when sand fly bites host
Invade macrophages and prevent immune response
Continue to infect cells, especially those of the liver and spleen

5. Molecular Basis Inhibits the macrophage proteolytic process
Inhibits the macrophage proteolytic process
Lipophosphoglycan surface protein
Prevent the fusion of the parasite’s vacuole with the cell’s lysosomes

6. Symptoms Fever Weight loss Swelling of spleen and liver
Lowered blood counts
If not treated, disease can be fatal within 2 years

7. Protective Immunity Strong type 1 CD4+ response to leishmania antigens
Antigen specific interferon gamma
Ability to kill intracellular leishmania
Asymptomatic
Up to 32% of healthy people

8. Diagnosis Serological testing for antibodies K39 dipstick
Impression smear

9. Prevention and Treatment
No vaccines or preventative medications
Best prevention is to avoid the sand flies by using nets and staying inside
Treatment
Liposomal amphotericin B (AmBisome)- antifungal
Miltefosine- first oral treatment- cure rate in stage III clinical trials is 95%
Parasite have become resistant to traditional treatments

10. “Toll like receptor 2 and CC chemokine receptor 5 cluster in the lipid raft enhances the susceptibility of Leishmania donovani infection in macrophages”
Expression of both TLR2 and CCR5 increased during infection
Silencing of these receptors reduced the number of intracellular parasites
Disruption of lipid raft affected cross-talk between receptors
Explains why parasite prefers macrophages

13. Sources