SeminarLeishmaniasis
Section snippets
Immunology
Scientists are studying the immunoregulation of leishmaniasis to improve understanding of the immune response to intracellular pathogens in general and leishmania in particular, to find out whether manipulations of the immune system could be therapeutic, and to rationalise vaccine development. Many insights about immunoregulation have been gained through murine models of leishmaniasis,11 but the complexities of clinical leishmaniasis require further study. The use of cytokine and other types of
General principles about diagnosis
Ideally, all cases of leishmaniasis should be confirmed by demonstration of the parasite, which is straightforward (except for needing an invasive procedure) if parasites are plentiful (eg, in kala-azar) but otherwise can be difficult (eg, for viscerotropic leishmaniasis, mucosal disease, and chronic skin lesions [panel 2]). Examination of giemsa-stained slides of the relevant tissue is still the technique most commonly used to visualise the parasite. The sample should be examined by light
General principles about treatment
The good news is that leishmaniasis is treatable. However, antileishmanial therapy is a bewildering subject, largely because of the complexities of the disease and the inadequacies of published information. The plethora of published reports based on anecdotal or otherwise suboptimal data creates the illusion that many good treatment options exist. The harsh realities are that few of the touted agents have been assessed adequately in clinical trials; few of the many combinations of syndromes,
Clinical manifestations
Visceral leishmaniasis encompasses a broad range of manifestations of infection. Infection remains asymptomatic or subclinical in many cases, or can follow an acute, subacute, or chronic course. The classic kala-azar syndrome is exemplified by patients such as those in Sudan15 who are heavily infected throughout the mononuclear phagocyte system; develop life-threatening disease after an incubation period of weeks to months; and have fever, severe cachexia (figure 1), hepatosplenomegaly
Clinical manifestations
Like visceral leishmaniasis, both old-world and new-world cutaneous leishmaniasis encompass a broad range of severity and manifestations of infection. Travellers can become infected even after short stays in leishmaniasis-endemic areas. Cutaneous infection can remain subclinical or become clinically apparent after a variable incubation period that averages several weeks. Stereotypically, lesions evolve from papules, to nodules, to ulcerative lesions, with a central depression and raised,
Mucosal leishmaniasis
Mucosal leishmaniasis, a dreaded sequela of new-world cutaneous leishmaniasis, is caused by parasites of the Viannia subgenus (panel 1) in most cases and results from haematogenous or lymphatic dissemination of amastigotes from the skin to the naso-oropharyngeal mucosa. In most cases it becomes evident within several years of resolution of the original cutaneous lesions, but it can ensue while the lesions are present or decades after they heal. Adequate systemic treatment of cutaneous
References (41)
Leishmaniasis: public health aspects and control
Clin Dermatol
(1996)Leishmaniasis reservoirs and their significance in control
Clin Dermatol
(1996)- et al.
T-cell and cytokine responses in leishmaniasis
Curr Opin Immunol
(1993) Diagnosis of leishmaniasis
Clin Dermatol
(1996)- et al.
Anthroponotic cutaneous leishmaniasis in Kabul, Afghanistan: vertical distribution of cases in apartment blocks
Trans R Soc Trop Med Hyg
(1998) - et al.
Evidence for a major gene controlling susceptibility to tegumentary leishmaniasis in a recently exposed Bolivian population
Am J Hum Genet
(1997) Laboratory tests for the diagnosis and evaluation of leishmaniasis
Dermatol Clin
(1994)- et al.
Rapid accurate field diagnosis of Indian visceral leishmaniasis
Lancet
(1998) - et al.
Trial of oral miltefosine for visceral leishmaniasis
Lancet
(1998) - et al.
Natural history, clinical evolution, and the host-parasite interaction in New World cutaneous leishmaniasis
Clin Dermatol
(1996)