10.1586/ERI.12.148 79 ISSN 1478-7210 © 2013 Expert Reviews Ltd www.expert-reviews.com
Review
Visceral leishmaniasis (VL) or kala-azar is a
chronic, vector-borne parasitic disease, which
has fatal consequences without treatment.
Leishmania donovani of the genus Leishmania
is the causative species of VL in the Indian sub-
continent and East Africa, where humans are
the sole reservoir (anthroponotic). In Europe,
North Africa and Latin America, the disease is
caused by other species such as Leishmania infan-
tum (syn. Leishmania chagasi ), which have both
humans and canines as reservoirs (zoonotic)
[1,2] . When an elongated, flagellar, promastig-
ote form of the parasite enters the human body,
it first infects the peripheral macrophages and
grows intracellularly as an oval and nonflagel-
lated amastigote. In the later stage of the disease,
infection spreads into the visceral organs such as
the liver, spleen, lymph nodes and bone marrow.
The parasite completes its extracellular digenic
lifecycle in the mid gut of the female sandfly
of the genus Phlebotomus (for L. donovani ) and
Lutzomyia (for L. infantum), the sandfly serves
as a vector for the natural transmission of the
disease [3,4] .
VL is endemic in the tropical and subtropical
regions of over five continents that offer suitable
habitat for the vectors. It affects more than 88
countries of the world [5] , most of which are in
remote rural areas of developing countries where
health systems are often weak. Approximately,
0.2–0.4 million cases of VL are estimated to occur
worldwide annually. During the last 5 years, more
than 58,000 VL cases per year have been reported
globally. The six worst affected countries are
India, Bangladesh, Sudan, Brazil, Ethiopia and
South Sudan, which contribute to more than 90%
of all VL cases [6] . However, the actual figure of
VL infection may exceed the official data. Because
of the limited and poor facilities of government
hospitals in endemic areas, many cases appear in
private or nongovernment organization hospitals
and these cases evade the total VL counts.
Sarfaraz Ahmad Ejazi
and Nahid Ali*
Infectious Diseases and Immunology
Division, Indian Institute of Chemical
Biology, 4 Raja S.C. Mullick Road,
Kolkata 700032, India
*Author for correspondence:
Tel.: +91 332 499 5757
Fax: +91 332 473 0284
nali@iicb.res.in
Human visceral leishmaniasis (VL) continues to be a life-threatening neglected tropical disease,
with close to 200 million people at risk of infection globally. Epidemics and resurgence of VL are
associated with negligence by the policy makers, economic decline and population movements.
Control of the disease is hampered by the lack of proficient vaccination, rapid diagnosis in a
field setting and severe side effects of current drug therapies. The diagnosis of VL relied largely
on invasive techniques of detecting parasites in splenic and bone marrow aspirates. rK39 and
PCR, despite problems related to varying sensitivities and specificities and field adaptability,
respectively, are considered the best options for VL diagnosis today. No single therapy of VL
currently offers satisfactory efficacy along with safety. The field of VL research only recently
shifted toward actively identifying new drugs for safe and affordable treatment. Oral miltefosine
and safe AmBisome along with better use of amphotericin B have been rapidly implemented in
the last decade. A combination therapy will substantially reduce the required dose and duration
of drug administration and reduce the chance of the development of resistance. In addition,
identification of asymptomatic cases, vector control and treatment of post-kala-azar dermal
leishmaniasis would allow new perspectives in VL control and management.
KEYWORDS: antileishmanial therapy • antimony resistance • liposomal amphotericin B • miltefosine • PCR diagnosis
• rK39 strip test • visceral leishmaniasis diagnosis
Developments in diagnosis
and treatment of visceral
leishmaniasis during the last
decade and future prospects
Expert Rev. Anti Infect. Ther. 11(1), 79–98 (2013)
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