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Leishmaniasis is an important vector-borne
disease with approximately
two million new cases
every year
and one tenth of the world's population at risk
of infection. The disease is endemic throughout
parts of Europe, North Africa, the middle east and central
and south America and occurs in epidemics with high mortality in
East Africa, parts of the Indian subcontinent and South
America.
Leishmania is exclusively transmitted by Phlebotomine
sandflies. The greatest concentration of sand flies is in South
America, where Lutzomyia longipalpis is the main vector
of visceral leishmaniasis (the most serious form of the disease)
in both sylvatic and peridomestic environments.
Colonisation of
urban areas by L. longipalpis is believed to be a
significant factor in the recent increase of visceral
leishmaniasis in South America. Even in sub-tropical regions
where the disease has not traditionally been as important, its
sub-clinical status has been elevated to clinical disease by
association with HIV infection.
Environmental changes including global warming
are expected to change the distribution of these vectors, with
for example the mediterranean vectors extending their range to
N. Europe. There are no vaccines available and chemotherapy is
principally using antimonial-based drugs developed nearly 100
years ago. Significant resistance to antimonials has been
reported in recent years. Insect vector control is likely to be an
important component of leishmaniasis
containment in the foreseeable future.
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