The term leishmaniasis refers to a heterogeneous group of anthropo-zoonoses caused by
protozoa obligate intracellular protozoa, parasites of humans and various wild and
domestic animals, belonging to the genus Leishmania. Despite being the cause of recurrent
epidemic outbreaks with high rates of morbidity and mortality rates in certain
geographical areas, the World Health Organisation (WHO) includes them among the Neglected
Tropical Diseases. About 350 million people live in areas at risk for leishmaniasis with
an estimated global prevalence of 12 million. The annual global incidence is estimated to
be between 0.2 and 0.4 million cases for Visceral Leishmaniasis (LV) and between 0.7 and
1.2 million cases for Cutaneous Leishmaniasis Cutaneous. Leishmaniases are endemic
infections in tropical, subtropical and temperate zones of all continents except
Australia and Antarctica. More than 90% of LV cases are diagnosed in six countries:
Bangladesh, Brazil, Ethiopia, India, South Sudan and Sudan, while the majority of LC
cases are diagnosed in Afghanistan, Algeria, Brazil, Colombia, Iran, Pakistan, Peru,
Saudi Arabia and Syria.
Leishmaniasis is also endemic in the Mediterranean Basin, including Italy, and in this
area about 5% of global cases are found there, with a clear prevalence of visceral forms.
The incubation period varies from 4 to 10 months, but cases have been described in which
incubation lasted for several years.
The onset is mostly gradual and insidious and the most characteristic clinical
manifestations are asthenia fever (often initially framed as FUO), night sweats, anorexia
and weight loss, splenomegaly, hepatomegaly and lymphadenomegaly. From a laboratory point
of view, characteristic are anaemia, leucopenia and thrombocytopenia, more or less
associated with each other, up to full-blown pancytopenia.
Dysprotidemia with hypergammaglobulinemia and hypoalbuminemia is typical. If not
adequately treated, visceral leishmaniasis evolves towards a condition of cachexia and
profound general decay and may prove fatal. A rare and serious complication of LV is the
haemophagocytic syndrome. According to the 2010 WHO Leishmaniasis Control Report, a
confirmed case of LV is defined as the association between typical clinical signs and
symptoms (fever, splenomegaly, weight loss, etc.) and positivity of a parasitological
examination (microscopy, RT-PCR or culture) in the presence or absence of positivity of
serological investigations.
The methods available for the diagnosis of LV include:
Serological tests: detection of Leishmania-specific IgG (or total Ig) in plasma or
serum. enzyme immunoassay (EIA), indirect immunofluorescence assay (IFAT),
immunochromatographic test (ICT) based on the immunochromatographic test (ICT) based
on rK39 antigen, Western blot (WB). Disadvantages: these tests remain positive over
time (it is not always possible to distinguish relapses); they may be positive in
individuals with asymptomatic infection; they may be falsely negative in
immunodepressed individuals (20-60% of cases).
Molecular biology tests: detection of Leishmania DNA by RT-PCR on peripheral blood
bone marrow blood or any other material. Molecular tests are now considered the most
sensitive methods sensitive for the diagnosis of LV and the accuracy in identifying
Leishmania DNA is high for bone marrow aspirate and peripheral blood samples. RT-PCR
should be performed in case the presence of suspicious symptoms and serological test
positivity. However, in the presence of strong suspicion clinical suspicion or in
immunocompromised patients, RT-PCR should also be performed in case of a negative
serology test.
Quantitative RT-PCR on peripheral blood may be useful in patients immunocompromised
patients for monitoring parasitukaemia during therapy.
Direct microscopic examination on bone marrow blood smear: sensitivity is variable
(25-85%) and lower than the sensitivity of molecular methods.
- Culture examination: culture isolation from bone marrow blood takes a long time (at
least 4 weeks). Culture allows the isolation of the strain of Leishmania responsible
for the disease and can also be can also be performed from biopsy tissue.
According to reports in the literature, from 2012 to date, there has been an increase in
the number of diagnosed cases of autochthonous visceral Leishmania in the Province of
Bologna.
In this context, it was decided to carry out a retrospective prospective observational
study, which is essential to describe the epidemiology of LV in order to outline the
scientific and rational bases necessary for the drafting of guidelines to standardise the
diagnostic and therapeutic approach to this disease, in order to reduce the diagnostic
delay and improve therapeutic results.
therapeutic outcome. In addition, epidemiological data will make it possible to identify
possible new strategies to control the disease, which are essential for reducing its
transmission.