Human leishmaniasis in Tuscany: a changing pattern of visceral disease?

The estimated distribution of autochthonous leishmaniasis by Leishmania infantum in Europe in 2005-2020

BACKGROUND

This study describes the spatial and temporal distribution between 2005 and 2020 of human and animal leishmaniasis by Leishmania infantum in European countries reporting autochthonous cases, and highlights potential activities to improve disease control.

METHODOLOGY/PRINCIPAL FINDINGS

It was based on a review of the scientific literature and data reported by the World Health Organization (WHO), the World Organization for Animal Health (WOAH) and the Ministries of Health, including hospital discharges in some countries. Autochthonous infections were reported in the scientific literature from 22 countries, including 13 and 21 countries reporting human and animal infections, respectively. In contrast, only 17 countries reported autochthonous human leishmaniasis cases to the WHO and 8 countries animal infections to the WOAH. The number of WOAH reported cases were 4,203, comprising 4,183 canine cases and 20 cases in wildlife. Of 8,367 WHO reported human cases, 69% were visceral leishmaniasis cases-of which 94% were autochthonous-and 31% cutaneous leishmaniasis cases-of which 53% were imported and mostly in France. The resulting cumulative incidence per 100,000 population of visceral leishmaniasis between 2005-2020, was highest in Albania (2.15 cases), followed by Montenegro, Malta, Greece, Spain and North Macedonia (0.53-0.42), Italy (0.16), Portugal (0.09) and lower in other endemic countries (0.07-0.002). However, according to hospital discharges, the estimated human leishmaniasis incidence was 0.70 in Italy and visceral leishmaniasis incidences were 0.67 in Spain and 0.41 in Portugal.

CONCLUSIONS/SIGNIFICANCE

Overall, there was no evidence of widespread increased incidence of autochthonous human leishmaniasis by L. infantum in European countries. Visceral leishmaniasis incidence followed a decreasing trend in Albania, Italy and Portugal, and peaked in Greece in 2013, 2014 and 2017, and in Spain in 2006-2007 and 2011-2013. Animal and human cutaneous leishmaniasis remain highly underreported. In humans, hospital discharge databases provide the most accurate information on visceral leishmaniasis and may be a valuable indirect source of information to identify hotspots of animal leishmaniasis. Integrated leishmaniasis surveillance and reporting following the One Health approach, needs to be enhanced in order to improve disease control.

Focal spleen lesions in visceral leishmaniasis, a neglected manifestation of a neglected disease: report of three cases and systematic review of literature

BACKGROUND

The Mediterranean area is endemic for the zoonotic form of visceral leishmaniasis (VL) caused by Leishmania infantum, a species which has been recently associated with unexpected epidemiological and clinical features.

METHOD

We report the result of a systematic review of the literature on VL unusually presenting with spleen focal lesions, including three previously unpublished cases.

RESULTS

A total of 28 cases of VL with multiple spleen focal lesions were retrieved. Twenty-six (93%) were acquired in the Mediterranean area, where L. infantum is endemic. Thirteen cases were diagnosed in children, and the remaining 15 cases in middle-aged adults, of whom 9 were immunosuppressed. Four patients (14%) underwent diagnostic splenectomy, while the diagnosis was confirmed by less invasive techniques in the remaining patients. The most common radiological patterns were: multiple subcentimetric or centimetric spleen lesions (size ≤ 1 cm in 14 of 19 cases, 74%), hypoechoic at ultrasonography (25 of 26 cases, 99%) and hypodense at CT scan (9 of 10 cases, 90%). PET-CT (available for four patients) showed an intense FDG spleen uptake. MRI and contrast-enhanced ultrasonography, available for two and one cases each, showed complex patterns.

CONCLUSIONS

VL must be added to the list of possible differential diagnosis of spleen focal lesions and health care provider awareness about this condition will avoid unnecessary invasive diagnostic procedures.