The recent geographical expansion of phlebotomine vectors of Leishmania infantum in the Mediterranean subregion has been attributed to ongoing climate changes. At these latitudes, the activity of sand flies is typically seasonal; because seasonal phenomena are also sensitive to general variations in climate, current phenological data sets can provide a baseline for continuing investigations on sand fly population dynamics that may impact on future scenarios of leishmaniasis transmission. With this aim, in 2011–2013 a consortium of partners from eight Mediterranean countries carried out entomological investigations in sites where L. infantum transmission was recently reported. A common protocol for sand fly collection included monthly captures by CDC light traps, complemented by sticky traps in most of the sites. Collections were replicated for more than one season in order to reduce the effects of local weather events. In each site, the trapping effort was left unchanged throughout the survey to legitimate inter-seasonal comparisons. Data from 99,000 collected specimens were analyzed, resulting in the description of seasonal dynamics of 56,000 sand flies belonging to L. infantum vector species throughout a wide geographical area, namely P. perniciosus (Portugal, Spain and Italy), P. ariasi (France), P. neglectus (Greece), P. tobbi (Cyprus and Turkey), P. balcanicus and P. kandelakii (Georgia). Time of sand fly appearance/disappearance in collections differed between sites, and seasonal densities showed variations in each site. Significant correlations were found between latitude/mean annual temperature of sites and i) the first month of sand fly appearance, that ranged from early April to the first half of June; ii) the type of density trend, varying from a single peak in July/August to multiple peaks increasing in magnitude from May through September. A 3-modal trend, recorded for P. tobbi in Cyprus, represents a novel finding for a L. infantum vector. Adults ended the activity starting from mid September through November, without significant correlation with latitude/mean annual temperature of sites. The period of potential exposure to L.infantum in the Mediterranean subregion, as inferred by adult densities calculated from 3 years, 37 sites and 6 competent vector species, was associated to a regular bell-shaped density curve having a wide peak center encompassing the July-September period, and falling between early May to late October for more than 99% of values. Apparently no risk for leishmaniasis transmission took place from December through March in the years considered. We found a common pattern of nocturnal females activity, whose density peaked between 11 pm and 2 am. Despite annual variations, multiple collections performed over consecutive years provided homogeneous patterns of the potential behavior of leishmaniasis vectors in selected sites, which we propose may represent sentinel areas for future monitoring. In the investigated years, higher potential risk for L. infantum transmission in the Mediterranean was identified in the June-October period (97% relative vector density), however such risk was not equally distributed throughout the region, since density waves of adults occurred earlier and were more frequent in southern territories. Recent projections on global warming indicate a constant rise of temperatures in the Mediterranean subregion in the near-mid future. While this phenomenon already caused geographical expansion of several arthropod-borne diseases, it is likely to affect also temporal parameters of seasonally transmitted diseases such as leishmaniasis, a protozoan infection spread by the bite of phlebotomine sand flies. Phenology of sand flies consists in the periods of emergence of adults and their disappearance from collections following an activity period during warm months, which can be characterized by peaks of abundance. Current phenological observations can be important for continuing investigations on sand fly dynamics that may impact on leishmaniasis transmission in the future. With this aim, partners from eight Mediterranean countries identified sites with documented Leishmania infantum transmission by six different vector species and performed multiannual trappings. From the high number of 56,000 specimens collected throughout an area spanning from Portugal at west to Georgia at east, the current seasonal dynamics of Mediterranean vectors was obtained. Both, period of adults emergence and type of density trend were found to be significantly correlated with latitude or mean annual temperature of trapping sites. At the southernmost latitudes, vector activity started as early as begin of April and ended by late November, showing that the no-risk period of potential exposure to L. infantum lasted only 4 months.

The incidence of clinical and clinicopathological signs associated with the progression of infection was evaluated prospectively in 329 naïve young dogs exposed to Leishmania infantum transmission and examined periodically during 22 months (M). The dogs were part of Leishmania vaccine investigations performed under natural conditions. Vaccinated groups were considered in the evaluation when the vaccine resulted non-protective and the appearance and progression of signs did not differ statistically from controls at each time point, otherwise only control groups were included. 115 beagles were part of 3 studies (A to C) performed in the same kennel; 214 owned dogs (29 breeds, 2.3% beagles) were included in a study (D) performed in 45 endemic sites. At M22 the prevalence of any Leishmania infection stage classified as subpatent, active asymptomatic, or symptomatic was 59.8% in studies A–C and 29.2% in study D. Despite different breed composition and infection incidence, the relative proportion of active infections and the progression and type of clinical and clinicopathological signs have been similar in both study sets. All asymptomatic active infections recorded have invariably progressed to full-blown disease, resulting in 56 sick dogs at M22. In these dogs, lymph nodes enlargement and weight loss — recorded from M12 — were the most common signs. Cutaneous signs were seen late (M18) and less frequently. Ocular signs appeared even later, being sporadically recorded at M22. Most clinicopathological alterations became evident from M12, although a few cases of thrombocytopenia or mild non-regenerative anemia were already observed at M6. Albumin/globulin inversions were recorded from M12 and urea/creatinine increase appeared mostly from M18. Altogether our findings indicate that any susceptible young dogs naturally infected by L. infantum present a common pattern of progression of signs during 2 years post infection, providing clues for medical and epidemiological applied aspects. Despite dogs representing the main reservoir for the most widespread entity of human leishmaniasis (zoonotic visceral leishmaniasis caused by Leishmania infantum, endemic in five continents), many aspects of canine leishmaniasis (CanL) are still poorly understood. Dog responses to the infection are complex and broadly follow the two patterns of substantial resistance or clinical susceptibility. The latter is a progressive condition eventually leading to a dog's death, being associated with an increasing infectiousness to phlebotomine vectors. Because most information on CanL comes from cross-sectional investigations such as in-clinic pet diagnosis or mass population surveys, knowledge on the individual natural course of the infection/disease is limited. Prospective investigations are rarely performed because they are difficult and expensive. We took advantage of 4 prospective studies on experimental Leishmania vaccines to investigate the time-course of clinical signs in susceptible young dogs exposed to natural infection. We found that, whatever the dog breed and the local incidence of leishmaniasis, any asymptomatic active infections detected in naïve animals invariably progress to full-blown disease, showing a common pattern of early and late signs during 2 years post infection. These findings may provide clues for medical and epidemiological applied aspects.

Little information is available about infantile visceral leishmaniasis (VL) in Albania as regards incidence, diagnosis and management of the disease. Demographic data, clinical and laboratory features and therapeutic findings were considered in children admitted to University Hospital of Tirana from 1995 to 2009, and diagnosed as having VL. The diagnosis was based on bone-marrow microscopy/culture in 77.5% of patients, serology in 16.1%, and ex juvantibus in 6.4%. A total of 1,210 children were considered, of whom 74% came from urbanized areas. All patients were in the age range 0–14 years, with a median of 4 years. Hepatosplenomegaly was recorded in 100%, fever in 95.4% and moderate to severe anemia in 88% of cases. Concomitant conditions were frequent: 84% had bronchopneumonia; diarrhea was present in 27%, with acute manifestations in 5%; 3% had salmonellosis. First-line therapy was meglumine antimoniate for all patients, given at the standard Sb^v dosage of 20 mg/kg/day for 21 to 28 days. Two children died under treatment, one of sepsis, the other of acute renal impairment. There were no cases of primary unresponsiveness to treatment, and only 8 (0.67%) relapsed within 6–12 months after therapy. These patients have been re-treated with liposomal amphotericin B, with successful cure. Visceral leishmaniasis in pediatric age is relatively frequent in Albania; therefore an improvement is warranted of a disease-specific surveillance system in this country, especially as regards diagnosis. Despite recent reports on decreased responses to antimonial drugs of patients with Mediterranean VL, meglumine antimoniate treatment appears to be still highly effective in Albania. Albania is a developing country that is rapidly improving in social, economic and sanitary conditions. The health care system in still in progress and the impact of some infectious diseases remains poorly understood. In particular, little information is available on incidence, clinical features and response to treatment of visceral leishmaniasis (VL) in childhood. We performed a retrospective analysis of data recorded from 1995 to 2009 at the national pediatric reference hospital of Tirana where any child suspected for VL is referred for specific diagnosis and treatment. Epidemiology, clinical features and management of the disease were considered. The main findings can be summarized as follows: i) The incidence of the disease in Albanian children (25/100,000 in the age group 0–6 years) is much higher than in developed Mediterranean countries endemic for VL; ii) The disease is associated with poor sanitary conditions as suggested by the high rate of severe clinical features and frequency of co-morbidities; iii) The cheapest drug available for Mediterranean VL treatment (meglumine antimoniate) is highly effective (99% full cure rate) and well tolerated. Limitations were identified in the low standard laboratory diagnostic capability and unsatisfactory medical surveillance in less urbanized areas. An improvement is warranted of a disease-specific surveillance system in Albania.