BackgroundVisceral leishmaniasis is a parasitic disease associated with high mortality. The most important foci of visceral leishmaniasis in Ethiopia are in the Northwest and are predominantly associated with high rates of HIV co-infection. Co-infection of visceral leishmaniasis patients with HIV results in higher mortality, treatment failure and relapse. We have previously shown that arginase, an enzyme associated with immunosuppression, was increased in patients with visceral leishmaniasis and in HIV seropositive patients; further our results showed that high arginase activity is a marker of disease severity. Here, we tested the hypothesis that increased arginase activities associated with visceral leishmaniasis and HIV infections synergize in patients co-infected with both pathogens.Methodology/Principal FindingsWe recruited a cohort of patients with visceral leishmaniasis and a cohort of patients with visceral leishmaniasis and HIV infection from Gondar, Northwest Ethiopia, and recorded and compared their clinical data. Further, we measured the levels of arginase activity in the blood of these patients and identified the phenotype of arginase-expressing cells. Our results show that CD4+ T cell counts were significantly lower and the parasite load in the spleen was significantly higher in co-infected patients. Moreover, our results demonstrate that arginase activity was significantly higher in peripheral blood mononuclear cells and plasma of co-infected patients. Finally, we identified the cells-expressing arginase in the PBMCs as low-density granulocytes.ConclusionOur results suggest that increased arginase might contribute to the poor disease outcome characteristic of patients with visceral leishmaniasis and HIV co-infection.

Malnutrition is commonly associated with increased infectious disease susceptibility and severity. Whereas malnutrition might enhance the incidence of disease as well as its severity, active infection can in turn exacerbate malnutrition. Therefore, in a malnourished individual suffering from a severe infection, it is not possible to determine the contribution of the pre-existing malnutrition and/or the infection itself to increased disease severity. In the current study we focussed on two groups of malnourished, but otherwise healthy individuals: moderately malnourished (BMI: 18.4–16.5) and severely malnourished (BMI <16.5) and compared several immune parameters with those of individuals with a normal BMI (≥18.5). Our results show a similar haematological profile in all three groups, as well as a similar ratio of CD4+ and CD8+ T cells. We found significant correlations between low BMI and increased levels of T helper (Th) 1 (Interferon (IFN)-γ, (interleukin (IL)-2, IL-12), Th2 (IL-4, IL-5, IL-13), as well as IL-10, IL-33 and tumor necrosis factor-α, but not IL-8 or C reactive protein. The activities of arginase, an enzyme associated with immunosuppression, were similar in plasma, peripheral blood mononuclear cells (PBMC) and neutrophils from all groups and no differences in the expression levels of CD3ζ, a marker of T cell activation, were observed in CD4+ and CD8+T cells. Furthermore, whereas the capacity of neutrophils from the malnourished groups to phagocytose particles was not impaired, their capacity to produce reactive oxygen species was impaired. Finally we evaluated the frequency of a subpopulation of low-density neutrophils and show that they are significantly increased in the malnourished individuals. These differences were more pronounced in the severely malnourished group. In summary, our results show that even in the absence of apparent infections, healthy malnourished individuals display dysfunctional immune responses that might contribute to increased susceptibility and severity to infectious diseases.

A fast agglutination screening test (FAST) for the detection of Leishmania antibodies in human serum samples was evaluated under harsh field conditions in northern Ethiopia. Test performance was compared with a standard serological test, namely the direct agglutination test (DAT), and with parasitology. In total, 103 suspected cases were recruited for the study. Based on parasitological examination, 49 patients were confirmed of having visceral leishmaniasis (VL) and the other 54 suspected cases were parasitologically negative. Field evaluation of FAST was possible in blood samples of 89 patients. FAST had 4 false negative results and 13 false positive results. DAT had 2 false negative results and 20 false positive results. A good degree of agreement (86.9%) was observed between FAST and DAT (kappa value 0.73). In this field-based evalauation, the sensitivity and specificity of FAST were found to be 91.1% (95% CI 77.9-97.1) and 70.5% (95% CI 54.6-82.8), respectively, compared with 95.3% (95% CI 82.9-99.2) and 62.3% (95% CI 47.9-74.9) for DAT. FAST had a high predictive value of a negative test, demonstrating that FAST could be utilised to exclude rapidly non-VL patients from a large population of suspects with fever and splenomegaly in endemic areas.

Background: Visceral leishmaniasis is a parasitic disease associated with high mortality. The most important foci of visceral leishmaniasis in Ethiopia are in the Northwest and are predominantly associated with high rates of HIV co-infection. Coinfection of visceral leishmaniasis patients with HIV results in higher mortality, treatment failure and relapse. We have previously shown that arginase, an enzyme associated with immunosuppression, was increased in patients with visceral leishmaniasis and in HIV seropositive patients; further our results showed that high arginase activity is a marker of disease severity. Here, we tested the hypothesis that increased arginase activities associated with visceral leishmaniasis and HIV infections synergize in patients co-infected with both pathogens.Methodology/Principal Findings: We recruited a cohort of patients with visceral leishmaniasis and a cohort of patients with visceral leishmaniasis and HIV infection from Gondar, Northwest Ethiopia, and recorded and compared their clinical data. Further, we measured the levels of arginase activity in the blood of these patients and identified the phenotype of arginaseexpressing cells. Our results show that CD4 + T cell counts were significantly lower and the parasite load in the spleen was significantly higher in co-infected patients. Moreover, our results demonstrate that arginase activity was significantly higher in peripheral blood mononuclear cells and plasma of co-infected patients. Finally, we identified the cells-expressing arginase in the PBMCs as low-density granulocytes. Conclusion:Our results suggest that increased arginase might contribute to the poor disease outcome characteristic of patients with visceral leishmaniasis and HIV co-infection.

Background: Sepsis isone of the major predictor of death in patients with visceral leishmaniasis(VL).However, there are currently no reliable data available on bacterial sepsis in VL patients in Ethiopia. This study aimed to assess the prevalence of bacterial sepsis, causative agents and their antimicrobial susceptibility patterns and focus of infection in patients with VL.Methods & Materials: A prospective cross sectional study was conducted among parasitologically confirmed VL patients suspected of sepsis admitted to University of Gondar Hospital, Northwest Ethiopia from February 2012 to May 2012.Sociodemographic characteristics and clinical manifestations were documented after patient interview and physical examination. Samples (blood, urine and others as indicated) were collected and culturedusing standard methods.Isolates were tested for antimicrobial susceptibility using the disc diffusionmethod.Data were entered and analyzed using SPSS version 20.Results: Most of the patients 81 (97.6%), 67 (80.7%), 75 (90.4%), 80 (96.4%) were febrile, tachycardic, tachypnic, and leukopenic, respectively. The prevalence of culture confirmed bacterial sepsis was 19.3% (16/83). The most frequently isolated organism was Staphylococcus aureus, accounting for 11/16 (68.8%) of cases. There was a concordance rate of 11/12 (91.6%) between bacterial isolates and their susceptibility pattern between focal infections and blood stream infections. The overall multiple resistance was 13/16 (81.3%). The highest rate of resistance was for ampicillin 11/11 (100%), and two were MRSA. Vancomycin, gentamicin and ceftriaxone were found to be effective against most isolates. Focal bacterial infection was showed significant association with bacterial sepsis (P = 0.00; Odds ratio = 11.65; 95% confidence interval 4. 29-31.60). Factors such as sex, age, HIV status, < 200 CD4 count, anemia, leucopenia, malnutritionand > 72 hour hospital staywere not associatedwith bacterial sepsis. Conclusion:The prevalence of culture confirmed bacterial sepsis was high, multiple drug resistant Staphylococcus aureus being the frequent isolate. Focal bacterial infections are potential sources for bacterial sepsis among VL patients. Therefore, clinicians should give emphasis to treat VL patients with focal bacterial infection before developing to sepsis. Rational use of antibiotics should be practiced in order to minimize the spread of drug resistant bacteria.