HisAK70: Progress towards a vaccine against different forms of leishmaniosis

Background: Leishmania major and Leishmania infantum are among the main species that are responsible for cutaneous leishmaniosis (CL) and visceral leishmaniosis (VL), respectively. The leishmanioses represent the second-largest parasitic killer in the world after malaria. Recently, we succeeded in generating a plasmid DNA (pCMV-HISA70m2A) and demonstrated that immunized mice were protected against L. major challenge. The efficacy of the DNA-vaccine was further enhanced by the inclusion of KMP-11 antigen into the antibiotic-free plasmid pVAX1-asd. Methods: Here, we describe the use of a HisAK70 DNA-vaccine encoding seven Leishmania genes (H2A, H2B, H3, H4, A2, KMP11 and HSP70) for vaccination of mice to assess the induction of a resistant phenotype against VL and CL. Results: HisAK70 was successful in vaccinated mice, resulting in a high amount of efficient sterile hepatic granulomas associated with a hepatic parasite burden fully resolved in the VL model; and resulting in 100 % inhibition of parasite visceralization in the CL model. Conclusions: The results suggest that immunization with the HisAK70 DNA-vaccine may provide a rapid, suitable, and efficient vaccination strategy to confer cross-protective immunity against VL and CL.This work was partially supported by grants from the Spanish Ministry of Economy and Competitiveness (AGL2010-17394 and AGL2013-44100R) and PLATESA (P2013/ABI-2906) from the Comunidad de Madrid (Spain).Peer Reviewe

A historical overview of the classification, evolution, and dispersion of Leishmania parasites and sandflies

Background The aim of this study is to describe the major evolutionary historical events among Leishmania, sandflies, and the associated animal reservoirs in detail, in accordance with the geographical evolution of the Earth, which has not been previously discussed on a large scale. Methodology and Principal Findings Leishmania and sandfly classification has always been a controversial matter, and the increasing number of species currently described further complicates this issue. Despite several hypotheses on the origin, evolution, and distribution of Leishmania and sandflies in the Old and New World, no consistent agreement exists regarding dissemination of the actors that play roles in leishmaniasis. For this purpose, we present here three centuries of research on sandflies and Leishmania descriptions, as well as a complete description of Leishmania and sandfly fossils and the emergence date of each Leishmania and sandfly group during different geographical periods, from 550 million years ago until now. We discuss critically the different approaches that were used for Leishmana and sandfly classification and their synonymies, proposing an updated classification for each species of Leishmania and sandfly. We update information on the current distribution and dispersion of different species of Leishmania (53), sandflies (more than 800 at genus or subgenus level), and animal reservoirs in each of the following geographical ecozones: Palearctic, Nearctic, Neotropic, Afrotropical, Oriental, Malagasy, and Australian. We propose an updated list of the potential and proven sandfly vectors for each Leishmania species in the Old and New World. Finally, we address a classical question about digenetic Leishmania evolution: which was the first host, a vertebrate or an invertebrate? Conclusions and Significance We propose an updated view of events that have played important roles in the geographical dispersion of sandflies, in relation to both the Leishmania species they transmit and the animal reservoirs of the parasites

Sero-prevalence of toxoplasmosis among patients visiting the Korle-Bu Teaching Hospital

Abstract Toxoplasmosis is a disease caused by the intracellular protozoan parasite Toxoplasma gondii. It affects up to about one third of the human population worldwide. Toxoplasmosis in neonates and immunocompromised patients can lead to severe disease and even death. However, there is a lack in knowledge concerning the extent of the toxoplasmosis problem in Ghana. In the present study, we determined the seroprevalence of Toxoplasma gondii infection among patients visiting visiting Korle-Bu Teaching Hospital using the enzyme-linked immunosorbent assay (ELISA). Of the 165 patients studied, IgG antibodies were found in 32.7% (95% CI: 25.0 -39.3%). IgM and IgA seroprevalence were 29.7% (95% CI: 22.2 -36.1%) respectively. There was significant association between seroprevalence of Toxoplasma gondii antibodies and gender (P< 0.05), with the male sex being at increased risk of Toxoplasma gondii seropositivity (OR ,95% CI: IgG -2.78,1.34-5.82; IgM -3.31, 1.57-6.981; IgA -3.31, 1.57-6.981). No significant association (P> 0.05) was observed between the age groups and seroprevalence of Toxoplasma gondii antibodies. Ourstudy reveals an overall high seroprevalence of Toxoplasmosis among patients visit ing the Korle-Bu Teaching Hospital. Public campaigns may be necessary to educate the Ghanaians about ways to minimise exposure Toxoplasma gondii

Socio-Behavioral Risk Factors Associated with Cryptosporidiosis in HIV/AIDS Patients Visiting the HIV Referral Clinic at Cape Coast Teaching Hospital, Ghana

bjective: To identify the socio-behavioral risk factors associated with cryptosporidiosis among HIV/AIDS patients with chronic diarrhea symptoms visiting the HIV referral clinic at Cape Coast Teaching Hospital, Ghana. Methods: A cross-sectional study was conducted among 50 HIV/AIDS patients with recurrent diarrhea. Questionnaires were administered to collect social and behavioral risk factors associated with Cryptosporidium and other opportunistic protozoan parasitic infections in HIV patients. Stool samples were collected for the diagnosis of enteric protozoan pathogens using modified Ziehl-Neelsen and acid-fast staining methods. CD4+ cells counts of study subjects were obtained from patients clinical records. The data obtained were analyzed using Pearson chi-square and multivariate-adjusted statistics tool on SPSS 16 for Windows. Results: Twenty-seven (54%) of the subjects were infected with enteric protozoan pathogens. The prevalences of Cryptosporidium, Cyclospora and Microsporidium infections were 46%, 32% and 16%, respectively. Cryptosporidium infection was significantly associated with drinking water (×2=13.528, p500 cells/mm3. Multivariate analysis showed that the risk factor for Cryptosporidium infection among HIV/AIDS patients was the source of drinking water (pipe borne water 76.2% prevalence: sachet water 25%; OR=0.10, 95%CI: 0.03-0.39, p<0.001). Conclusion: We report the risk factor for exposure of Cryptosporidium infection among HIV/AIDS patients for the first time in Ghana. The contamination of drinking water by protozoan parasites should be a public health concern. These results provide the stepping block to understand the transmission dynamics of Cryptosporidium and other opportunistic pathogens in HIV/AIDS infected patients in Ghana