D engue virus (DENV), the causative agent of dengue fever, is a mosquitoborne single-stranded RNA virus from the genus Flavivirus, often defined as 4 related serotypes (DENV-1, DENV-2, DENV-3, and DENV-4) (1). Globally, ≈4 billion persons in 128 countries are at risk for dengue fever (2). An estimated 390 million infections occur annually, of which 96 million are symptomatic (3), making DENV the most prevalent and rapidly spreading mosquitoborne viral disease of human beings (4). Clinical manifestations vary from a self-limited, potentially debilitating illness to hypovolemic shock; the mortality rate can be as high as 20% if left untreated ( 4).An estimated 750 million persons are at risk for acquiring DENV in Africa, and the disease burden is estimated to be nearly equivalent to that of the Americas (3,5). Many countries in Africa lack a national surveillance system and reporting mechanism (6), causing dengue fever cases to be misdiagnosed as malaria (7), which might explain why among the 34 countries in Africa to report dengue fever, 12 were not reported by the country where it occurred but by travelers returning to their country of origin (8). Travel, particularly to Africa, is emerging as a well-recognized mechanism of intercontinental DENV spread (9,10).Less than 1% of all global DENV envelope sequence data, key information for vaccine targets, come from isolates from Africa (11). A need exists for additional DENV sequencing, especially in Africa (12,13). The lack of genomic DENV data from Africa combined with complex transmission dynamics involving urban and sylvatic cycles impairs our understanding of DENV's evolutionary history, transmission and spread (13), molecular diagnostics (14), antiviral targets (15), vector susceptibility (16), human immune response (17), vaccine development (17), and DENV spillover events (18). Determining which contemporary genotypes are in circulation is crucial to ensuring effective diagnostics and developing preventive and therapeutic countermeasures (19).

Chikungunya viruses containing the A226V mutation detected retrospectively in Cameroon form a new geographical subclade,

Leishmaniasis is an infectious disease transmitted by the sand fly. It is caused by over 20 different species of Leishmania and has affected over 14 million people worldwide. One of the main forms of control of leishmaniasis is chemotherapy, but this is limited by the high cost and/or toxicity of available drugs. We previously found three novel compounds with an iridoid tetracyclic skeleton to have activity against trypanosome parasites. In this study, we determined the activity of the three anti-trypanosome compounds against Leishmania using field strain, 010, and the lab strain Leishmania hertigi. The minimum inhibitory concentration (MIC) of the compounds against 010 was determined by microscopy while the IC50 of compounds against L. hertigi was determined by fluorescence-activated cell sorting with Guava viacount analysis. We found two of the three compounds, molucidin and ML-F52, to have anti-Leishmania activity against both strains. The fluor-microscope observation with DAPI stain revealed that both Molucidin and ML-F52 induced abnormal parasites with two sets of nucleus and kinetoplast in a cell, suggesting that compounds might inhibit cytokinesis in Leishmania parasites. Molucidin and ML-F52 might be good lead compounds for the development of new anti-Leishmania chemotherapy.

Background Ticks are important vectors of various pathogenic protozoa, bacteria and viruses that cause serious and life-threatening illnesses in humans and animals worldwide. Estimating tick-borne pathogen prevalence in tick populations is necessary to delineate how geographical differences, environmental variability and host factors influence pathogen prevalence and transmission. This study identified ticks and tick-borne pathogens in samples collected from June 2016 to December 2017 at seven sites within the Coastal, Sudan and Guinea savanna ecological zones of Ghana. Methods A total of 2016 ticks were collected from domestic animals including cattle, goats and dogs. Ticks were morphologically identified and analysed for pathogens such as Crimean-Congo haemorrhagic fever virus (CCHFV), Alkhurma haemorrhagic fever virus (AHFV), Rickettsia spp. and Coxiella burnetii using polymerase chain reaction assays (PCR) and sequence analysis. Results Seven species were identified, with Amblyomma variegatum (60%) most frequently found, followed by Rhipicephalus sanguineus sensu lato (21%), Rhipicephalus spp. (9%), Hyalomma truncatum (6%), Hyalomma rufipes (3%), Rhipicephalus evertsi (1%) and Rhipicephalus (Boophilus) sp. (0.1%). Out of 912 pools of ticks tested, Rickettsia spp. and Coxiella burnetii DNA was found in 45.6% and 16.7% of pools, respectively, whereas no CCHFV or AHFV RNA were detected. Co-infection of bacterial DNA was identified in 9.6% of tick pools, with no statistical difference among the ecozones studied. Conclusions Based on these data, humans and animals in these ecological zones are likely at the highest risk of exposure to rickettsiosis, since ticks infected with Rickettsia spp. displayed the highest rates of infection and co-infection with C. burnetii, compared to other tick-borne pathogens in Ghana. Graphical Abstract