Analysis of 179 new Ebola virus sequences from patient samples collected in Guinea between March 2014 and January 2015 shows how different lineages evolved and spread in West Africa. Supplementary information The online version of this article (doi:10.1038/nature14594) contains supplementary material, which is available to authorized users.

The ability for public/veterinary health agencies to assess the risks posed by tick-borne pathogens is reliant on an understanding of the main tick vector species. Crucially, the status, distribution, and changing trends in tick distribution and abundance are implicit requirements of any risk assessment; however, this is contingent on the quality of tick distribution data. Since 2005 the Health Protection Agency has promoted an enhanced tick surveillance program. Through engagement with a variety of public and veterinary health agencies and practitioners (e.g., clinicians and veterinarians), wildlife groups (deer society, zoos, animal refuge centers, and academics), and amateur entomologists, >4000 ticks from 900 separate records across Great Britain have been submitted, representing 14 tick species (Ixodes ricinus, Ixodes hexagonus, Ixodes acuminatus, Ixodes arboricola, Ixodes canisuga, Ixodes frontalis, Ixodes lividus, Ixodes trianguliceps, Ixodes ventalloi, Carios vespertilionis, Dermacentor reticulatus, Haemaphysalis punctata, Hyalomma marginatum, and Amblyomma species). The majority of ticks submitted were I. ricinus (81%), followed by I. hexagonus (10%) and I. frontalis (2.5%). Predominant host groups include companion animals (411 records), humans (198 records), wild birds (111 records), and large wild mammals (88 records), with records also from small/medium wild mammals, livestock, the environment and domestic/aviary birds. The scheme has elucidated the detection of two nonnative tick species, the expansion of previously geographically restricted D. reticulatus and produced ground data on the spread of I. ricinus in southwest England. It has also provided a forum for submission of ticks from the concerned public and particularly those infected with Lyme borreliosis, thus raising awareness among public health agencies of the increased peri-urban tick problem in Britain. Our results demonstrate that it is possible to run a cost-effective nationwide surveillance program to successfully monitor endemic tick species, identify subtle changes in their distribution, and detect the arrival and presence of exotic species.

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This review aims to summarize the current knowledge of the eco-epidemiology of Crimean-Congo hemorrhagic fever (CCHF) virus transmission reviewing the most recent scientific advances in the last few decades of epidemic and non-epidemic ("silent") periods. We explicitly aim to highlight the dynamics of transmission that are still largely unknown. Recent knowledge gathered from research in Africa and Europe explains the very focal nature of the virus, and indicates that research on the ecology of the virus in the inter-epidemic periods of the disease has not yet been addressed. Hyalomma spp. ticks have been incriminated in the transmission of the virus under field conditions, but the role of other ticks found infected in nature remains to be tested under experimental conditions. Published evidence suggests that the increase in human cases reported in the Balkans, Turkey, and Russia is perhaps less due to the effect of changes in climate, but rather result from the impact of yet unexplored mechanisms of amplification that might be supported by wild animal hosts. Assessment of the available data suggests that epidemics in Eastern Europe are not the result of a spreading viral wave, but more likely are due to a combination of factors, such as habitat abandonment, landscape fragmentation, and proliferation of wildlife hosts that have exacerbated prevalence rates in tick vectors. There is an urgent need to empirically demonstrate these assumptions as well as the role of birds in introducing infected ticks, and also to evaluate the potential for survival of introduced ticks. Either a replacement of the pathogenic virus in the western Mediterranean or a lack of westward dissemination of infected tick populations may explain the absence of the virus in Western Europe.