A nanopore DNA sequencer is used for real-time genomic surveillance of the Ebola virus epidemic in the field in Guinea; the authors demonstrate that it is possible to pack a genomic surveillance laboratory in a suitcase and transport it to the field for on-site virus sequencing, generating results within 24 hours of sample collection. This paper reports the use of nanopore DNA sequencers (known as MinIONs) for real-time genomic surveillance of the Ebola virus epidemic, in the field in Guinea. The authors demonstrate that it is possible to pack a genomic surveillance laboratory in a suitcase and transport it to the field for on-site virus sequencing, generating results within 24 hours of sample collection. The Ebola virus disease epidemic in West Africa is the largest on record, responsible for over 28,599 cases and more than 11,299 deaths1. Genome sequencing in viral outbreaks is desirable to characterize the infectious agent and determine its evolutionary rate. Genome sequencing also allows the identification of signatures of host adaptation, identification and monitoring of diagnostic targets, and characterization of responses to vaccines and treatments. The Ebola virus (EBOV) genome substitution rate in the Makona strain has been estimated at between 0.87 × 10−3 and 1.42 × 10−3 mutations per site per year. This is equivalent to 16–27 mutations in each genome, meaning that sequences diverge rapidly enough to identify distinct sub-lineages during a prolonged epidemic2,3,4,5,6,7. Genome sequencing provides a high-resolution view of pathogen evolution and is increasingly sought after for outbreak surveillance. Sequence data may be used to guide control measures, but only if the results are generated quickly enough to inform interventions8. Genomic surveillance during the epidemic has been sporadic owing to a lack of local sequencing capacity coupled with practical difficulties transporting samples to remote sequencing facilities9. To address this problem, here we devise a genomic surveillance system that utilizes a novel nanopore DNA sequencing instrument. In April 2015 this system was transported in standard airline luggage to Guinea and used for real-time genomic surveillance of the ongoing epidemic. We present sequence data and analysis of 142 EBOV samples collected during the period March to October 2015. We were able to generate results less than 24 h after receiving an Ebola-positive sample, with the sequencing process taking as little as 15–60 min. We show that real-time genomic surveillance is possible in resource-limited settings and can be established rapidly to monitor outbreaks.

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. Miles Carroll and colleagues report describe the genetic evolution of Ebola virus circulating in West Africa, based on 179 new virus sequences from patient samples collected in Guinea between March 2014 and January 2015. Their analysis shows how different lineages evolved and spread in West Africa between Sierra Leone, Guinea and Liberia. West Africa is currently witnessing the most extensive Ebola virus (EBOV) outbreak so far recorded1,2,3. Until now, there have been 27,013 reported cases and 11,134 deaths. The origin of the virus is thought to have been a zoonotic transmission from a bat to a two-year-old boy in December 2013 (ref. 2). From this index case the virus was spread by human-to-human contact throughout Guinea, Sierra Leone and Liberia. However, the origin of the particular virus in each country and time of transmission is not known and currently relies on epidemiological analysis, which may be unreliable owing to the difficulties of obtaining patient information. Here we trace the genetic evolution of EBOV in the current outbreak that has resulted in multiple lineages. Deep sequencing of 179 patient samples processed by the European Mobile Laboratory, the first diagnostics unit to be deployed to the epicentre of the outbreak in Guinea, reveals an epidemiological and evolutionary history of the epidemic from March 2014 to January 2015. Analysis of EBOV genome evolution has also benefited from a similar sequencing effort of patient samples from Sierra Leone. Our results confirm that the EBOV from Guinea moved into Sierra Leone, most likely in April or early May. The viruses of the Guinea/Sierra Leone lineage mixed around June/July 2014. Viral sequences covering August, September and October 2014 indicate that this lineage evolved independently within Guinea. These data can be used in conjunction with epidemiological information to test retrospectively the effectiveness of control measures, and provides an unprecedented window into the evolution of an ongoing viral haemorrhagic fever outbreak.

Fatal Ebola virus disease is characterized by a high proportion of CD4+ and CD8+ T cells expressing the inhibitory molecules CTLA-4 and PD-1, correlating with high virus load; individuals who survive the infection exhibit lower expression of these inhibitory molecules and generate Ebola-specific CD8+ T cells, suggesting that dysregulation of the T cell response is a key component of Ebola virus disease pathophysiology. César Muñoz-Fontela and colleagues have tracked the T cell response in individuals infected with Ebola virus in Guinea. Following patients from the time of their admission at the Ebola Treatment Centre in Guinea until their discharge or death, the authors identify an immune signature that is characteristic of fatal Ebola virus disease. In fatal infection, a high proportion of CD4+ and CD8+ cells expressed the inhibitory molecules CTLA-4 and PD-1, correlating with high virus load. By contrast, individuals who survived the infection showed lower expression of these inhibitory molecules, suggesting that dysregulation of the T cell response is a key component of Ebola virus disease pathophysiology. Despite the magnitude of the Ebola virus disease (EVD) outbreak in West Africa, there is still a fundamental lack of knowledge about the pathophysiology of EVD1. In particular, very little is known about human immune responses to Ebola virus2,3. Here we evaluate the physiology of the human T cell immune response in EVD patients at the time of admission to the Ebola Treatment Center in Guinea, and longitudinally until discharge or death. Through the use of multiparametric flow cytometry established by the European Mobile Laboratory in the field, we identify an immune signature that is unique in EVD fatalities. Fatal EVD was characterized by a high percentage of CD4+ and CD8+ T cells expressing the inhibitory molecules CTLA-4 and PD-1, which correlated with elevated inflammatory markers and high virus load. Conversely, surviving individuals showed significantly lower expression of CTLA-4 and PD-1 as well as lower inflammation, despite comparable overall T cell activation. Concomitant with virus clearance, survivors mounted a robust Ebola-virus-specific T cell response. Our findings suggest that dysregulation of the T cell response is a key component of EVD pathophysiology.

Summary: During the past decade several notable viruses have suddenly emerged from obscurity or anonymity to become serious global health threats, provoking concern regarding their sustained epidemic transmission in immunologically naive human populations. With each new threat comes the call for rapid vaccine development. Indeed, vaccines are considered a critical component of disease prevention for emerging viral infections because, in many cases, other medical options are limited or non-existent, or that infections result in such a rapid clinical deterioration that the effectiveness of therapeutics is limited. While classic approaches to vaccine development are still amenable to emerging viruses, the application of molecular techniques in virology has profoundly influenced our understanding of virus biology, and vaccination methods based on replicating, attenuated and non-replicating virus vector approaches have become useful vaccine platforms. Together with a growing understanding of viral disease emergence, a range of vaccine strategies and international commitment to underpin development, vaccine intervention for new and emerging viruses may become a possibility.

Altered protein glycosylation compared with the disease-free state is a universal feature of cancer cells. It has long been established that distinct glycan structures are associated with specific forms of cancer, but far less is known about the complete array of glycans associated with certain tumors. The cancer glycome has great potential as a source of biomarkers, but progress in this field has been hindered by a lack of available techniques for the elucidation of disease-associated glycosylation. In the present study, lectin microarrays consisting of 45 lectins with different binding preferences covering N- and O-linked glycans were coupled with evanescent-field activated fluorescent detection in the glycomic analysis of primary breast tumors and the serum and urine of patients with metastatic breast cancer. A single 50 µm section of a primary breast tumor or <1 µL of breast cancer patient serum or urine was sufficient to detect glycosylation alterations associated with metastatic breast cancer, as inferred from lectin-binding patterns. The high-throughput, sensitive and relatively simple nature of the simultaneous analysis of N- and O-linked glycosylation following minimal sample preparation and without the need for protein deglycosylation makes the lectin microarray analysis described a valuable tool for discovery phase glycomic profiling.