Rapid outbreak sequencing of Ebola virus in Sierra Leone identifies transmission chains linked to sporadic cases.

To end the largest known outbreak of Ebola virus disease (EVD) in West Africa and to prevent new transmissions, rapid epidemiological tracing of cases and contacts was required. The ability to quickly identify unknown sources and chains of transmission is key to ending the EVD epidemic and of even greater importance in the context of recent reports of Ebola virus (EBOV) persistence in survivors. Phylogenetic analysis of complete EBOV genomes can provide important information on the source of any new infection. A local deep sequencing facility was established at the Mateneh Ebola Treatment Centre in central Sierra Leone. The facility included all wetlab and computational resources to rapidly process EBOV diagnostic samples into full genome sequences. We produced 554 EBOV genomes from EVD cases across Sierra Leone. These genomes provided a detailed description of EBOV evolution and facilitated phylogenetic tracking of new EVD cases. Importantly, we show that linked genomic and epidemiological data can not only support contact tracing but also identify unconventional transmission chains involving body fluids, including semen. Rapid EBOV genome sequencing, when linked to epidemiological information and a comprehensive database of virus sequences across the outbreak, provided a powerful tool for public health epidemic control efforts

Development and Implementation of Electronic Disease Early Warning Systems for Optimal Disease Surveillance and Response during Humanitarian Crisis and Ebola Outbreak in Yemen, Somalia, Liberia and Pakistan

Objective: To share lessons learned with experience in concept development of electronic disease early warning system (eDEWS) as a standardized informatic tool for optimal disease surveillance for early warning and response Network (EWARN) during humanitarian crisis.Methods: We did literature search, review and analysis to document system attributes of existing electronic tools being used for disease surveillance, early warning and health management information system (HMIS). We generated baseline information and conducted multiple planning sessions with stakeholders for EWARN system requirement elicitation and validation to inform concept development of standardized electronic tool.Results: We identified 98 electronic health projects, classified 22 projects under ‘Disease and epidemic outbreak surveillance’ theme, whereas only four electronic tools met our selection criteria and were reported to be implemented in humanitarian settings complimentary to EWARN. Baseline information was obtained to guide work on requirement gathering and analysis process, and development of concept for a standardized electronic tool for EWARN.Discussion: The eDEWS was enhanced with an objective to develop standardize electronic tools and data collection procedures to monitor diseases and health events for alert detection in global humanitarian settings. The enhanced system could be harnessed as a powerful tool by outbreak response teams in getting vital epidemiological information for appropriate and timely response during emergencies.Conclusion: eDEWS experiences in Yemen, Somalia, Liberia and Pakistan offers an opportunity to learn and apply lessons to improve future health informatics initiatives or adapt eDEWS as a feasible standardized approach to enhance EWARN implementation during humanitarian crisis, and potential integration into routine surveillance systems

Nodding Syndrome

An epidemic illness characterized by head nodding associated with onchocerciasis has been described in eastern Africa since the early 1960s; we summarize published reports and recent studies. Onset of nodding occurs in previously healthy 5–15-year-old children and is often triggered by eating or cold temperatures and accompanied by cognitive impairment. Its incidence has increased in Uganda and South Sudan over the past 10 years. Four case–control studies identified modest and inconsistent associations. There were nonspecific lesions seen by magnetic resonance imaging, no cerebrospinal fluid inflammation, and markedly abnormal electroencephalography results. Nodding episodes are atonic seizures. Testing has failed to demonstrate associations with trypanosomiasis, cysticercosis, loiasis, lymphatic filariasis, cerebral malaria, measles, prion disease, or novel pathogens; or deficiencies of folate, cobalamin, pyridoxine, retinol, or zinc; or toxicity from mercury, copper, or homocysteine. There is a consistent enigmatic association with onchocerciasis detected by skin snip or serologic analysis. Nodding syndrome is an unexplained epidemic epilepsy

Ebola Virus Infection Associated with Transmission from Survivors

Ebola virus (EBOV) can persist in immunologically protected body sites in survivors of Ebola virus disease, creating the potential to initiate new chains of transmission. From the outbreak in West Africa during 2014–2016, we identified 13 possible events of viral persistence–derived transmission of EBOV (VPDTe) and applied predefined criteria to classify transmission events based on the strength of evidence for VPDTe and source and route of transmission. For 8 events, a recipient case was identified; possible source cases were identified for 5 of these 8. For 5 events, a recipient case or chain of transmission could not be confidently determined. Five events met our criteria for sexual transmission (male-to-female). One VPDTe event led to at least 4 generations of cases; transmission was limited after the other events. VPDTe has increased the importance of Ebola survivor services and sustained surveillance and response capacity in regions with previously widespread transmission