SARS-CoV-2 variants of interest and concern naming scheme conducive for global discourse

A group convened and led by the Virus Evolution Working Group of the World Health Organization reports on its deliberations and announces a naming scheme that will enable clear communication about SARS-CoV-2 variants of interest and concern.Molecular basis of virus replication, viral pathogenesis and antiviral strategie

A quantitative framework for defining the end of an infectious disease outbreak: application to Ebola virus disease

The end-of-outbreak declaration is an important step in controlling infectious disease outbreaks. Objective estimation of the confidence level that an outbreak is over is important to reduce the risk of postdeclaration flare-ups. We developed a simulation-based model with which to quantify that confidence and tested it on simulated Ebola virus disease data. We found that these confidence estimates were most sensitive to the instantaneous reproduction number, the reporting rate, and the time between the symptom onset and death or recovery of the last detected case. For Ebola virus disease, our results suggested that the current World Health Organization criterion of 42 days since the recovery or death of the last detected case is too short and too sensitive to underreporting. Therefore, we suggest a shift to a preliminary end-of-outbreak declaration after 63 days from the symptom onset day of the last detected case. This preliminary declaration should still be followed by 90 days of enhanced surveillance to capture potential flare-ups of cases, after which the official end of the outbreak can be declared. This sequence corresponds to more than 95% confidence that an outbreak is over in most of the scenarios examined. Our framework is generic and therefore could be adapted to estimate end-of-outbreak confidence for other infectious diseases

Incidence and patterns of detection and management of childhood-onset hereditary retinal disorders in the UK

Background: A prospective, national population-based cross-sectional study to enable understanding of the burden and management in the UK of hereditary retinal disorders presenting in childhood. Methods: Children aged <16 years with a new diagnosis of an inherited retinal disorder made between September 2006 and February 2008 in the UK were identified through two national active surveillance schemes. Clinical and socio-demographic information was collected on each child at diagnosis and 9 months later using standardised questionnaires. Results 241 patients were reported with 24 distinct diagnoses. 14% had additional systemic disorders and 13% had dual sensory impairment. Annual incidence was 1.4/100 000 children (aged 0–15 years) and the cumulative incidence by age 16 years was 22.3/100 000 children. The most common mode of inheritance was autosomal recessive. A significantly higher rate was seen in males than females (relative rate (RR) 1.53), in children of Asian compared with White ethnicity (RR 7.12) and in those in the worst quintile of socio-economic deprivation compared with those in the best (RR 1.43). Parents most commonly detected a problem with their child's vision. Up to seven different health professionals were involved in a child's early management, and variations were noted in the proportion of eligible children having assessments for low vision aids, statement of educational needs and certification as sight-impaired. Conclusions: These findings illustrate the highly heterogeneous nature of childhood retinal dystrophies and provide previously unavailable data on disease incidence, distributions and management, which are important for service provision and for planning future treatment programmes, particularly as novel therapies become available

The challenges of detecting and responding to a Lassa fever outbreak in an Ebola-affected setting

Objectives: Lassa fever (LF), a priority emerging pathogen likely to cause major epidemics, is endemic in much of West Africa and is difficult to distinguish from other viral hemorrhagic fevers, including Ebola virus disease (EVD). Definitive diagnosis requires laboratory confirmation, which is not widely available in affected settings. The public health action to contain a LF outbreak and the challenges encountered in an EVD-affected setting are reported herein. Methods: In February 2016, a rapid response team was deployed in Liberia in response to a cluster of LF cases. Active case finding, case investigation, contact tracing, laboratory testing, environmental investigation, risk communication, and community awareness raising were undertaken. Results: From January to June 2016, 53 suspected LF cases were reported through the Integrated Disease Surveillance and Response system (IDSR). Fourteen cases (26%) were confirmed for LF, 14 (26%) did not have a sample tested, and 25 (47%) were classified as not a case following laboratory analysis. The case fatality rate in the confirmed cases was 29%. One case of international exportation was reported from Sweden. Difficulties were identified in timely specimen collection, packaging, and transportation (in confirmed cases, the time from sample collection to sample result ranged from 2 to 64 days) and a lack of response interventions for early cases. Conclusions: The delay in response to this outbreak could have been related to a number of challenges in this EVD-affected setting: a need to strengthen the IDSR system, develop preparedness plans, train rapid response teams, and build laboratory capacity. Prioritizing these actions will aid in the timely response to future outbreaks

The World Health Organization’s public health intelligence activities during the COVID-19 pandemic response, December 2019 to December 2021

The coronavirus disease (COVID-19) presented a unique opportunity for the World Health Organization (WHO) to utilise public health intelligence (PHI) for pandemic response. WHO systematically captured mainly unstructured information (e.g. media articles, listservs, community-based reporting) for public health intelligence purposes. WHO used the Epidemic Intelligence from Open Sources (EIOS) system as one of the information sources for PHI. The processes and scope for PHI were adapted as the pandemic evolved and tailored to regional response needs. During the early months of the pandemic, media monitoring complemented official case and death reporting through the International Health Regulations mechanism and triggered alerts. As the pandemic evolved, PHI activities prioritised identifying epidemiological trends to supplement the information available through indicator-based surveillance reported to WHO. The PHI scope evolved over time to include vaccine introduction, emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, unusual clinical manifestations and upsurges in cases, hospitalisation and death incidences at subnational levels. Triaging the unprecedented high volume of information challenged surveillance activities but was managed by collaborative information sharing. The evolution of PHI activities using multiple sources in WHO’s response to the COVID-19 pandemic illustrates the future directions in which PHI methodologies could be developed and used.</jats:p