Long, thin transmission chains of Severe Acute Respiratory Syndrome Coronavirus 2 may go undetected for several weeks at low to moderate reproduction numbers: Implications for containment and elimination strategy.

Severe Acute Respiratory Syndrome Coronavirus 1 (SARS-CoV-1) infections almost always caused overt symptoms, so effective case and contact management enabled its effective eradication within months. However, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) usually causes only mild symptoms, so transmission chains may grow to include several individuals before at least one index case becomes ill enough to self-report for diagnosis and care. Here, simple mathematical models were developed to evaluate the implications of delayed index case detection for retrospective contact tracing and management responses. Specifically, these simulations illustrate how: (1) Contact tracing and management may effectively contain most but not all large SARS-CoV-2 clusters arising at foci with high reproduction numbers because rapidly expanding transmission chains ensure at least one overtly symptomatic index case occurs within two viral generations a week or less apart. (2) However, lower reproduction numbers give rise to thinner transmission chains extending through longer sequences of non-reporting asymptomatic and paucisymptomatic individuals, often spanning three or more viral generations (≥2 weeks of transmission) before an overtly symptomatic index case occurs. (3) Consequently, it is not always possible to fully trace and contain such long, thin transmission chains, so the community transmission they give rise to is underrepresented in surveillance data. (4) Wherever surveillance systems are weak and/or transmission proceeds within population groups with lower rates of overt clinical symptoms and/or self-reporting, case and contact management effectiveness may be more severely limited, even at the higher reproduction numbers associated with larger outbreaks. (5) Because passive surveillance platforms may be especially slow to detect the thinner transmission chains that occur at low reproduction numbers, establishing satisfactory confidence of elimination may require that no confirmed cases are detected for two full months, throughout which presumptive preventative measures must be maintained to ensure complete collapse of undetected residual transmission. (6) Greater scope exists for overcoming these limitations by enhancing field surveillance for new suspected cases than by improving diagnostic test sensitivity. (7) While population-wide active surveillance may enable complete traceability and containment, this goal may also be achievable through enhanced passive surveillance for paucisymptomatic infections, combining readily accessible decentralized testing with population hypersensitization to self-reporting with mild symptoms. Containment and elimination of SARS-CoV-2 will rely far more upon presumptive, population-wide prevention measures than was necessary for SARS-CoV-1, necessitating greater ambition, political will, investment, public support, persistence and patience. Nevertheless, case and contact management may be invaluable for at least partially containing SARS-CoV-2 transmission, especially larger outbreaks, but only if enabled by sufficiently sensitive surveillance. Furthermore, consistently complete transmission chain containment may be enabled by focally enhanced surveillance around manageably small numbers of outbreaks in the end stages of successful elimination campaigns, so that their endpoints may be accelerated and sustained.

Community first responders for out-of-hospital cardiac arrest in adults and children.

BACKGROUND: Mobilization of community first responders (CFRs) to the scene of an out-of-hospital cardiac arrest (OHCA) event has been proposed as a means of shortening the interval from occurrence of cardiac arrest to performance of cardiopulmonary resuscitation (CPR) and defibrillation, thereby increasing patient survival. OBJECTIVES: To assess the effect of mobilizing community first responders (CFRs) to out-of-hospital cardiac arrest events in adults and children older than four weeks of age, in terms of survival and neurological function. SEARCH METHODS: We searched the following databases for relevant trials in January 2019: CENTRAL, MEDLINE (Ovid SP), Embase (Ovid SP), and Web of Science. We also searched the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov, and we scanned the abstracts of conference proceedings of the American Heart Association and the European Resuscitation Council. SELECTION CRITERIA: We included randomized and quasi-randomized trials (RCTs and q-RCTs) that compared routine emergency medical services (EMS) care versus EMS care plus mobilization of CFRs in instances of OHCA.Trials with randomization by cluster were eligible for inclusion, including cluster-design studies with intervention cross-over.In some communities, the statutory ambulance service/EMS is routinely provided by the local fire service. For the purposes of this review, this group represents the statutory ambulance service/EMS, as distinct from CFRs, and was not included as an eligible intervention.We did not include studies primarily focused on opportunistic bystanders. Individuals who were present at the scene of an OHCA event and who performed CPR according to telephone instruction provided by EMS call takers were not considered to be CFRs.Studies primarily assessing the impact of specific additional interventions such as administration of naloxone in narcotic overdose or adrenaline in anaphylaxis were also excluded.We included adults and children older than four weeks of age who had experienced an OHCA. DATA COLLECTION AND ANALYSIS: Two review authors independently reviewed all titles and abstracts received to assess potential eligibility, using set inclusion criteria. We obtained and examined in detail full-text copies of all papers considered potentially eligible, and we approached authors of trials for additional information when necessary. We summarized the process of study selection in a PRISMA flowchart.Three review authors independently extracted relevant data using a standard data extraction form and assessed the validity of each included trial using the Cochrane 'Risk of bias' tool. We resolved disagreements by discussion and consensus.We synthesized findings in narrative fashion due to the heterogeneity of the included studies. We used the principles of the GRADE system to assess the certainty of the body of evidence associated with specific outcomes and to construct a 'Summary of findings' table. MAIN RESULTS: We found two completed studies involving a total of 1136 participants that ultimately met our inclusion criteria. We also found one ongoing study and one planned study. We noted significant heterogeneity in the characteristics of interventions and outcomes measured or reported across these studies, thus we could not pool study results.One completed study considered the dispatch of police and fire service CFRs equipped with automatic external defibrillators (AEDs) in an EMS system in Amsterdam and surrounding areas. This study was an RCT with allocation made by cluster according to non-overlapping geographical regions. It was conducted between 5 January 2000 and 5 January 2002. All participants were 18 years of age or older and had experienced witnessed OHCA. The study found no difference in survival at hospital discharge (odds ratio (OR) 1.3, 95% confidence interval (CI) 0.8 to 2.2; 1 RCT; 469 participants; low-certainty evidence), despite the observation that all 72 incidences of defibrillation performed before EMS arrival occurred in the intervention group (OR and 95% CI - not applicable; 1 RCT; 469 participants; moderate-certainty evidence). This study reported increased survival to hospital admission in the intervention group (OR 1.5, 95% CI 1.1 to 2.0; 1 RCT; 469 participants; moderate-certainty evidence).The second completed study considered the dispatch of nearby lay volunteers in Stockholm, Sweden, who were trained to perform cardiopulmonary resuscitation (CPR). This represented a supplementary CFR intervention in an EMS system where police and fire services were already routinely dispatched to OHCA in addition to EMS ambulances. This study, an RCT, included both witnessed and unwitnessed OHCA and was conducted between 1 April 2012 and 1 December 2013. Participants included adults and children eight years of age and older. Researchers found no difference in 30-day survival (OR 1.34, 95% CI 0.79 to 2.29; 1 RCT; 612 participants; low-certainty evidence), despite a significant increase in CPR performed before EMS arrival (OR 1.49, 95% CI 1.09 to 2.03; 1 RCT; 665 participants; moderate-certainty evidence).Neither of the included completed studies considered neurological function at hospital discharge or at 30 days, measured by cerebral performance category or by any other means. Neither of the included completed studies considered health-related quality of life. The overall certainty of evidence for the outcomes of included studies was low to moderate. AUTHORS' CONCLUSIONS: Moderate-certainty evidence shows that context-specific CFR interventions result in increased rates of CPR or defibrillation performed before EMS arrival. It remains uncertain whether this can translate to significantly increased rates of overall patient survival. When possible, further high-quality RCTs that are adequately powered to measure changes in survival should be conducted.The included studies did not consider survival with good neurological function. This outcome is likely to be important to patients and should be included routinely wherever survival is measured.We identified one ongoing study and one planned trial whose results once available may change the results of this review. As this review was limited to randomized and quasi-randomized trials, we may have missed some important data from other study types.

Paediatric airway management and concerns: a survey of advanced paramedics in Ireland.

BACKGROUND: Paediatric airway management is of fundamental importance in the critically unwell child. Pre-hospital paediatric airway management especially endotracheal intubation is however controversial. AIM: To explore Irish Advanced Paramedics (APs) training, experience and clinical practice in paediatric airway management as well as to examine clinician attitudes toward this topic. METHODS: An anonymous online survey of all graduates of the University College Dublin AP training program (N = 453). RESULTS: With duplicates and failed email deliveries excluded a valid sample of 382 individuals was obtained from whom a response rate of 185/382 (48.4%) was achieved. Three quarters of responding APs worked in urban or mixed practice with the remaining minority operating primarily in rural areas. One quarter of responding APs reported formal training in paediatric intubation. Almost 70% of APs had encountered a child requiring significant airway management in the preceding year. However, this was a rare exposure in terms of overall workload. Basic airway adjuncts were used frequently in such circumstances, with endotracheal intubation having been attempted by only a small minority of APs. Lack of practice was identified by many responding APs as a key issue causing concern in terms of paediatric intubation. CONCLUSION: Paediatric airway management has key relevance for pre-hospital care in Ireland. The overall frequency of exposure to children who may benefit from definitive airway management is however likely to represent a significant barrier to the acquisition and maintenance of competency. The ongoing practice of pre-hospital paediatric intubation by APs may not justify its risks.

Mapping the potential of community first responders to increase cardiac arrest survival.

Objective: Resuscitation from out-of-hospital cardiac arrest (OHCA) is largely determined by the availability of cardiopulmonary resuscitation (CPR) and defibrillation within 5-10 min of collapse. The potential contribution of organised groups of volunteers to delivery of CPR and defibrillation in their communities has been little studied. Ireland has extensive networks of such volunteers; this study develops and tests a model to examine the potential impact at national level of these networks on early delivery of care. Methods: A geographical information systems study considering all statutory ambulance resource locations and all centre point locations for community first responder (CFR) schemes that operate in Ireland were undertaken. ESRI ArcGIS Desktop 10.4 was used to map CFR and ambulance base locations. ArcGIS Online proximity analysis function was used to model 5-10 min drive time response areas under sample peak and off-peak conditions. Response areas were linked to Irish population census data so as to establish the proportion of the population that have the potential to receive a timely cardiac arrest emergency response. Results: This study found that CFRs are present in many communities throughout Ireland and have the potential to reach a million additional citizens before the ambulance service and within a timeframe where CPR and defibrillation are likely to be effective treatments. Conclusion: CFRs have significant potential to contribute to survival following OHCA in Ireland. Further research that examines the processes, experiences and outcomes of CFR involvement in OHCA resuscitation should be a scientific priority.

Ten years of cardiac arrest resuscitation in Irish general practice.

AIM: The aim of this study is to establish the role and outcome of general practitioner (GP) involvement in out of hospital cardiac arrest (OHCA) resuscitation in the Republic of Ireland. METHODS: A ten year prospective observational study involving a cohort of Irish general practices. SETTING: 521 general practice settings distributed throughout the Republic of Ireland, representing approximately one quarter of all practices and a third of Irish GPs. PARTICIPANTS: 534 patients suffering cardiac arrest in the community for whom resuscitation was attempted. INTERVENTIONS: Cardiac arrest with resuscitation attempted (CARA) in which a GP played a role. RESULTS: Over a ten year period almost half of participating practices reported one or more CARAs. A total of 534 CARAs were reported at a variety of locations; 161 (30%) had ROSC (return of spontaneous circulation) at some point, with outcome data available for 147/161; 90 patients survived to hospital discharge. Most survivors for whom follow up data are available were discharged home and were completely independent. The highest rate of survival was achieved when CARAs occurred at a GP practice premises (47.4%). CONCLUSIONS: Resuscitation following OHCA is a key task in general practice. Over time a significant number of GPs encounter OHCA, attempt resuscitation and achieve higher survival to hospital discharge rates than occur nationally among OHCAs in Ireland. We conclude that a defibrillator should be routinely available at all general practices and staff should have appropriate resuscitation skills.

Count every newborn; a measurement improvement roadmap for coverage data.

BACKGROUND: The Every Newborn Action Plan (ENAP), launched in 2014, aims to end preventable newborn deaths and stillbirths, with national targets of ≤12 neonatal deaths per 1000 live births and ≤12 stillbirths per 1000 total births by 2030. This requires ambitious improvement of the data on care at birth and of small and sick newborns, particularly to track coverage, quality and equity. METHODS: In a multistage process, a matrix of 70 indicators were assessed by the Every Newborn steering group. Indicators were graded based on their availability and importance to ENAP, resulting in 10 core and 10 additional indicators. A consultation process was undertaken to assess the status of each ENAP core indicator definition, data availability and measurement feasibility. Coverage indicators for the specific ENAP treatment interventions were assigned task teams and given priority as they were identified as requiring the most technical work. Consultations were held throughout. RESULTS: ENAP published 10 core indicators plus 10 additional indicators. Three core impact indicators (neonatal mortality rate, maternal mortality ratio, stillbirth rate) are well defined, with future efforts needed to focus on improving data quantity and quality. Three core indicators on coverage of care for all mothers and newborns (intrapartum/skilled birth attendance, early postnatal care, essential newborn care) have defined contact points, but gaps exist in measuring content and quality of the interventions. Four core (antenatal corticosteroids, neonatal resuscitation, treatment of serious neonatal infections, kangaroo mother care) and one additional coverage indicator for newborns at risk or with complications (chlorhexidine cord cleansing) lack indicator definitions or data, especially for denominators (population in need). To address these gaps, feasible coverage indicator definitions are presented for validity testing. Measurable process indicators to help monitor health service readiness are also presented. A major measurement gap exists to monitor care of small and sick babies, yet signal functions could be tracked similarly to emergency obstetric care. CONCLUSIONS: The ENAP Measurement Improvement Roadmap (2015-2020) outlines tools to be developed (e.g., improved birth and death registration, audit, and minimum perinatal dataset) and actions to test, validate and institutionalise proposed coverage indicators. The roadmap presents a unique opportunity to strengthen routine health information systems, crosslinking these data with civil registration and vital statistics and population-based surveys. Real measurement change requires intentional transfer of leadership to countries with the greatest disease burden and will be achieved by working with centres of excellence and existing networks.

Using serology to assist with complicated post-exposure prophylaxis for rabies and Australian bat lyssavirus.

BACKGROUND: Australia uses a protocol combining human rabies immunoglobulin (HRIG) and rabies vaccine for post-exposure prophylaxis (PEP) of rabies and Australian bat lyssavirus (ABLV), with the aim of achieving an antibody titre of ≥0.5 IU/ml, as per World Health Organization (WHO) guidelines, as soon as possible. METHODOLOGY/PRINCIPAL FINDINGS: We present the course of PEP administration and serological testing for four men with complex requirements. Following dog bites in Thailand, two men (62 years old, 25 years old) received no HRIG and had delayed vaccine courses: 23 days between dose two and three, and 18 days between dose one and two, respectively. Both seroconverted following dose four. Another 62-year-old male, who was HIV-positive (normal CD4 count), also suffered a dog bite and had delayed care receiving i.m. rabies vaccine on days six and nine in Thailand. Back in Australia, he received three single and one double dose i.m. vaccines followed by another double dose of vaccine, delivered intradermally and subcutaneously, before seroconverting. A 23-year-old male with a history of allergies received simultaneous HRIG and vaccine following potential ABLV exposure, and developed rash, facial oedema and throat tingling, which was treated with a parenteral antihistamine and tapering dose of steroids. Serology showed he seroconverted following dose four. CONCLUSIONS/SIGNIFICANCE: These cases show that PEP can be complicated by exposures in tourist settings where reliable prophylaxis may not be available, where treatment is delayed or deviates from World Health Organization recommendations. Due to the potentially short incubation time of rabies/ABLV, timely prophylaxis after a potential exposure is needed to ensure a prompt and adequate immune response, particularly in patients who are immune-suppressed or who have not received HRIG. Serology should be used to confirm an adequate response to PEP when treatment is delayed or where a concurrent immunosuppressing medical condition or therapy exists.