The rise of Zika infection and microcephaly: what can we learn from a public health emergency?

OBJECTIVES: To consider why Zika was declared a Public Health Emergency of International Concern (PHEIC), why it stopped being one and what we can learn from this for the future. STUDY DESIGN: This paper reviews the sequence of events and evidence base for the decision to declare Zika a PHEIC, the global response to this, the challenges in maintaining an evidence-based approach to outbreak response and identifies learning outcomes. METHODS: Evidence review, all published articles in reputable UK and international journals were identified. RESULTS: The association between Zika virus infection and congenital malformations including microcephaly became a PHEIC on 1st February 2016 and was declared to be no longer an emergency in November 2016. This shaped the global response led by WHO in the first global emergency since Ebola in West Africa. CONCLUSION: The response to Zika highlights important issues and lessons for future outbreaks that might pose an international risk. Particular challenges arose in trying to maintain an evidence-based approach to public risk communication when the evidence is unclear or still evolving. The Zika incident also demonstrates the importance of public health practitioners and agencies understanding the political context in which outbreaks must be managed and understanding the competing factors that shape the political response.

What is the experience from previous mass gathering events? Lessons for Zika virus and the Olympics 2016.

All previous experiences from different mass gathering show that vaccine preventable diseases is the most important infections like influemza, hepatitis A, polio and meningitis. Three mass gathering held in Africa during the Ebola outbreak accepted participants from West Africa and was able to handle the theoretical risk without any incident. Therefore we believe that the Olympc games in Rio de Janeiro should not be canceled. The number of visitors to the games is a tine fraction (1%) of other visitors to Zika endemic con tries and it will have no measurable effect on the risk of spreading Zika virus, if the games was cancelled.

Using an Emergency Department Syndromic Surveillance System to investigate the impact of extreme cold weather events.

This report describes the development of novel syndromic cold weather public health surveillance indicators for use in monitoring the impact of extreme cold weather on attendances at EDs, using data from the 2010-11 and 2011-12 winters. A number of new surveillance indicators were created specifically for the identification and monitoring of cold weather related ED attendances, using the diagnosis codes provided for each attendance in the Emergency Department Syndromic Surveillance System (EDSSS), the first national syndromic surveillance system of its kind in the UK. Using daily weather data for the local area, a time series analysis to test the sensitivity of each indicator to cold weather was undertaken. Diagnosis codes relating to a health outcome with a potential direct link to cold weather were identified and assigned to a number of 'cold weather surveillance indicators'. The time series analyses indicated strong correlations between low temperatures and cold indicators in nearly every case. The strongest fit with temperature was cold related fractures in females, and that of snowfall was cold related fractures in both sexes. Though currently limited to a small number of sentinel EDs, the EDSSS has the ability to give near real-time detail on the magnitude of the impact of weather events. EDSSS cold weather surveillance fits well with the aims of the Cold Weather Plan for England, providing information on those particularly vulnerable to cold related health outcomes severe enough to require emergency care. This timely information aids those responding to and managing the effects on human health, both within the EDs themselves and in the community as a whole.

The impact of thunderstorm asthma on emergency department attendances across London during July 2013.

BACKGROUND: This study illustrates the potential of using emergency department attendance data, routinely accessed as part of a national syndromic surveillance system, to monitor the impact of thunderstorm asthma. METHODS: The Emergency Department Syndromic Surveillance System (EDSSS) routinely monitors anonymised attendance data on a daily basis across a sentinel network of 35 emergency departments. Attendance data for asthma, wheeze and difficulty breathing are analysed on a daily basis. RESULTS: A statistically significant spike in asthma attendances in two EDSSS emergency departments in London was detected on 23 July 2013, coinciding with a series of large violent thunderstorms across southern England. There was also an increase in the reported severity of these attendances. CONCLUSIONS: This preliminary report illustrates the potential of the EDSSS to monitor the impact of thunderstorms on emergency department asthma attendances. Further work will focus on how this system can be used to quantify the impact on emergency departments, thus potentially improving resource planning and also adding to the thunderstorm asthma evidence-base.

Using public health scenarios to predict the utility of a national syndromic surveillance programme during the 2012 London Olympic and Paralympic Games.

During 2012 real-time syndromic surveillance formed a key part of the daily public health surveillance for the London Olympic and Paralympic Games. It was vital that these systems were evaluated prior to the Games; in particular what types and scales of incidents could and could not be detected. Different public health scenarios were created covering a range of potential incidents that the Health Protection Agency would require syndromic surveillance to rapidly detect and monitor. For the scenarios considered it is now possible to determine what is likely to be detectable and how incidents are likely to present using the different syndromic systems. Small localized incidents involving food poisoning are most likely to be detected the next day via emergency department surveillance, while a new strain of influenza is more likely to be detected via GP or telephone helpline surveillance, several weeks after the first seed case is introduced.

Implications of CO2 Contamination in Rechargeable Nonaqueous Li-O2 Batteries.

In this Letter, the effect of CO2 contamination on nonaqueous Li-O2 battery rechargeability is explored. Although CO2 contamination was found to increase the cell's discharge capacity, it also spontaneously reacts with Li2O2 (the primary discharge product of a nonaqueous Li-O2 battery) to form Li2CO3. CO2 evolution from Li2CO3 during battery charging was found to occur only at very high potentials (>4 V) compared to O2 evolution from Li2O2 (∼3-3.5 V), and as a result, the presence of CO2 during discharge dramatically reduced the voltaic efficiency of the discharge-charge cycle. These results emphasize the importance of not only completely removing CO2 from air fed to a Li-air battery, but also developing stable cathodes and electrolytes that will not decompose during battery operation to form carbonate deposits.

Developing a new syndromic surveillance system for the London 2012 Olympic and Paralympic Games.

Syndromic surveillance is vital for monitoring public health during mass gatherings. The London 2012 Olympic and Paralympic Games represents a major challenge to health protection services and community surveillance. In response to this challenge the Health Protection Agency has developed a new syndromic surveillance system that monitors daily general practitioner out-of-hours and unscheduled care attendances. This new national system will fill a gap identified in the existing general practice-based syndromic surveillance systems by providing surveillance capability of general practice activity during evenings/nights, over weekends and public holidays. The system will complement and supplement the existing tele-health phone line, general practitioner and emergency department syndromic surveillance systems. This new national system will contribute to improving public health reassurance, especially to meet the challenges of the London 2012 Olympic and Paralympic Games.

Twin Problems of Interfacial Carbonate Formation in Nonaqueous Li-O2 Batteries.

We use XPS and isotope labeling coupled with differential electrochemical mass spectrometry (DEMS) to show that small amounts of carbonates formed during discharge and charge of Li-O2 cells in ether electrolytes originate from reaction of Li2O2 (or LiO2) both with the electrolyte and with the C cathode. Reaction with the cathode forms approximately a monolayer of Li2CO3 at the C-Li2O2 interface, while reaction with the electrolyte forms approximately a monolayer of carbonate at the Li2O2-electrolyte interface during charge. A simple electrochemical model suggests that the carbonate at the electrolyte-Li2O2 interface is responsible for the large potential increase during charging (and hence indirectly for the poor rechargeability). A theoretical charge-transport model suggests that the carbonate layer at the C-Li2O2 interface causes a 10-100 fold decrease in the exchange current density. These twin "interfacial carbonate problems" are likely general and will ultimately have to be overcome to produce a highly rechargeable Li-air battery.

Limitations in Rechargeability of Li-O2 Batteries and Possible Origins.

Quantitative differential electrochemical mass spectrometry (DEMS) is used to measure the Coulombic efficiency of discharge and charge [(e(-)/O2)dis and (e(-)/O2)chg] and chemical rechargeability (characterized by the O2 recovery efficiency, OER/ORR) for Li-O2 electrochemistry in a variety of nonaqueous electrolytes. We find that none of the electrolytes studied are truly rechargeable, with OER/ORR <90% for all. Our findings emphasize that neither the overpotential for recharge nor capacity fade during cycling are adequate to assess rechargeability. Coulometry has to be coupled to quantitative measurements of the chemistry to measure the rechargeability truly. We show that rechargeability in the various electrolytes is limited both by chemical reaction of Li2O2 with the solvent and by electrochemical oxidation reactions during charging at potentials below the onset of electrolyte oxidation on an inert electrode. Possible mechanisms are suggested for electrolyte decomposition, which taken together, impose stringent conditions on the liquid electrolyte in Li-O2 batteries.

Electrical conductivity in Li2O2 and its role in determining capacity limitations in non-aqueous Li-O2 batteries.

Non-aqueous Li-air or Li-O(2) cells show considerable promise as a very high energy density battery couple. Such cells, however, show sudden death at capacities far below their theoretical capacity and this, among other problems, limits their practicality. In this paper, we show that this sudden death arises from limited charge transport through the growing Li(2)O(2) film to the Li(2)O(2)-electrolyte interface, and this limitation defines a critical film thickness, above which it is not possible to support electrochemistry at the Li(2)O(2)-electrolyte interface. We report both electrochemical experiments using a reversible internal redox couple and a first principles metal-insulator-metal charge transport model to probe the electrical conductivity through Li(2)O(2) films produced during Li-O(2) discharge. Both experiment and theory show a "sudden death" in charge transport when film thickness is ~5 to 10 nm. The theoretical model shows that this occurs when the tunneling current through the film can no longer support the electrochemical current. Thus, engineering charge transport through Li(2)O(2) is a serious challenge if Li-O(2) batteries are ever to reach their potential.

From containment to community: Trigger points from the London pandemic (H1N1) 2009 influenza incident response.

OBJECTIVE: In the UK, during the first wave of pandemic (H1N1) 2009 influenza, a national 'containment' strategy was employed from 25 April to 2 July 2009, with case finding, treatment of cases, contact tracing and prophylaxis of close contacts. The aim of the strategy was to delay the introduction and spread of pandemic flu in the UK, provide a better understanding of the course of the novel disease, and thereby allow more time for the development of treatment and vaccination options. STUDY DESIGN: Descriptive study of the management of the containment phase of pandemic (H1N1) 2009 influenza. METHODS: Analysis of data reported to the London Flu Response Centre (LFRC). RESULTS: The average number of telephone calls and faxes per day from health professionals before 15 June 2009 was 188, but this started to rise from 363 on 12 June, to 674 on 15 June, and peaked on 22 June at 2206 calls. The number of cases confirmed [by pandemic (H1N1) 2009 influenza specific H1 and N1 polymerase chain reaction] in London rose to a peak of 200 cases per day. There were widespread school outbreaks reporting large numbers of absences with influenza-like illnesses. Activity in the LFRC intensified to a point where London was declared a 'hot spot' for pandemic (H1N1) 2009 influenza on 19 June 2009 because of sustained community transmission. The local incident response was modified to the 'outbreak management phase' of the containment phase. CONCLUSIONS: The sharp rise in the number of telephone calls and the rise in school outbreaks appeared to be trigger points for community transmission. These indicators should inform decisions on modifying public health strategy in pandemic situations.

Solvents' Critical Role in Nonaqueous Lithium-Oxygen Battery Electrochemistry.

Among the many important challenges facing the development of Li-air batteries, understanding the electrolyte's role in producing the appropriate reversible electrochemistry (i.e., 2Li(+) + O2 + 2e(-) ↔ Li2O2) is critical. Quantitative differential electrochemical mass spectrometry (DEMS), coupled with isotopic labeling of oxygen gas, was used to study Li-O2 electrochemistry in various solvents, including carbonates (typical Li ion battery solvents) and dimethoxyethane (DME). In conjunction with the gas-phase DEMS analysis, electrodeposits formed during discharge on Li-O2 cell cathodes were characterized using ex situ analytical techniques, such as X-ray diffraction and Raman spectroscopy. Carbonate-based solvents were found to irreversibly decompose upon cell discharge. DME-based cells, however, produced mainly lithium peroxide on discharge. Upon cell charge, the lithium peroxide both decomposed to evolve oxygen and oxidized DME at high potentials. Our results lead to two conclusions; (1) coulometry has to be coupled with quantitative gas consumption and evolution data to properly characterize the rechargeability of Li-air batteries, and (2) chemical and electrochemical electrolyte stability in the presence of lithium peroxide and its intermediates is essential to produce a truly reversible Li-O2 electrochemistry.

Syndromic surveillance to assess the potential public health impact of the Icelandic volcanic ash plume across the United Kingdom, April 2010.

The Health Protection Agency and Health Protection Scotland used existing syndromic surveillance systems to monitor community health in the UK following the volcanic eruption in Iceland in April 2010.

The impact of a PCR assay for candidemia on antifungal drug prescribing in critical care: an interrupted time series pilot study.

SUMMARY OBJECTIVE: To evaluate the feasibility of conducting a definitive study to assess the impact of introducing a rapid PCR-based test for candidemia on antifungal drug prescribing. METHOD: Prospective, single centre, interrupted time series study consisting of three periods of six months' duration. The assay was available during the second period, during which the PCR assay was available for routine use by physicians Monday-Friday with guaranteed 24-h turnaround time. For each period total antifungal drug use, expressed as treatment-days, was recorded and an adjustment was made to exclude estimated use for proven candidemia. Also, during the intervention period, antifungal prescribing decisions for up to 72 h after each PCR result became available were recorded as either concordant or discordant with that result. RESULTS: While overall antifungal use remained relatively stable throughout, after adjustment for candidemia, there was a 38% reduction in use following introduction of the PCR test; however, this was nonsignificant at the 95% level. During the intervention period overall concordance between the PCR result and prescribing decisions was 84%. CONCLUSIONS: The PCR assay for candidemia was requested, prescribing decisions were generally concordant with the results produced and there was an apparent decrease in antifungal prescription, although this was sustained even after withdrawal of the intervention; these findings should be more thoroughly evaluated in a larger trial.

Investigations and control measures following a case of inhalation anthrax in East London in a drum maker and drummer, October 2008.

The patient is believed to have acquired the infection from making animal hide drums. Environmental investigations identified one drum and two pieces of animal skins contaminated with anthrax spores.

Comparison of serum and whole-blood specimens for the detection of Candida DNA in critically ill, non-neutropenic patients.

In contrast to the multitude of studies on fungal PCR assay methods, little work has been reported evaluating Candida PCR performance when using whole blood compared with serum in candidaemic patients. Here, a comparison of the performance of whole-blood and serum specimens using a set of real-time PCR Candida species assays is described. Specimens were collected prospectively from non-neutropenic adults who were recruited to a diagnostic clinical trial, the primary purpose of which was to verify the performance of the assays using serum; in all, 104 participants also had whole-blood specimens submitted for analysis in addition to the serum specimen. Of these participants, 10 had laboratory-confirmed candidaemia and 94 were categorized as being 'unlikely' to have invasive Candida infection. PCR results from the whole-blood specimens are presented here and compared with the results from serum specimens in this subgroup among whom both specimen types were obtained contemporaneously. All participants with candidaemia were PCR-positive from serum samples; however, only seven were PCR-positive from whole blood. All specimens from patients in the 'unlikely' category were PCR-negative in both types of specimen. Moreover, DNA extraction from serum required 1 h; extraction from whole blood required approximately 3 h. These data tentatively suggest that, overall, serum is an appropriate specimen for Candida PCR for detection of candidaemia in non-neutropenic adults.

A prospective clinical trial of a real-time polymerase chain reaction assay for the diagnosis of candidemia in nonneutropenic, critically ill adults.

BACKGROUND: Invasive Candida infection among nonneutropenic, critically ill adults is a clinical problem that has received increasing attention in recent years. Poor performance of extant diagnostic modalities has promoted risk-based, preemptive prescribing in view of the poor outcomes associated with inadequate or delayed antifungal therapy; this risks unnecessary overtreatment. A rapid, reliable diagnostic test could have a substantial impact on therapeutic practice in this patient population. METHODS: Three TaqMan-based real-time polymerase chain reaction assays were developed that are capable of detecting the main medically important Candida species, categorized according to the likelihood of fluconazole susceptibility. Assay 1 detected Candida albicans, Candida parapsilosis, Candida tropicalis, and Candida dubliniensis. Assays 2 and 3 detected Candida glabrata and Candida krusei, respectively. The clinical performance of these assays, applied to serum, was evaluated in a prospective trial of nonneutropenic adults in a single intensive care unit. RESULTS: In all, 527 specimens were obtained from 157 participants. All 3 assays were run in parallel for each specimen; they could be completed within 1 working day. Of these, 23 specimens were obtained from 23 participants categorized as having proven Candida infection at the time of sampling. If a single episode of Candida famata candidemia was excluded, the estimated clinical sensitivity, specificity, and positive and negative predictive values of the assays in this trial were 90.9%, 100%, 100% and 99.8%, respectively. CONCLUSIONS: These data suggest that the described assays perform well in this population for enhancing the diagnosis of candidemia. The extent to which they may affect clinical outcomes, prescribing practice, and cost-effectiveness of care remains to be ascertained.