Beverley J. Paterson

Case Definitions, Diagnostic Algorithms, and Priorities in Encephalitis: Consensus Statement of the International Encephalitis Consortium

BACKGROUND Encephalitis continues to result in substantial morbidity and mortality worldwide. Advances in diagnosis and management have been limited, in part, by a lack of consensus on case definitions, standardized diagnostic approaches, and priorities for research. METHODS In March 2012, the International Encephalitis Consortium, a committee begun in 2010 with members worldwide, held a meeting in Atlanta to discuss recent advances in encephalitis and to set priorities for future study. RESULTS We present a consensus document that proposes a standardized case definition and diagnostic guidelines for evaluation of adults and children with suspected encephalitis. In addition, areas of research priority, including host genetics and selected emerging infections, are discussed. CONCLUSIONS We anticipate that this document, representing a synthesis of our discussions and supported by literature, will serve as a practical aid to clinicians evaluating patients with suspected encephalitis and will identify key areas and approaches to advance our knowledge of encephalitis.

Consensus guidelines for the investigation and management of encephalitis in adults and children in Australia and New Zealand

Encephalitis is a complex neurological syndrome caused by inflammation of the brain parenchyma. The management of encephalitis is challenging because: the differential diagnosis of encephalopathy is broad; there is often rapid disease progression; it often requires intensive supportive management; and there are many aetiologic agents for which there is no definitive treatment. Patients with possible meningoencephalitis are often encountered in the emergency care environment where clinicians must consider differential diagnoses, perform appropriate investigations and initiate empiric antimicrobials. For patients who require admission to hospital and in whom encephalitis is likely, a staged approach to investigation and management is preferred with the potential involvement of multiple medical specialties. Key considerations in the investigation and management of patients with encephalitis addressed in this guideline include: Which first-line investigations should be performed?; Which aetiologies should be considered possible based on clinical features, risk factors and radiological features?; What tests should be arranged in order to diagnose the common causes of encephalitis?; When to consider empiric antimicrobials and immune modulatory therapies?; and What is the role of brain biopsy?

The remarkable adaptability of syndromic surveillance to meet public health needs

Abstract The goal of syndromic surveillance is the earlier detection of epidemics, allowing a timelier public health response than is possible using traditional surveillance methods. Syndromic surveillance application for public health purposes has changed over time and reflects a dynamic evolution from the collection, interpretation of data with dissemination of data to those who need to act, to a more holistic approach that incorporates response as a core component of the surveillance system. Recent infectious disease threats, such as severe acute respiratory syndrome (SARS), avian influenza (H5N1) and pandemic influenza (H1N1), have all highlighted the need for countries to be rapidly aware of the spread of infectious diseases within a region and across the globe. The International Health Regulations (IHR) obligation to report public health emergencies of international concern has raised the importance of early outbreak detection and response. The emphasis in syndromic surveillance is changing from automated, early alert and detection, to situational awareness and response. Published literature on syndromic surveillance reflects the changing nature of public health threats and responses. Syndromic surveillance has demonstrated a remarkable ability to adapt to rapidly shifting public health needs. This adaptability makes it a highly relevant public health tool.

Pacific-wide simplified syndromic surveillance for early warning of outbreaks

The International Health Regulations require timely detection and response to outbreaks. Many attempts to set up an outbreak early warning system in Pacific island countries and territories (PICTs) have failed. Most were modelled on systems from large countries; large amounts of data often overwhelmed small public health teams. Many conditions required overseas laboratory confirmation, further reducing timeliness and completeness. To improve timeliness and reduce the data burden, simplified surveillance was proposed, with case definitions based on clinical signs and symptoms without the need for laboratory confirmation or information on symptoms, location, sex and age. After trials in three PICTs, this system was implemented throughout the Pacific. Enthusiastic adoption by public health staff resulted in 20 of 22 PICTs reporting weekly to the World Health Organization within 12 months of starting to use the system. In the first year, the system has detected many infectious disease outbreaks and facilitated timely implementation of control measures. For several Pacific countries and territories, this is the first functional and timely infectious disease surveillance system. When outbreak detection is the principal objective, simplification of surveillance should be a priority in countries with a limited public health system capacity.

Sustaining surveillance: Evaluating syndromic surveillance in the Pacific

Prior to the 2009 H1N1 pandemic, the Pacific Island Countries and Territories (PICTs) had agreed to develop a standardised, simple syndromic surveillance system to ensure compliance with International Health Regulations requirements (rapid outbreak detection, information sharing and response to outbreaks). In October 2010, the new system was introduced and over the next 12 months implemented in 20 of 22 PICTs. An evaluation was conducted to identify strengths and weaknesses of the system, ease of use and possible points for improvement. An in-country quantitative and qualitative evaluation in five PICTs identified that the most important determinants of the systems success were: simplicity of the system; support from all levels of government; clearly defined roles and responsibilities; feedback to those who collect the data; harmonisation of case definitions; integration of data collection tools into existing health information systems; and availability of clinical and epidemiological advice from external agencies such as the World Health Organization and the Secretariat of the Pacific Community. Regional reporting of alerts, outbreaks and outbreak updates has dramatically increased since implementation of the system. This syndromic system will assist PICTs to detect future influenza pandemics and other emerging infectious diseases and to rapidly contain outbreaks in the Pacific.

A review of the epidemiology and surveillance of viral zoonotic encephalitis and the impact on human health in Australia.

Human encephalitis in Australia causes substantial mortality and morbidity, with frequent severe neurological sequelae and long-term cognitive impairment. This review discusses a number of highly pathogenic zoonotic viruses which have recently emerged in Australia, including Hendra virus and Australian bat lyssavirus which present with an encephalitic syndrome in humans. Encephalitis surveillance currently focuses on animals at sentinel sites and animal disease or definitive diagnosis of notifiable conditions that may present with encephalitis. This is inadequate for detecting newly emerged viral encephalatides. Hospital-based sentinel surveillance may aid in identifying increases in known pathogens or emergence of new pathogens that require a prompt public health response.

Acute flaccid paralysis incidence and Zika virus surveillance, Pacific Islands

Abstract Problem The emergence of Zika virus has challenged outbreak surveillance systems in many at-risk, low-resource countries. As the virus has been linked with Guillain–Barré syndrome, routine data on the incidence of acute flaccid paralysis (AFP) may provide a useful early warning system for the emergence of Zika virus. Approach We documented all Zika virus outbreaks and cases in 21 Pacific Islands and territories for the years 2007 to 2015. We extracted data from the Global Polio Eradication Initiative database on the reported and expected annual incidence of AFP in children younger than 15 years. Using a Poisson probability test, we tested the significance of unexpected increases in AFP in years correlating with Zika virus emergence. Data were analysed separately for each Pacific Island country and territory. Local setting In most Pacific Island countries, early warning surveillance for acute public health threats such as Zika virus is hampered by poor health infrastructure, insufficient human resources and geographical isolation. Relevant changes Only one example was found (Solomon Islands in 2015) of a significant increase in reported AFP cases correlating with Zika virus emergence. Lessons learnt We found no conclusive evidence that routinely reported AFP incidence data in children were useful for detecting emergence of Zika virus in this setting. More evidence may be needed from adult populations, who are more likely to be affected by Guillain–Barré syndrome. Reporting of AFP may be deficient in regions certified as polio-free.

Understanding human - bat interactions in NSW, Australia: improving risk communication for prevention of Australian bat lyssavirus

BackgroundAustralian bat lyssavirus (ABLV) infects a number of flying fox and insectivorous bats species in Australia. Human infection with ABLV is inevitably fatal unless prior vaccination and/or post-exposure treatment (PET) is given. Despite ongoing public health messaging about the risks associated with bat contact, surveillance data have revealed a four-fold increase in the number of people receiving PET for bat exposure in NSW between 2007 and 2011. Our study aimed to better understand these human – bat interactions in order to identify additional risk communication messages that could lower the risk of potential ABLV exposure. All people aged 18 years or over whom received PET for non-occupation related potential ABLV exposure in the Hunter New England Local Health District of Australia between July 2011 and July 2013 were considered eligible for the study. Eligible participants were invited to a telephone interview to explore the circumstances of their bat contact. Interviews were then transcribed and thematically analysed by two independent investigators.ResultsOf 21 eligible participants that were able to be contacted, 16 consented and participated in a telephone interview. Participants reported bats as being widespread in their environment but reported a general lack of awareness about ABLV, particularly the risk of disease from bat scratches. Participants who attempted to ‘rescue’ bats did so because of a deep concern for the bat’s welfare. Participants reported a change in risk perception after the exposure event and provided suggestions for public health messages that could be used to raise awareness about ABLV.ConclusionsReframing the current risk messages to account for the genuine concern of people for bat welfare may enhance the communication. The potential risk to the person and possible harm to the bat from an attempted ‘rescue’ should be promoted, along with contact details for animal rescue groups. The potential risk of ABLV from bat scratches merits greater emphasis.

Historical data and modern methods reveal insights in measles epidemiology: a retrospective closed cohort study

Objectives Measles was endemic in England during the early 1800s; however, it did not arrive in Australia until 1850 whereas other infectious diseases were known to have arrived much earlier—many with the First Fleet in 1788—leading to the question of why there was a difference. Design Ships surgeons’ logbooks from historical archives, 1829–1882, were retrospectively reviewed for measles outbreak data. Infectious disease modelling techniques were applied to determine whether ships would reach Australia with infectious measles cases. Setting Historical ship surgeon logbooks of measles outbreaks occurring on journeys from Britain to Australia were examined to provide new insights into measles epidemiology. Primary and secondary outcome measures Serial intervals and basic reproduction numbers (R0), immunity, outbreak generations, age-distribution, within-family transmission and outbreak lengths for measles within these closed cohorts. Results Five measles outbreaks were identified (163 cases). The mean serial interval (101 cases) was 12.3 days (95% CI 12.1 to 12.5). Measles R0 (95 cases) ranged from 7.7–10.9. Immunity to measles was lowest among children ≤10 years old (range 37–42%), whereas 94–97% of adults appeared immune. Outbreaks ranged from 4–6 generations and, before 1850, were 41 and 38 days in duration. Two outbreaks after 1850 lasted longer than 70 days and one lasted 32 days. Conclusions Measles syndrome reporting in a ship surgeons logs provided remarkable detail on prevaccination measles epidemiology in the closed environment of ship voyages. This study found lower measles R0 and a shorter mean clinical serial interval than is generally reported. Archival ship surgeon log books indicate it was unlikely that measles was introduced into Australia before 1850, owing to high levels of pre-existing immunity in ship passengers, low numbers of travelling children and the journeys length from England to Australia.

Measurement of surveillance signal response effectiveness

report the limitations and benefi ts of the use of internet-based syndromic surveillance systems to monitor and detect infectious disease syndromes, notably influenza-like illness and dengue. They show in their Review the success of surveillance systems in improving early detection of infectious diseases. They note the crucial issue that few studies have explored how these types of surveillance systems are translated into public health responses. We contend that it is important to understand the effect, beyond timeliness, that these surveillance systems have on public health responses. We postulate that the scarcity of published work on this subject is not a result of limited use of surveillance systems or because this literature is not useful to public health practitioners, but rather that there are few ways to measure the eff ectiveness of the response to the systems. Frameworks and guidelines