Text 1: Is Australia prepared for the next pandemic?

Infectious diseases continue to threaten global health security, despite decades of advances in hygiene, vaccination and antimicrobial therapies. Population growth, widespread international travel and trade, political instability and climate change have caused rapid changes in human populations, wildlife and agriculture, in turn increasing the risk of infection transmission within and between countries and from animal species. New human pathogens have emerged, and previously “controlled” diseases have re-emerged or expanded their range. In the past decade alone, the global community has experienced infection outbreaks of pandemic influenza, Ebola and Zika viruses and Middle East respiratory syndrome (MERS). Planning for an effective response to the next pandemic is complex and requires extensive engagement between public health experts, clinicians, diagnostic laboratory staff, general and at-risk communities and jurisdictional and federal agencies. An effective response also requires access to real-time data, management of uncertainty, clear and rapid communication, coordination and, importantly, strong leadership. Are all these pieces of the plan currently in place in Australia?

The 2009 influenza pandemic tested Australia’s capacity to respond to a highly transmissible emerging infectious disease. Public health units and frontline practitioners around the country were affected in different ways. The pandemic reached our states and territories at different times, leading to staggered and varied responses and pointing to clear gaps and challenges in logistics and governance. Although higher than usual rates of hospitalisation and intensive care admission, particularly among Aboriginal and Torres Strait Islander people and pregnant women, were observed early in the pandemic, most cases were mild. As the spectrum of disease became apparent, the existing plan, which had been based on a Spanish influenza-like worst-case scenario, was modified. The focus shifted from containing or limiting the spread of disease at a whole-of-population level to mitigation strategies targeted at key risk groups.

In keeping with similar exercises globally, the Review of Australia’s health sector response to pandemic (H1N1) 2009 identified a need for greater flexibility in implementation plans to achieve an optimal response. Improved data sharing and synthesis within and between jurisdictions and internationally was defined as a key priority, to enable better understanding of the situation and evolving needs, to advise evidence-based practice and to inform clear, consistent messaging. The review also recommended development of a set of overarching ethical principles, to guide resource allocation in alignment with community expectations and values and to identify feasible interventions that are not disproportionately disruptive to society (disruptive interventions include social distancing measures such as school and workplace closures or travel restrictions). Failure to engage key populations at risk, including Aboriginal and Torres Strait Islander peoples, in preparedness activities before the 2009 pandemic was recognised as a critical deficiency.

Much has happened since 2009. The Australian health management plan for pandemic influenza, redrafted in 2014, is a nationally agreed plan for flexible and scalable responses in the health sector. It was developed in consultation with key stakeholders, including state and territory health departments and practitioner groups involved in implementing responses. The plan emphasises engaging with existing committees and practitioners to provide input to decision making under the leadership of the Australian Health Protection Principal Committee (AHPPC), the key decision maker in a national health emergency. The plan’s recommendations on the use of infection control measures and pharmaceuticals, including antivirals and vaccines, are based on a wealth of national and international evidence emerging from the 2009 experience. Corresponding efforts have gone into strengthening the National Medical Stockpile and ensuring onshore vaccine manufacturing capacity to safeguard against the emergence of novel influenza strains.

However, influenza is not the only threat to Australia’s health security. Recent outbreaks of MERS and Ebola and Zika virus infections have provided opportunities for the AHPPC and key stakeholders to practise and refine coordination and communication strategies to prevent, prepare for and respond to threats posed to Australians. These new threats highlighted the need to develop response plans that are agile, can be adapted to known and unknown pathogens and syndromes and are well coordinated with international responses. The CDPLAN: Emergency response plan for communicable disease incidents of national significance, released in September 2016, provides a generic national framework for a primary response to outbreaks for which there is no pre-existing disease-specific plan. This plan is supported by the National Framework for Communicable Disease Control, a roadmap to improve national information sharing and facilitate a coordinated response to events of public health importance.

We are unable to predict when the next pandemic will occur or which new pathogen may appear, emphasising that every country must be well prepared. Australia has many pieces of the plan in place, but we must continue to fill gaps, test and refine existing systems and continually review what works to make sure we are as ready as possible for the next emerging infectious disease challenge. Louis Pasteur once said, “Gentlemen, it is the microbes who will have the last word”. We need to ensure that he was wrong!

Text 2: Alzheimer's burden to double by 2060

Alzheimer's disease is a neurological disorder in which the death of brain cells causes memory loss and cognitive decline. At first, symptoms are mild, but they become more severe over time. Alzheimer’s disease also accounts for 60 to 80 percent of cases of dementia in the United States. In 2013, 6.8 million people in the U.S. had been diagnosed with dementia. Of these, 5 million had a diagnosis of Alzheimer's.

Now, a report newly published by the Centers for Disease Control and Prevention estimates that the burden of Alzheimer's disease and related forms of dementia in the United States will double by the year 2060. This neurodegenerative disease is one of the leading causes of disability and the sixth-leading cause of mortality in the U.S. With annual healthcare costs of more than $250 billion, the disease also puts a significant strain on the nation's healthcare system. Additionally, unpaid caregivers spend over 18 billion hours tending to those living with Alzheimer's.

Age is the most significant risk factor for Alzheimer's disease. Thus, as the population of the United States — along with that of the world — increases, it is important to ask: how many people will develop this form of dementia in the coming decades? Researchers from the Centers for Disease Control and Prevention (CDC) set out to investigate, and they published their findings in Alzheimer's & Dementia: The Journal of the Alzheimer's Association. Researcher Kevin Matthews, who currently works at the CDC's National Center for Chronic Disease Prevention and Health Promotion in Atlanta, GA, is the first author of the paper. He and his colleagues also looked at race and ethnicity, which are two "important demographic risk factors" for Alzheimer's. This made the study the first to predict Alzheimer's prevalence based on race and ethnicity.

Matthews and his colleagues used population projections obtained from the U.S. Census Bureau to calculate the projected number of seniors with Alzheimer's in the year 2060. To calculate the number of people living with Alzheimer's disease, researchers accessed data from the Centers for Medicare & Medicaid Services; specifically, they examined the number of Medicare Fee-for-Service beneficiaries aged 65 and above. The study revealed that compared with 2014, when the number of people with Alzheimer's disease and other forms of dementia was 5 million, in 2060, this number will grow to 13.9 million. In terms of the population percentage, it represents an increase from 1.6 percent of the entire U.S. population in 2014 to 3.3 percent of the projected U.S. population in 2060. "Alzheimer's disease and other dementias burden will double to 3.3 percent by 2060 when 13.9 million Americans are projected to have the disease," write the study authors.

Also, the authors caution that in 2060, 3.2 million Hispanic people and 2.2 million African American people aged 65 and above will be living with the condition. African American people have the highest risk of developing Alzheimer's and other dementias; 13.8 percent of African American people who are aged 65 and over have the condition. Hispanic people fall second, with 12.2 percent, and non-Hispanic white people come third, with 10.3 percent. American Indian people and Alaska Natives fall fourth in the line-up, with 9.1 percent, and Asian and Pacific Islanders come fifth, with 8.4 percent. "These estimates," conclude the authors, "can be used to guide planning and interventions related to caring for the Alzheimer's disease and related dementias population and supporting caregivers."

Dr Robert R. Redfield, the director of the CDC, commented on the findings, saying, "Early diagnosis is key to helping people and their families cope with loss of memory, navigate the healthcare system, and plan for their care in the future. This study shows that as the U.S. population increases, the number of people affected by Alzheimer's disease and related dementias will rise, especially among minority populations."