Before the COVID pandemic, the World Health Organization (WHO) had made a list of priority infectious diseases. These were felt to pose a threat to international public health, but where research was still needed to improve their surveillance and diagnosis. In 2018, “disease X” was included, which signified that a pathogen previously not on our radar could cause a pandemic.

While it’s one thing to acknowledge the limits to our knowledge of the microbial soup we live in, more recent attention has focused on how we might systematically approach future pandemic risks.

Former US Secretary of Defense Donald Rumsfeld famously talked about “known knowns” (things we know we know), “known unknowns” (things we know we don’t know), and “unknown unknowns” (the things we don’t know we don’t know).

Although this may have been controversial in its original context of weapons of mass destruction, it provides a way to think about how we might approach future pandemic threats.

Influenza: a ‘known known’

Influenza is largely a known entity; we essentially have a minor pandemic every winter with small changes in the virus each year. But more major changes can also occur, resulting in spread through populations with little pre-existing immunity. We saw this most recently in 2009 with the swine flu pandemic.

However, there’s a lot we don’t understand about what drives influenza mutations, how these interact with population-level immunity, and how best to make predictions about transmission, severity and impact each year.

The current H5N1 subtype of avian influenza (“bird flu”) has spread widely around the world. It has led to the deaths of many millions of birds and spread to several mammalian species including cows in the United States and marine mammals in South America.

Human cases have been reported in people who have had close contact with infected animals, but fortunately there’s currently no sustained spread between people.

While detecting influenza in animals is a huge task in a large country such as Australia, there are systems in place to detect and respond to bird flu in wildlife and production animals.

It’s inevitable there will be more influenza pandemics in the future. But it isn’t always the one we are worried about.

Attention had been focused on avian influenza since 1997, when an outbreak in birds in Hong Kong caused severe disease in humans. But the subsequent pandemic in 2009 originated in pigs in central Mexico.

Coronaviruses: an ‘unknown known’

Although Rumsfeld didn’t talk about “unknown knowns”, coronaviruses would be appropriate for this category. We knew more about coronaviruses than most people might have thought before the COVID pandemic.

We’d had experience with severe acute respiratory syndrome (SARS) and Middle Eastern respiratory syndrome (MERS) causing large outbreaks. Both are caused by viruses closely related to SARS-CoV-2, the coronavirus that causes COVID. While these might have faded from public consciousness before COVID, coronaviruses were listed in the 2015 WHO list of diseases with pandemic potential.

Previous research into the earlier coronaviruses proved vital in allowing COVID vaccines to be developed rapidly. For example, the Oxford group’s initial work on a MERS vaccine was key to the development of AstraZeneca’s COVID vaccine.

Similarly, previous research into the structure of the spike protein – a protein on the surface of coronaviruses that allows it to attach to our cells – was helpful in developing mRNA vaccines for COVID.

It would seem likely there will be further coronavirus pandemics in the future. And even if they don’t occur at the scale of COVID, the impacts can be significant. For example, when MERS spread to South Korea in 2015, it only caused 186 cases over two months, but the cost of controlling it was estimated at US$8 billion (A$11.6 billion).

The 25 viral families: an approach to ‘known unknowns’

Attention has now turned to the known unknowns. There are about 120 viruses from 25 families that are known to cause human disease. Members of each viral family share common properties and our immune systems respond to them in similar ways.

An example is the flavivirus family, of which the best-known members are yellow fever virus and dengue fever virus. This family also includes several other important viruses, such as Zika virus (which can cause birth defects when pregnant women are infected) and West Nile virus (which causes encephalitis, or inflammation of the brain).

The WHO’s blueprint for epidemics aims to consider threats from different classes of viruses and bacteria. It looks at individual pathogens as examples from each category to expand our understanding systematically.

The US National Institute of Allergy and Infectious Diseases has taken this a step further, preparing vaccines and therapies for a list of prototype pathogens from key virus families. The goal is to be able to adapt this knowledge to new vaccines and treatments if a pandemic were to arise from a closely related virus.

Pathogen X, the ‘unknown unknown’

There are also the unknown unknowns, or “disease X” – an unknown pathogen with the potential to trigger a severe global epidemic. To prepare for this, we need to adopt new forms of surveillance specifically looking at where new pathogens could emerge.

In recent years, there’s been an increasing recognition that we need to take a broader view of health beyond only thinking about human health, but also animals and the environment. This concept is known as “One Health” and considers issues such as climate change, intensive agricultural practices, trade in exotic animals, increased human encroachment into wildlife habitats, changing international travel, and urbanisation.

This has implications not only for where to look for new infectious diseases, but also how we can reduce the risk of “spillover” from animals to humans. This might include targeted testing of animals and people who work closely with animals. Currently, testing is mainly directed towards known viruses, but new technologies can look for as yet unknown viruses in patients with symptoms consistent with new infections.

We live in a vast world of potential microbiological threats. While influenza and coronaviruses have a track record of causing past pandemics, a longer list of new pathogens could still cause outbreaks with significant consequences.

Continued surveillance for new pathogens, improving our understanding of important virus families, and developing policies to reduce the risk of spillover will all be important for reducing the risk of future pandemics.

This article is part of a series on the next pandemic.

Allen Cheng, Professor of Infectious Diseases, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The death of premature twins in Byron Bay in an apparent “wild birth”, or free birth, last week has prompted fresh concerns about giving birth without a midwife or medical assistance.

This follows another case from Victoria this year, where a baby was born in a critical condition following a reported free birth.

It’s unclear how common free birthing is, as data is not collected, but there is some evidence free births increased during the COVID pandemic.

Planned home births also became more popular during the pandemic, as women preferred to stay away from hospitals and wanted their support people with them.

But while free births and home births might sound similar, they are a very different practice, with free births much riskier. So what’s the difference, and why might people opt for a free birth?

What are home births?

Planned home births involve care from midwives, who are registered experts in childbirth, in a woman’s home.

These registered midwives work privately, or are part of around 20 publicly funded home birth programs nationally that are attached to hospitals.

They provide care during the pregnancy, labour and birth, and in the first six weeks following the birth.

The research shows that for women with low risk pregnancies, planned home births attended by competent midwives (with links to a responsive mainstream maternity system) are safe.

Home births result in less intervention than hospital births and women perceive their experience more positively.

What are free births?

A free birth is when a woman chooses to have a baby, usually at home, without a registered health professional such as a midwife or doctor in attendance.

Different terms such as unassisted birth or wild pregnancy or birth are also used to refer to free birth.

The parents may hire an unregulated birth worker or doula to be a support at the birth but they do not have the training or medical equipment needed to manage emergencies.

Women may have limited or no health care antenatally, meaning risk factors such as twins and breech presentations (the baby coming bottom first) are not detected beforehand and given the right kind of specialist care.

Why do some people choose to free birth?

We have been studying the reasons women and their partners choose to free birth for more than a decade. We found a previous traumatic birth and/or feeling coerced into choices that are not what the woman wants were the main drivers for avoiding mainstream maternity care.

Australia’s childbirth intervention rates – for induction or augmentation of labour, episiotomy (cutting the tissue between the vaginal opening and the anus) and caesarean section – are comparatively high.

One in ten women report disrespectful or abusive care in childbirth and some decide to make different choices for future births.

Lack of options for a natural birth and birth choices such as home birth or birth centre birth also played a major role in women’s decision to free birth.

Publicly funded home birth programs have very strict criteria around who can be accepted into the program, excluding many women.

In other countries such as the United Kingdom, Netherlands and New Zealand, publicly funded home births are easier to access.

Only around 200 midwives provide private midwifery services for home births nationally. Private midwives are yet to obtain insurance for home births, which means they are risking their livelihoods if something goes wrong and they are sued.

The cost of a home birth with a private midwife is not covered by Medicare and only some health funds rebate some of the cost. This means women can be out of pocket A$6-8,000.

Access to home birth is an even greater issue in rural and remote Australia.

How to make mainstream care more inclusive

Many women feel constrained by their birth choices in Australia. After years of research and listening to thousands of women, it’s clear more can be done to reduce the desire to free birth.

As my co-authors and I outline in our book, Birthing Outside the System: The Canary in the Coal Mine, this can be achieved by:

• making respectful care a reality so women aren’t traumatised and alienated by maternity care and want to engage with it
• supporting midwifery care. Women are seeking more physiological and social ways of birthing, minimising birth interventions, and midwives are the experts in this space
• supporting women’s access to their chosen place of birth and model of care and not limiting choice with high out-of-pocket expenses
• providing more flexible, acceptable options for women experiencing risk factors during pregnancy and/or birth, such as having a previous caesarean birth, having twins or having a baby in breech position. Women experiencing these complications experience pressure to have a caesarean section
• getting the framework right with policies, guidelines, education, research, regulation and professional leadership.

Ensuring women’s rights and choices are informed and respected means they’re less likely to feel they’re left with no other option.

Hannah Dahlen, Professor of Midwifery, Associate Dean Research and HDR, Midwifery Discipline Leader, Western Sydney University

This article is republished from The Conversation under a Creative Commons license. Read the original article.