Global Health Challenges: Disease Eradication, Emerging Threats, and the Role of International Cooperation

At the moment, the International Task Force for Disease Eradication has identified eight possibilities: Guinea worm, also known as dracunculiasis, poliomyelitis (polio), mumps, rubella, lymphatic filariasis, cysticercosis, measles, and yaws. Politically speaking, governments worldwide need to care about the disease, its impact, and possible harm; eradication efforts need to be affordable and cost-effective; and complete removal of the disease needs to have a significant benefit over simply controlling the disease long term.

Yaws, a chronic, debilitating, bacterial infection that affects the skin, bone and cartilage, was among the first diseases targeted for eradication, in the 1950s, as it can be cured with inexpensive antibiotics. But success was limited. Efforts to eradicate the disease were renewed by the WHO in 2012, but yaws is still prevalent, with more than 80,000 suspected cases in 2018, though just 888 were confirmed using laboratory tests. Fifteen countries remain endemic for the disease, meaning they experience continuous transmission.

Guinea worm is possibly one of the most gruesome diseases you could imagine, where drinking contaminated water leads to the development of a metre-long worm, or many worms, inside the body, which then burst out of the skin one year after infection. It’s easy diagnosis, possibilities for prevention through simple interventions to stop people drinking contaminated water, and the economic benefits to be gained from its demise made it a top candidate for eradication soon after the victory over smallpox. The recent discovery of the parasite also infecting dogs, however, has recently brought the idea of eradication into question.

Polio then showed promise as it had an effective vaccine, immunity against the disease was lifelong, and the disease only affects humans, meaning there were no animals to deal with that could act as reservoirs or spread the disease, as is the case with malaria, for example. Elimination of polio had also been achieved in the Americas, showing it was possible to stop transmission of the disease. But complete eradication of polio would be far from easy, as the vaccine is not heat stable and requires multiple doses.

Spanish flu pandemic, in which infections were powerful enough to kill young, healthy adults, not just the elderly and infirm as per regular, seasonal influenza. Striking at a time when vaccines and treatments were not available and a world war was under-way, the virus unsurprisingly had devastating consequences as the only weapons to hand were isolation and quarantine along with attempts to promote good hygiene. H1N1 would leave its mark as something to be feared throughout history, ending in 1920 with no clear understanding about how it was stopped.

In 1957, another influenza strain emerged in East Asia, H2N2, triggering a pandemic known as the Asian flu, first reported in Singapore and spreading as far as the United States, killing an estimated 1.1 million people worldwide.

Yet another strain, H3N2, began spreading in the United States in 1968, killing a further 1 million people worldwide. These latter two pandemics are lesser known, but their damage was extensive and reminded populations at the time of the damage a new infection, particularly influenza, can do.

In 2003 we saw SARS, a previously unknown virus, surge across an unprotected population to infect thousands across Asia and reach all corners of the globe. Six years later, in 2009, we were reminded of the power of influenza as a new form of H1N1 emerged in Mexico, soon reaching the United States, Canada and promptly the rest of the world. The severity of the pandemic was lower than predicted, but 214 countries globally reported cases and at least 18,500 people died, though some studies show this to be a vast underestimate. This time the world had antiviral treatments and vaccine technologies as well as international agreements to help countries work together to curtail the spread, but there was a new societal norm to contend with: population mobility. People harboring the virus were on planes and trains traveling to new destinations before they even knew they were sick, helping H1N1 reach six continents within just nine weeks of it first being reported.

Air travel was a key player in the 2003 SARS pandemic, for example, resulting in the virus reaching a range of new countries within days of emerging. The pandemic led to the revision of the International Health Regulations (IHR) in 2005, an international agreement among 196 WHO member states, first implemented in 1969 when the scope was limited to just four infectious diseases: cholera, plague, yellow fever and smallpox. The 2005 updates aimed to address modern-day needs, with the goal of helping to ‘prevent and respond to acute public health risks that have the potential to cross borders and threaten people worldwide,’ according to the World Health Organization. The regulations include provisions for outbreaks that are a ‘public health emergency of international concern’ (PHEIC), based on an unexpected or sudden situation that could cross borders and therefore become an international concern, requiring a coordinated international response. A PHEIC is decided on by an emergency committee made up of relevant international experts and a declaration means countries must be ready to work together to stop the outbreak by providing vaccines, teams on the ground, funding etc.

Since SARS surprised and scared the planet, six emergencies have been declared to be of international concern.

The first was the 2009 H1N1 swine flu pandemic, followed by polio in 2014, the 2015 Zika virus epidemic, two outbreaks of Ebola – one that hit West Africa in 2014 and another in the eastern region of the Democratic Republic of Congo that began in 2018 – and the novel coronavirus outbreak that began in China at the end of 2019. Four very different families of viruses, given SARS was also a corona-virus, but all deemed to be a significant risk to the global population if not managed appropriately.

Air travel and transport has been a key factor in their spread, but just as influential have been rising global temperatures, the increasing mobility of populations, and a rise in urban or peri-urban populations living close together, often with poor infrastructure and poorly managed health services around them.

Dense, poorly planned urban environments provide the perfect ecosystem for infections to be introduced and then thrive.

Uncommon, emerging, diseases are a further worry among public health officials as the element of surprise they bring means countries will lack effective drugs or vaccines and be unprepared if they strike. SARS and the novel coronavirus COVID-19 are prime examples of this.

In an attempt to be ready for future unknowns, the WHO maintains a list of emerging diseases it considers to be a priority for research and development due to their potential to generate a public health emergency, and for which insufficient or no preventive and curative solutions exist’.

An acronym for Middle East Respiratory Syndrome, the coronavirus behind the disease is in the same family as SARS and COVID-19. As its name suggests, MERS is most common in the Middle East where it was first identified in 2012, but the first outbreak of global concern was in 2015 when a Korean man contracted the virus while visiting the region on a business trip. He returned home to South Korea, sparking an outbreak that would go on to infect 186 people, killing 36 of them.

We’re dealing with an epidemic, news reports say, with respect to diseases such as malaria, Zika, a regional outbreak of cholera, but also obesity, diabetes, mental health and habits such as vaping, opioid use, and now screen time among children. What began as one case, or a cluster, grew to become an outbreak, and soon an epidemic. If not controlled it could go on to become a pandemic, or over time, endemic.

It all starts with health, defined by the WHO as a state of complete physical, social and mental well-being, and not merely the absence of disease or infirmity. Then comes public health, a seemingly straightforward term, but not quite.

More accurately it is a social and political concept, WHO glossaries state, aimed at improving health, prolonging life and improving the quality of life among whole populations using interventions such as disease prevention, healthcare policies or health promotion programmes that are, importantly, organized through society.

Source – Outbreaks and Epidemics: Battling Infection in the Modern World by Meera Senthilingam, Brian Clegg (Series Editor)

Goodreads – https://www.goodreads.com/book/show/44784435-outbreaks-and-epidemics