A worldwide alert for Disease X has been released by the World Health Organization (WHO). This novel and potentially deadly disease is one of eight diseases named in the organisation’s 2018 annual evaluation of diseases prioritised under the Research and Development Blueprint that might potentially cause an international epidemic. The WHO releases an annual blueprint review each year to identify which infections and diseases should receive priority attention in terms of research and development. Health experts warn that this potential new pandemic has the capacity to result in 20 times more fatalities than in the COVID-19 pandemic.
As per the WHO, Disease X is designated to represent a potential unidentified pathogen capable of triggering a severe global epidemic. Currently, the priority diseases include COVID-19, Crimean-Congo haemorrhagic fever, Ebola virus disease and Marburg virus disease, Lassa fever, Middle East respiratory syndrome coronavirus (MERS-CoV) and severe acute respiratory syndrome (SARS), Nipah virus and henipavirus diseases, Rift Valley fever (RVF), Zika, and Disease X itself. Disease X is hypothetical. As of now, it does not exist. However, the concept of Disease X represents an increasingly serious threat to human health, for which the world has to be better prepared.
About Disease X
Disease X refers to unknown pathogens with pandemic potential that may emerge in the future. Pathogen X is likely zoonotic in origin. To track the spread of Pathogen X at all interfaces involving people, animals, and the environment, vigilant surveillance is necessary. The disease was coined by the WHO, in 2017, placing the disease in the list of priority diseases along with deadly diseases like SARS and Ebola to highlight the danger associated with the disease.
Zoonotic diseases, often referred to as zoonoses, are illnesses that can be transmitted from animals to humans. These diseases can be caused by various pathogens including bacteria, fungi, viruses, and parasites. A wide range of animals, including mammals, birds, reptiles, and possibly amphibians can serve as hosts for these infectious agents.
Zoonotic diseases encompass a diverse array of pathogens. Bacterial zoonoses include salmonellosis, brucellosis, plague, and leptospirosis. Fungal infections such as cryptococcosis and histoplasmosis are also zoonotic, as are parasitic diseases like leishmaniasis, hydatid disease, schistosomiasis, and toxoplasmosis. Additionally, viral zoonoses like rabies, influenza, and yellow fever pose significant health risks to humans.
In India, numerous zoonotic diseases are prevalent, including Nipah virus, avian influenza, rabies, Japanese encephalitis, and leptospirosis, among others. Emerging zoonotic diseases of public health concern include avian influenza, Nipah, trypanosomiasis, Crimean Congo haemorrhagic fever (CCHF), and H1N1, known as swine flu.
The emergence and spread of zoonotic diseases are influenced by various factors such as rapid urbanisation, encroachment into natural habitats, and dietary changes, which increase interaction between humans and animals. Climate change and ecological shifts further exacerbate the transmission of these diseases.
It is estimated that a significant proportion of new infectious diseases in humans originate in animals, with many known infectious diseases being transmissible from animals to humans. Major outbreaks like Ebola, SARS, MERS, and Zika have highlighted the substantial public health threat posed by zoonotic diseases.
Between 1940 and 2004, 335 pathogens have emerged. Almost 60 per cent of human infections have been of zoonotic origin of which 71 per cent come from wildlife.
Researchers about Disease X
Researchers are of the opinion that the chance of a pandemic which is similar to the impact of COVID-19 is about one in 50 in any year. Environmental change has been a major contributor to increasing the risk of a pandemic. It is likely that the next pandemic threat could emerge as a novel Disease X. There is also a chance that already known pathogens could be mutating and/or re-emerging and causing global epidemics.
Novel diseases have been emerging in all parts of the world. The human species has always been affected by infectious disease pandemics. They often spread from animals (such as bats) to humans. Researchers predict that one of the approximately 25 virus families that have already shown their ability to infect humans would give rise to a novel virus that would be the source of the next Disease X. This is why WHO has been emphasising the importance of studying Disease X. This would enable early cross-cutting research and development preparedness for unforeseen diseases.
Prediction-Based Characteristics of Disease X
Though not every pathogen could cause a pandemic, it is likely to spread through respiration as that is more efficient for a pathogen. Instead of bacteria or fungus, it could be a virus. It could be something that an animal species could spill over humans. Alternatively, it could be a human pathogen that acquires novel traits or modifies its genetic make-up in a way that increases its capacity to spread a pandemic. The emergence of Disease X could be unpredictable.
Challenges regarding Disease X include compromised health systems, increasing scepticism towards science resulting in vaccine reluctance, and the risk of reduced funding for detecting and preparing for outbreaks.
Preparedness and Planning to Fight Disease X Pandemic
It is necessary to prepare and plan for Disease X, though it is difficult to predict the time and features of its arrival. Scientists are conducting researches to know more about viral families that are most likely to harbour Disease X. This could help them get a head start in creating new medical defences such as vaccines and treatments that could be swiftly adapted to target a new viral disease.
Along with the WHO, agencies like, the Centre for Disease Control and Prevention (CDC), the European CDC, the UK Health Security Agency (UKHSA) and Biomedical Advanced Research and Development Authority (BARDA) at the National Institutes of Health (NIH) have been planning and preparing to face Disease X. It also involves business groups such as the World Economic Forum, the United Nations and every level of government. Pharmaceutical companies are also considering vaccination platform technologies and the speed at which they could scale up, when necessary. To tackle these challenges and bolster global preparedness for future health crises, ongoing initiatives such as the US government’s US$ 5 billion project (Project NextGen) and the establishment of worldwide centres for pandemic treatments are underway.
COVID-19 has been a real-world example of Disease X, which was caused by a novel coronavirus. The pandemic, which began in late 2019, highlighted the necessity of being ready. Since wildlife reservoirs harbour viruses, which have the potential to cause and spread diseases to which humans are not immune, this emphasises the urgent need for creation of adaptable tools like medication, therapy, vaccination, and diagnostic tests.
India and Disease X
India being an agricultural country, animal husbandry is very crucial to its economy. Further, the ecological system has been disturbed due to risk factors such as rising population, industrialisation, urbanisation, deforestation, etc. All these factors may bring about zoonotic diseases and help in spreading infections that were once confined to non-human species.
According to the Indian Council of Medical Research (ICMR), India has to strengthen its surveillance with a strong laboratory network. There is a need to identify diseases, both in animals and humans, at the earliest in order to launch immediate containment action before the outbreak, so that a pandemic could be avoided.
According to the warning issued by the WHO, the Ministry of Health and Family Welfare (MoHFW) has been focusing on at least 20 zoonotic diseases. These include, anthrax, scrub typhus, rabies, swine flu, bird flu, bovine tuberculosis, Nipah, brucellosis, blastomycosis, psittacosis, trichinosis, cat scratch disease, histoplasmosis, etc. India is preparing to launch the ‘One Health Programme’, a surveillance programme for significant bacterial, viral, and parasitic illnesses of zoonotic and transboundary pathogens.
The central government has asked the states to involve all stakeholders, including agriculture, veterinary and wildlife wings, to strengthen the public health laboratories. This would help in early diagnosis and development of additional methodologies for surveillance and understanding the spread of emerging diseases.
Conclusion
Overall, it is essential to understand that the swifter the availability of vaccines, antivirals, monoclonal antibodies, and diagnostic tests during an infectious disease crisis, the more lives are likely to be saved. It is a multisectoral effort as readiness includes not only medical countermeasures but also societal responses and business continuity.
© Spectrum Books Pvt Ltd.
