Infectious disease epidemics and pandemics have the potential to affect people, anywhere, and at any time. With increasing connectivity through international travel, intercontinental trade and livestock husbandry, as well as rising human population density, particularly in urban areas and changing interactions between humans and wild animals in more remote areas, the risk of contracting infectious diseases is amplifying day by day.
Historically, records of disease outbreaks have been documented for millennia with Chinese writings mentioning malaria breakouts as far back as 2700 B.C. The 1918 influenza pandemic killed 50 million individuals across the world in an era where little was known about viruses, their sources, how they spread and treatment. Even though epidemiology and medical sciences have advanced greatly, large scale outbreaks are still commonplace today. Recent examples include the Ebola epidemic of 2013-2016 that terrorised West Africa and then re-emerged in Congo in 2018 and is still continuing, the Zika epidemic that originated in Latin America in 2016, India reporting cases of the deadly Nipah virus in 2018 and 2019, and the two recent cases of pneumonic plague from Inner Mongolia.
In the future, the drivers of infectious diseases are only going to intensify. Climate and ecological changes and disruptions will exacerbate the emergence risk of diseases.
Given the public health risk posed by epidemics and pandemics, it is critical to systematically assess global preparedness, identify regions that are not well equipped to respond to such threats related to public health and think through what response strategies should be developed as proactive approaches.
Sensitive surveillance to detect threats that are known and predictable — for instance, vector-borne diseases like dengue and malaria, lesser-known diseases like Ebola and unknown emerging threats, such as the Zika virus was in 2016 and new influenza strains — is essential to develop and deploy defensive and management strategies.
The framework of outbreak alert and response has four phases: systematic detection, outbreak verification, real-time alerts and rapid response.
For detection of outbreaks, formal and informal sources need to be constantly monitored for disease outbursts and other events of potential concern-providing real-time gathering of disease intelligence.
Up to 60 per cent of reports in a rapidly digitalised world now come from unofficial and informal sources that need to be verified. The verification requires epidemiological and laboratory techniques that detect, investigate and confirm the cause, and if possible, the source of the outbreak.
Unfortunately, the countries where disease outbreaks are most likely to occur — in the tropics, with dense populations, high animal-human contact, unknown or high population migration — are the ones where laboratory infrastructure is the weakest. The lack of identification of the cause of disease in the early stages of an outbreak leads to confusion, misunderstanding and propagation of conspiracy theories that significantly impact subsequent control efforts.
Many programmes established by the WHO, the US Centers for Disease Control and Prevention (CDC) and others seek to build better capacity for laboratory investigations. In India, the National Centre for Disease Control under the health ministry partially serves this function, with variable levels of success in different parts of the country.
For response, different strategies are required to combat known risks and unexpected events, and the ability to use these strategies is dependent on what is available within the existing health system. The scale and severity of the 2013–2016 West Africa Ebola epidemic was as bad as it was, with uncontrolled spread for several months, because of the weak state of health systems in West Africa, and in particular, limited local capacity for public health surveillance and outbreak response.
Efficacy of Kerala’s health system
In India, unlike other nations, health is a state subject. State governments work closely with the central government in responding to high-priority infectious disease outbreaks. They are responsible for the treatment of patients, and early recognition of infection and development of management protocols for supportive therapy and specific treatment, as well as isolation if required.
Trained staff, adequate hospital facilities, equipment for patient care, diagnosis and availability of drugs are not easy to organise quickly for emerging diseases, especially with weak or unprepared health systems in countries like India. But an outstanding example of a well-prepared health system response was the single case of Nipah virus infection in Kerala in June, where Kerala’s prompt action resulted in limiting the outbreak.
To prevent and treat pathogens-causing outbreaks, emerging technologies are becoming available. Immunotherapy is a new potential treatment that may be useful against many pathogens if they can be made quickly in large volumes.
Vaccine technologies offer the opportunity to rapidly make a vaccine against a new or unknown pathogen, including vaccines based on DNA or RNA. Many of these vaccination approaches are being supported by the Coalition for Epidemic Preparedness Innovations, which is a new grouping supported by governments and philanthropic organisations to protect the world by making vaccines against new and emerging diseases.
New and emerging diseases crossing international borders are a given. We must use new technologies and approaches, and collaborate across agencies and countries, sharing information and resources, to use what we have learnt from Severe Acute Respiratory Syndrome [SARS], Ebola and Nipah to protect ourselves from the next inevitable threat to global health.
This article is part of a series examining The Future of Data in partnership with Carnegie India leading up to its Global Technology Summit 2019 in Bengaluru from 4-6 December 2019. More details about the summit are available here.
The author is the executive director of the Translational Health Science and Technology Institute. Views are personal.