Event 201 simulated the outbreak of a novel coronavirus, modelled largely on SARS, with no known vaccines
On October 18 last year, John Hopkins Center for Health Security, in partnership with the Bill and Melinda Gates Foundation and the World Economic Forum, conducted a pandemic simulation exercise.
Named Event 201, the exercise simulated the outbreak of a novel coronavirus, modelled largely on SARS, with no known vaccines. From bats to pigs to people, the hypothetical pathogen was assumed to be efficiently transmissible with mild symptoms in a community.
A simulation is an iteration of a process or system operating over time. Using computation, a simulation plays out a scenario based on assumptions that are presumed realistic, but not an exercise based on real data of a previous scenario. The method has been widely applied in epidemiology research. Though simulations rely on assumptions, it depicts probable trajectories of real-life scenarios given the concurrence between the two. Hence, simulations often end up with over or underestimations when compared to real events but provides insight into the nature of the scenarios.
In the Event 201 simulation, the disease presumably starts in pig farms in Brazil and initially spreads quietly. Transmission gains momentum in the healthcare settings and the virus is initially exported via air travel to Portugal, United States and China. The outbreak, henceforth, skyrockets in spreading randomly to 300 major cities in the world through international travel. Initial number of imported cases range from 1-4 for each city with an infectious period of 5 days. After initial imports, each city is presumed to follow a transmission rate R0 (number of new infections generated by each case on average over the infectious period) ranging from 1.1 to 2.6 per case. Holding the whole human population susceptible, cumulative number of infected cases double every week during the initial months.
The pace presumably declines approaching a peak at the end of 18 months, a timeline when the vaccine is assumed to be developed and administered effectively or the disease is assumed to turn endemic. The study further assumes that infections result in mild illnesses for 50 percent cases and severe illnesses for the rest. While the mildly infectious group recovers in seven days, the severely infectious group presumably holds a 14 percent fatality rate after 10 days.
The simulation assumes that each person can be infected only once, and no medicine or vaccine is invented during the simulation to affect the transmission rate. The model does not consider several other factors of further escalation, such as inter-city mobility within an affected country, medium of transmission, level of human interaction and behaviour. Nor did it consider such important sources of deceleration as, extent of healthcare efforts, diffusion mitigation measures, restricting mobility and collective behavioural change. Under these assumptions, the scenario ends at the 18-month-point with 65 million deaths, which appears to be an overestimation.
Regardless, the simulation bearing eerie similarities hints at an extreme trajectory of the novel coronavirus originating in Wuhan, China. Though, these similarities have fuelled apprehension along the line of conspiracy theories, it has also outlined a worst-case scenario. The Wuhan coronavirus outbreak and the pre-emptive research initiative taken by John Hopkins Center for Health Security points out the room for improvement in the Bangladeshi health sector and the emergency countermeasures in place.
Surpassing SARS in the number of cases, as of Thursday, Wuhan coronavirus cases have been reported in nearly 18 countries including our neighbours – India, Nepal, Sri Lanka and Thailand – and its intrusion in Bangladesh is inevitable. Despite the assurance by health minister Zahid Maleque in restricting the access of the virus into Bangladesh, vigilance of the general public is of utmost importance. In a country where sneezing and coughing on someone else's face is the norm, preparation and consumption of street food or cha (tea) takes place in a largely unhygienic manner, and medicine for flu or fever or cold is self-administered paracetamol, any outbreak may reach an unprecedented scale in mere days. But is Bangladesh truly prepared for it? Can an outbreak of this nature be controlled if it enters?
Dr Mike Catton of the Peter Doherty Institute for Infection and Immunity stated "We've planned for an incident like this for many, many years and that's really why we were able to get an answer [in growing a copy of the novel coronavirus to use as 'control material' for testing and possibly develop an early diagnosis test] so quickly."
But has Bangladesh gone through extensive planning and adequate preparation? There are reports of returnee Bangladeshis among 267 passengers leaving Wuhan mere minutes before lockdown and not all of them may have exercised self-imposed isolation.
Current efforts include monitoring all air, land and maritime ports, scanning all incoming people for symptoms and subjecting those coming directly from China under 14 days of observation. Additionally, separate wards have been opened at Kurmitola General Hospital and Infectious Diseases Hospital in Dhaka to treat those potentially infected. Though the Centers for Disease Control and Prevention (CDC) states that there is no evidence to support the Chinese health authority's claim of the virus being transmissible through asymptomatic people, would these measures be adequate at fighting the pathogen if the worse is true? Moreover, what measures are in place for minimising local level spreading of the disease? Separate wards may slow down spread in health setting but fails to address transmission in non-health settings. So, what additional countermeasures are imperative?
Retraction of WHO chief Tedros Adhanom Ghebreyesus' assessment of a global risk of outbreak as "moderate" and reinstating it as "high" is a cause for concern. Though panicking is not helpful, necessary precautions must be put in place. Adequate quantities of advanced medical equipment need to be distributed at all air, land and maritime ports. All immigrants, be them from China or some other nation, must be instructed to limit social interaction for at least the incubation period of 14 days, in addition to using surgical masks.
The digital outreach of the health sector in Bangladesh is very limited and lack of data restricts conducting even rudimentary outbreak projection exercises at a local level. Essentially, Bangladesh has no estimate on the extent of damage any outbreak can bring upon her. Every crisis is an opportunity to usher in change and Bangladesh must strengthen its health sector. Technology infusion in the health sector is hence necessary to make informed decisions in the wake of any health emergencies. Creating and maintaining health profile of all individuals to be used collaboratively by all facilities is paramount. A real-time database of inter-city passengers can give some indication of projected spread of outbreaks.
In addition to the health authorities, the burden of responsibilities falls on the general public and social groups as well. Collective behavioural change is required in improving personal and social hygiene standards. Sufficient social pressure must be generated to compel street food vendors to maintain a certain degree of hygiene, and discourage the general public from irresponsible spitting, sneezing and coughing. Self-imposed confinement by all household members of returnee Bangladeshis for two weeks may also help lower the probability of an outbreak. Social activism and creating awareness of spill over health concerns of our behaviour is the first of the many steps required to prepare ourselves for the coming days.
The author, Mutasim Billah Mubde, is a research associate at the Economic Research Group (ERG).