Analysing past pandemics to inform future responses

Otago Daily Times

3 days ago

About 9000 people died in six weeks when the 1918 influenza pandemic swept through New Zealand, making it the largest natural disaster in the country's history.
Now University of Otago researchers have joined forces with researchers at Durham University (United Kingdom) and the University of Tubingen (Germany) to complete the first digital analysis of the pandemic, in a bid to provide insights for managing future infectious disease emergencies.
Also known as the Great Influenza Epidemic and the Spanish flu, the deadly global pandemic lasted from 1918-20, and was caused by the H1N1 subtype of the influenza A virus.
The earliest documented case was in March 1918, in Kansas, United States, and a month later there were cases in France, Germany and the UK.
It was quickly spread around the globe by troops during World War 1.
Between 1918 and 1920, nearly a third of the global population (an estimated 500 million people) had been infected, and up to 50 million people are estimated to have died from the virus, making it the deadliest pandemic in history.
Project co-leader and University of Otago Health Protection Aotearoa Research Centre director Prof Michael Baker said the pandemic was still the largest natural disaster in New Zealand's history, killing about 0.8% of the population — the equivalent of about 40,000 people today.
"While the social history of this pandemic has been comprehensively described by historians, notably Prof Geoff Rice, there has not been a full epidemiological analysis using case data.
"This project will fill that gap and provide insights into how a poorly controlled modern influenza pandemic could affect the country."
The researchers now had a digital database that showed who got infected and when in 1918, and who died, which would allow them to see how the virus moved through New Zealand.
"This is why influenza is actually quite worrying, because it has a very short incubation period, and it would sweep through the country very rapidly.
"If we had a comparable influenza virus arriving in New Zealand tomorrow, it would probably infect most of the country within a few weeks, it would absolutely overwhelm the health system, and we would not be using an elimination approach at that stage — it would be a mitigation approach, where we just try to dampen it down.
"It would put massive strain on our ability to manage people with ventilators and so on, so it could cause 40,000 deaths in that period of time if it behaved the same way."
Project leader and Durham University bioarchaeologist Prof Rebecca Gowland said the project was the first step towards a more comprehensive programme aimed at better understanding past global pandemics, including the Black Death in 1348, the 6th century Justinian plague in Europe and the Tudor-era English Sweating Sickness.
The aim was to better understand how social connections and differences influenced the spread of pandemics through the centuries, and how individuals and societies responded to the threat they pose.
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