An Ebola outbreak that ravaged Sierra Leone, Guinea and Liberia in 2014 cost economies an estimated $53-billion, according to a study in this month's Journal of Infectious Diseases.

The study aimed to combine the direct economic burden and the indirect social impact to generate a comprehensive cost of the outbreak, which was the worst in the world.

The outbreak ran from 2013 to 2016 and killed at least 11 300 people, more than all other known Ebola outbreaks combined. The vast majority of cases were in Guinea, Liberia and Sierra Leone.

The report's authors, Caroline Huber, Lyn Finelli and Warren Stevens, put the economic costs at $14-billion and said the human cost was even greater, based on the people affected and a dollar figure that reflects the value of each human life.

The total is far higher than previous estimates. In October 2014, the World Bank said the Ebola epidemic could cost $32.6-billion by the end of 2015 in a worst case scenario, but by November 2014 it dialled back that forecast to $3-4-billion. In 2016 the World Bank estimate of economic loss was $2.8-billion.

The 2003 severe acute respiratory syndrome (SARS) cost an estimated $40-billion, while the 2015-2016 Zika virus outbreak in the Americas was estimated to have caused $20-billion in social costs, the new study said.

But a repeat of the 1918 influenza pandemic could cost an annual 700 000 lives and $490-billion, the authors said, citing research published in 2016.

The new Ebola study factored in the impact on healthworkers, long-term conditions suffered by 17 000 Ebola survivors, and costs of treatment, infection control, screening and deployment of personnel beyond West Africa.

The biggest cost not previously accounted for was deaths from other diseases, as Ebola tied up healthcare resources and hospital admissions fell dramatically, adding $18.8-billion to the total bill.

During the outbreak there were 10 623 additional deaths from HIV/AIDS, tuberculosis and malaria, with 3.5-million additional untreated malaria cases.

Measles caused 2 000-16 000 extra deaths as 1-million children missed being vaccinated for measles, and 600 000-700 000 missed other vaccines.

But the authors added that they had limited information on the cost of deploying international health staff and military personnel, and they were obliged to place a value on human life, a widely accepted economic measurement.

Although the "value of a statistical life" (VSL) in North America and Europe is estimated at $7-million-9-million, the authors said, they took a figure from the only study in a West African context, with a VSL of $577 000 in Sierra Leone.