Study finds that risk of Madagascar’s pneumonic plague spreading elsewhere is limited

A study by researchers at Hokkaido University recently used mathematical models to determine that the risk of the pneumonic plague epidemic in Madagascar spreading elsewhere in the world is limited.

The researchers estimated that the number of exported cases was below 0.1 person in each country between Aug. 1 and Oct. 17. They found that the estimated basic reproduction number of the epidemic, the average number of secondary cases generated by a single primary case, is 1.73. The case fatality risk is 5.5 percent.

“Unlike the Zika virus epidemic that internationally spread from South America to other nations, the overall magnitude of the ongoing pneumonic plague epidemic in Madagascar is very limited,” Hiroshi Nishiura, the Hokkaido University professor who led the study, said. “Our finding objectively endorses the notion of the World Health Organization to recognize the risk of international spread as very low.”

The researchers used data from the Institut Pasteur de Madagascar’s epidemiological bulletin to conduct statistical analysis and calculate a basic reproduction number. They used data from the U.N. World Tourism Organization on travel volume in and out of Madagascar to estimate the probability of the epidemic spreading to other countries.

The research team plans to continue its study of Madagascar’s ongoing plague epidemic.

Madagascar has seen an increase in pneumonic plague cases since August 2017. It was reported that 2,217 people were diagnosed positive. By Nov. 14, there had been 113 fatal cases.