An outbreak of pneumonic plague in Madagascar and Seychelles carries a moderate risk of spread to neighboring Indian Ocean islands, which is mitigated by the naturally short incubation period of the virus and the institution of exit screening measures at ports of entry, according to a recent update from the World Health Organization (WHO).
On Oct. 10, the Seychellois Ministry of Health notified the WHO of a probable case of pneumonic plague from an individual who recently visited Madagascar, a country currently experiencing an outbreak of pneumonic plague, and returned to Seychelles on Oct. 6.
According to public health officials, the man began experiencing symptoms on Oct. 9 and checked himself into a local health center shortly thereafter. Based on a brief medical examination and his reported history of travel, pneumonic plague was suspected and he was immediately transferred to an area hospital for isolation and treatment.
Two days later, a sputum sample was tested and came back “weakly positive.” From Oct. 9 to Oct. 11, eight individuals who had contact with the man developed mild symptoms and were isolated for treatment. Two other cases, who had no epidemiological link to the man, were also identified and placed into treatment.
A total of 10 samples were taken from each suspected case and were sent to the Institut Pasteur Paris, all of which test negative on Oct. 17.
More than 320 individuals who had contact with the probable case, including 41 passengers and crew from the Madagascar flight, 12 close family members, and 18 staff from the man’s local health center, were all provided a prophylactic course of antibiotics to prevent infection.
In order to mitigate the further spread of the virus, WHO advised the government of Seychelles on the implementation of public health measures that are in-line with WHO international health regulations, including enhanced surveillance, contact tracing, isolation and prophylactic treatment of suspected cases.
WHO noted that plague has never been reported in Seychelles before and, at this stage, no plague cases have been confirmed. Further, no suspected cases have died as a result of possible infection. WHO added that the risk of a pneumonic plague epidemic in Seychelles was considered low and the overall regional and global risk as very low.
WHO also advised against any restriction of travel or trade for Seychelles or Madagascar based on available information.