Johannesburg - The South African health department has advised travellers to Madagascar to wear surgical masks while in transit and to avoid highly populated areas when they arrive because of a plague outbreak on the island that has resulted in the deaths of 48 people.

The World Health Organisation (WHO) has confirmed the deaths and 449 cases of the plague.

In a statement on Thursday, the department said the case fatality rate was 11 percent.

"The outbreak is primarily located in the middle third of the island, around the Antananarivo (239 cases and 21 deaths) and Toamasina province on the east coast (147 cases and 9 deaths). A single area on the northern coast is affected," the department said. 

"The majority of cases are presenting as pneumonic plague unlike the usual bubonic form. 

"The WHO has classified the outbreak as Grade 2 with the level of risk for local spread being high. Risk to the region is moderate because of frequent air and sea travel, but the global risk is perceived to be low."

The department said that there was an international concern regarding infection with the bacterium after a South African basketball player, who was attending the Indian Ocean Club Championships, contracted the plague while there.

The basketball player was successfully treated in Madagascar and has returned to South Africa. He and his team members are being followed up, the department said. The department said they do not, however, pose any risk. 

While there are no travel restrictions to Madagascar, a multi-sectoral national response coordination committee has been established, the department said.

"Enhanced contact tracing, improved surveillance and diagnostic capacity, restriction of public gatherings, infection prevention and control and community mobilisation are all under way." 

The plague is a zoonotic disease caused by a bacterium Yersinia pestis. Where plague is endemic, it is usually found in rodents and is spread by fleas from rodent to rodent, or to other mammals. 

"Humans may acquire plague from persons with pneumonic plague through droplet transmission or from direct contact with infected rodents or through the bite of an infected flea. The incubation period ranges from two to eight days. Symptoms of pneumonic plague include cough, fever and chest pain."

South Africa has put several measures in place including alerting all airline companies to remain vigilant for suspected ill passengers; port health officials have enhanced their screening measures to detect ill passengers arriving.

Provincial outbreak response teams have already been alerted to enhance preparedness.

"All travellers returning from Madagascar must monitor their health for 15 days and seek medical care immediately at their nearest health facility," the health department said.

"If they develop fever, chills, head and body aches, painful and inflamed lymph nodes, or shortness of breath with coughing and/or blood-tainted sputum. They should tell the doctor about their recent travel and their symptoms."