South Africa is one of nine countries which have been warned by the World Health Organisation (WHO) to be on high alert for "black death".
The other eight countries at risk include the Comoros, Ethiopia, Kenya, Mauritius, Mozambique, France's La Réunion, the Seychelles, and Tanzania.
An update on the outbreak, released in a WHO report, states that South Africa's travel and trade links with Madagascar, where the outbreak has already killed 124 people and infected 1 133, has put it at risk.
The organisation says that the overall risk of the plague is very high and that, depending on the type of plague, there is a 30 to 100% chance of death within 72 hours if it is left untreated.
Antibiotics can be used to treat it upon early detection.
"Historically, the plague was responsible for widespread pandemics with high mortality. It was known as the 'Black Death' during the fourteenth century, causing more than 50 million deaths in Europe. "Nowadays, the plague is easily treated with antibiotics and the use of standard precautions to prevent acquiring infection," the report stated.
Madagascar was reportedly hit with the black death in September, and health authorities are concerned because it has affected urban areas, increasing the risk of transmission and spread, according to the WHO.
"Some of the neighbouring countries, namely Comoros, Mauritius and South Africa, have put in place measures to protect their population, including entry screening, information provision to passengers on how to seek medical care in case of symptoms, and other preparedness measures," the report stated.
Symptoms include sudden fevers, head and body aches, vomiting and nausea. There are two main clinical forms of infection: bubonic and pneumonic, according to a WHO fact sheet.
The bubonic plague is transmitted to humans by infected fleas.
The most common, but less dangerous form of the plague is the bubonic plague, causing "inflamed lymph nodes, which can then turn to puss-filled, open sores if the condition worsens", the report read.
This can then develop into the pneumonic plague if the infection spreads to the lungs. From 2010 to 2015, there were 3 248 cases reported worldwide, including 584 deaths.
"Effective risk communication, social mobilisation and community engagement are critical. In addition, preparedness and readiness in neighbouring regions and countries, including at the points of entry, should be enhanced," the report stated further.
SAA, which flies to Madagascar, and health department spokesperson Popo Maja, were not available for comment.