Volunteers search for plague cases and disinfect houses, 1894. Photo: The University of Hong Kong

What will you do during your first five days in Hong Kong? It is safe to say that you probably will not surpass the achievement of Alexander Yersin (1863-1943) who, within his first five days here, isolated the bacillus of the Black Death – also known as the bubonic plague – and changed history.

A French-Swiss scientist who lived most of his life in what is now Vietnam, Yersin spent only 54 days in the colony of Hong Kong, and later also developed the vaccine against the disease. Today, the scientific name for the bacterium, Yersinia Pestis, honours his efforts.

The Black Death was a great human scourge. In medieval times, it killed about one-third of the world’s population, causing great social upheaval. However, it met its match in Hong Kong.

In the late 1800s, the Tai Ping Shan area near Hollywood Road in Sheung Wan – now part of the city’s antiques district – was in a terrible state, filled with unhygienic slums that housed both humans and farm animals in the same rooms. Not surprisingly, rats and fleas flourished here, eventually bringing the Black Death to this small port city in 1894. Half the population fled and the ships that were Hong Kong’s life-blood would not enter the harbour, apart from bringing in Yersin, and a team of Japanese microbiologists headed by a man named Shibasaburo Kitasato. The horrific state of Hong Kong at this time was the answer to their dreams for, as microbiologists, they were eager to study an outbreak of bubonic plague using the latest scientific knowledge.

The smart money would have been on the Japanese, who set up a laboratory in Kennedy Town Police Station. Not only did they have more researchers and better facilities, but their director had already discovered the Tetanus bacteria. Meanwhile, the rookie scientist, Alexander Yersin, occupied a “matshed” building (a bamboo structure similar to a straw hut) nearby.

Yersin lost no time in starting work. He was aided only by a long-standing Hong Kong resident, an Italian priest named Father Vigano, a former soldier who had become a military chaplain. Yersin believed the best place to find the plague bacillus was in a patient’s boils, so he and Vigano paid military burial parties to stop near his laboratory so that he could take samples from the victim’s sores. He also found the bacillus in local rats. As a lone researcher, he bred the microbes and beat the Japanese into the scientific press.

Both Yersin and the Japanese team contributed significantly to science. Kitasato later made major discoveries in the field of dysentery. And after Yersin returned to Vietnam, where he died in 1943, he founded a medical school as well as the Vietnamese rubber industry. Today he is still revered by the Vietnamese people.

After Yersin’s discovery, things in Hong Kong began to change. The Whitewash Brigade, made up of mainly British soldiers, disinfected the worst slum areas and tore them down. Today, the sight of urban pigs, chickens and cows sharing accommodation with city dwellers is history and a public park, Blake Garden, now stands on part of the old Sheung Wan plague site.

Government City Hospital in Sai Ying Pun. Photo: The University of Hong Kong