Hong Mei House. Photo: Google Maps

The Wuhan coronavirus could be spreading through toilet drainage systems, Hong Kong experts have said, citing the example of two people on different floors of the same building becoming infected.

On Monday evening, a 62-year-old woman was confirmed to be infected with the virus, according to Hong Kong’s Centre for Health Protection. She lived in a unit on the third floor in Hong Mei House, Cheung Hong Estate. A 75-year-old man, who was confirmed to be the 12th infected person in the city on January 30, was living in the same unit on the 13th floor.

The government decided to evacuate more than 100 people from 32 families from the same units on all floors in the same building because they think the coronavirus could have been transmitted through the toilet drain pipe. Twenty-one of the families were sent to quarantine camps on Tuesday morning, while nine families have not yet been reached.

Four people in three families have shown flu-like symptoms and have been taken to a hospital isolation ward, while the others were taken to quarantine camps, said Sophia Chan Siu-chee, the Secretary for Food and Health.

Photo: Drainguard.info
Yuen Kwok-yung. Photo: RTHK

The exhaust pipe connecting the toilet drain pipe of the woman’s flat had been modified, said Yuen Kwok-yung, chair of Infectious Diseases at the University of Hong Kong’s Department of Microbiology. When the exhaust fan pumped air out of the toilet, the air with germs and viruses could have been sucked out from the exhaust pipe in the toilet, Yuen said.

Yuen said the possibility that the Wuhan virus was transmitted through the toilet drainage system could not be ruled out. He said it was also possible that the woman was infected in other ways. He said more investigations were needed.

The virus could have been leaked into the woman’s toilet by air through the exhaust pipe, which was not completely sealed, said Tse Chin-wan, Under Secretary for the Environment. However, this case was different from the severe acute respiratory syndrome (SARS) outbreak in Amoy Garden in Kowloon Bay when the virus was transmitted through drain outlets, or U-traps, Tse said.

Tse added that the drain outlets in Hong Mei House were all qualified facilities and had no risk of virus transmission.

“We are not sure what was the exact route of transmission,” said Wong Ka-hing, the Controller of the Centre for Health Protection. “It could still be through the usual method of droplets or contact.”

Police and staff from the Housing Department evacuate the residents of the Hong Mei House. Photo: RTHK

A 59-year-old resident surnamed Chan, who was living with her husband, son, daughter-in-law and grandchildren in Hong Mei House, told AFP that she was scared by the infected cases there.

“We seldom go out already because we don’t have enough masks. I don’t allow my grandchildren to play in the hallway,” she said. “Now we can’t even stay at home.”

Hong Kong is on high alert for any potential “super spreader” events, especially in the towering housing blocks that make the city one of the world’s most densely populated places.

In 2003, 331 people were infected with the SARS virus through aerosol transmission in Amoy Gardens. It was reported that aerosol particles were created after drain outlets with an outdated design had dried up. Forty-two people from one housing block in Amoy Gardens died. The death toll from the 2003 SARS outbreak was 299 in Hong Kong.

The government has urged people to regularly pour water into drain outlets and to put the toilet lid down before flushing.

Chief Executive Carrie Lam said in a media briefing before the weekly Executive Council meeting that the government was highly concerned about the situation in Hong Mei House and would continue to investigate the cause of the virus transmission. Lam emphasized that this case was not the same as the SARS outbreak in Amoy Gardens in 2003.

Lam also reiterated that the government would not completely shut down the city’s border with the mainland as the number of incoming travelers had significantly decreased since compulsory 14-day quarantine measures came into effect from Saturday. She said the idea of a border shutdown was meaningless.

On January 22, a 75-year-old Hong Kong man, who was living in Hong Mei House, developed a cough and shortness of breath. On January 24, he was admitted to Princess Margaret Hospital. He has been staying in the general ward in the hospital.

Before he was identified as infected on January 30, the man had not told the Hong Kong medical staff about his latest visit to Shunde in Guangdong province, between December 30 last year and January 7. He had also sought medical treatment at a clinic in Shunde and took day trips to Macau from January 10 to 14.

A lot of medical staff complained that the government did not do enough to protect them and local residents. Thousands of medical staff held a five-day strike last week to call for a complete border closure. The government did not completely shut down the border with the mainland but launched a compulsory 14-day quarantine program for all incoming travelers.

Additional reporting AFP

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