1/ Evidence pointing to COVID-19 longer-range transmission through fecal aerosols (from flushing) when there is air communication thru sewer pipes (e.g. U traps dry out)
Prof. Yuguo Li (world-leading outbreak investigator in our group) has authorized me to post this info.
Prof. Yuguo Li (world-leading outbreak investigator in our group) has authorized me to post this info.
Hong Mei House outbreak at Cheung Hong Estate (close to HK airport), 75-yr-old man lived in A1307 on 13 floor was probably infected by early confirmed case lived in A307 on floor 3. Note that A1307 is 10 stories above A307, the 2 are connected by the same drainage stack & vents
This news piece reports on that outbreak: amp.cnn.com/cnn/2020/02/12…
There were actually two other similar COVID-19 outbreaks in HK involving vertically aligned flats, 1 is the Heng Tai House at Fu Heng Estate, in which a 59-year-old man in flat 13 on the 34th floor was probably...
There were actually two other similar COVID-19 outbreaks in HK involving vertically aligned flats, 1 is the Heng Tai House at Fu Heng Estate, in which a 59-year-old man in flat 13 on the 34th floor was probably...
infected by two confirmed cases lived in flat 13 on the 32nd floor, and the second is the larger Luk Chuen House outbreak.
Luk Chuen House is part of the Lek Yuen Estate, Sha Tin. The Lek Yuen Estate was built in 1975, and Luk Chuen House is one of the seven blocks in the estate
Luk Chuen House is part of the Lek Yuen Estate, Sha Tin. The Lek Yuen Estate was built in 1975, and Luk Chuen House is one of the seven blocks in the estate
5/ Index patient had symptom onset on May 22. She lives in flat 812 (8th floor, unit 12). The other two family members in the same flat were also infected. On the same 8th floor, two other flats (813 and 817) just on the other side of corridor of flat 812 were also infected...
6/ (possibly by the airborne route as 813 and 817 is on the downwind location). Other infected flats were vertically associated, i.e., flats 710, 810 1012, and1112, connected by the connected drainage system. The Luk Chuen House outbreak is characterized by two spatial...
7/ sub-clusters, i.e., those on the 8F not associated with the drainage system, and those on the same façade associated with the drainage system, which makes it challenging to explain how the virus was transmitted there.
8/ Now have 6 similar outbreaks, 2003 Amoy Garden, 3 COVID in HK & 2 in Guangzhou. To me, the fecal droplets within the drainage system was transported by the flushing induced foul gas flows, which are also affected by stack effect.
9/ Hence the common features include only upper stories were infected even the source is at the lower stories.
(All text in tweets 2-9 provided by Prof. Yuguo Li -- except news report link)
(All text in tweets 2-9 provided by Prof. Yuguo Li -- except news report link)
But don't panic. We don't know that it is *easy* to transmit this way. But evidence points to it being *possible*
Still, (a) try to avoid overlap around flushing times in public bathrooms, and (b) making sure all U-traps have water in apartment buildings, would seem useful.
Still, (a) try to avoid overlap around flushing times in public bathrooms, and (b) making sure all U-traps have water in apartment buildings, would seem useful.
Prof. @linseymarr has a good point. This could possibly be also explained by respiratory aerosols, e.g. person coughing in one bathroom, aerosols going through air connection onto 2nd bathroom. Will ask Yuguo for his take on that.
Viable virus has been found in faeces:
They should smell the sewer gas & do something.
But in these outbreaks, the investigators go in and find U-traps without water, providing the air communication. Maybe people with poor sense of smell? Or maybe other strong odors? Or oblivious due to age, cognitive issues etc?
But in these outbreaks, the investigators go in and find U-traps without water, providing the air communication. Maybe people with poor sense of smell? Or maybe other strong odors? Or oblivious due to age, cognitive issues etc?
