This is definitely an improvement over the US CDC and Shenzhen papers, but I still have reservations about it. The first issue is that it’s based on calling people and asking about symptoms, not based on testing. So it doesn’t count asymptomatic people, nor people with mild symptoms who don’t disclose them. The second issue is that their numbers imply an average household size of 6.4, which implies a definition of “household” which is somehow not as expected.
They track contacts of the first 30 identified cases of COVID-19 in South Korea, and find 119 household contacts, of which 9 are infected. Table 2 describes every transmission they found, and whether it was a household transmission. Of the first 30 cases, 8 of them got it by household transmission from someone else who was also one of the first 30 cases, so that’s 22 distinct households.
(30 people + (119 contacts − 8 already counted)) / 22 households = 141⁄22 = 6.4 people per household.
This is definitely an improvement over the US CDC and Shenzhen papers, but I still have reservations about it. The first issue is that it’s based on calling people and asking about symptoms, not based on testing. So it doesn’t count asymptomatic people, nor people with mild symptoms who don’t disclose them. The second issue is that their numbers imply an average household size of 6.4, which implies a definition of “household” which is somehow not as expected.
They track contacts of the first 30 identified cases of COVID-19 in South Korea, and find 119 household contacts, of which 9 are infected. Table 2 describes every transmission they found, and whether it was a household transmission. Of the first 30 cases, 8 of them got it by household transmission from someone else who was also one of the first 30 cases, so that’s 22 distinct households.
(30 people + (119 contacts − 8 already counted)) / 22 households = 141⁄22 = 6.4 people per household.