Thread by @DrZoeHyde

(1/12) Study of #SARSCoV2 transmission by children. 12 children infected in childcare transmitted the virus to at least 12 of 46 (26%) contacts at home or in the community. One parent was hospitalised. Transmission by 2 of 3 asymptomatic children was seen.
cdc.gov/mmwr/volumes/6…

(2/12) This was a retrospective study of outbreaks that occurred at 3 childcare centres.

The index cases in all 3 clusters were staff members. Two of the 3 staff had a household contact with confirmed or probable #COVID19, and had gone to work while this person was symptomatic.

(3/12) A total of 22 #COVID19 cases were reported at the 3 childcare centres. Twelve cases (54%) were in children.

(4/12) The number of cases in each facility was as follows:

A: 2 cases (0 children) / 12 persons (17%)

B: 5 cases (2 children) / 5 persons (100%)

C: 15 cases (10 children) / 84 persons (18%)

(5/12) The number of confirmed or probable #COVID19 cases in contacts linked to the facility was as follows:

A: 0 cases / 25 contacts (0%)
B: 7 cases / 28 contacts (25%)
C: 9 cases / 109 contacts (8%)

(6/12) However, not all contacts were tested. The proportion of asymptomatic contacts who were not tested was as follows:

A: 80%
B: 29%
C: 61%

It's possible that more transmission occurred than was reported.

(7/12) Daily temperature checks were required at facility A and B, and were requested at facility C. Daily symptom screening was required at facility A, and was requested at facility C. Staff wore masks at A and B. Masks were not worn at C.

(8/12) This suggests that temperature screening alone is insufficient to detect cases before they are infectious. Masks may have been helpful.

(9/12) The 12 infected children had mild or no symptoms (3 were asymptomatic), demonstrating the difficulty of detecting cases in children.

However, transmission from them to adults and other children occurred.

(10/12) Importantly, transmission was observed in 2 of 3 asymptomatic children, one of whom infected their mother, who was subsequently hospitalised.

(11/12) Transmission was also observed in very young children. One child who was 8 months old transmitted the virus to both parents.

(12/12) The authors noted that while #COVID19 is less severe in children than in adults, they can still play a role in transmission.

This demonstrates the importance of testing children, both to prevent transmission, and also to better understand how the virus spreads.