THREAD (1/20) in which I present evidence for the continuation of school closures.

Summary: children can infect others; some children experience severe disease; re-opening #schools is potentially high-risk for the community. #COVID19 #auspol
(2/20) First, a recap. Evidence that children can experience severe disease; how children might spread the virus to others; and that school closures saved lives during the 1918-19 influenza pandemic. https://twitter.com/DrZoeHyde/status/1241290582024007682
(3/20) Since I wrote that initial thread, more evidence has emerged regarding children and #COVID19.
(4/20) US data shows 20% of cases in children are severe enough to warrant hospitalisation, and ~2% are admitted to the ICU. The authors of this study state children likely play a role in transmission and that social distancing should apply to all ages. https://twitter.com/DrZoeHyde/status/1249994438434144258
(5/20) At 6 April, at least 74 children were admitted to US ICUs. Modelling suggests a total of 176,190 children infected. Although #COVID19 is generally less severe in children, paediatric cases will still overwhelm the health system if virus unchecked. https://twitter.com/DrZoeHyde/status/1253216155692462080
(6/20) Importantly, the long-term outcomes of #COVID19 are unknown. At least some patients who recover may have lasting health problems. This is more likely to be the case for adults with severe disease, but there may also be some risk for children too.
(7/20) In this study, 31% of children with #COVID19 had elevated cardiac enzymes despite having generally mild disease. This proportion is similar to adult cases. In some circumstances, this can indicate injury to the heart. https://twitter.com/DrZoeHyde/status/1243045581112496128
(8/20) There is now growing evidence that #COVID19 is more than a respiratory virus, and can damage the cardiovascular system. This is probably more likely in severe cases, but the exact risk is unknown. https://twitter.com/DrZoeHyde/status/1251365866412761089
(9/20) The virus which causes #COVID19 is easily transmitted. It is now well documented that people without symptoms can spread the virus. Thus, the presence of symptoms is not a guide to how infectious a person is.
(10/20) In this study, the amount of viral RNA detected in nasopharyngeal swabs did not differ between symptomatic, pre-symptomatic, and asymptomatic #COVID19 cases. https://twitter.com/DrZoeHyde/status/1249975434357272576
(11/20) People with #COVID19 are most infectious up to 2 days before symptom onset. It's estimated that 44% of secondary cases are infected by people in the pre-symptomatic stage. https://twitter.com/DrZoeHyde/status/1250424341772136449
(12/20) This study of a 6-month old infant in Singapore with almost no symptoms found that the child's hospital room was extensively contaminated with viral RNA. https://twitter.com/DrZoeHyde/status/1251794542262509570
(13/20) Speech alone is sufficient to produce respiratory droplets which could carry the virus causing #COVID19. Coughs or sneezes may not be necessary for transmission of the virus. https://twitter.com/DrZoeHyde/status/1250805357997289472
(14/20) Schools are important places because they serve as community hubs. They are a connection point for people who might not otherwise interact (and would not be interacting with the current social distancing measures in place).
(15/20) There are also large networks within schools. This study of a primary school in France showed that on average, children had 323 contacts per day with 47 other children. https://twitter.com/DrZoeHyde/status/1251785029383884804
(16/20) Some have stated that children are less likely to be infected by the virus which causes #COVID19. This may not be accurate. Instead, it may reflect a lack of testing in children.
(17/20) Iceland tested 6% of the population & found young children (<10 years) were less likely to test positive than older children (but unknown if due to less exposure). However the % of children aged >=10 years who tested positive was similar to adults. https://twitter.com/DrZoeHyde/status/1253629416850067457
(18/20) Testing for #COVID19 in children in Australia has been limited. The majority of close contacts of known cases in schools were not tested.

However, two children were likely infected in schools; one by another student at a high school. https://twitter.com/DrZoeHyde/status/1254287354832941058
(19/20) There are almost certainly undetected #COVID19 cases in Australia. We have not yet eradicated the virus. How many cases remain undetected is unclear, and determining how large this number is likely to be should be a priority.
(20/20) Evidence clearly shows children can experience severe disease, the virus causing #COVID19 is easily spread, and that transmission has occurred in Australian schools.

Given we don't know the number of undetected cases in Australia, re-opening schools would be high-risk.
Dear @unionsaustralia @sallymcmanus @AEUfederal @IEUofA @SSTUWA @NTEUNational @Unions_WA @VicUnions @TheQCU @cpsucsa @SAUnions, please consider reading this thread (and sharing with colleagues). It contains the latest evidence on the risk of re-opening schools.
You can follow @DrZoeHyde.
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