Australian study finds low SARS-CoV-2 transmission in educational settings in first wave
During the first wave of COVID-19 in New South Wales, transmission rates of SARS-CoV-2 in educational settings was low, consistent with mild infrequent disease in the child population, according to research published in The Lancet Child and Adolescent Health.1
Australian researchers prospectively examined COVID-19 transmission among children and adults in the 7700 educational settings in NSW. During Term 1 (25 January to 10 April), they identified 12 children and 15 adults who attended 15 schools and 10 early childhood education and care (ECEC) settings while infectious (defined as 24 hours before symptom onset). They identified and monitored 1448 close contacts, 43.7% of whom had nucleic acid testing, antibody testing, or both.
Eighteen secondary cases were identified among the close contacts (attack rate, 1.2%). Five secondary cases were identified in three schools (three children and two adults; attack rate, 0.5%). Although no secondary transmission occurred in nine of the 10 ECEC settings, in one, transmission occurred in six adults and seven children. Excluding this single ECEC setting, the overall attack rate in all settings was 0.4%, or one in every 282 contacts.
The researchers noted that the data should be viewed in context of the epidemic characteristics and COVID-19 response in NSW at the time. Most educational facilities were closed briefly after case identification and close contacts were required to home quarantine for 14 days. During much of the study period, educational settings were open but attendance rates in schools dropped in mid to late March when distance learning was implemented.
‘Higher SARS-CoV-2 primary case and transmission rates might have occurred in schools and ECEC settings if the epidemic had escalated or if extensive testing, tracing, quarantine of exposed close contacts, and other public health mitigation measures were not simultaneously and effectively implemented,’ they wrote. Nevertheless, ‘our findings provide evidence that SARS-CoV-2 transmission in educational settings can be kept low and manageable in the context of an effective epidemic response.’
Macartney and colleagues’ prospective cohort study in NSW involving 12 children and 15 adults who attended daycare/schools while infectious described a low transmission rate of 1.2% of the 1448 contacts (but only 43.7% had PCR or antibody testing done). While this data is encouraging, data from other studies suggest that the transmission rate from children may be higher in children aged over 10 years.
A South Korean study reported that transmission is likely to be age dependent.2 From their nationwide COVID-19 contact tracing program involving 59,073 contacts of 5,706 COVID-19 index patients, Park and colleagues found that the household transmission of SARS-CoV-2 was highest if the index patient was 10 to 19 years of age (rate of 18.6%; 95% CI, 14.0%–24.0%) and lowest in children 0 to 9 years (5.3%; 95% CI, 1.3%–13.7%). The data are supported by the findings of Goldstein and colleagues’ systematic review (in preprint).3
Update on clinical presentation and management of COVID-19
This Australian narrative review summarises the latest knowledge, at the time of publication, on presentation, diagnosis, assessment and management of patients with COVID-19.1
Among the topics covered by Victorian infectious diseases experts in their narrative review, published in the Medical Journal of Australia, is the emerging evidence of clinical benefit for some specific therapies for COVID-19.
The authors note the findings of the large international randomised controlled trial on remdesivir that have led Australian national guidelines to adopt a conditional recommendation for its use outside a trial setting when necessary. In this trial, remdesivir improved recovery time in hospitalised patients with severe COVID (see summary on page 38).
The authors also discuss the preliminary report on the interim findings from the UK RECOVERY trial on dexamethasone. This trial found low-dose dexamethasone substantially reduced mortality in patients hospitalised with COVID-19 who were given supplemental oxygen or mechanical ventilation (see summary on page 38).
Other treatments being investigated include lopinavir-ritonavir; chloroquine and hydroxychloroquine; the combination of interferon beta-1b, lopinavir-ritonavir and ribavirin; and interleukin 6 (IL-6) antagonists.
The authors stress that the WHO interim guidance on the clinical management of COVID-19 states that investigational therapies for COVID-19 should be used only in approved randomised controlled trials.
On the assessment of patients with suspected or confirmed COVID-19, the authors say features of severe disease and risk factors for progression to severe disease, including older age and comorbidities, should be sought. Clinical features found more often in patients who have had a fatal outcome compared with survivors include dyspnoea at presentation and lower initial oxygen saturation. They note that most patients with COVID-19 have mild illness and can usually be managed in the community, but patients should be warned about symptoms of concern, such as increasing breathlessness, and seek prompt medical review if they occur.