Risk of transmission of respiratory viruses during aerosol-generating medical procedures (AGMPs) revisited in the COVID-19 pandemic: a systematic review.

BACKGROUND: In many jurisdictions healthcare workers (HCWs) are using respirators for aerosol-generating medical procedures (AGMPs) performed on adult and pediatric populations with all suspect/confirmed viral respiratory infections (VRIs). This systematic review assessed the risk of VRIs to HCWs in the presence of AGMPs, the role respirators versus medical/surgical masks have on reducing that risk, and if the risk to HCWs during AGMPs differed when caring for adult or pediatric patient populations. MAIN TEXT: We searched MEDLINE, EMBASE, Cochrane Central, Cochrane SR, CINAHL, COVID-19 specific resources, and MedRxiv for English and French articles from database inception to September 9, 2021. Independent reviewers screened abstracts using pre-defined criteria, reviewed full-text articles, selected relevant studies, abstracted data, and conducted quality assessments of all studies using the ROBINS-I risk of bias tool. Disagreements were resolved by consensus. Thirty-eight studies were included; 23 studies on COVID-19, 10 on SARS, and 5 on MERS/ influenza/other respiratory viruses. Two of the 16 studies which assessed associations found that HCWs were 1.7 to 2.5 times more likely to contract COVID-19 after exposure to AGMPs vs. not exposed to AGMPs. Eight studies reported statistically significant associations for nine specific AGMPs and transmission of SARS to HCWS. Intubation was consistently associated with an increased risk of SARS. HCWs were more likely (OR 2.05, 95% CI 1.2-3.4) to contract human coronaviruses when exposed to an AGMP in one study. There were no reported associations between AGMP exposure and transmission of influenza or in a single study on MERS. There was limited evidence supporting the use of a respirator over a medical/surgical mask during an AGMP to reduce the risk of viral transmission. One study described outcomes of HCWs exposed to a pediatric patient during intubation. CONCLUSION: Exposure to an AGMP may increase the risk of transmission of COVID-19, SARS, and human coronaviruses to HCWs, however the evidence base is heterogenous and prone to confounding, particularly related to COVID-19. There continues to be a significant research gap in the epidemiology of the risk of VRIs among HCWs during AGMPs, particularly for pediatric patients. Further evidence is needed regarding what constitutes an AGMP.

Lead levels in Canadian children: Do we have to review the standard?

Research indicates that the blood lead levels that were once considered safe can adversely affect the neurodevelopment of children. The purpose of the present article is to review issues surrounding lead exposure in Canadian children, including sources, chronic low levels of exposure, and recommendations for prevention. Information was obtained through searches of MEDLINE and Web of Science using a combination of: "Canada" or "Canadian" plus "child" or "paediatrics" plus "lead" or "lead poisoning" or "blood lead". Centers for Disease Control and Prevention data and American peer-reviewed literature were also used. On-line Health Canada advisories (available since 1995), as well as relevant reports from nongovernmental organization and the media, were reviewed. The present review found that there has been limited surveillance of blood lead levels of Canadian children and, mainly, among high-risk groups. Harmful health effects may occur below the current standards and the threat of lead in consumer products remains. The current regulation seems to be inadequate to protect Canadian children.