Customer-facing shop staff are about five times more likely to test positive for COVID-19 than their colleagues in other positions, a small American study has found.
Writing in Occupational & Environmental Medicine, the researchers say that of those testing positive, three out of four had no symptoms, which suggests that these key workers could be an important source of infection.
Led by Harvard University, Boston, Mass, USA, the observational study team followed 104 employees working in one grocery shop in the city.
Each employee was tested for SARS-CoV-2 in May as part of a mandatory testing policy across Boston and they also completed detailed questionnaires on: their lifestyle; medical history; employment history; working patterns and role at the store; commuting to and from work; and the protective measures they were able to take against infection at work.
They were also asked to provide information on COVID-19, including any symptoms and exposure to anyone with confirmed SARS-CoV-2 over the previous 14 days.
Out of the 104 participants, 21 – one in five – tested positive for SARS-CoV-2, significantly higher than the 0.9-1.3% prevalence of the infection in the local community at the time. Three out of four of those testing positive had no symptoms.
Of those testing positive, 91% had a customer-facing role compared with 59% of those testing negative.
Although it is a small observational study, the authors write: “This is the first study to demonstrate the significant asymptomatic infection rate, exposure risks, and associated psychological distress of grocery retail essential workers during the pandemic. Once essential workers are infected with SARS-CoV-2, they may become a significant transmission source for the community they serve.”
New evidence has also emerged that some long-COVID patients experience skin problems and “COVID toes” that can last for months, a conference has heard.
EADV Virtual, the conference of the European Academy of Dermatology and Venereology, heard the results from a late-breaking abstract that analysed the largest registry of COVID-19 patients with dermatological symptoms to reveal a subset of patients who experience skin symptoms, such as urticaria, chilblains and papulosquamous eruptions.
Data from 990 cases from 39 countries input into the registry, which is a collaboration between the International League of Dermatological Societies and the American Academy of Dermatology, show an average duration of 12 days for all dermatological symptoms, with some lasting as long as 150 days.
They found urticaria lasted for median five days, and pernio/chilblains – COVID toes – lasted 15 days but sometimes as long as 130-150 days, while papulosquamous eruptions, was experienced for median 20 days.
The researchers say that identifying COVID toes may have implications for understanding the prolonged inflammatory response in some patients after infection.
They found that some symptoms, such as retiform purpura, are associated with severe COVID-19, as every patient with it had received hospital treatment for the virus, while COVID toes appeared to be associated with milder cases as only 16% had been hospitalised.
The researchers also found that COVID toes often appear one to four weeks after initial infection and that 15% were still be positive for the virus.
Lan F-U, Suharlim C, Kales SN et al. Association between SARS-CoV-2 infection, exposure risk and mental health among a cohort of essential retail workers in the USA. Occupational & Environmental Medicine 30 October 2020
https://oem.bmj.com/lookup/doi/10.1136/oemed-2020-106774
McMahon, D, Gallman, A, et al. COVID-19 "long-haulers" in dermatology? Duration of dermatologic symptoms in an international registry from 39 countries. Late breaking abstract no 3090, presented 29 October 2020 at EADV Virtual.
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