Occupational health practitioners should be alert to the fact that people who have had Covid-19 may be at increased risk of developing serious blood clots for six months following their infection.
Research by Swedish academics has highlighted that people who have had Covid-19 are at increased risk of blood clots in the leg, or deep vein thrombosis (DVT), for up to three months.
There can also be a heightened risk of blood clots in the lungs, or pulmonary embolism, for up to six months, as well as internal bleeding, such as a stroke, for up to two months.
The researchers, from the Umea University in Sweden, also found that four in every 10,000 Covid patients developed DVT compared with one in every 10,000 people who had not had the virus.
Approximately 17 in every 10,000 Covid patients had a blood clot in the lung compared with fewer than one in every 10,000 who had not had Covid.
The study, published in the BMJ, concluded: “The findings of the study suggest that Covid-19 is a risk factor for deep vein thrombosis, pulmonary embolism, and bleeding. These results could impact recommendations on diagnostic, and prophylactic strategies against venous thromboembolism after Covid-19.”
However, there were some caveats. First, the research concluded that people with the highest clot risk were those who have had a severe Covid infection as well as those infected during the first wave.
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The study, in fact, was quite focused on the earlier stages of the pandemic, with the researchers tracking the health of more than one million people who tested positive in Sweden between February 2020 and May 2021. They then compared the results with four million people of the same age and sex who had not had a positive test.
The raised risk of blood clots had decreased as the pandemic progressed through later waves, largely because treatments had improved and because of the rollout of vaccines.
Furthermore, vaccination can provide an important mitigating effect, it highlighted, not least because of reducing the likelihood of severe infection.
Covid-19 public inquiry
Separately, the TUC has said that the Covid-19 public inquiry expected to start later this year must include a focus on workplace safety and enforcement.
In its response to a public consultation on the inquiry’s terms of reference that closed this week, the union body has emphasised that the draft terms of reference should be expanded to fully cover the experiences of workers in the pandemic – especially those who remained in workplaces throughout lockdowns.
The TUC has warned workers faced greater risks and unions remain concerned that many were affected by a lack of adequate PPE, lax workplace safety and inadequate enforcement.
TUC general secretary Frances O’Grady said: “Everyone has a right to be safe at work. The threat of workplace infections was not insurmountable. But many workers were put at unacceptable risk – especially key workers on the frontline.
“The inquiry must take a deep dive into workplace safety – especially into those workplaces and sectors where outbreaks occurred, and where government Covid safety rules fell short.
“And the inquiry must look in detail into how some workers – especially Black and minority ethnic, disabled and women workers – were particularly hard hit by the response to the pandemic,” O’Grady added.
