Arrival of Covid-19 in NL earlier than thought, study reveals

A person in a medical mask in front of the Dutch flag
Artist's rendering of a person in a medical mask in front of the Dutch flagValeryBrozhinskyDepositPhotosDeposit Photos

The Covid-19 disease was already being transmitted among health care workers in Noord-Brabant from as early as Feb. 19, new research reveals—indicating that transmission was occurring over a week before the first case was officially recorded in the Netherlands late last month.

According to a survey published Friday by a joint team of Dutch researchers, as many as 86 health care workers in two Noord-Brabant hospitals were infected with severe acute respiratory syndrome coronavirus 2, more commonly referred to simply as "coronavirus," from late February and into early March. Of these, eight were apparently showing symptoms of the coronavirus disease before the case of Joost Boons, the official "patient zero," was reported by health authorities on Feb. 27.

While the 86 infected health care workers were indeed a small sample (6.4 percent) of the total sample taken of hospital employees; the findings do nevertheless represent a “relatively high prevalence of mild clinical presentations that may go undetected,” the researchers write.

The survey included samples from Elisabeth-TweeSteden Ziekenhuis in Tilburg and Amphia in Breda, two hospitals which were quickly affected by the initial spike in new cases in Noord-Brabant earlier this month.

When presented with the results of the survey, ETZ director Bart Berden told local newspaper BD that he had already been taking into account that unrecorded transmissions were likely occurring in his hospital. “In the first weeks, we still thought that if you don't have a fever, you’re not contagious,” he acknowledged.

Berden went on to call the carnival that was happening in Noord-Brabant at the time “really a kickstart” for the spread of Covid-19, adding that he foresees a “remarkably rapid growth” of the virus outside of the province.

The research further reiterates that transmissions frequently tend to occur within hospitals a a result of health care workers falling ill and continuing to work. According to the researchers, nearly two thirds (62.8 percent) of all the tested employees continued working in spite of symptoms that they were experiencing. The researchers did not, however, test whether or not the infected health care workers had indeed been transmitting the virus to others while at work.