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An outbreak of severe acute respiratory syndrome coronavirus 2 caused by the Gamma variant of concern infected 24/44 (55%) employees of a gold mine in French Guiana (87% symptomatic, no severe forms). The attack rate was 60% (15/25) among fully vaccinated miners and 75% (3/4) among unvaccinated miners without a history of infection.
On May 31, 2021, a gold miner tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at the Cacao health center, French Guiana. He worked in a legal gold mine located 72 km from Cayenne (including 13 km of forest trail) in the Amazon Forest. Other workers from the same site were reported as symptomatic, although a large part of this specific population had benefited from complete coronavirus disease (COVID-19) vaccination in the previous month. A medical team went on site to investigate, examine, and screen the 44 employees of the mine. We describe results of the outbreak investigation.
We collected data by completing standardized forms with data gathered through interviews and medical examination of all gold miners and by reviewing the health center records. All employees of the mine were examined by a physician and screened by nasopharyngeal Panbio COVID-19 Ag Rapid Test device (Abbott Laboratories, https://www.abbott.com) if they were symptomatic; all miners underwent SARS-CoV-2 PCR EurobioPlex SARS-CoV-2 Multiplex (Eurobio Scientific, https://www.eurobio-scientific.com) testing on June 2, 2021. All employees were reassessed on June 8 and 15, 2021; those with negative results were rescreened by PCR. We performed serologic tests on blood specimens collected from 39 gold miners whether PCR was negative or positive. Serum samples were initially tested with anti–SARS-CoV-2 ELISA IgG (Euroimmun, https://www.euroimmun.com). We used descriptive statistics to analyze the variables and performed univariate analyses. Intervention was a public health response as part of activities of Cayenne Hospital. All gold miners gave their verbal informed consent for recording and processing of information during interviews and for the use of their biologic results for research purposes, and physicians completed a nonobjection form in accordance with laws of France.