I haven't seen the article you are referring to. The 'official' (I loathe to call something on a Facebook page 'official') but the official Facebook page for Anguilla has a link which states in part

"On 21 April, a case of COVID-19 was confirmed in a symptomatic female resident of Anguilla who had no apparent direct links to any imported case of the virus. Linked to this case, two further persons have tested positive on the evening of 21 April. In accordance with public health practices for containment and prevention of spread: • All three persons who tested positive have been placed in isolation; and • The Ministry of health and health Authority colleagues have initiated aggressive contact tracing to identify every individual who may have come into close contact with these three persons. All individuals thus identified will be placed under quarantine and tested. "

BUT all of this is really about Anguilla, not SXM...