Senior Medical Officer of Health in the Ministry of Health and Wellness Dr Anton Best has sought to clarify COVID-19-related terms which have been causing confusion.
Best noted that people have been misinterpreting the terms community spread and local transmission and emphasised that they are different categories.
Best was speaking on Tuesday during a COVID-19 press conference which was also addressed by Ambassador Elizabeth Thompson – head of the Health Communications Team and Minister of Health Jeffrey Bostic.
He said the World Health Organisation has four categories for describing COVID-19 in a pandemic: No cases, sporadic cases, clusters and community transmission – also known as community spread.
He explained that sporadic cases are small – one or more imported or locally detected cases.
Clusters were defined as cases that are linked to each other “in time, geographical location or by common exposure”. A cluster can also refer to larger outbreaks of local transmission, including big numbers of cases not linked to transmission chains or multiple unrelated events.
With regard to local transmission, he said: “When you have detected a case and you can explain that case being exposed to another person, that is local transmission.” Best said these cases also make up sporadic cases. When linking they are all part of a cluster.
Alternatively, “When you talk about community transmission, it means that you can have multiple cases where you cannot explain how this person got COVID-19.”
He said there is no set number of cases for this category, WHO’s definition is a “large number”.
In addressing the label “super spreader event”, Best said there is no scientific definition or public health definition and that this type of event is usually identified in retrospect. He said it is a relatively new label and means different things to different populations. He said, however, that it was a fair description in relation to the much discussed Boxing Day bus crawl.
With further probing from Thompson, Best explained that the bus crawl was identified as a “super spreader event” because it was a single event on a particular day. In contrast, the other clusters happened over different days and at different locations.
“The bus crawl was one event involving a large number of people and from that we have an outbreak of cases attributed to the bus crawl.”
He noted that the majority of cases are linked to clusters, however, “We have about 120 persons right now that we cannot say or definitively link to any of the larger clusters. . . .
“When we have exhausted all of our investigations and we cannot say why this particular person . . . has COVID and we have large numbers, that is when we can say Barbados has community spread, but at this current point we cannot say that because contact tracing is continuing.”