The only parties who would have access to your test results data (negative results) would be yourself, and Prenetics - i.e. the testing party. Prenetics does not share the data with any third party or any other member of the companies involved in the Project Screen consortium without your prior consent.
For data pertaining to any positive test results, Prenetics is legally obligated to notify the Hong Kong Centre for Health Protection as COVID-19 is deemed a statutory notifiable disease. The Centre for Health Protection is an agency under the Department of Health in Hong Kong responsible for disease prevention and control. The information would be used to track new infections for the purpose of public health awareness and response. Additionally, for any positive test results, Prenetics will share the physical sample - that has been anonymised - with CUHK who will sequence the genome of the virus to identify its strain, which could be used to pinpoint the source of infection and also provide important information about how the virus may be mutating.