HONG KONG, June 13 (Xinhua) -- Hong Kong's Center for Health Protection (CHP) reported an additional confirmed case of COVID-19 on Saturday, taking the total number of confirmed cases in Hong Kong to 1,109.

The case involves a 33-year-old male with good past health who resides at the unit No. 10 in Luk Chuen House, a residential building in Sha Tin area. His unit is on the same floor and adjacent to the unit of a 34-year-old female patient who was diagnosed on May 31.

The new patient was sent to a quarantine center on June 4 as infection control measures were carried out in the building after a cluster outbreak was found there. He developed fever on the same day and was admitted to hospital.

The patient's nasopharyngeal and throat swab, deep throat saliva sample and stool specimen collected during his stay in the hospital tested negative for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). He underwent a bronchoscopy on Friday due to persistent fever and pneumonia and his bronchoalveolar lavage specimen collected during the bronchoscopy was tested positive for SARS-CoV-2.

The patient is in a stable condition. His two elder brothers and mother living with him were also arranged for quarantine on June 4.

According to the CHP's initial epidemiological investigation, as the patient lived adjacent to the family cluster of a previous case, there is a possibility that he was infected due to environmental factors. The case is thus classified as epidemiologically linked with local cases.

The CHP has been conducting epidemiological investigation in regard to the cluster in Luk Chuen House. As of 4:00 p.m. Saturday local time, 1,399 deep throat saliva samples had been collected in the building, among which six samples need to be collected again owing to leakage, while 1,393 samples have had testing for COVID-19 completed. Except for the four confirmed cases announced on June 2 with positive results, other samples have tested negative.