The Centre for Health Protection is investigating an outbreak of respiratory tract infection affecting 22 children at a Causeway Bay residential child-care centre.

The 14 boys and eight girls, aged four months to two years, came down with a fever, cough and runny nose from January 31 to February 20. Of the four children who were hospitalised, two have been discharged. All are stable.

They tested positive for respiratory syncytial virus and adenovirus. The former is spread by direct contact with infectious secretions and can be easily transmitted among people in institutional settings. The incubation period is one to 10 days and is usually five to seven days. Common symptoms include fever, chills, headache and decreased appetite.

Adenovirus is a group of viruses that commonly cause viral infection in children. Its symptoms vary from a fever, cough and sore throat, to gastroenteritis illnesses such as vomiting and diarrhoea. There can be associated conjunctivitis. It is usually transmitted by direct contact. Most infections are mild and require no therapy or only symptomatic treatment.