(ECNS)--An outbreak of dengue fever in Hong Kong has sickened 23 people as of August 23. Authorities found that 16 of the infected had visited Lion Rock. Some of the others live in Cheung Chau. The patients are in stable condition, and none of their families have shown signs of infection. Lion Rock has been closed since August 17 for a month-long mosquito eradication campaign. Closure of more areas is under consideration.