The number of new HIV cases in Hong Kong rose by over 7 per cent in the second quarter of the year compared to the first three months, according to Health Department figures released on Tuesday. A total of 131 new cases of human immunodeficiency virus infections were reported in the second quarter, up from 122 in the preceding period. The latest cases bring the total to 5,523 since 1984, the department’s Centre for Health Protection said. Homosexual contact remained the largest single route of HIV transmission, the health centre’s Dr Wong Ka-hing told a press conference on Tuesday. The new cases in the second quarter involved 99 men and 32 women. Of them, 65 acquired the infection through homosexual contact and 29 via heterosexual contact. “The routes of transmission of the remaining 37 cases were undetermined due to inadequate information,” Wong said. Most of the cases were reported by three sources: public hospitals and clinics (48 cases), private hospitals and clinics (31 cases) and the Department of Health’s Aids Unit (26 cases). Thirty new cases of Aids were reported this quarter, bringing to 1,311 the total number of confirmed cases reported since 1985. Forty-three per cent of the new Aids cases were related to homosexual contact and 50 per cent were attributed to heterosexual contact. HIV is the cause of Aids, which is characterised by clinical complications such as infections and cancers due to a suppressed immune system. Without treatment, about half of all HIV patients progress to Aids within 10 years, Wong said. In the second quarter, the most common Aids-related illness was a form of pneumonia called pneumocystosis.