{'fraction_non_alphanumeric': 0.027924528301886794, 'fraction_numerical': 0.024150943396226414, 'mean_word_length': 5.314285714285714, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Age‐specific seroprevalence of dengue infection in Hong Kong

A newly developed dengue virus vaccine (chimeric yellow fever virus‐tetravalent dengue vaccine [CYD‐TDV]) has recently been licensed for clinical use. The World Health Organization recommends vaccination for populations with seroprevalence of at least 70% to maximize public health impact. This study aimed to delineate the seroprevalence of dengue infection in Hong Kong. A total of 105 972 serum samples submitted for clinical testing during the period 2013‐2015 were age‐stratified and sex‐stratified. For each year of collection, 25 samples were randomly selected from each age‐sex group. Altogether, 2100 samples were tested for the dengue immunoglobulin G (IgG) antibody using a non‐type–specific ELISA kit. The overall dengue IgG‐positive rate was 4.6% and showed no significant change over the 3 years. The positive rate was not associated with sex, but a steep rise in seroprevalence for persons above 65 years (32.7%) was observed. The low dengue seroprevalence in Hong Kong does not support implementation of a national immunization program. Majority of the population in Hong Kong are susceptible to dengue infection, and a substantial proportion of persons older than 65 years could acquire secondary infection and are prone to develop severe dengue.