Seroepidemiologic survey of Dirofilaria immitis infection among domestic dogs in Taipei City and mountain aboriginal districts in Taiwan (1998-1999)

To estimate the seroprevalence of Dirofilaria immitis infection in domestic dogs in Taiwan, we utilized a commercial ELISA kit (Snap (TM), IDEXX, USA) for detecting circulating antigens released by adult female worms. Serum s pecimens of 664 domestic dogs sampled from Taipei City in northern Taiwan a nd 14 mountain aboriginal districts in eastern Taiwan were screened for D. immitis antigens. Multivariate-adjusted odds ratios (ORs) with their 95% co nfidence intervals (CIs) were estimated by multiple logistic regression ana lysis. A total of 89 subjects were antigen-positive, giving a seroprevalenc e of 13.4%, of which the seroprevalence in Taipei City and mountain aborigi nal districts were 13.8 and 12.1%, respectively. The mean overall seroposit ive rates were 6.3% in 1-3-year-old age group, 14.1% in 3-6-year-old age gr oup and 23.7% in the greater than or equal to 6-year-old age group. The old er the age, the higher the seroprevalence (OR = 4.6, 95% CI = 2.4-9.0 for t he greater than or equal to 6-year-old age group versus 1-3-year-old age gr oup, P < 0.001) for all the dogs in the present study. Moreover, seropreval ence was not different between female and male dogs in either Taipei City o r mountain aboriginal districts (P > 0.05). Also, no significant difference in seroprevalence among dogs between the two geographical areas was found (P > 0.05). In the logistic regression analysis, the seroprevalence of A im mitis remained significantly increased with age after multivariate adjustme nt in the present study. To our knowledge, this is the first report on the status of A immitis infection in domestic dogs in Taipei City and mountain aboriginal districts in Taiwan to date. (C) 2001 Elsevier Science B.V. All rights reserved.