Evaluation of performance of human immunodeficiency virus antigen/antibody combination assays in Taiwan.

BACKGROUND: The fourth-generation human immunodeficiency virus (HIV) combination assay, which can simultaneously detect the presence of anti-HIV antibody and HIV antigen, has been shown to shorten the window period in HIV diagnosis compared with the third-generation HIV antibody immunoassay. This study was aimed to determine the performance of HIV combination assays in Taiwan, where the HIV-1 seroprevalence is 0.007% and HIV-2 infection has never been reported. METHODS: Performance of three fourth-generation HIV Ag/Ab combination assays (Dia.Pro, Wantai, and Bio-Rad) and one third-generation HIV Ab immunoassay (AxSYM HIV 1/2 gO) was assessed. RESULTS: A total of 152 specimens, including 86 confirmed HIV-seropositive and 66 HIV-seronegative samples, were used in the study. The sensitivity of four assays varied from 98.8% to 100%, and specificity varied from 98.5% to 100%. Performance of the 75 equivocal samples, the HIV status of which was confirmed later, in terms of negative prediction varied from 81.8% to 87.5%. The Bio-Rad and Dia.Pro assays exhibited higher sensitivity for the detection of p24 antigen among the three fourth-generation HIV combination assays. CONCLUSION: The three fourth-generation HIV Ag/Ab combination assays exhibited better sensitivity, specificity, and negative prediction than the third-generation HIV Ab immunoassay.

Risk factors for acute Toxoplasma gondii diseases in Taiwan: a population-based case-control study.

Although human toxoplasmosis is a notifiable disease in Taiwan since 2007, little is known about its risk factors. This study aimed to investigate the risk factors for acute Toxoplasma gondii diseases in Taiwan. We conducted a nationwide population-based case-control study. Cases of acute human toxoplasmosis notified to the Taiwan Centers for Diseases Control (Taipei, Taiwan) during 2008-2013 were compared with controls that were randomly selected from healthy T. gondii-seronegative blood donors who participated in a nationwide T. gondii seroepidemiologic study during 2009-2010. Cases and controls were matched according to age, gender and residency at an 1:8 ratio. Structured questionnaires were used to gather information regarding risk factors. A total of 30 laboratory-confirmed acute T. gondii disease cases and 224 controls were enrolled. The most common clinical manifestation of the cases was flu-like symptoms (n = 20), followed by central nervous system disease (n = 4), ocular diseases (n = 3), abortion (n = 2), and congenital infection (n = 1). Multivariate conditional logistic regression showed that raw clam consumption (adjusted odds ratio [OR] = 3.7; 95% confidence interval [CI] = 1.4-9.9) and having a cat in the household (adjusted OR = 2.9; 95% CI = 1.1-7.9) were two independent risk factors for acute T. gondii disease. We conclude that raw shellfish consumption and domestic cat exposure were risk factors for acquiring acute T. gondii diseases in Taiwan. This finding may guide future research and control policies.

Surveillance of HIV type 1 recent infection and molecular epidemiology among different risk behaviors between 2007 and 2009 after the HIV type 1 CRF07_BC outbreak in Taiwan.

The objective of this study was to analyze recent infections and the molecular epidemiology of human immunodeficiency virus type 1 (HIV-1) among different risk groups since the outbreak of circulating recombinant form CRF07_BC among intravenous drug users (IDUs) in 2004 in Taiwan. Phylogenetic analysis was performed using the env and pol fragment sequences amplified from these specimens. The BED IgG capture incidence EIA (BED-CEIA assay) was used to determine recent infections. Among the 683 HIV-1-positive individuals enrolled between 2007 and 2009, 394 (57.7%) were subtype B, 260 (38.1%) were CRF07_BC, 26 (3.8%) were CRF01_AE, two (0.3%) were CRF08_BC, and one (0.1%) was CRF06_cpx. While the percentage of CRF07_BC decreased (58.5-17.9%, p < 0.001) from 2007 to 2009, the percentage of subtype B increased (37.6% to 74.9%, p < 0.001). A concordant decrease in the proportion of recent infections to new infections among IDUs (63.6% to 9.8%, p < 0.001), accompanied with an increase of the proportion of recent infections in MSM (men having sex with men) (22.4-67.1%, p = 0.77) and heterosexual groups (13.1- 23.2%, p = 0.852), was observed. The decrease in CRF07_BC infections and the reduction in the proportion of recent infections among IDUs reflected the success of harm reduction strategies initiated by the government in 2005.

An uncommon case of HIV-1 transmission due to a knife fight.

This article describes a case of human immunodeficiency virus type 1 (HIV-1) infection transmission caused by a bloody knife fight in a robbery. The victim was a 69-year-old man who was not infected with HIV-1, and his wife was HIV-antibody negative. A robber, a 42-year-old man, was HIV antibody-positive since December 2005 and had not taken antiretroviral therapy. The BED IgG Capture incidence EIA (BED-CEIA assay) data showed that the specimens from the victim were compatible with a recent seroconversion. Phylogenetic analysis of fragments of pol, encompassing protease and a portion of reverse transcriptase, and of env genes isolated from the victim, the robber, and a local population samples of HIV-1 positive individuals showed that the victim's HIV-1 sequences were most closely related to and nested within a lineage comprised of the robber's HIV-1 sequences. We provide HIV-1 seroconversion data and phylogenetic analysis as evidence that the HIV-1 transmission likely occurred from contact during the robbery.