OBJECTIVETo analyze the proportion and associated factors of taking subsequent confirmation test among men who have sex with men (MSM) after being tested positive in oral fluid HIV antibody test.

METHODSBy using successive sampling, 1 003 MSM, who were tested positive in oral fluid HIV antibody test in China-Bill & Melinda Gates Foundation AIDS prevention Program (Extension program) in Beijing during May 1 to December 31, 2013, were recruited. The inclusion criteria included: the objects were men who reported having sex with men; the objects aged more than 18 years old; the objects were tested positive in oral fluid HIV antibody test; the objects had not been reported as HIV positives in China Information System for Disease Control and Prevention previously. According to the program strategy, MSM grassroots organizations transferred the respondents to seek subsequent confirmation tests in specific Center for Disease Control and Prevention (CDCs) or hospitals. The subsequent confirmation tests included: fingertip blood HIV antibody rapid test, venous blood Enzyme Linked Immunosorbent Assay (ELISA) HIV antibody test and venous blood Western Blot (WB) HIV antibody test. Chi-square test was adopted to compare the proportion of taking subsequent confirmation tests in different groups. Nonconditional multivaritae binarylogistic regression analysis was taken to identify the associated factors with whether taking subsequent confirmation tests and to calculate the OR (95% CI) values.

RESULTSThe 1 003 respondents were (30.9 ± 9.1) years old. Among all objects, 87.8% (881/1 003) of them took fingertip blood HIV antibody rapid tests and the positive rate was 85.4% (752/881). 98.0% (737/752) of those who were identified as positive in fingertip blood HIV rapid tests took ELISA and WB tests, and the positive rate was 94.4% (696/737). Comparing with those who were expected to seek subsequent confirmation tests in CDCs, the OR (95% CI) value of those who were expected to seek tests in hospitals was 5.10 (1.69-15.36). The OR (95% CI) values of those who used condom sometimes and those who never used condom in anal sex were 5.81 (2.14-15.77) and 3.45 (2.00-5.97) respectively, in comparison with those who reported not having anal sex or using condom consistently in anal sex during the past 6 months. Comparing with the respondents recruited from the internet, the OR (95% CI) values of those recruited in bathrooms, parks/toilets and bars were 0.17 (0.05-0.53), 0.10 (0.04-0.29) and 0.22 (0.06-0.79) respectively. The likelihood of taking subsequent confirmation test decreased with the increase of number of male sexual partners in the past 3 months, and the OR (95% CI) value was 0.92 (0.86-0.99).

CONCLUSIONThe potential HIV positive MSM in the bathroom, park/toilet and bars are less likely to take subsequent confirmation test. Those who do not use condom consistently during anal sex are more likely to seek subsequent confirmation test. Medical organization conducting subsequent confirmation tests is more likely to increase the confirmation test rate of potential HIV positive MSM. The number of male sexual partners has negative correlation with whether to accept the subsequent confirmation test.

Beijing ; Condoms ; HIV Antibodies ; analysis ; HIV Seropositivity ; diagnosis ; Homosexuality, Male ; Humans ; Male ; Mass Screening ; Patient Acceptance of Health Care ; Risk-Taking ; Sexual Behavior ; Sexual Partners ; Surveys and Questionnaires

OBJECTIVETo explore the follow-up visit, outcome and auxiliary diagnosis method on the cases with indeterminate antibody level measured by Western blotting as well as the related biological factors.

METHODSThe cases with indeterminate result were followed up according to the National Guideline for Detection of HIV/AIDS (2009) and samples were collected for HIV antibody detection, p24 antigen and nucleic acid were detected as a supplementary diagnosis at the same time. The samples were also be detected for HBV, HCV, TP, HTLV-I/II, ANA, and AFP, and the results were compared to that of screened positive and confirmed negative cases.

RESULTSA total of 73 were followed up successfully and taken a second HIV test, 25 cases were tested positive and 48 were tested negative for HIV during the follow-up period. For the 25 HIV positive cases, the HIV seroconversion rate was 100.00% at any time point when the interval between the first and returning detection was longer than 1 week. The major Western blotting bands for the cases with indeterminate result were p24 and gp160 and it was different between HIV positive and negative cases in Western blotting band profiles. The consistency and sensitivity of nucleic acid detection were higher than 90.00%, and were higher than that of p24 antigen (69.09% (38/55) and 27.27% (6/22)) (χ(2)(consistency) = 6.875, χ(2)(sensitivity) = 18.893, P < 0.05). The positive rates of ANA and AFP of indeterminate cases excluded from HIV infection were 20.83% (10/28) and 6.25% (3/48) and higher than that of screened positive and confirmed negative cases (0.00%), the difference had statistic significance (χ(2)(ANA) = 19.430, χ(2)(AFP) = 5.520, P < 0.05).

CONCLUSIONIt is critical to get timely diagnosis for the indeterminate cases according to the new national guideline for detection of HIV/AIDS. Nucleic acid detection has higher application value as auxiliary diagnosis for HIV infection than p24 antigen. The increased levels of ANA and AFP may be the factors resulting in the nonspecific indeterminate results.

Antibodies, Antinuclear ; blood ; Female ; Follow-Up Studies ; HIV Antibodies ; blood ; HIV Infections ; diagnosis ; immunology ; Humans ; Male ; alpha-Fetoproteins ; analysis

To research piezoelectric immunosensor array for rapid detecting HIV(1+2), piezoelectric immunosensor array matrix was designed. HIV(1+2)C1 antigen was immobilized onto the silver electrodes of quartz-crystal microbalance, which was modified with adsorption and cross-linked method. In the clean air flow and monitoring environment, standard quality control and clinical serum sample were detected. The linear range for the measurement of HIV(1+2) was 0.01-0.2 NCU/ml. The sensitivity, specificity and accuracy of HIV(1+2) piezoelectric protein sensor array were 91.7%, 93.3% and 92.7% respectively.
Biosensing Techniques ; instrumentation ; methods ; Electrodes ; HIV ; isolation & purification ; HIV Antibodies ; blood ; Humans ; Immunoassay ; methods ; Protein Array Analysis ; instrumentation ; methods ; Quartz ; Reproducibility of Results ; Sensitivity and Specificity

BACKGROUND/AIMS: Toxoplasmic encephalitis (TE) is one of the most common causes of focal brain lesions, which complicate the course of acquired immunodeficiency syndrome (AIDS). There is wide geographic variation in the prevalence of toxoplasma infection. This study was performed to characterize toxoplasma infection in human immunodeficiency virus (HIV)-infected patients in South Korea. METHODS: We retrospectively examined the incidence and clinical characteristics of TE in 683 HIV-infected patients who were enrolled between 1990 and 2008 at four university hospitals in Busan, Korea. We also assessed the seroprevalence of IgG antibodies to Toxoplasma gondii, risk factors for toxoplasma seropositivity, and seroconversion rates during the course of HIV infection. RESULTS: Among 683 HIV-infected patients, six (0.9%) patients were diagnosed with TE. The incidence of TE was 0.34 per 100 person-years (py) during the study period. Of the 414 patients who had undergone serological examinations for Toxoplasma gondii, 35 (8.5%) patients were seropositive. Univariate analysis showed that the risk factors associated with toxoplasma seropositivity included increased age, heterosexual transmission, marriage, and a history of overseas residence (p<0.05). Of these factors, a history of overseas residence was a significant risk factor in a multivariate analysis (p<0.05). A total of 95 patients who were seronegative on their initial screen showed serial toxoplasma IgG antibodies (mean duration of follow-up, 2.1 years). Among these patients, only two (2.1%) acquired IgG antibodies to Toxoplasma gondii during the follow-up period. CONCLUSIONS: The seroprevalence of anti-toxoplasma IgG antibodies in HIV-infected patients in Korea was 8.5%. A history of overseas residence was a significant risk factor for toxoplasma seropositivity. The incidence of TE was 0.34/100 py, which is lower than that reported in other countries. Toxoplasma seroconversion was also uncommon (2.1%).
Acquired Immunodeficiency Syndrome ; Antibodies ; Brain ; Encephalitis ; Follow-Up Studies ; Heterosexuality ; HIV ; HIV Infections ; Hospitals, University ; Humans ; Immunoglobulin G ; Incidence ; Korea ; Marriage ; Multivariate Analysis ; Prevalence ; Republic of Korea ; Retrospective Studies ; Risk Factors ; Seroepidemiologic Studies ; Toxoplasma

OBJECTIVETo determine the epidemiologic features and distribution of human immunodeficiency virus-1 (HIV-1) and hepatitis C virus (HCV) infection among intravenous drug users and illegal blood donors in China.

METHODSPolymerase chain reaction (PCR) amplification and DNA sequencing were used to evaluate the HIV-1 gag p17 and env C2-V3 regions, as well as the HCV 5'NCR and E1/E2 regions.

RESULTSAmong 239 subjects with reported HIV-1 infection, 56.9% (136/239) were seropositive for anti-HCV. Of those, 96.3% (131/136) were co-infected with HCV through intravenous drug use and illegal blood donation. Intravenous drug users in Yunnan, Guangxi and Xinjiang provinces were infected with HIV-1 subtype C and HCV genotypes 1b, 3a, 3b and 4, whereas illegal blood donors in Henan province harbored HIV-1 subtype B' and HCV genotypes 1b and 2a. Five different HIV-1 subtypes were identified among 17 HIV-1-infected individuals from Beijing.

CONCLUSIONSMultiple HIV-1 subtypes and HCV genotypes were identified in China which were associated with several different modes of transmission. Homogeneity within the sequences of the two viruses suggested the recent, but separate, outbreaks of HIV-1 and HCV infection. The distinct distribution patterns of HIV-1 and HCV genotypes in two high-risk groups seemed to be more closely linked to the mode of transmission than to geographic proximity.

Adolescent ; Adult ; Aged ; Blood Donors ; legislation & jurisprudence ; Blotting, Western ; Child ; Child, Preschool ; China ; epidemiology ; Enzyme-Linked Immunosorbent Assay ; Female ; Flow Cytometry ; Genotype ; HIV Infections ; epidemiology ; transmission ; HIV-1 ; genetics ; Hepacivirus ; genetics ; Hepatitis C ; epidemiology ; transmission ; Hepatitis C Antibodies ; analysis ; Humans ; Infant ; Male ; Middle Aged ; Phylogeny ; Substance Abuse, Intravenous ; blood ; virology

Current diagnosis of human immunodeficiency virus (HIV) infection relies on the detection of anti-HIV antibodies by enzyme-linked immunosorbent assay (ELISA). Recently, kits detecting both p24 antigenemia and anti-HIV/anti-HIV2 antibodies have been developed. Thus, it is necessary to compare those kits developed as such. The aim of this study was to evaluate the diagnostic efficiency of a simultaneous detection test of p24 antigen and anti-HIV1/2 antibodies in a low prevalence area. Eight hundred and four randomly selected sera proven negative for HIV infection and 110 sera from 54 patients diagnosed as HIV infected, obtained between 1999 and 2000, were used for this study. One commercial lot of panels composed of consecutive sera obtained from known HIV-infected patient was included. Anti-HIV1/2 antibodies were detected by two different commercial ELISA kits, one from Korean and the other from German manufacturer. P24 antigen test was performed by ELISA. The simultaneous HIV antigen and antibody detection test was carried out. In the meantime, HIV RNA PCR and anti-HIV and anti-HIV2 western blot assays were also performed to confirm the test results in cases the test results didn't agree. The simultaneous detection kit showed 100% sensitivity and 99.6% specificity. Furthermore, the test displayed the possibility of earlier diagnosis than conventional anti-HIV1/2 ELISA with the results obtained from a group of consecutive panel sera infected with HIV. From these results, we concluded that the simultaneous HIV antigen and antibody detection test can be applied as a substitute clinical screening test in the place of conventional anti-HIV1/2 ELISA, and there is the probable benefit of early diagnosis.
Enzyme-Linked Immunosorbent Assay/standards* ; Enzyme-Linked Immunosorbent Assay/instrumentation ; HIV Antibodies/analysis* ; HIV Antigens/analysis* ; Human ; Korea ; Reagent Kits, Diagnostic/standards

The virology of human immunodeficiency virus (HIV) infection is reviewed. The transmission of HIV is restricted to direct contact with the blood or other body fluids of infected human beings. Ordinary social contact with infected individuals holds no risk but in the health care setting all patients must be considered to be potentially infectious and universal precautions taken. The replication of HIV in cells of the immune system carrying the CD4 receptor creates a complex relationship between the virus infection and the host immune response. The pathogenesis and the principles of the laboratory diagnosis of HIV infection are reviewed. Since its discovery HIV has quickly become one of the most studied and best characterized of human pathogens. The diagnosis of HIV infection, because of its implications, has been made more accurate than for any other infection. This understanding has significantly improved treatment but has yet to provide curative therapy, and prevention of infection is still the basis of the fight against AIDS.
Acquired Immunodeficiency Syndrome - pathology ; Acquired Immunodeficiency Syndrome - transmission ; Animals ; HIV Antibodies - analysis ; HIV Infections - diagnosis ; Serologic Tests ; Virus Replication - physiology