Dual screening.

W O Johnson; L M Pearson

doi:10.1111/j.0006-341x.1999.00867.x

Home/Archive/PubMed

PubMed · 11315019

Dual screening.

W O Johnson·L M Pearson

View original source ↗Export metadata ↓

Abstract

We discuss the problem of screening a general population for characteristics such as HIV or drug use. Our main approach is Bayesian, which allows for the incorporation of prior information about parameters. In the particular problem we consider, there is currently no information in the data for estimating the sensitivity of the screening test, and consequently, the prevalence of the characteristic among screened negatives cannot be estimated from the collected data alone. Our inferences are straightforward to obtain using Gibbs sampling techniques, and they are valid for large or small samples and for arbitrary prevalence or accuracy of screening tests. We also develop the maximum-likelihood approach using the EM algorithm.

Explore related subjects

AIDS Serodiagnosis Algorithms Bayes Theorem Biometry Blood Donors Humans Likelihood Functions Mass Screening Journal Article

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

W O Johnson, L M Pearson. 1999. Dual screening.. https://doi.org/10.1111/j.0006-341x.1999.00867.x

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2002

Impact of HIV vaccination on laboratory diagnosis: case reports.

BACKGROUND: It has not been clearly demonstrated whether HIV vaccination can complicate routine HIV testing. In this report, we describe the laboratory data of two prisoners who received rgp120 vaccine in a phase III trial underway in Thailand. These data indicate that previous vaccination may complicate the interpretation of screening HIV diagnostic tests. CASE PRESENTATION: The participants were identified from a cohort study on "Health factors related to HIV-1 and other viral infections among incarcerated people" that was approved by The Ethical Committee for Research in Human Subjects, Ministry of Public Health, Thailand. HIV diagnosis was definitively established with serial specimens using multi-screening tests, Western blot and diagnostic PCR.Anti-HIV screening tests consistently exhibited either weakly reactive or inconclusive results. The band patterns of the Western blot analysis corresponded to those found in individuals who received the rgp120 vaccination. Definite results were established using diagnostic PCR, which exhibited consistently negative results with follow-up specimens. Such problems in HIV testing are not easily resolved in the routine clinical setting in Thailand. CONCLUSIONS: These data demonstrate that HIV-1 vaccination interferes with routine diagnostic tests. Similar cases will not be uncommon in Thailand, where 2,545 people have already participated in a phase III trial.

AIDS Serodiagnosis↗

PubMed2002

Explosive spread and high prevalence of HIV infection among injecting drug users in Togliatti City, Russia.

OBJECTIVE: To establish the prevalence of antibodies to HIV (anti-HIV) and associated risk factors among injecting drug users (IDU) in Togliatti City, Samara Oblast, Russian Federation. DESIGN: An unlinked anonymous cross-sectional community recruited survey with oral fluid sample collection. METHODS: Between September and October 2001, 426 IDU were recruited by trained fieldworkers. Participants completed an interviewer administered questionnaire, and oral fluid samples were tested for anti-HIV. Univariate and multivariate analyses compared potential risk factors for anti-HIV. RESULTS: Anti-HIV prevalence was 56% (234/418). Three-quarters of anti-HIV-positive IDU (74%) were unaware of their positive status. In an adjusted model, the odds of HIV infection were higher among IDU who had ever injected home-produced drugs, who reported injecting with used needles and syringes in the past 4 weeks, and who were living in one particular district of the city (Komsomolksii). CONCLUSION: The high prevalence of HIV, and a recent increase in HIV detected through routine screening tests since 2000, suggests that an explosive epidemic has occurred among IDU in Togliatti City. In the face of currently inadequate HIV prevention coverage among IDU, this has urgent implications for maximizing the distribution of sterile injecting equipment as well as for enhancing sexual risk reduction. Recognizing that it is likely that similar explosive epidemics are taking place in other Russian cities, we recommend community-wide HIV prevention coverage supported by city and state policies oriented to harm reduction.

AIDS Serodiagnosis↗

PubMed2002

Increases in HIV incidence among men who have sex with men undergoing repeat diagnostic HIV testing in Ontario, Canada.

OBJECTIVE: To estimate HIV incidence density for different exposure categories among people undergoing repeat testing in Ontario, Canada. METHODS: Persons using voluntary, diagnostic HIV testing at least twice were identified by computerized and manual record linkage. In the 1992-2000 period, 980 seroconverters and 340 994 repeat negative testers contributed 936 145 person years (PY) of observation. Incidence density (ID) was calculated according to Kitayaporn et al. Poisson regression was used to evaluate differences in incidence. RESULTS: Among men who have sex with men (MSM), ID declined between 1992-1996, from 1.23 per 100 PY in 1992 to 0.79 per 100 PY in 1996 [relative risk (RR), 0.86 per year; 95% confidence interval (CI), 0.77-0.96]. Subsequently, ID increased to 1.39 per 100 PY in 1999 (RR, 1.18 per year; 95% CI, 1.05-1.34). In 2000, ID was 1.16 per 100 PY but this decrease was not statistically significantly different from 1999. MSM in their twenties had the highest ID in 1992-1996, but in 1996-2000 MSM in their thirties had the highest risk of infection. Among injecting drug users (IDU), ID decreased from 0.64 per 100 PY in 1992 to 0.14 per 100 PY in 2000 (RR, 0.87 per year; 95% CI, 0.80-0.94). Among heterosexuals, annual incidence remained constant at about 0.03 per 100 PY in 1992-2000. CONCLUSIONS: Increases in ID were identified among MSM from 1996 to 1999. These findings are consistent with other research. Continued vigilance and improved surveillance are needed to better understand and control the epidemic.

AIDS Serodiagnosis↗