Diagnostic detection of human immunodeficiency virus type 1 antibodies in urine: a brazilian study

Diagnostic performance evaluation of urine HIV-1 antibody rapid test kits in a real-life routine care setting in China

OBJECTIVES

To evaluate the diagnostic performance of urine HIV antibody rapid test kits in screening diverse populations and to analyse subjects' willingness regarding reagent types, purchase channels, acceptable prices, and self-testing.

DESIGNS

Diagnostic accuracy studies PARTICIPANTS: A total of 2606 valid and eligible samples were collected in the study, including 202 samples from female sex workers (FSWs), 304 persons with injection drug use (IDU), 1000 pregnant women (PW), 100 subjects undergoing voluntary HIV counselling and testing (VCT) and 1000 students in higher education schools or colleges (STUs). Subjects should simultaneously meet the following inclusion criteria: (1) being at least 18 years old and in full civil capacity, (2) signing an informed consent form and (3) providing truthful identifying information to ensure that the subjects and their samples are unique.

RESULTS

The sensitivity, specificity and area under the curve (AUC) of the urine HIV-1 antibody rapid test kits were 92.16%, 99.92% and 0.960 (95% CI: 0.952 to 0.968, p<0.001), respectively, among 2606 samples collected during on-site screenings. The kits showed good diagnostic performance in persons with IDU (AUC, 1.000; 95% CI, 1.000 to 1.000, p<0.001), PW (AUC, 0.999; 95% CI, 0.999 to 1.000, p<0.001) and FSWs (AUC, 1.000; 95% CI, 1.000 to 1.000, p<0.001). The AUC of the urine reagent kits in subjects undergoing VCT was 0.941 (95% CI: 0.876 to 0.978, p<0.001). The 'acceptable price' had the greatest influence on STUs (Pi=1.000) and PW (Pi=1.000), the 'purchase channel' had the greatest influence on subjects undergoing VCT (Pi=1.000) and persons with IDU (Pi=1.000) and the 'reagent types' had the greatest influence on FSWs (Pi=1.000).

CONCLUSIONS

The rapid urine test kits showed good diagnostic validity in practical applications, despite a few cases involving misdiagnosis and underdiagnosis.

Protein glycosylation in urine as a biomarker of diseases

Human body fluids have become an indispensable resource for clinical research, diagnosis and prognosis. Urine is widely used to discover disease-specific glycoprotein biomarkers because of its recurrently non-invasive collection and disease-indicating properties. While urine is an unstable fluid in that its composition changes with ingested nutrients and further as it is excreted through micturition, urinary proteins are more stable and their abnormal glycosylation is associated with diseases. It is known that aberrant glycosylation can define tumor malignancy and indicate disease initiation and progression. However, a thorough and translational survey of urinary glycosylation in diseases has not been performed. In this article, we evaluate the clinical applications of urine, introduce methods for urine glycosylation analysis, and discuss urine glycoprotein biomarkers. We emphasize the importance of mining urinary glycoproteins and searching for disease-specific glycosylation in various diseases (including cancer, neurodegenerative diseases, diabetes, and viral infections). With advances in mass spectrometry-based glycomics/glycoproteomics/glycopeptidomics, characterization of disease-specific glycosylation will optimistically lead to the discovery of disease-related urinary biomarkers with better sensitivity and specificity in the near future.

Serological and Molecular Methods to Study Epidemiological Aspects of Human T-Cell Lymphotropic Virus Type 1 Infection

We estimated that at least 5-10 million individuals are infected with HTLV-1. Importantly, this number is based on the study of nearly 1.5 billion people living in known human T-cell lymphotropic virus type 1 (HTLV-1) endemic areas, for which reliable epidemiological data are available. However, for some highly populated regions including India, the Maghreb, East Africa, and some regions of China, no consistent data are yet available which prevents a more accurate estimation. Thus, the number of HTLV-1 infected people in the world is probably much higher. The prevalence of HTLV-1 prevalence varies depending on age, sex, and economic level in most HTLV-1 endemic areas. HTLV-1 seroprevalence gradually increases with age, especially in women. HTLV-1 has a simian origin and was originally acquired by humans through interspecies transmission from STLV-1 infected monkeys in the Old World. Three main modes of HTLV-1 transmission have been described; (1) from mother-to-child after prolonged breast-feeding lasting more than six months, (2) through sexual intercourse, which mainly, but not exclusively, occurs from male to female and lastly, (3) from contaminated blood products, which contain HTLV-1 infected lymphocytes. In specific areas, such as Central Africa, zoonotic transmission from STLV-1 infected monkeys to humans is still ongoing.The diagnostic methods used to study the epidemiological aspects of HTLV-1 infection mainly consist of serological assays for the detection of antibodies specifically directed against different HTLV-1 antigens. Screening tests are usually based on enzyme-linked immunoabsorbent assay (ELISA), chemiluminescence enzyme-linked immunoassay (CLEIA) or particle agglutination (PA). Confirmatory tests include mostly Western blots (WB)s or innogenetics line immunoassay (INNO-LIA™) and to a lesser extent immunofluorescence assay (IFA). The search for integrated provirus in the DNA from peripheral blood cells can be performed by qualitative and/or quantitative polymerase chain reaction (qPCR). qPCR is widely used in most diagnostic laboratories and quantification of proviral DNA is useful for the diagnosis and follow-up of HTLV-1 associated diseases such as adult T-cell leukemia (ATL) and tropical spastic paraparesis/HTLV-1 associated myelopathy (TSP/HAM). PCR also provides amplicons for further sequence analysis to determine the HTLV-1 genotype present in the infected person. The use of new generation sequencing methodologies to molecularly characterize full and/or partial HTLV-1 genomic regions is increasing. HTLV-1 genotyping generates valuable molecular epidemiological data to better understand the evolutionary history of this virus.

An alternative strategy to western blot as a confirmatory diagnostic test for HIV infection

BACKGROUND

In China, western blot (WB) is the recommended procedure for the diagnosis of HIV infection. However, this technique is time consuming and labor intensive, and its complexity restricts wide application in resource-limited regions.

OBJECTIVE

The aim of this study was to evaluate the efficacy of a dry blood spots (DBS)-urine paired enzyme-linked immunosorbent assay (ELISA) test, instead of WB, for HIV antibody detection.

STUDY DESIGN

Plasma, DBS, and urine samples were collected from 1213 subjects from different populations. Two diagnostic testing strategies were conducted in parallel. The equivalence of the paired ELISA and WB strategies was assessed.

RESULTS

A diagnosis of HIV was determined in 250 subjects according to the paired ELISA test, and in 249 according to the WB strategy. The discordant case was judged HIV-positive during follow-up. In total, 18 subjects were diagnosed with possible HIV using the paired ELISA test, among whom, 11 subjects tested negative with WB, and one was confirmed to be HIV-positive during follow-up. For the remaining 945 subjects, both strategies indicated a negative result. The kappa test indicated good conformity (kappa=0.954) between the two diagnostic strategies.

CONCLUSION

The DBS-urine paired ELISA could be applied as an alternative to WB in HIV diagnosis, which would be valuable in resource-limited regions owing to the associated affordability and ease of use.

Are teachers at higher risk of HIV infection than the general population in Burkina Faso?

In order to assess the human immunodeficiency virus (HIV) prevalence among teachers in Burkina Faso, we carried out a national survey in 336 primary and secondary schools from urban and rural areas. Among 2088 teachers who agreed to participate, 1498 (71.7%) provided urine for HIV testing. The crude prevalence of HIV among teachers was 2.8% (95% confidence interval [CI]: 2.0-3.6), with no difference between teachers from primary schools (2.9%, 95%CI: 2.1-4.0) and those from secondary schools (2.5%, 95%CI: 0.5-4.5). Age- and area-standardized HIV prevalence was 1.0% (95%CI: 0.4-1.2) in male teachers, 2.5 times lower than among men in the general population (as assessed from a concomitant Demographic Health Survey), and it was 3.5% (95%CI: 2.5-5.2) in female teachers, 1.7 times higher than in Demographic Health Survey women. This finding calls for the implementation of specific HIV prevention programmes in the education sector targeting women more specifically.

Are healthcare workers at higher risk of HIV infection than the general population in Burkina Faso?

In order to assess the HIV prevalence in healthcare workers (HCWs) in Burkina Faso, we conducted a national survey in 97 health facilities from urban and rural areas. Of 1570 HCWs who agreed to participate, 1013 (64·5%) provided a urine sample for HIV testing. The crude prevalence of HIV in HCWs was 3·5% (95% CI 2·3-4·6). HIV prevalence was 0·7% in students and trainees, 3·8% in nurses and midwives, 4·5% in administrative workers, and 4·6% in laboratory workers. After age and area standardization, men from the Demographic Health Survey (DHS) had a similar HIV prevalence (2·3%, 95% CI 1·4-2·9) as male HCWs (2·5%, 95% CI 1·1-4·0), while female HCWs were more infected (4·5%, 95% CI 2·5-6·0) than women from the DHS (2·1%, 95% CI 1·3-2·4). A voluntary counselling and testing (VCT) programme should be specifically implemented and adapted for female HCWs.

Decline in HIV prevalence among young men in the general population of Cotonou, Benin, 1998-2008

OBJECTIVE

To assess changes in the prevalence of HIV and other sexually transmitted infections, as well as in different proximal and distal factors related to HIV infection, in the general population of Cotonou between 1998 and 2008, while an intensive preventive intervention targeting the sex work milieu was ongoing.

METHODS

A two-stage cluster sampling procedure was used to select the participants in each study. Subjects aged 15-49 who agreed to participate were interviewed and tested for HIV, syphilis, HSV-2, gonorrhoea and chlamydia. We used the Roa-Scott Chi-square test (proportions) and the Student's t test (means) for bivariate comparisons, and adjusted logistic regression models taking into account the cluster effect for multivariate analyses.

RESULTS

HIV prevalence decreased significantly in men (3.4% in 1998 versus 2.0% in 2008, p = 0.048), especially in those aged 15-29 (3.0% to 0.5%, p = 0.002). Among men, the prevalence of gonorrhoea decreased significantly (1.1% to 0.3%, p = 0.046) while HSV-2 prevalence increased from 12.0% to 18.1% (p = 0.0003). The proportion of men who reported condom use at least once (29.3% to 61.0%, p<0.0001) and of those having attained a secondary educational level or more (17.1% to 61.3%, p<0.0001) also increased significantly. There was an overall decrease in the prevalence of syphilis (1.5% to 0.6%, p = 0.0003).

CONCLUSION

This is the first population-based study reporting a significant decline in HIV prevalence among young men in an African setting where overall prevalence has never reached 5%. The decline occurred while preventive interventions targeting the sex work milieu were ongoing and the educational level was increasing.

Factors associated with sexual violence against men who have sex with men and transgendered individuals in Karnataka, India

Objectives

There is a lack of information on sexual violence (SV) among men who have sex with men and transgendered individuals (MSM-T) in southern India. As SV has been associated with HIV vulnerability, this study examined health related behaviours and practices associated with SV among MSM-T.

Design

Data were from cross-sectional surveys from four districts in Karnataka, India.

Methods

Multivariable logistic regression models were constructed to examine factors related to SV. Multivariable negative binomial regression models examined the association between physician visits and SV.

Results

A total of 543 MSM-T were included in the study. Prevalence of SV was 18% in the past year. HIV prevalence among those reporting SV was 20%, compared to 12% among those not reporting SV (p = .104). In multivariable models, and among sex workers, those reporting SV were more likely to report anal sex with 5+ casual sex partners in the past week (AOR: 4.1; 95%CI: 1.2–14.3, p = .029). Increased physician visits among those reporting SV was reported only for those involved in sex work (ARR: 1.7; 95%CI: 1.1–2.7, p = .012).

Conclusions

These results demonstrate high levels of SV among MSM-T populations, highlighting the importance of integrating interventions to reduce violence as part of HIV prevention programs and health services.

The laboratory diagnosis of HIV infections

HIV diagnostic testing has come a long way since its inception in the early 1980s. Current enzyme immunoassays are sensitive enough to detect antibody as early as one to two weeks after infection. A variety of other assays are essential to confirm positive antibody screens (Western blot, polymerase chain reaction [PCR]), provide an adjunct to antibody testing (p24 antigen, PCR), or provide additional information for the clinician treating HIV-positive patients (qualitative and quantitative PCR, and genotyping). Most diagnostic laboratories have complex testing algorithms to ensure accuracy of results and optimal use of laboratory resources. The choice of assays is guided by the initial screening results and the clinical information provided by the physician; both are integral to the laboratory's ability to provide an accurate laboratory diagnosis. Laboratories should also provide specific information on specimen collection, storage and transport so that specimen integrity is not compromised, thereby preserving the accuracy of laboratory results. Point of Care tests have become increasingly popular in the United States and some places in Canada over the past several years. These tests provide rapid, on-site HIV results in a format that is relatively easy for clinic staff to perform. However, the performance of these tests requires adherence to good laboratory quality control practices, as well as the backup of a licensed diagnostic laboratory to provide confirmation and resolution of positive or indeterminate results. Laboratory quality assurance programs and the participation in HIV proficiency testing programs are essential to ensure that diagnostic laboratories provide accurate, timely and clinically relevant laboratory results.

Interventions among male clients of female sex workers in Benin, West Africa: an essential component of targeted HIV preventive interventions

OBJECTIVES

To assess the impact of interventions targeted towards female sex workers (FSWs) and their male clients on client HIV/STI prevalence and sexual behaviour.

METHODS

From 1993 to 2006, an HIV/STI preventive intervention focusing on condom promotion and STI care was implemented among FSWs in Cotonou, Benin, and then expanded to cover their male sexual partners in 2000. The interventions were scaled up to five other cities of Benin in 2001-2002. Serial cross-sectional surveys of HIV/STI prevalence and sexual behaviour were carried out among clients in Cotonou in 1998, 2002 and 2005; and in the five other cities (O/Cotonou) in 2002 and 2005.

RESULTS

Significant declines in gonorrhoea prevalence among clients of FSWs: Cotonou, from 5.4% in 1998 to 1.6% in 2005; O/Cotonou: from 3.5% in 2002 to 0.59% in 2005. Chlamydia prevalence also declined O/Cotonou, from 4.8% to 1.8%, while HIV prevalence remained stable. Reported condom use by clients with both FSWs and casual non-FSW partners, but not regular partners, increased significantly. While condom use at last sex with an FSW was similar in Cotonou to O/Cotonou around the time of implementation of the interventions (56% in 1998 vs 49% in 2002, respectively), it had risen to similar levels by 2005 (95% and 96%, respectively).

CONCLUSIONS

These results demonstrate that it is possible to implement preventive and clinical services for clients of FSWs, and suggest that such interventions, integrated with those targeted towards FSWs, can have a significant effect on sexual behaviour and STI prevalence (particularly gonorrhoea) among this population.

Evaluation of a commercial enzyme immunoassay for HIV screening in urine

A cross-sectional study was conducted to evaluate the utility of a commercial enzyme immunoassay (EIA) as a screening test for detecting HIV-1 antibody in urine in a population at risk for HIV infection in Catalonia, Spain. Paired urine and serum samples were collected consecutively from 99 patients who attended two drug-dependency treatment centres and 151 patients who attended a sexually transmitted diseases (STD) clinic in Barcelona. Antibodies against HIV in urine samples were detected using the Calypte HIV-1 Urine EIA (Calypte Biomedical Corporation, Berkeley, CA, USA) and confirmed by urine-based Western blot (WB) analysis. Sera were analysed using Bioelisa HIV-1+2 EIA (Biokit Laboratories, Barcelona, Spain), and the results were verified using serum-based WB analysis. Results of both urine and serum testing were available for 246 of 250 participants. For 52 individuals the results of both urine and serum testing were positive and for five the results were discordant (2 with urine-negative/serum-positive results and 3 with urine-positive/serum-negative results). The respective sensitivity and specificity values obtained for the urine EIA were 100% and 96.2% for intravenous drug users (IDUs) and 80% and 99.3% for persons attending the STD clinic. According to the 1997 UNAIDS/WHO strategy I recommendations, these values are acceptable for surveillance purposes, particularly in populations with a high prevalence of HIV infection.