Human Antibody and Antigen Response to INCA Antibody of Chlamydia Trachomatis

The high prevalence of C. trachomatis worldwide has underscored the importance of identifying specific immunogenic antigens in facilitating diagnosis as well as vaccine development The aim of this study is to evaluate IncA antibody and antigen production in natural human infections. Our temporal expression study showed that IncA transcription and protein expression could be detected as early as 4 hours after the start of infection. Antibody responses could be detected in urine and genital swab samples from C. trachomatis-positive patients. It is especially interesting to note that the IncA antigen could be detected in urine. In conclusion, we have identified IncA as an important antigen in human. The potential applicability of the IncA antibody or antigen in the diagnosis as well as to vaccine development for C. trachomatis is also discussed.

HIV testing patterns for United States Air Force personnel, 2008-2012

OBJECTIVE

This study evaluated 3rd generation human immunodeficiency virus (HIV) test patterns and HIV infection rates in the United States Air Force (USAF).

STUDY DESIGN

Retrospective database study.

METHODS

HIV enzyme-linked immunoassay (ELISA) and Western blot tests were analysed for all USAF personnel from 2008 to 2012. For new HIV cases, unadjusted and adjusted annual rates were calculated per 100,000 persons.

RESULTS

In total, 1,608,665 tests were performed in 626,298 individuals, with a reactive ELISA observed in 809 (0.001%) persons. Western blot (n = 1949) results included 378 (19.4%) positive, 1283 (65.8%) negative, and 288 (15.0%) indeterminate (WBi). Unadjusted annual HIV rates were between 16.7 and 20.6 per 100,000 persons during the study period. The overall age-adjusted rate was 14.8 cases per 100,000 persons tested. Blacks/African Americans had the highest risk of HIV (risk ratio 7.9 [95% confidence interval 5.78, 9.95] compared to Whites).

CONCLUSIONS

WBi results, which can cause delays in determining HIV status, were relatively common with the 3rd generation assay. However, this will be mitigated by a planned transition to a 4th generation assay. Although the overall rate of HIV in the USAF is lower than US civilian adults, HIV prevention efforts targeting young Blacks/African Americans may help to reduce HIV incidence in the USAF.

An electrochemical peptide-based biosensing platform for HIV detection

We have fabricated a potentially generalizable electrochemical peptide-based (E-PB) sensor for the detection of HIV anti-p24 antibodies. The E-PB sensor is sensitive, specific and fares well even when challenged in a realistically complex medium such as human urine proxy.

Cost-effectiveness of antenatal HIV-testing: reviewing its pharmaceutical and methodological aspects

This paper reviews the pharmacoeconomic aspects of antenatal testing for HIV. HIV is a retrovirus which is transmitted among humans through sexual contact, infected blood or blood products (needle sharing or percutaneous accidents) and from mother to child (vertical transmission). Vertical transmission from the HIV-infected mother can occur in utero during and after delivery, through breastfeeding. Effective interventions available to reduce the risk of vertical transmission include: pharmacotherapy prior, during and after delivery; voluntary caesarean section; and replacing breastfeeding by bottle-feeding [1,2]. The existence of these effective interventions underlies the need to detect yet undiagnosed HIV-infection in pregnancy through antenatal testing. Contemporary pharmacotherapy consists of a combination of three or more antiretroviral drugs, also referred to as highly-active antiretroviral therapy (HAART). For newly detected HIV-infected mothers, the Centers for Disease Control suggests the use of a zidovudine-comprising combination with one other nucleoside analogue reverse transcriptase inhibitor and a protease inhibitor (PI) [3]. As HIV in pregnancy may be asymptomatic, structured antenatal HIV-testing therefore seems to offer an attractive prevention strategy. Two broad types of approaches exist: selective or targeted testing versus universal testing. The availability of effective - but expensive - combination therapies since 1996 has greatly enhanced the importance of pharmacoeconomic assessments in the field of HIV-infection. Treatment of the mother will incur additional costs but will also make any programme more effective. Furthermore, avoiding children becoming infected with HIV will also incur monetary benefits, as children are also being treated with HAART. In summary, the background of antenatal HIV-testing has undergone major changes compared with the early 1990s. This review of the pharmacoeconomics of antenatal HIV-testing followed a systematic approach as it was performed according to prespecified criteria, allowing valid comparisons in methodologies and findings of those studies that have yet been conducted in this area.

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.

Paucity of antigen-specific IgA responses in sera and external secretions of HIV-type 1-infected individuals

This study was undertaken to resolve existing controversies with respect to the detection of IgA HIV-1-specific mucosal antibodies in infected individuals. External secretions, including tears, nasal, rectal, and vaginal washes, saliva, semen, urine, and sera were obtained from 50 HIV-1-infected individuals and 20 controls using collection procedures that minimize the irritation of mucosal surfaces. Levels of total and antigen (gp120 and gp160)-specific antibodies of the IgG and IgA isotypes were measured by assays that proved reliable in a large multicenter study: quantitative ELISA and chemiluminescence-enhanced Western blot analyses. Although the levels of total IgG and IgA were increased or remained unchanged in body fluids of HIV-1-infected individuals as compared to the controls, HIV-1-specific IgA antibodies were either absent or present at low levels even in secretions with characteristically high relative contents of total IgA vs. IgG (saliva, tears, and rectal and nasal washes). In these secretions, HIV-1-specific IgG antibodies dominated. In assessing levels and frequency of detection of IgG antibodies, both female and male genital tract secretions, urine, and nasal wash were preferable to parotid saliva and especially to rectal wash. External secretions contained IgG antibodies to gp160> gp120> gp41 and p24; when present, IgA antibodies were predominantly directed at gp160. Analyses of peripheral blood antibody-secreting cells (ASC) isolated from the same individuals paralleled these serological findings: gp160-specific IgG-secreting ASC were dominant. Therefore, in striking contrast to other mucosally encountered microbial infections, HIV-1 does not induce vigorous specific IgA responses in any body fluid examined or in ASC in peripheral blood.

Foci of endemic simian immunodeficiency virus infection in wild-living eastern chimpanzees (Pan troglodytes schweinfurthii)

Simian immunodeficiency virus of chimpanzees (SIVcpz) is the immediate precursor to human immunodeficiency virus type 1 (HIV-1), yet remarkably, the distribution and prevalence of SIVcpz in wild ape populations are unknown. Studies of SIVcpz infection rates in wild chimpanzees are complicated by the species' endangered status and by its geographic location in remote areas of sub-Saharan Africa. We have developed sensitive and specific urine and fecal tests for SIVcpz antibody and virion RNA (vRNA) detection and describe herein the first comprehensive prevalence study of SIVcpz infection in five wild Pan troglodytes schweinfurthii communities in east Africa. In Kibale National Park in Uganda, 31 (of 52) members of the Kanyawara community and 39 (of approximately 145) members of the Ngogo community were studied; none were found to be positive for SIVcpz infection. In Gombe National Park in Tanzania, 15 (of 20) members of the Mitumba community, 51 (of 55) members of the Kasekela community, and at least 10 (of approximately 20) members of the Kalande community were studied. Seven individuals were SIVcpz antibody and/or vRNA positive, and two others had indeterminate antibody results. Based on assay sensitivities and the numbers and types of specimens analyzed, we estimated the prevalence of SIVcpz infection to be 17% in Mitumba (95% confidence interval, 10 to 40%), 5% in Kasekela (95% confidence interval, 4 to 7%), and 30% in Kalande (95% confidence interval, 15 to 60%). For Gombe as a whole, the SIVcpz prevalence was estimated to be 13% (95% confidence interval, 7 to 25%). SIVcpz infection was confirmed in five chimpanzees by PCR amplification of partial pol and gp41/nef sequences which revealed a diverse group of viruses that formed a monophyletic lineage within the SIVcpzPts radiation. Although none of the 70 Kibale chimpanzees tested SIVcpz positive, we estimated the likelihood that a 10% or higher prevalence existed but went undetected because of sampling and assay limitations; this possibility was ruled out with 95% certainty. These results indicate that SIVcpz is unevenly distributed among P. t. schweinfurthii in east Africa, with foci or "hot spots" of SIVcpz endemicity in some communities and rare or absent infection in others. This situation contrasts with that for smaller monkey species, in which infection rates by related SIVs are generally much higher and more uniform among different groups and populations. The basis for the wide variability in SIVcpz infection rates in east African apes and the important question of SIVcpz prevalence in west central African chimpanzees (Pan troglodytes troglodytes) remain to be elucidated.

Noninvasive detection of new simian immunodeficiency virus lineages in captive sooty mangabeys: ability to amplify virion RNA from fecal samples correlates with viral load in plasma

The sooty mangabey (SM) (Cercocebus atys) is the natural host of a simian immunodeficiency virus, termed SIVsm, which gave rise to human immunodeficiency virus type 2. Data on the geographic distribution, prevalence, and genetic diversity of SIVsm in the wild remains limited. To address this issue, noninvasive strategies based on screening SM fecal and urine specimens for SIVsm-specific antibodies and virion RNA (vRNA) were developed, and the results were correlated with viral loads in plasma. Twenty-three SIVsm-infected and 27 uninfected SMs were evaluated. Time-matched urine, fecal and plasma samples were collected over a 2-month period from 16 captive naturally infected SMs. The remaining 7 infected and 27 uninfected SMs were sampled once. Each specimen was subjected to enhanced chemiluminescence-Western blot analysis and nested reverse transcriptase (RT) PCR. The results showed that urine was highly sensitive (96%) and specific (100%) for detection of SIVsm antibodies, while fecal detection was much less sensitive (16%). Conversely, vRNA detection was more sensitive in feces (50%) than in urine (2%) samples. Fecal-vRNA detection correlated with viral loads in plasma (P < 0.002). SMs with detectable fecal vRNA had a mean viral load in plasma of 458,006 copies/ml, while those with undetectable fecal vRNA had a mean viral load in plasma of 29,428 copies/ml. Moreover, for every log increase in the viral load in plasma, the odds of detecting virus in fecal samples increased 87-fold. Genetic diversity of SIVsm in the SM colony was characterized by sequencing partial gag (846 bp) and gp43 (439 bp) fragments. Surprisingly, four new SIVsm lineages were identified, two of which were initially detected by fecal RT-PCR. This study documents the suitability of noninvasive methods for the detection and molecular characterization of new SIV variants. These assays will be useful for studying the phylogeny and epidemiology of SIVsm infections in the wild, and they hold promise as tools for investigating natural SIV infections in endangered nonhuman primates.

New methods for the detection of HIV

In the past few years, several strides have been made in the ability to detect the presence of HIV-1 and HIV-2. This article discusses recent advances in serologic testing, including routine ELISA and Western blot tests, rapid HIV tests, home collection kits, and HIV tests using nonserum samples. The clinical application of nucleic acid-based tests also is discussed. Finally, appropriate use of these tests in both acute HIV-1 infection and in infants is reviewed.

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

We evaluated, for the first time in Latin America, the performance of a commercial enzyme immunoassay (EIA) (Calypte Biomedical Corporation, Berkeley, Calif.) that detects human immunodeficiency virus type 1 (HIV-1)-specific antibodies in urine in comparison to standard serological assays (two commercial EIAs and a commercial Western blot [WB] assay). Paired serum and urine specimens were collected from two different groups of Brazilian patients: 225 drug users with unknown HIV status who attended drug treatment centers in Rio de Janeiro, Brazil, and 135 subjects with known HIV status. Patients showing positive results in the serum EIAs and/or in the urine EIA were serologically confirmed by WB assay. For 135 individuals with known HIV status, the urine EIA showed 100% sensitivity (74 positive samples) and 95.1% specificity (58 of 61 negative specimens). For 225 drug users, the test showed 100% sensitivity (2 positive samples) and 98.7% specificity (220 of 223 negative samples) compared to WB-confirmed serological EIA results. Thus, in a total of 360 samples, the urine EIA correctly identified all 76 HIV-positive samples and 278 of 284 negative samples (100% sensitivity and 97.9% specificity). Detailed analysis of the urine EIA results indicates that an increase of the recommended cutoff value might raise the specificity of the assay without affecting its sensitivity. Our results suggest that the HIV-1 urine EIA is a good screening test suitable for developing countries like Brazil. However, as for all other HIV screening tests on the market, it is not specific enough to be used as a one-step test and therefore requires confirmation.

Deciding where and how to be tested for HIV: what matters most?

This study examined preferences for specific types of HIV tests as well as for test attributes such as cost, counseling, and privacy. A survey was administered to 354 clients of public testing services. Nonparametric tests and logistic regression were used to compare test preferences and attribute ratings, and to assess differences by demographic and risk groups. Nearly two thirds of respondents chose a public clinic test as their first choice, whereas 24% chose a home self-test, 12% chose a test at a doctor's office, and 1% chose a home specimen-collection test. Three attributes (accuracy/timeliness, privacy of test disclosure, and linking of test results) were rated equally-and most-important. In-person counseling was endorsed as the fourth most important attribute. Availability of in-person counseling was the strongest predictor of "loyalty" to public clinic tests-a consistent preference for that type of test even when the other tests were offered as additional no-cost options. There was also substantial interest in home self-tests. The results suggest specific attributes of testing that may be particularly important to individuals from diverse demographic and risk backgrounds.

Polio, hepatitis B and AIDS: an integrative theory on a possible vaccine induced pandemic

The hypothesis that simian virus 40 (SV40) infected polio vaccines may be linked to the evolution of acquired immunodeficiency disorder (AIDS), and certain cancers, has been advanced. Most recently, investigators discussed the likelihood of gene-reshuffling following SV40 infection as a precursor to acquired immune dysfunction. Findings of recent SV40 infections in four children born after 1982 suggest infections were transmitted vertically along gene lines. Earlier observations proved activation of a retrovirus gene by a hepatitis B virus (HBV) protein. This paper proposes a new integrative theory on the origin of AIDS. It advances the possibility of genetic recombinations with oncogene activation by HBV involving simian viruses that likely infected polio vaccinated blood donors to the initial hepatitis B (HB) vaccine trials conducted on gay men in New York City and Ugandan Blacks in the early to mid-1970s. The socio-economic and even military ramifications associated with this politically challenging thesis are discussed.

AIDS epidemic at the beginning of the third millennium: time for a new AIDS vaccine strategy

Current expansion of AIDS pandemic significantly accelerates AIDS vaccine research resulting in development and clinical testing of several AIDS vaccine candidates. At the same time, available experimental and clinical data demonstrate that current AIDS vaccine strategy is unsuccessful resulting in development of inefficient and harmful vaccines. This overview briefly summarizes reported results which point out the requirement for moratorium on the current clinical trials of HIV-1 gp120/160 vaccines and urgent need for development of a new, efficient and safe AIDS vaccine strategy.

Laboratory testing for infection with the human immunodeficiency virus: established and novel approaches

The enzyme-linked immunosorbent assay (ELISA) and the Western blot are the primary tests for the diagnosis and confirmation of human immunodeficiency virus (HIV) infection. The ELISA, an inexpensive screening test for antibodies to HIV-1, is both sensitive and specific. The HIV-1 Western blot is a reliable confirmatory test following a repeatedly reactive ELISA. False-positive HIV-1 results with this sequence of tests are extremely rare but can occur, and test results that are inconsistent with clinical or other laboratory information should be questioned, repeated, or supplemented. The US Food and Drug Administration has also approved rapid and more accessible testing methods. Oral mucosal transudate and urine testing are noninvasive testing methods; rapid and home sample collection kits offer easier access to testing.