Ability of Alere™ HIV Combo to diagnose acute HIV infection is based mainly on HIV-1 p24 antigen detection.

BACKGROUND: Alere™ HIV Combo is the only rapid and sensitive point-of-care 4th generation (antigen/antibody) HIV test newly available in Thailand which is advantageous of differentiating between positivity of antigen or antibody or both, especially in acute HIV infection (AHI). AHI in this study was defined by positive machine-based 4th generation test with measurable HIV-RNA but negative 3rd generation (IgM/IgG antibody only) tests. OBJECTIVE: To evaluate the performance characteristics of Alere™ HIV Combo. METHODS: Fifty stored plasma samples of subjects diagnosed with AHI were used to evaluate Alere™ HIV Combo. RESULTS: Of the 50 AHI samples, Alere™ HIV Combo was positive in 37 (74%): 5 with antibody positive only (R1), 26 with p24 antigen positive only (R2), and 6 with both p24 antigen and antibody positive (R3). Mean sample/cut-off (S/ CO) ratios from machine-based 4th generation test of R1, R2 and R3 were 21.55, 148.38 and 72.97 respectively as compared to 7.57 for the 13 non-reactive (NR) samples. The corresponding median log10 HIV-RNA of NR, R1, R2 and R3 were 5.59, 5.86, 7.00 and 6.61 copies/mL respectively. R2 and R3 had significantly higher S/CO and HIV-RNA than NR and R1. Alere™ HIV Combo detected mainly p24 antigen in AHI as seen in 32/50 (64%) subjects and could detect 11/50 (22%) antibody in AHI samples which were missed by the two 3rd generation HIV tests used in our testing algorithm. CONCLUSIONS: Alere™ HIV Combo is the ideal screening test in a setting with high AHI where machine-based 4th generation test is not available.

First characterization of Tn1546-like structures of vancomycin-resistant Enterococcus faecium Thai isolates.

INTRODUCTION: Vancomycin-resistant Enterococcus faecium (VREfm) carrying vanA was first isolated from patient at Siriraj Hospital, Thailand in 2004. Since then, VREfm isolates have been detected increasingly in this 2500-bed university hospital. To understand the epidemiology of vanA VREfm in this setting, the isolates collected during 2004-2013 were characterized. METHODS: A total of 49 vanA VREfm isolates previously confirmed by multiplex PCR were characterized by determining resistance phenotypes to vancomycin, teicoplanin, ampicillin and ciprofloxacin by broth microdilution method. Multilocus sequence typing (MLST) and virulence genes of those isolates were investigated. The Tn1546 structure diversity was studied by long-range overlapping PCR and primer walking sequencing. RESULTS: Of all isolates studied, 9 sequence types (ST17, ST80, ST78, ST730, ST203, ST18, ST280, ST64, ST323) in clonal complex 17 and a novel ST1051 were revealed. The esp-positive isolates were 73.5%. Of all vanA operons characterized, at least 9 types of Tn1546-like structures were detected. All of vanA determinants contained 5'-end different from the Tn1546 prototype. Approximately 47% of them also carried the insertion sequence IS1251 at the intergenic region between vanS and vanH. Interestingly, another IS (ISEfa4) was found to be inside the sequence of IS1251 in ST17 isolate. CONCLUSION: Heterogeneity of vanA VREfm was observed. Nearly all of isolates studied belonged to CC17. One novel ST1051 strain was detected. Isolates in the initial period carried vanA operon similar to the prototype. The diversity of vanA determinants has been increased in the recent isolates. A novel vanA operon structure was detected.

Inflammatory Biomarkers Do Not Differ Between Persistently Seronegative vs Seropositive People With HIV After Treatment in Early Acute HIV Infection.

Persistent viral activity may cause enduring seropositivity and inflammation in treated people with HIV (PWH). We compared inflammatory biomarkers between early treated PWH who remained seronegative or seroconverted and found similar levels of D-dimer, soluble cluster of differentiation 14, C-reactive protein, and interleukin-6, indicating that seronegativity does not affect chronic inflammation in early treated PWH.

Pattern and Frequency of Seroreactivity to Routinely Used Serologic Tests in Early-Treated Infants With HIV.

BACKGROUND: Previous studies have shown low frequencies of seroreactivity to HIV diagnostic assays for infected infants treated with antiretroviral therapy (ART) early in infection. METHODS: Fifty-eight HIV-infected infants treated with ART at a median age of 1.9 months (range: 0.2-5.4) for up to 4 years of life were assessed for seroreactivity to 4 routinely used HIV clinical immunoassays (IA): Second-generation (2ndG) IA and 2 rapid diagnostic tests (RDT), based on third-generation principles, measuring antibody only and a fourth-generation (4thG) antigen/antibody IA. HIV Western blot assay was also performed to assess HIV-specific antibodies. RESULTS: The 2ndG IA demonstrated the highest frequency of seroreactivity in children (69%) followed by the 4thG IA (40%) and the RDT (26%) after one year of ART. Infants initiating ART during ages 3-6 months (N = 15) showed a greater frequency (range: 53%-93%) and breadth (median and range: 3 [1-4]) of reactivity across the assays compared with those treated within 3 months (N = 43):16%-61% and breadth (1 [0-4]). The 4thG IA showed significantly reduced reactivity relative to the 2ndG IA at one (P = 0.016) and 3 (P = 0.004) years of ART. Western blot profiles following 3 years of ART showed the highest frequency of reactivity to HIV Gag p24 (76%) and lowest reactivity to Env gp120 and gp41, with only 24% of children confirmed positive by the assay. CONCLUSIONS: These results suggest that the use of 4thG IA and RDT test combination algorithms with limited HIV antigen breadth may not be adequate for diagnosis of HIV-infected children following early treatment.

Changes in risk behaviors among Thai men who have sex with men and transgender women enrolled in the test and treat cohort.

The test-and-treat approach has the potential to reduce high-risk sexual behaviors by linking high-risk individuals to health education, although this has not been proven yet. We used longitudinal data from the Test and Treat Demonstration Project among Thai men who have sex with men (MSM) and transgender women (TGW) who were not known to be HIV-positive to analyze changes in risk behaviors during the 24-month study period categorized by three groups: HIV-negative without seroconversion, seroconverters, and HIV-positive at enrollment. Five binary risk behavior outcomes - laboratory-diagnosed sexually transmitted infections (STIs); multiple sexual partners, unprotected anal intercourse, self-perceived HIV risk, and amphetamine-type stimulants use in the past month - were assessed. Among 689 participants, with a mean (SD) age of 23.1 (6.2) years, 165 participants were diagnosed with HIV: 115 at enrollment and 50 with seroconversions. HIV-positive participants at enrollment showed significant reductions in all five behavioral risk outcomes. Seroconverters demonstrated higher risks at enrollment than HIV-negative participants, and continued to practice high-risk behaviors even after seroconversion despite a significant reduction in self-perceived moderate-to-high HIV risk. Continuation of risk behaviors among seroconverters could negatively affect the ending AIDS goal, thus the integration of other effective preventive measures into HIV/STIs management programs are needed.

High subsequent and recurrent sexually transmitted infection prevalence among newly diagnosed HIV-positive Thai men who have sex with men and transgender women in the Test and Treat cohort.

We determined subsequent and recurrent sexually transmitted infections (STIs) among men who have sex with men (MSM) and transgender women (TGW) in the Test and Treat cohort. Thai MSM and TGW adults with previously unknown HIV status were enrolled and tested for HIV. Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and syphilis were tested at baseline, month 12, and month 24 to identify subsequent STIs (any STIs diagnosed after baseline) and recurrent STIs (any subsequent STIs diagnosed among those with positive baseline STIs). Among 448 participants, 17.8% were HIV-positive, the prevalence of subsequent STIs and recurrent STIs was 42% (HIV-positive versus HIV-negative: 66.3% versus 36.7%, p < 0.001) and 62.3% (81% versus 52.5%, p < 0.001), respectively. Common subsequent STIs by anatomical site were rectal CT infection (21.7%), rectal NG infection (13.8%), pharyngeal NG infection (13.1%), and syphilis (11.9%). HIV-positive status was associated with both subsequent STIs (adjusted hazard ratio [aHR] 2.38; 95%CI 1.64-3.45, p < 0.001) and recurrent STIs (aHR 1.83; 95%CI 1.16-2.87, p = 0.01). The results show that newly diagnosed HIV-positive MSM and TGW were at increased risk of STIs despite being in the healthcare system. STI educational counseling is necessary to improve STI outcomes among MSM and TGW in both HIV prevention and treatment programs.

Sexually transmitted infections and HIV RNA levels in blood and anogenital compartments among Thai men who have sex with men before and after antiretroviral therapy: implication for Treatment as Prevention programme.

INTRODUCTION: Sexually transmitted infections (STIs) are common among HIV-positive men who have sex with men (MSM). There have been concerns that undiagnosed and untreated STIs could undermine efforts to use antiretroviral therapy (ART) for prevention due to genital secretion infectiousness. We evaluated the correlation between STIs and HIV RNA in anogenital compartments among HIV-positive MSM before and after ART. METHODS: MSM participants newly diagnosed with HIV were offered ART regardless of CD4 count during November 2012 to November 2015. Syphilis serology, oropharyngeal swab, rectal swab, urine collection for gonorrhoea and chlamydia nucleic acid amplification testing, and HIV RNA measurement in blood, semen and rectal samples were performed at baseline, 12 and 24 months thereafter. RESULTS: Of 143 HIV-positive MSM, 16.1% had syphilis, 23.1% had gonorrhoea and 32.8% had chlamydia at baseline. Participants with STIs at baseline had higher median HIV RNA levels in blood plasma (p = 0.053), seminal plasma (p = 0.01) and rectal secretions (p = 0.002) than those without STIs. Multivariate models identified HIV RNA 100,000 to 500,000 (OR 6.74, 95% CI 2.24 to 20.28, p = 0.001) and >500,000 (OR 9.39, 95% CI 1.08 to 81.72, p = 0.04) copies/mL in blood, CD4 count <350 cells/mm3 (OR 4.20, 95% CI 1.05 to 16.70, p = 0.04) and having any STIs (OR 2.62, 95% CI 1.01 to 6.80 p = 0.047) to be associated with detectable (>40 copies/mL) seminal plasma HIV RNA. Having chlamydia at any sites (OR 3.17, 95% CI 1.07 to 9.44, p = 0.04) was associated with detectable rectal HIV RNA. Incidences of syphilis, gonorrhoea and chlamydia were 13.4, 16.4 and 18.1 per 100 person-years respectively. Nine participants had detectable HIV RNA (five in blood, one in semen, two in rectal samples and one in both blood and rectal samples) at 12 and/or 24 months after ART. CONCLUSIONS: STIs were extremely common among HIV-positive MSM prior to and after ART. ART effectively reduced HIV RNA in all compartments. The correlation between STIs and anogenital HIV RNA, especially prior to ART and likely until complete HIV RNA suppression from ART is achieved, points to the importance of integrating asymptomatic STIs screening into Treatment as Prevention programme for MSM.

HIV rapid diagnostic testing by lay providers in a key population-led health service programme in Thailand.

Introduction: Rapid diagnostic testing (RDT) for HIV has a quick turn-around time, which increases the proportion of people testing who receive their result. HIV RDT in Thailand has traditionally been performed only by medical technologists (MTs), which is a barrier to its being scaled up. We evaluated the performance of HIV RDT conducted by trained lay providers who were members of, or worked closely with, a group of men who have sex with men (MSM) and with transgender women (TG) communities, and compared it to tests conducted by MTs. Methods: Lay providers received a 3-day intensive training course on how to perform a finger-prick blood collection and an HIV RDT as part of the Key Population-led Health Services (KPLHS) programme among MSM and TG. All the samples were tested by lay providers using Alere Determine HIV 1/2. HIV-reactive samples were confirmed by DoubleCheckGold Ultra HIV 1&2 and SD Bioline HIV 1/2. All HIV-positive and 10% of HIV-negative samples were re-tested by MTs using Serodia HIV 1/2. Results: Of 1680 finger-prick blood samples collected and tested using HIV RDT by lay providers in six drop-in centres in Bangkok, Chiang Mai, Chonburi and Songkhla, 252 (15%) were HIV-positive. MTs re-tested these HIV-positive samples and 143 randomly selected HIV-negative samples with 100% concordant test results. Conclusion: Lay providers in Thailand can be trained and empowered to perform HIV RDT as they were found to achieve comparable results in sample testing with MTs. Based on the task-shifting concept, this rapid HIV testing performed by lay providers as part of the KPLHS programme has great potential to enhance HIV prevention and treatment programmes among key at-risk populations.

Initiation of Antiretroviral Therapy During Acute HIV-1 Infection Leads to a High Rate of Nonreactive HIV Serology.

BACKGROUND: Third- and fourth-generation immunoassays (IAs) are widely used in the diagnosis of human immunodeficiency virus (HIV) infection. Antiretroviral therapy (ART) during acute HIV infection (AHI) may impact HIV-specific antibodies, with failure to develop antibody or seroreversion. We report on the ability of diagnostic tests to detect HIV-specific antibodies in Thai participants initiating ART during AHI. METHODS: Participants with detectable plasma HIV RNA but nonreactive HIV-specific immunoglobulin G, enrolled in an AHI study, were offered immediate initiation of ART. Participants were tested at initiation and at 12 and 24 weeks following treatment using standard second-, third-, and fourth-generation IAs and Western blot (WB). RESULTS: Participants (N = 234) initiating ART at a median of 19 days (range, 1-62 days) from HIV exposure demonstrated different frequencies of reactivity prior to and following 24 weeks of ART depending on the IA. Third-generation IA nonreactivity prior to ART was 48%, which decreased to 4% following ART (P < .001). Fourth-generation IA nonreactivity was 18% prior to ART and 17% following ART (P = .720). Negative WB results were observed in 89% and 12% of participants prior to and following 24 weeks of ART, respectively (P < .001). Seroreversion to nonreactivity during ART was observed to at least one of the tests in 20% of participants, with fourth-generation IA demonstrating the highest frequency (11%) of seroreversion. CONCLUSIONS: HIV-specific antibodies may fail to develop and, when detected, may decline when ART is initiated during AHI. Although fourth-generation IA was the most sensitive at detecting AHI prior to ART, third-generation IA was the most sensitive during treatment. CLINICAL TRIALS REGISTRATION: NCT00796146 and NCT00796263.

Anogenital HIV RNA in Thai men who have sex with men in Bangkok during acute HIV infection and after randomization to standard vs. intensified antiretroviral regimens.

INTRODUCTION: HIV transmission risk is highest during acute HIV infection (AHI). We evaluated HIV RNA in the anogenital compartment in men who have sex with men (MSM) during AHI and compared time to undetectable HIV RNA after three-drug versus five-drug antiretroviral therapy (ART) to understand risk for onward HIV transmission. METHODS: MSM with AHI (n=54) had blood, seminal plasma and anal lavage collected for HIV RNA at baseline, days 3 and 7, and weeks 2, 4, 12 and 24. Data were compared between AHI stages: 1 (fourth-generation antigen-antibody combo immunoassay [IA]-, third-generation IA-, n=15), 2 (fourth-generation IA+, third-generation IA-, n=9) and 3 (fourth-generation IA+, third-generation IA+, western blot-/indeterminate, n=30) by randomization to five-drug (tenofovir+emtricitabine+efavirenz+raltegravir+maraviroc, n=18) versus three-drug (tenofovir+emtricitabine+efavirenz, n=18) regimens. RESULTS: Mean age was 29 years and mean duration since HIV exposure was 15.4 days. Mean baseline HIV RNA was 5.5 in blood, 3.9 in seminal plasma and 2.6 log10 copies/ml in anal lavage (p<0.001). Blood and seminal plasma HIV RNA were higher in AHI Stage 3 compared to Stage 1 (p<0.01). Median time from ART initiation to HIV RNA <50 copies/ml was 60 days in blood, 15 days in seminal plasma and three days in anal lavage. Compared with the three-drug ART, the five-drug ART had a shorter time to HIV RNA <1500 copies/ml in blood (15 vs. 29 days, p=0.005) and <50 copies/ml in seminal plasma (13 vs. 24 days, p=0.048). CONCLUSIONS: Among MSM with AHI, HIV RNA was highest in blood, followed by seminal plasma and anal lavage. ART rapidly reduced HIV RNA in all compartments, with regimen intensified by raltegravir and maraviroc showing faster HIV RNA reductions in blood and seminal plasma.

Impact of nucleic acid testing relative to antigen/antibody combination immunoassay on the detection of acute HIV infection.

OBJECTIVE: To assess the addition of HIV nucleic acid testing (NAT) to fourth-generation (4thG) HIV antigen/antibody combination immunoassay in improving detection of acute HIV infection (AHI). METHODS: Participants attending a major voluntary counseling and testing site in Thailand were screened for AHI using 4thG HIV antigen/antibody immunoassay and sequential less sensitive HIV antibody immunoassay. Samples nonreactive by 4thG antigen/antibody immunoassay were further screened using pooled NAT to identify additional AHI. HIV infection status was verified following enrollment into an AHI study with follow-up visits and additional diagnostic tests. RESULTS: Among 74 334 clients screened for HIV infection, HIV prevalence was 10.9% and the overall incidence of AHI (N = 112) was 2.2 per 100 person-years. The inclusion of pooled NAT in the testing algorithm increased the number of acutely infected patients detected, from 81 to 112 (38%), relative to 4thG HIV antigen/antibody immunoassay. Follow-up testing within 5 days of screening marginally improved the 4thG immunoassay detection rate (26%). The median CD4 T-cell count at the enrollment visit was 353 cells/µl and HIV plasma viral load was 598 289 copies/ml. CONCLUSION: The incorporation of pooled NAT into the HIV testing algorithm in high-risk populations may be beneficial in the long term. The addition of pooled NAT testing resulted in an increase in screening costs of 22% to identify AHI: from $8.33 per screened patient to $10.16. Risk factors of the testing population should be considered prior to NAT implementation given the additional testing complexity and costs.

Two unique recombinant forms identified in incident HIV type 1 infections in Thai blood donors.

HIV-1 genetic diversity of recently seroconverting (<12 months) Thai repeated blood donors attending the National Blood Centre, Thai Red Cross Society (NBC, TRCS) from September 2007 until March 2008 was assessed. Ten HIV-1 recent seroconvertors (10/239,134 donations) were identified during the study period. The estimated median time to seroconversion was 67.3 days (range: 45.5-102.0 days), and viral load ranged from 307 to 341,805 copies HIV-1 RNA/ml. MHAbce, a real-time-based PCR genotyping assay, identified six CRF01_AE, two CRF01_AE/B recombinants, one subtype B, and one CRF01_AE/B dual infection. Nine samples were further characterized by full genome sequencing, identifying CRF01_AE (N=6), unique CRF01_AE/B recombinants (N=2), and subtype B (N=1). One recombinant contained 13 breakpoints located in gag, pol, vif, vpr, env, and nef while the other recombinant contained 10 breakpoints located in pol, vif, env, and nef. This study found two unique CRF01B recombinants circulating in 10 recent HIV-1-positive subjects from a blood donor population in Thailand.

Active voluntary counseling and testing with integrated CD4 count service can enhance early HIV testing and early CD4 count measurement: experiences from the Thai Red Cross Anonymous Clinic in Bangkok, Thailand.

BACKGROUND: Low CD4 count at antiretroviral therapy initiation is common both in developed and developing countries. Active voluntary counseling and testing (VCT) center with integrated CD4 count service may facilitate early HIV testing and CD4 count measurement. METHOD: We analyzed data from clients who had HIV testing at our VCT center between June 1, 2006 to May 31, 2009. HIV testing was provided through routine VCT, health check-up, nutrition, and sexual health services. CD4 count measurement was available in the clinic. The first CD4 count and duration between HIV diagnosis and the first CD4 count measurement were extracted from the database along with available demographic data. RESULTS: Among 19,525 Thai clients who had HIV testing, 2580 clients (13.2%) were tested HIV positive for the first time. CD4 count measurement was performed in 73.3% of HIV-positive clients and 91.4% of these occurred within the first month of HIV diagnosis. Median first CD4 count was 287.0 (IQR = 114.0-434.3) cells per cubic millimeter, 62% had CD4 count <350 cells per cubic millimeter. CONCLUSIONS: As HIV programs are moving toward earlier initiation of antiretroviral therapy, efforts are needed to promote "early HIV testing" among general population with different levels of HIV risks and to enhance "early CD4 count measurement" after HIV diagnosis.

Early-onset prosthetic valve endocarditis caused by Inquilinus sp.

Inquilinus is the newly described genus and has never been recognized as a cause of infective endocarditis. We report a case of early-onset prosthetic valve endocarditis caused by Inquilinus sp. in a tetralogy of Fallot patient who presented with heart failure. The bacterium was recovered from 11 consecutive blood cultures and identified by 16S rRNA gene sequencing.