Displaying publications 21 - 40 of 137 in total

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  1. Prasad AN, Woolsey C, Geisbert JB, Agans KN, Borisevich V, Deer DJ, et al.
    J Infect Dis, 2020 05 11;221(Suppl 4):S436-S447.
    PMID: 32022850 DOI: 10.1093/infdis/jiz613
    BACKGROUND: The henipaviruses, Hendra virus (HeV) and Nipah virus (NiV), are capable of causing severe and often lethal respiratory and/or neurologic disease in animals and humans. Given the sporadic nature of henipavirus outbreaks, licensure of vaccines and therapeutics for human use will likely require demonstration of efficacy in animal models that faithfully reproduce the human condition. Currently, the African green monkey (AGM) best mimics human henipavirus-induced disease.

    METHODS: The pathogenic potential of HeV and both strains of NiV (Malaysia, Bangladesh) was assessed in cynomolgus monkeys and compared with henipavirus-infected historical control AGMs. Multiplex gene and protein expression assays were used to compare host responses.

    RESULTS: In contrast to AGMs, in which henipaviruses cause severe and usually lethal disease, HeV and NiVs caused only mild or asymptomatic infections in macaques. All henipaviruses replicated in macaques with similar kinetics as in AGMs. Infection in macaques was associated with activation and predicted recruitment of cytotoxic CD8+ T cells, Th1 cells, IgM+ B cells, and plasma cells. Conversely, fatal outcome in AGMs was associated with aberrant innate immune signaling, complement dysregulation, Th2 skewing, and increased secretion of MCP-1.

    CONCLUSION: The restriction factors identified in macaques can be harnessed for development of effective countermeasures against henipavirus disease.

    Matched MeSH terms: Viral Load
  2. Ansari AW, Ahmad F, Shankar EM, Kong YY, Tan HY, Jacobs R, et al.
    PMID: 32398557 DOI: 10.1097/QAI.0000000000002399
    BACKGROUND: We have previously shown an association of elevated co-inhibitory molecule 2B4 expression with iNKT cells alterations in HIV disease. Herein we show a comparative analysis of 2B4 expression on iNKT cells of HIV long-term non-progressors (LTNPs) and progressors.

    METHODS: Anti-retroviral therapy (ART) naïve HIV-seropositive individuals (progressors, n=16) and long-term non-progressors (LTNPs, n=10) were recruited for this study. We employed multi-color flow cytometry on frozen peripheral blood mononuclear cells (PBMCs) to determine iNKT subset frequencies, the levels of co-inhibitory 2B4 expression, and intracellular IFN-γ production. CD1d tetramer was used to characterize iNKT cells.

    RESULTS: We report significantly lower level of 2B4 expression on bulk LTNPs iNKT cells as well as on their CD4 subsets compared to HIV progressors. Furthermore, the iNKT cells from LTNPs produced higher amount of IFN-γ than HIV progressors as detected by intracellular cytokine staining. Interestingly, the frequency of 2B4iNKT cells of progressors but not LTNPs significantly correlates with CD4 T cell count, HIV viral load and IFNγ production by iNKT cells.

    CONCLUSION: Our results suggest that in addition to suppressed HIV replication, diminished 2B4 expression and associated co-inhibitory signaling, and substantial production of IFN-γ could contribute to preserved iNKT cell phenotype in LTNPs.

    Matched MeSH terms: Viral Load
  3. Mawaddah A, Gendeh HS, Lum SG, Marina MB
    Malays J Pathol, 2020 Apr;42(1):23-35.
    PMID: 32342928
    INTRODUCTION: To review the present literature on upper respiratory tract sampling in COVID-19 and provide recommendations to improve healthcare practices and directions in future studies.

    METHODS: Twelve relevant manuscripts were sourced from a total of 7288 search results obtained using PubMed, Medline and Google Scholar. The search keywords used were COVID-19, nasopharyngeal, oropharyngeal, swabs, SARS and CoV2. Original manuscripts were obtained and analysed by all authors. The review included manuscripts which have not undergone rigorous peer-review process in view of the magnitude of the topic discussed.

    RESULTS: The viral load of SARS-CoV-2 RNA in the upper respiratory tract was significantly higher during the first week and peaked at 4-6 days after onset of symptoms, during which it can be potentially sampled. Nasopharyngeal swab has demonstrated higher viral load than oropharyngeal swab, where the difference in paired samples is best seen at 0-9 days after the onset of illness. Sensitivity of nasopharyngeal swab was higher than oropharyngeal swabs in COVID-19 patients. Patient self-collected throat washing has been shown to contain higher viral load than nasopharyngeal or oropharyngeal swab, with significantly higher sensitivity when compared with paired nasopharyngeal swab.

    RECOMMENDATIONS: Routine nasopharyngeal swab of suspected COVID-19 infection should take anatomy of the nasal cavity into consideration to increase patient comfort and diagnostic yield. Routine oropharyngeal swab should be replaced by throat washing which has demonstrated better diagnostic accuracy, and it is safe towards others.

    Matched MeSH terms: Viral Load
  4. Mohd Isa F, Ahmed Al-Haj N, Mat Isa N, Ideris A, Powers C, Oladapo O, et al.
    PMID: 31837598 DOI: 10.1016/j.cimid.2019.101399
    Among different inbred chickens' lines, we previously showed that lines P and N of Institute for Animal Health, Compton, UK are the most susceptible and the least affected lines, respectively, following infection with very virulent infectious bursal disease virus (vvIBDV). In this study, the differential expressions of 29 different immune-related genes were characterized. Although, birds from both lines succumbed to infection, line P showed greater bursal lesion scores and higher viral copy numbers compared to line N. Interestingly, line N showed greater down-regulation of B cell related genes (BLNK, TNFSF13B and CD72) compared to line P. While up-regulation of T-cell related genes (CD86 and CTLA4) and Th1 associated cytokines (IFNG, IL2, IL12A and IL15) were documented in both lines, the expression levels of these genes were different in the two lines. Meanwhile, the expression of IFN-related genes IFNB, STAT1, and IRF10, but not IRF5, were up-regulated in both lines. The expression of pro-inflammatory cytokines (IL1B, IL6, IL18, and IL17) and chemokines (CXCLi2, CCL4, CCL5 and CCR5) were up-regulated in both lines with greater increase documented in line P compared to line N. Strikingly, the expression of IL12B was detected only in line P whilst the expression of IL15RA was detected only in line N. In conclusion, the bursal immunopathology of IBDV correlates more with expression of proinflammatory response related genes and does not related to expression of B-cell related genes.
    Matched MeSH terms: Viral Load
  5. Sohn AH, Chokephaibulkit K, Lumbiganon P, Hansudewechakul R, Gani YM, Van Nguyen L, et al.
    J Adolesc Health, 2020 01;66(1):92-99.
    PMID: 31627925 DOI: 10.1016/j.jadohealth.2019.07.025
    PURPOSE: The aim of this article was to study the clinical and social outcomes of health care transition among Asian adolescents and young adults with HIV (AYHIV).

    METHODS: AYHIV who transferred from a pediatric to an adult clinic within the past year across five sites in Malaysia, Thailand, and Vietnam had clinical and laboratory evaluations and completed questionnaires about their health, socioeconomic factors, and transition experiences. Multiple logistic regression was used to assess associations with HIV viremia.

    RESULTS: Of 93 AYHIV enrolled between June 2016 and April 2017, 56% were female, 87% acquired HIV through perinatal exposure, median age was 20 years (interquartile range [IQR] 18.5-21). Two-thirds were in a formal education program, 43% were employed, 43% of females and 35% of males were sexually active. Median lifetime antiretroviral therapy duration was 6.2 years (IQR 3.3-10.7); 45% had received second-line therapy. Median CD4 was 601 cells/mm3 (IQR 477-800); 82% had HIV-RNA <40 copies/mL. Being in a relationship, a shorter posttransition duration, self-reported adherence of ≥95%, and higher CD4 were inversely associated with HIV viremia. Half felt very prepared for the transfer to adult care, and 20% frequently and 43% sometimes still met with pediatric providers. Two-thirds reported needing to keep their HIV a secret, and 23%-38% reported never or rarely having someone to discuss problems with.

    CONCLUSIONS: Asian AYHIV in our cohort were concerned about the negative social impact of having and disclosing HIV, and one-third lacked people they could trust with their personal problems, which could have negative implications for their ability to navigate adult life.

    Matched MeSH terms: Viral Load
  6. Abdul-Kadir MA, Lim LT
    BMJ Open Ophthalmol, 2020;5(1):e000630.
    PMID: 33195813 DOI: 10.1136/bmjophth-2020-000630
    The 2019 novel coronavirus which causes severe acute respiratory syndrome (SARS) known as SARS-CoV-2 still remains as a global pandemic since its discovery and continues to spread across the world, given how highly contagious the virus is. We reviewed various articles that explore eye involvement in COVID-19 and other human coronaviruses, its human manifestations in comparison to animal studies and potential mechanism of viral entry into the eye surface. Evidence of animal studies depicted various complications of coronaviruses infection into the eyes, in both anterior and posterior segments of the eye. Conjunctival inflammation remains uncommon in association with COVID-19, with other ophthalmic findings. The risk of transmission via the ocular surface remains likely low, though it is inarguably present based on preliminary finding of viral load in ocular samples and expression of ACE2 on the ocular surface. Testing the tears sample for diagnosing SARS-CoV-2 was unreliable due to limitations of the testing kits and conflicting evidence of the viral titre in the ocular samples. Further larger, more precise and specific studies are required to allow us to better understand the pattern of virulence underlying the associations of SARS-CoV-2 in the eye despite its rare occurrence. This review article aims to enhance better awareness among clinicians regarding ocular manifestations associated with COVID-19 and necessary precautions should be implemented to minimise the risk of person-to-person especially in the nosocomial setting.
    Matched MeSH terms: Viral Load
  7. Jiamsakul A, Azwa I, Zhang F, Yunihastuti E, Ditangco R, Kumarasamy N, et al.
    Antivir Ther, 2020;25(7):377-387.
    PMID: 33616550 DOI: 10.3851/IMP3384
    BACKGROUND: The World Health Organization recommends continuation with the failing second-line regimen if third-line option is not available. We investigated treatment outcomes among people living with HIV in Asia who continued with failing second-line regimens compared with those who had treatment modifications after failure.

    METHODS: Treatment modification was defined as a change of two antiretrovirals, a drug class change or treatment interruption (TI), all for >14 days. We assessed factors associated with CD4 changes and undetectable viral load (UVL <1,000 copies/ml) at 1 year after second-line failure using linear and logistic regression, respectively. Survival time was analysed using competing risk regression.

    RESULTS: Of the 328 patients who failed second-line ART in our cohorts, 208 (63%) had a subsequent treatment modification. Compared with those who continued the failing regimen, the average CD4 cell increase was higher in patients who had a modification without TI (difference =77.5, 95% CI 35.3, 119.7) while no difference was observed among those with TI (difference =-5.3, 95% CI -67.3, 56.8). Compared with those who continued the failing regimen, the odds of achieving UVL was lower in patients with TI (OR=0.18, 95% CI 0.06, 0.60) and similar among those who had a modification without TI (OR=1.97, 95% CI 0.95, 4.10), with proportions of UVL 60%, 22% and 75%, respectively. Survival time was not affected by treatment modifications.

    CONCLUSIONS: CD4 cell improvements were observed in those who had treatment modification without TI compared with those on the failing regimen. When no other options are available, maintaining the same failing ART combination provided better VL control than interrupting treatment.

    Matched MeSH terms: Viral Load
  8. Bartlett AW, Lumbiganon P, Jamal Mohamed TA, Lapphra K, Muktiarti D, Du QT, et al.
    J Acquir Immune Defic Syndr, 2019 12 15;82(5):431-438.
    PMID: 31714422 DOI: 10.1097/QAI.0000000000002184
    BACKGROUND: Perinatally HIV-infected adolescents (PHIVA) are an expanding population vulnerable to loss to follow-up (LTFU). Understanding the epidemiology and factors for LTFU is complicated by varying LTFU definitions.

    SETTING: Asian regional cohort incorporating 16 pediatric HIV services across 6 countries.

    METHODS: Data from PHIVA (aged 10-19 years) who received combination antiretroviral therapy 2007-2016 were used to analyze LTFU through (1) an International epidemiology Databases to Evaluate AIDS (IeDEA) method that determined LTFU as >90 days late for an estimated next scheduled appointment without returning to care and (2) the absence of patient-level data for >365 days before the last data transfer from clinic sites. Descriptive analyses and competing-risk survival and regression analyses were used to evaluate LTFU epidemiology and associated factors when analyzed using each method.

    RESULTS: Of 3509 included PHIVA, 275 (7.8%) met IeDEA and 149 (4.3%) met 365-day absence LTFU criteria. Cumulative incidence of LTFU was 19.9% and 11.8% using IeDEA and 365-day absence criteria, respectively. Risk factors for LTFU across both criteria included the following: age at combination antiretroviral therapy initiation <5 years compared with age ≥5 years, rural clinic settings compared with urban clinic settings, and high viral loads compared with undetectable viral loads. Age 10-14 years compared with age 15-19 years was another risk factor identified using 365-day absence criteria but not IeDEA LTFU criteria.

    CONCLUSIONS: Between 12% and 20% of PHIVA were determined LTFU with treatment fatigue and rural treatment settings consistent risk factors. Better tracking of adolescents is required to provide a definitive understanding of LTFU and optimize evidence-based models of care.

    Matched MeSH terms: Viral Load
  9. Ellan K, Thayan R, Phan CW, Sabaratnam V
    Trop Biomed, 2019 Dec 01;36(4):1087-1098.
    PMID: 33597478
    Pathogenesis of dengue fever has been associated with the activation of the cytokine cascade that triggered inflammatory responses. The inflammatory reactions in dengue haemorrhagic fever/dengue shock syndrome (DHF/DSS) are the main cause of haemorrhagic manifestations, coagulation disorders, vascular permeability, hypotension and shock which could exacerbate the condition of the disease. In an earlier study, extracts belonging to Lignosus rhinocerotis, Pleurotus giganteus, Hericium erinaceus, Schizophyllum commune and Ganoderma lucidium mushrooms were screened for antidengue virus activities. We found that hot aqueous extract (HAE) and aqueous soluble separated from ethanol extract (ASE) exhibited their potential to reduce dengue viral load which were observed in plaque reduction assay and real-time RT-PCR. In continuation of our previous findings, this study was initiated to further investigate the other aspect; the anti-inflammatory activities of HAE and ASE of L. rhinocerotis, P. giganteus, H. erinaceus, S. commune and G. lucidium on human monocytes infected with dengue virus-2 (DENV-2) New guinea C strain. Human monocytes infected with DENV-2 were treated with mushroom extracts for 48 hours. The cytokine profile coincides with dengue infection, i.e. IFN-γ, TNF-α, IL-1β, IL-6, IL-8, and IL-10 were measured by BD OptEIATM Elisa Kit. The expression of these cytokines was significantly elevated in untreated infected cells two days after infection. However, after treated with mushroom extracts prominent anti-inflammatory effect were detected towards IFN-γ, IL-10, TNF-α, IL-6, and IL-1β. The most significant anti-inflammatory effects were detected in HAE of G. lucidium, S. commune, P. giganteus and ASE of L. rhinocerotis and the effects were comparable with dexamethasone, the reference inhibitor. These results demonstrated that mushroom HAE or ASE could successfully have suppressed cytokine production in dengue-infected monocytes and has a great potential to develop an antiinflammatory agent from mushroom extract for the treatment of dengue infection.
    Matched MeSH terms: Viral Load
  10. Bartlett AW, Lumbiganon P, Kurniati N, Sudjaritruk T, Mohamed TJ, Hansudewechakul R, et al.
    J Adolesc Health, 2019 11;65(5):651-659.
    PMID: 31395514 DOI: 10.1016/j.jadohealth.2019.05.025
    PURPOSE: Antiretroviral monotherapy and treatment interruption are potential strategies for perinatally HIV-infected adolescents (PHIVA) who face challenges maintaining effective combination antiretroviral therapy (ART). We assessed the use and outcomes for adolescents receiving monotherapy or undergoing treatment interruption in a regional Asian cohort.

    METHODS: Regional Asian data (2001-2016) were analyzed to describe PHIVA who experienced ≥2 weeks of lamivudine or emtricitabine monotherapy or treatment interruption and trends in CD4 count and HIV viral load during and after episodes. Survival analyses were used for World Health Organization (WHO) stage III/IV clinical and immunologic event-free survival during monotherapy or treatment interruption, and a Poisson regression to determine factors associated with monotherapy or treatment interruption.

    RESULTS: Of 3,448 PHIVA, 84 (2.4%) experienced 94 monotherapy episodes, and 147 (4.3%) experienced 174 treatment interruptions. Monotherapy was associated with older age, HIV RNA >400 copies/mL, younger age at ART initiation, and exposure to ≥2 combination ART regimens. Treatment interruption was associated with CD4 count <350 cells/μL, HIV RNA ≥1,000 copies/mL, ART adverse event, and commencing ART age ≥10 years compared with age <3 years. WHO clinical stage III/IV 1-year event-free survival was 96% and 85% for monotherapy and treatment interruption cohorts, respectively. WHO immunologic stage III/IV 1-year event-free survival was 52% for both cohorts. Those who experienced monotherapy or treatment interruption for more than 6 months had worse immunologic and virologic outcomes.

    CONCLUSIONS: Until challenges of treatment adherence, engagement in care, and combination ART durability/tolerability are met, monotherapy and treatment interruption will lead to poor long-term outcomes.

    Matched MeSH terms: Viral Load/drug effects
  11. Mohd A, Zainal N, Tan KK, AbuBakar S
    Sci Rep, 2019 10 04;9(1):14336.
    PMID: 31586088 DOI: 10.1038/s41598-019-50674-3
    Zika virus (ZIKV) infection is a serious public health concern. ZIKV infection has been associated with increased occurrences of microcephaly among newborns and incidences of Guillain-Barré syndrome among adults. No specific therapeutics or vaccines are currently available to treat and protect against ZIKV infection. Here, a plant-secreted phytoalexin, resveratrol (RES), was investigated for its ability to inhibit ZIKV replication in vitro. Several RES treatment regimens were used. The ZIKV titers of mock- and RES-treated infected cell cultures were determined using the focus-forming assay and the Zika mRNA copy number as determined using qRT-PCR. Our results suggested that RES treatment reduced ZIKV titers in a dose-dependent manner. A reduction of >90% of virus titer and ZIKV mRNA copy number was achieved when infected cells were treated with 80 µM of RES post-infection. Pre-incubation of the virus with 80 µM RES showed >30% reduction in ZIKV titers and ZIKV mRNA copy number, implying potential direct virucidal effects of RES against the virus. The RES treatment reduced >70% virus titer in the anti-adsorption assay, suggesting the possibility that RES also interferes with ZIKV binding. However, there was no significant decrease in ZIKV titer when a short-period of RES treatment was applied to cells before ZIKV infection (pre-infection) and after the virus bound to the cells (virus internalization inhibition), implying that RES acts through its continuous presence in the cell cultures after virus infection. Overall, our results suggested that RES exhibited direct virucidal activity against ZIKV and possessed anti-ZIKV replication properties, highlighting the need for further exploration of RES as a potential antiviral molecule against ZIKV infection.
    Matched MeSH terms: Viral Load
  12. Ross JL, Teeraananchai S, Lumbiganon P, Hansudewechakul R, Chokephaibulkit K, Khanh TH, et al.
    J Acquir Immune Defic Syndr, 2019 06 01;81(2):e28-e38.
    PMID: 30865173 DOI: 10.1097/QAI.0000000000002008
    BACKGROUND: Adolescents living with HIV (ALHIV) have poorer adherence and clinical outcomes than adults. We conducted a study to assess behavioral risks and antiretroviral therapy outcomes among ALHIV in Asia.

    METHODS: A prospective cohort study among ALHIV and matched HIV-uninfected controls aged 12-18 years was conducted at 9 sites in Malaysia, Thailand, and Vietnam from July 2013 to March 2017. Participants completed an audio computer-assisted self-interview at weeks 0, 48, 96, and 144. Virologic failure (VF) was defined as ≥1 viral load (VL) measurement >1000 copies/mL. Generalized estimating equations were used to identify predictors for VF.

    RESULTS: Of 250 ALHIV and 59 HIV-uninfected controls, 58% were Thai and 51% females. The median age was 14 years at enrollment; 93% of ALHIV were perinatally infected. At week 144, 66% of ALHIV were orphans vs. 28% of controls (P < 0.01); similar proportions of ALHIV and controls drank alcohol (58% vs. 65%), used inhalants (1% vs. 2%), had been sexually active (31% vs. 21%), and consistently used condoms (42% vs. 44%). Of the 73% of ALHIV with week 144 VL testing, median log VL was 1.60 (interquartile range 1.30-1.70) and 19% had VF. Over 70% of ALHIV had not disclosed their HIV status. Self-reported adherence ≥95% was 60% at week 144. Smoking cigarettes, >1 sexual partner, and living with nonparent relatives, a partner or alone, were associated with VF at any time.

    CONCLUSIONS: The subset of ALHIV with poorer adherence and VF require comprehensive interventions that address sexual risk, substance use, and HIV-status disclosure.

    Matched MeSH terms: Viral Load
  13. Sudjaritruk T, Boettiger DC, Nguyen LV, Mohamed TJ, Wati DK, Bunupuradah T, et al.
    J Int AIDS Soc, 2019 Jun;22(6):e25312.
    PMID: 31179641 DOI: 10.1002/jia2.25312
    INTRODUCTION: Recommendations on the optimal frequency of plasma viral load (pVL) monitoring in children living with HIV (CLWH) who are stable on combination antiretroviral therapy (cART) are inconsistent. This study aimed to determine the impact of annual versus semi-annual pVL monitoring on treatment outcomes in Asian CLWH.

    METHODS: Data on children with perinatally acquired HIV aged <18 years on first-line, non-nucleoside reverse transcriptase inhibitor-based cART with viral suppression (two consecutive pVL <400 copies/mL over a six-month period) were included from a regional cohort study; those exposed to prior mono- or dual antiretroviral treatment were excluded. Frequency of pVL monitoring was determined at the site-level based on the median rate of pVL measurement: annual 0.75 to 1.5, and semi-annual >1.5 tests/patient/year. Treatment failure was defined as virologic failure (two consecutive pVL >1000 copies/mL), change of antiretroviral drug class, or death. Baseline was the date of the second consecutive pVL <400 copies/mL. Competing risk regression models were used to identify predictors of treatment failure.

    RESULTS: During January 2008 to March 2015, there were 1220 eligible children from 10 sites that performed at least annual pVL monitoring, 1042 (85%) and 178 (15%) were from sites performing annual (n = 6) and semi-annual pVL monitoring (n = 4) respectively. Pre-cART, 675 children (55%) had World Health Organization clinical stage 3 or 4, the median nadir CD4 percentage was 9%, and the median pVL was 5.2 log10 copies/mL. At baseline, the median age was 9.2 years, 64% were on nevirapine-based regimens, the median cART duration was 1.6 years, and the median CD4 percentage was 26%. Over the follow-up period, 258 (25%) CLWH with annual and 40 (23%) with semi-annual pVL monitoring developed treatment failure, corresponding to incidence rates of 5.4 (95% CI: 4.8 to 6.1) and 4.3 (95% CI: 3.1 to 5.8) per 100 patient-years of follow-up respectively (p = 0.27). In multivariable analyses, the frequency of pVL monitoring was not associated with treatment failure (adjusted hazard ratio: 1.12; 95% CI: 0.80 to 1.59).

    CONCLUSIONS: Annual compared to semi-annual pVL monitoring was not associated with an increased risk of treatment failure in our cohort of virally suppressed children with perinatally acquired HIV on first-line NNRTI-based cART.

    Matched MeSH terms: Viral Load*
  14. Mire CE, Geisbert JB, Agans KN, Versteeg KM, Deer DJ, Satterfield BA, et al.
    Emerg Infect Dis, 2019 Jun;25(6):1144-1152.
    PMID: 31107231 DOI: 10.3201/eid2506.181620
    Nipah virus (NiV) is a zoonotic pathogen that causes high case-fatality rates (CFRs) in humans. Two NiV strains have caused outbreaks: the Malaysia strain (NiVM), discovered in 1998-1999 in Malaysia and Singapore (≈40% CFR); and the Bangladesh strain (NiVB), discovered in Bangladesh and India in 2001 (≈80% CFR). Recently, NiVB in African green monkeys resulted in a more severe and lethal disease than NiVM. No NiV vaccines or treatments are licensed for human use. We assessed replication-restricted single-injection recombinant vesicular stomatitis vaccine NiV vaccine vectors expressing the NiV glycoproteins against NiVB challenge in African green monkeys. All vaccinated animals survived to the study endpoint without signs of NiV disease; all showed development of NiV F Ig, NiV G IgG, or both, as well as neutralizing antibody titers. These data show protective efficacy against a stringent and relevant NiVB model of human infection.
    Matched MeSH terms: Viral Load
  15. Pham MD, Haile BA, Azwa I, Kamarulzaman A, Raman N, Saeidi A, et al.
    J Clin Microbiol, 2019 04;57(4).
    PMID: 30700508 DOI: 10.1128/JCM.01683-18
    HIV viral load (VL) testing is the recommended method for monitoring the response of people living with HIV and receiving antiretroviral therapy (ART). The availability of standard plasma VL testing in low- and middle-income countries (LMICs), and access to this testing, are limited by the need to use fresh plasma. Good specimen collection methods for HIV VL testing that are applicable to resource-constrained settings are needed. We assessed the diagnostic performance of the filtered dried plasma spot (FDPS), created using the newly developed, instrument-free VLPlasma device, in identifying treatment failure at a VL threshold of 1,000 copies/ml in fresh plasma. Performance was compared with that of the conventional dried blood spot (DBS). Venous blood samples from 201 people living with HIV and attending an infectious disease clinic in Malaysia were collected, and HIV VL was quantified using fresh plasma (the reference standard), FDPS, and DBS specimens. VL testing was done using the Roche Cobas AmpliPrep/Cobas TaqMan v2.0 assay. At a threshold of 1,000 copies/ml, the diagnostic performance of the FDPS was superior (sensitivity, 100% [95% confidence interval {CI}, 89.1 to 100%]; specificity, 100% [95% CI, 97.8 to 100%]) to that of the DBS (sensitivity, 100% [95% CI, 89.4 to 100%]; specificity, 36.8% [95% CI, 29.4 to 44.7%]) (P 
    Matched MeSH terms: Viral Load/methods*; Viral Load/standards
  16. Yee PTI, Tan SH, Ong KC, Tan KO, Wong KT, Hassan SS, et al.
    Sci Rep, 2019 03 18;9(1):4805.
    PMID: 30886246 DOI: 10.1038/s41598-019-41285-z
    Besides causing mild hand, foot and mouth infections, Enterovirus A71 (EV-A71) is associated with neurological complications and fatality. With concerns about rising EV-A71 virulence, there is an urgency for more effective vaccines. The live attenuated vaccine (LAV) is a more valuable vaccine as it can elicit both humoral and cellular immune responses. A miRNA-based vaccine strain (pIY) carrying let-7a and miR-124a target genes in the EV-A71 genome which has a partial deletion in the 5'NTR (∆11 bp) and G64R mutation (3Dp°l) was designed. The viral RNA copy number and viral titers of the pIY strain were significantly lower in SHSY-5Y cells that expressed both let-7a and miR-124a. Inhibition of the cognate miRNAs expressed in RD and SHSY-5Y cells demonstrated de-repression of viral mRNA translation. A previously constructed multiply mutated strain, MMS and the pIY vaccine strain were assessed in their ability to protect 4-week old mice from hind limb paralysis. The MMS showed higher amounts of IFN-γ ex vivo than the pIY vaccine strain. There was absence of EV-A71 antigen in the skeletal muscles and spinal cord micrographs of mice vaccinated with the MMS and pIY strains. The MMS and pIY strains are promising LAV candidates developed against severe EV-A71 infections.
    Matched MeSH terms: Viral Load
  17. Mu W, Bartlett AW, Bunupuradah T, Chokephaibulkit K, Kumarasamy N, Ly PS, et al.
    J Acquir Immune Defic Syndr, 2019 03 01;80(3):308-315.
    PMID: 30531299 DOI: 10.1097/QAI.0000000000001921
    BACKGROUND: Virologic failure is a major threat to maintaining effective combination antiretroviral therapy, especially for children in need of lifelong treatment. With efforts to expand access to HIV viral load testing, our understanding of pediatric virologic failure is evolving.

    SETTING: An Asian cohort in 16 pediatric HIV services across 6 countries.

    METHODS: From 2005 to 2014, patients younger than 20 years who achieved virologic suppression and had subsequent viral load testing were included. Early virologic failure was defined as a HIV RNA ≥1000 copies per milliliter within 12 months of virologic suppression, and late virologic as a HIV RNA ≥1000 copies per milliliter after 12 months following virologic suppression. Characteristics at combination antiretroviral therapy initiation and virologic suppression were described, and a competing risk time-to-event analysis was used to determine cumulative incidence of virologic failure and factors at virologic suppression associated with early and late virologic failure.

    RESULTS: Of 1105 included in the analysis, 182 (17.9%) experienced virologic failure. The median age at virologic suppression was 6.9 years, and the median time to virologic failure was 24.6 months after virologic suppression. The incidence rate for a first virologic failure event was 3.3 per 100 person-years. Factors at virologic suppression associated with late virologic failure included older age, mostly rural clinic setting, tuberculosis, protease inhibitor-based regimens, and early virologic failure. No risk factors were identified for early virologic failure.

    CONCLUSIONS: Around 1 in 5 experienced virologic failure in our cohort after achieving virologic suppression. Targeted interventions to manage complex treatment scenarios, including adolescents, tuberculosis coinfection, and those with poor virologic control are required.

    Matched MeSH terms: Viral Load/drug effects*
  18. Bartlett AW, Mohamed TJ, Sudjaritruk T, Kurniati N, Nallusamy R, Hansudewechakul R, et al.
    Pediatr Infect Dis J, 2019 03;38(3):287-292.
    PMID: 30281549 DOI: 10.1097/INF.0000000000002208
    BACKGROUND: Perinatally HIV-infected adolescents (PHIVA) are exposed to a chronic systemic infection and long-term antiretroviral therapy (ART), leaving them susceptible to morbidities associated with inflammation, immunodeficiency and drug toxicity.

    METHODS: Data collected 2001 to 2016 from PHIVA 10-19 years of age within a regional Asian cohort were analyzed using competing risk time-to-event and Poisson regression analyses to describe the nature and incidence of morbidity events and hospitalizations and identify factors associated with disease-related, treatment-related and overall morbidity. Morbidity was defined according to World Health Organization clinical staging criteria and U.S. National Institutes of Health Division of AIDS criteria.

    RESULTS: A total 3,448 PHIVA contributed 17,778 person-years. Median age at HIV diagnosis was 5.5 years, and ART initiation was 6.9 years. There were 2,562 morbidity events and 307 hospitalizations. Cumulative incidence for any morbidity was 51.7%, and hospitalization was 10.0%. Early adolescence was dominated by disease-related infectious morbidity, with a trend toward noninfectious and treatment-related morbidity in later adolescence. Higher overall morbidity rates were associated with a CD4 count <350 cells/µL, HIV viral load ≥10,000 copies/mL and experiencing prior morbidity at age <10 years. Lower overall morbidity rates were found for those 15-19 years of age compared with 10-14 years and those who initiated ART at age 5-9 years compared with <5 or ≥10 years.

    CONCLUSIONS: Half of our PHIVA cohort experienced a morbidity event, with a trend from disease-related infectious events to treatment-related and noninfectious events as PHIVA age. ART initiation to prevent immune system damage, optimize virologic control and minimize childhood morbidity are key to limiting adolescent morbidity.

    Matched MeSH terms: Viral Load
  19. Ku SW, Jiamsakul A, Joshi K, Pasayan MKU, Widhani A, Chaiwarith R, et al.
    J Int AIDS Soc, 2019 Mar;22(3):e25264.
    PMID: 30924281 DOI: 10.1002/jia2.25264
    INTRODUCTION: Cotrimoxazole (CTX) is recommended as prophylaxis against Pneumocystis jiroveci pneumonia, malaria and other serious bacterial infections in HIV-infected patients. Despite its in vitro activity against Mycobacterium tuberculosis, the effects of CTX preventive therapy on tuberculosis (TB) remain unclear.

    METHODS: Adults living with HIV enrolled in a regional observational cohort in Asia who had initiated combination antiretroviral therapy (cART) were included in the analysis. Factors associated with new TB diagnoses after cohort entry and survival after cART initiation were analysed using Cox regression, stratified by site.

    RESULTS: A total of 7355 patients from 12 countries enrolled into the cohort between 2003 and 2016 were included in the study. There were 368 reported cases of TB after cohort entry with an incidence rate of 0.99 per 100 person-years (/100 pys). Multivariate analyses adjusted for viral load (VL), CD4 count, body mass index (BMI) and cART duration showed that CTX reduced the hazard for new TB infection by 28% (HR 0.72, 95% CI l 0.56, 0.93). Mortality after cART initiation was 0.85/100 pys, with a median follow-up time of 4.63 years. Predictors of survival included age, female sex, hepatitis C co-infection, TB diagnosis, HIV VL, CD4 count and BMI.

    CONCLUSIONS: CTX was associated with a reduction in the hazard for new TB infection but did not impact survival in our Asian cohort. The potential preventive effect of CTX against TB during periods of severe immunosuppression should be further explored.

    Matched MeSH terms: Viral Load
  20. Abdul Ahmad SA, Palanisamy UD, Khoo JJ, Dhanoa A, Syed Hassan S
    Virol J, 2019 02 27;16(1):26.
    PMID: 30813954 DOI: 10.1186/s12985-019-1127-7
    BACKGROUND: Dengue continues to be a major international public health concern. Despite that, there is no clinically approved antiviral for treatment of dengue virus (DENV) infections. In this study, geraniin extracted from the rind of Nephelium lappaceum was shown to inhibit the replication of DENV-2 in both in vitro and in vivo experiments.

    METHODS: The effect of geraniin on DENV-2 RNA synthesis in infected Vero cells was tested using quantitative RT-PCR. The in vivo efficacy of geraniin in inhibiting DENV-2 infection was then tested using BALB/c mice with geraniin administered at three different times. The differences in spleen to body weight ratio, DENV-2 RNA load and liver damage between the three treatment groups as compared to DENV-2 infected mice without geraniin administration were determined on day eight post-infection.

    RESULTS: Quantitative RT-PCR confirmed the decrease in viral RNA synthesis of infected Vero cells when treated with geraniin. Geraniin seemed to provide a protective effect on infected BALB/c mice liver when given at 24 h pre- and 24 h post-infection as liver damage was observed to be very mild even though a significant reduction of DENV-2 RNA load in serum was not observed in these two treatment groups. However, when administered at 72 h post-infection, severe liver damage in the form of necrosis and haemorrhage had prevailed despite a substantial reduction of DENV-2 RNA load in serum.

    CONCLUSIONS: Geraniin was found to be effective in reducing DENV-2 RNA load when administered at 72 h post-infection while earlier administration could prevent severe liver damage caused by DENV-2 infection. These results provide evidence that geraniin is a potential candidate for the development of anti-dengue drug.

    Matched MeSH terms: Viral Load
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