Last data update: Jan 13, 2025. (Total: 48570 publications since 2009)
Records 1-30 (of 33 Records) |
Query Trace: Samandari T[original query] |
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Anti-inflammatory SARS-CoV-2 T cell immunity in asymptomatic seronegative Kenyan adults (preprint)
Samandari T , Ongalo J , McCarthy K , Biegon RK , Madiega P , Mithika A , Orinda J , Mboya GM , Mwaura P , Anzala O , Onyango C , Oluoch FO , Osoro E , Dutertre CA , Tan N , Hang SK , Hariharaputran S , Lye DC , Herman-Roloff A , Le Bert N , Bertoletti A . medRxiv 2023 18 Antibodies are used to estimate prevalence of past infection. However, T cell responses against SARSCoV-2 may more accurately define prevalence because SARS-CoV-2-specific antibodies wane. In November-December 2021, we studied serological and cellular immune responses in residents of rural Kenya who had not experienced any respiratory symptom nor had contact with COVID-19 cases. Among participants we detected anti-spike antibodies in 41.0% and T cell responses against >=2 SARSCoV-2 proteins in 82.5%, which implies that serosurveys underestimate SARS-CoV-2 prevalence in settings where asymptomatic infections prevail. Distinct from cellular immunity in European and Asian COVID-19 convalescents, strong T cell immunogenicity was observed against viral accessory proteins in these asymptomatic Africans, as well as a higher IL-10/IFN-gamma ratio cytokine profile, suggesting that environmental or genetic factors modulate pro-inflammatory responses. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available for use under a CC0 license. |
Randomized controlled phase IIa clinical trial of safety, pharmacokinetics and pharmacodynamics of tenofovir and tenofovir plus levonorgestrel releasing intravaginal rings used by women in Kenya
Mugo NR , Mudhune V , Heffron R , Thomas KK , McLellan-Lemal E , Njoroge B , Peacock S , O'Connor SM , Nyagol B , Ouma E , Ridzon R , Wiener J , Isoherranen N , Erikson DW , Ouattara LA , Yousefieh N , Jacot TA , Haaland RE , Morrison SA , Haugen HS , Thurman AR , Allen SA , Baeten JM , Samandari T , Doncel GF . Front Reprod Health 2023 5 1118030 INTRODUCTION: Globally, many young women face the overlapping burden of HIV infection and unintended pregnancy. Protection against both may benefit from safe and effective multipurpose prevention technologies. METHODS: Healthy women ages 18-34 years, not pregnant, seronegative for HIV and hepatitis B surface antigen, not using hormonal contraception, and at low risk for HIV were randomized 2:2:1 to continuous use of a tenofovir/levonorgestrel (TFV/LNG), TFV, or placebo intravaginal ring (IVR). In addition to assessing genital and systemic safety, we determined TFV concentrations in plasma and cervicovaginal fluid (CVF) and LNG levels in serum using tandem liquid chromatography-mass spectrometry. We further evaluated TFV pharmacodynamics (PD) through ex vivo CVF activity against both human immunodeficiency virus (HIV)-1 and herpes simplex virus (HSV)-2, and LNG PD using cervical mucus quality markers and serum progesterone for ovulation inhibition. RESULTS: Among 312 women screened, 27 were randomized to use one of the following IVRs: TFV/LNG (n = 11); TFV-only (n = 11); or placebo (n = 5). Most screening failures were due to vaginal infections. The median days of IVR use was 68 [interquartile range (IQR), 36-90]. Adverse events (AEs) were distributed similarly among the three arms. There were two non-product related AEs graded >2. No visible genital lesions were observed. Steady state geometric mean amount (ssGMA) of vaginal TFV was comparable in the TFV/LNG and TFV IVR groups, 43,988 ng/swab (95% CI, 31,232, 61,954) and 30337 ng/swab (95% CI, 18,152, 50,702), respectively. Plasma TFV steady state geometric mean concentration (ssGMC) was <10 ng/ml for both TFV IVRs. In vitro, CVF anti-HIV-1 activity showed increased HIV inhibition over baseline following TFV-eluting IVR use, from a median of 7.1% to 84.4% in TFV/LNG, 15.0% to 89.5% in TFV-only, and -27.1% to -20.1% in placebo participants. Similarly, anti-HSV-2 activity in CVF increased >50 fold after use of TFV-containing IVRs. LNG serum ssGMC was 241 pg/ml (95% CI 185, 314) with rapid rise after TFV/LNG IVR insertion and decline 24-hours post-removal (586 pg/ml [95% CI 473, 726] and 87 pg/ml [95% CI 64, 119], respectively). CONCLUSION: TFV/LNG and TFV-only IVRs were safe and well tolerated among Kenyan women. Pharmacokinetics and markers of protection against HIV-1, HSV-2, and unintended pregnancy suggest the potential for clinical efficacy of the multipurpose TFV/LNG IVR. CLINICAL TRIAL REGISTRATION: NCT03762382 [https://clinicaltrials.gov/ct2/show/NCT03762382]. |
Prevalence and functional profile of SARS-CoV-2 T cells in asymptomatic Kenyan adults
Samandari T , Ongalo J , McCarthy K , Biegon RK , Madiega P , Mithika A , Orinda J , Mboya GM , Mwaura P , Anzala O , Onyango C , Oluoch FO , Osoro EM , Dutertre CA , Tan N , Hang SK , Hariharaputran S , Lye DC , Herman-Roloff A , Le Bert N , Bertoletti A . J Clin Invest 2023 133 (13) BACKGROUND: SARS-CoV-2 infection in Africa has been characterized by less severe disease than elsewhere but the profile of SARS-CoV-2 specific adaptive immunity in this largely asymptomatic spread has not been studied. METHODS: We collected blood and nasopharyngeal samples from rural Kenyans (n=80) without respiratory symptoms since 2019, had no contact with COVID-19 cases or received COVID-19 vaccines and were negative for current SARS-CoV-2 infection. We analyzed spike-specific antibodies and T cells specific for SARS-CoV-2 structural (membrane, nucleocapsid and spike) and accessory (ORF3a, ORF7, ORF8) proteins. Pre-pandemic samples collected in urban Nairobi, Kenya (n=13) between 2015-2016 and samples of mild-moderately symptomatic COVID-19 convalescents (n=36) living in the urban environment of Singapore were also studied. RESULTS: Among asymptomatic Kenyans, we detected anti-spike antibodies in 41.0% and T cell responses against ≥2 SARS-CoV-2 proteins in 82.5%. The pre-pandemic samples from Nairobi had low-level, monospecific responses. Furthermore, distinct from cellular immunity in European and Asian COVID-19 convalescents, strong T cell immunogenicity was observed against viral accessory proteins (ORF3a, ORF8) and not structural proteins, as well as a higher IL-10/IFN-γ ratio cytokine profile. CONCLUSIONS: The high incidence of T cell responses against different SARS-CoV-2 proteins in largely seronegative participants suggests that serosurveys underestimate SARS-CoV-2 prevalence in settings where asymptomatic infections prevail. Similar observations have been made with other coronavirus infections such as MERS and SARS-CoV-1. The functional and antigen-specific profile of SARS-CoV-2 specific T cells in these African individuals suggests that genetic or environmental factors play a role in the development of protective antiviral immunity. FUNDINGS: U.S. Centers for Disease Control and Prevention, Division of Global Health Protection; the Singapore Ministry of Health's National Medical Research Council. |
Non-adherence among women enrolled in a contraceptive vaginal ring use study in Kisumu, Kenya, 2014-2015
McLellan-Lemal E , Gvetadze R , Desai MA , Makanga EM , Pan Y , Haaland RE , Holder AN , Mudhune V , Williams T , Samandari T . J Glob Health Rep 2018 2 BACKGROUND: Given future potential use of vaginal rings to prevent HIV infection, we examined the association of contraceptive vaginal ring (CVR) non-adherence with user dissatisfaction, tolerability, demographic, and behavioral factors. METHODS: In an open-label single-group study, sexually active women aged 18-34 years using oral or injectable hormonal contraception, conveniently sampled from general population, were assigned to 6-month use of a commercial CVR currently not licensed for use in Kenya. Non-adherence in any CVR cycle completed was assessed from: (1) self-report (not used for at least 1 day), and (2) pharmacy record (failure to timely receive a new CVR or return a used one). Additionally, non-adherence was assessed in a subset of participants by residual progestin and estrogen levels measured in returned CVRs. RESULTS: Of 202 participants who underwent CVR insertion by a study clinician, 142 completed all 6 visits, 172 responded to questions about ring use, and 43 provided used CVRs from months 1, 3, and 6 for residual hormone analysis. Non-adherence was 14.0% (24/172) by self-report and 54.5% (110/202) by pharmacy record. Non-adherence by pharmacy record was significantly reduced among women with a salary-based income (prevalence ratio (PR) 0.71, 95% confidence interval (CI) (0.55-0.91)] compared to women with income not salary-based or no income. Participants dissatisfied with CVR on ≥4 aspects (ambiguity of instructions, inconvenience of use, sensation, sexual discomfort, etc.) were more likely to report non-adherence (PR 2.69, 95% CI=(1.31-5.52)] compared to those dissatisfied with ≤3 aspects. Non-adherence by residual hormone levels was identified in 46.5% (20/43) participants. Over time, this subset of participants showed increasing non-adherence (P=0.004). We found lack of agreement among the various measures of non-adherence. CONCLUSIONS: Economic empowerment interventions, especially those emphasizing partner-independent income options, and expanded education on CVR features may alleviate non-adherence. Addressing CVR dissatisfaction preemptively may also help mitigate non-adherence. |
The Cooperative Re-Engagement Controlled Trial (CoRECT): Durable viral suppression assessment
O'Shea J , Fanfair RN , Williams T , Khalil G , Brady KA , DeMaria A Jr , Villanueva M , Randall LM , Jenkins H , Altice FL , Camp N , Lucas C , Buchelli M , Samandari T , Weidle PJ . J Acquir Immune Defic Syndr 2023 93 (2) 134-142 BACKGROUND: A collaborative, data-to-care strategy to identify persons with HIV (PWH) newly out-of-care, combined with an active public health intervention, significantly increases the proportion of PWH re-engaged in HIV care. We assessed this strategy's impact on durable viral suppression (DVS). METHODS: A multi-site, prospective randomized controlled trial for out-of-care individuals using a data-to-care strategy and comparing public health field services to locate, contact, and facilitate access to care versus the standard of care (SOC). DVS was defined as the last viral load (VL), the VL at least three months prior, and any VL between the two were all <200 copies/mL during the 18 months post-randomization. Alternative definitions of DVS were also analyzed. RESULTS: Between August 1, 2016 - July 31, 2018, 1,893 participants were randomized from Connecticut (CT) (n=654), Massachusetts (MA) (n=630), and Philadelphia (PHL) (n=609). Rates of achieving DVS were similar in the intervention and SOC arms in all jurisdictions (All sites: 43.4% vs 42.4%, p=0.67; CT: 46.7% vs 45.0%, p=0.67; MA: 40.7 vs 44.4%, p=0.35; PHL: 42.4% vs 37.3%, p=0.20). There was no association between DVS and the intervention (RR:1.01, CI: 0.91-1.12; p=0.85) adjusting for site, age categories, race/ethnicity, birth sex, CD4 categories, and exposure categories. CONCLUSION: A collaborative, data-to-care strategy, and active public health intervention did not increase the proportion of PWH achieving DVS suggesting additional support to promote retention in care and antiretroviral adherence may be needed. Initial linkage and engagement services, through data-to-care or other means, are likely necessary but insufficient for achieving DVS for all PWH. |
Diagnostic accuracy of the Panbio COVID-19 antigen rapid test device for SARS-CoV-2 detection in Kenya, 2021: A field evaluation
Irungu JK , Munyua P , Ochieng C , Juma B , Amoth P , Kuria F , Kiiru J , Makayotto L , Abade A , Bulterys M , Hunsperger E , Emukule GO , Onyango C , Samandari T , Barr BAT , Akelo V , Weyenga H , Munywoki PK , Bigogo G , Otieno NA , Kisivuli JA , Ochieng E , Nyaga R , Hull N , Herman-Roloff A , Aman R . PLoS One 2023 18 (1) e0277657 BACKGROUND: Accurate and timely diagnosis is essential in limiting the spread of SARS-CoV-2 infection. The reference standard, rRT-PCR, requires specialized laboratories, costly reagents, and a long turnaround time. Antigen RDTs provide a feasible alternative to rRT-PCR since they are quick, relatively inexpensive, and do not require a laboratory. The WHO requires that Ag RDTs have a sensitivity ≥80% and specificity ≥97%. METHODS: This evaluation was conducted at 11 health facilities in Kenya between March and July 2021. We enrolled persons of any age with respiratory symptoms and asymptomatic contacts of confirmed COVID-19 cases. We collected demographic and clinical information and two nasopharyngeal specimens from each participant for Ag RDT testing and rRT-PCR. We calculated the diagnostic performance of the Panbio™ Ag RDT against the US Centers for Disease Control and Prevention's (CDC) rRT-PCR test. RESULTS: We evaluated the Ag RDT in 2,245 individuals where 551 (24.5%, 95% CI: 22.8-26.3%) tested positive by rRT-PCR. Overall sensitivity of the Ag RDT was 46.6% (95% CI: 42.4-50.9%), specificity 98.5% (95% CI: 97.8-99.0%), PPV 90.8% (95% CI: 86.8-93.9%) and NPV 85.0% (95% CI: 83.4-86.6%). Among symptomatic individuals, sensitivity was 60.6% (95% CI: 54.3-66.7%) and specificity was 98.1% (95% CI: 96.7-99.0%). Among asymptomatic individuals, sensitivity was 34.7% (95% CI 29.3-40.4%) and specificity was 98.7% (95% CI: 97.8-99.3%). In persons with onset of symptoms <5 days (594/876, 67.8%), sensitivity was 67.1% (95% CI: 59.2-74.3%), and 53.3% (95% CI: 40.0-66.3%) among those with onset of symptoms >7 days (157/876, 17.9%). The highest sensitivity was 87.0% (95% CI: 80.9-91.8%) in symptomatic individuals with cycle threshold (Ct) values ≤30. CONCLUSION: The overall sensitivity and NPV of the Panbio™ Ag RDT were much lower than expected. The specificity of the Ag RDT was high and satisfactory; therefore, a positive result may not require confirmation by rRT-PCR. The kit may be useful as a rapid screening tool only for symptomatic patients in high-risk settings with limited access to rRT-PCR. A negative result should be interpreted based on clinical and epidemiological information and may require retesting by rRT-PCR. |
Adapting Longstanding Public Health Collaborations between Government of Kenya and CDC Kenya in Response to the COVID-19 Pandemic, 2020-2021.
Herman-Roloff A , Aman R , Samandari T , Kasera K , Emukule GO , Amoth P , Chen TH , Kisivuli J , Weyenga H , Hunsperger E , Onyango C , Juma B , Munyua P , Wako D , Akelo V , Kimanga D , Ndegwa L , Mohamed AA , Okello P , Kariuki S , DeCock KM , Bulterys M . Emerg Infect Dis 2022 28 (13) S159-s167 Kenya's Ministry of Health (MOH) and the US Centers for Disease Control and Prevention in Kenya (CDC Kenya) have maintained a 40-year partnership during which measures were implemented to prevent, detect, and respond to disease threats. During the COVID-19 pandemic, the MOH and CDC Kenya rapidly responded to mitigate disease impact on Kenya's 52 million residents. We describe activities undertaken jointly by the MOH and CDC Kenya that lessened the effects of COVID-19 during 5 epidemic waves from March through December 2021. Activities included establishing national and county-level emergency operations centers and implementing workforce development and deployment, infection prevention and control training, laboratory diagnostic advancement, enhanced surveillance, and information management. The COVID-19 pandemic provided fresh impetus for the government of Kenya to establish a national public health institute, launched in January 2022, to consolidate its public health activities and counter COVID-19 and future infectious, vaccine-preventable, and emerging zoonotic diseases. |
Impact of viral suppression among persons with HIV upon estimated HIV incidence between 2010 and 2015 in the United States
Samandari T , Wiener J , Huang YA , Hoover KW , Siddiqi AE . PLoS One 2020 15 (10) e0240727 BACKGROUND: The suppression of viremia among persons with HIV (PWH) using antiretroviral therapy has been hypothesized to reduce HIV incidence at the population level. We investigated the impact of state level viral suppression among PWH in the United States on estimated HIV incidence between 2010 and 2015. METHODS: Viral suppression data and HIV incidence estimates from the National HIV Surveillance System were available from 29 states and the District of Columbia. We assumed a one year delay for viral suppression to impact incidence. Poisson regression models were used to calculate the estimated annual percent change (EAPC) in incidence rate. We employed a multivariable mixed-effects Poisson regression model to assess the effects of state level race/ethnicity, socioeconomic status, percent men who have sex with men (MSM) and hepatitis C virus prevalence as a proxy for injection drug use on HIV incidence. FINDINGS: Fitted HIV incidence for 30 jurisdictions declined from 11.5 in 2010 to 10.0 per 100,000 population by 2015 corresponding with an EAPC of -2.67 (95% confidence interval [95%CI] -2.95, -2.38). Southern states experienced the highest estimated incidence by far throughout this period but upon adjustment for viral suppression and demographics there was a 36% lower incidence rate than Northeast states (adjusted rate ratio [aRR] 0.64; 95%CI 0.42, 0.99). For every 10 percentage point (pp) increase in viral suppression there was an adjusted 4% decline in HIV incidence rate in the subsequent year (aRR 0.96; 95%CI 0.93, 0.99). While controlling for viral suppression, HIV incidence rate increased by 42% (aRR 1.42 95%CI 1.31, 1.54) for every 5 pp increase in percent Black race and by 27% (aRR 1.27 95%CI 1.10, 1.48) for every 1 pp increase in percent MSM in states. INTERPRETATION: A decline in estimated HIV incidence from 2010 to 2015 was associated with increasing viral suppression in the United States. Race and sexual orientation were important HIV acquisition risk factors. |
HIV prescriptions on the frontlines: Primary care providers' use of antiretrovirals for prevention in the Southeast United States, 2017
Henny KD , Duke CC , Buchacz K , Brooks JT , Samandari T , Sutton MY . Prev Med 2019 130 105875 HIV disproportionately affects persons in Southeast United States. Primary care providers (PCPs) are vital for HIV prevention. Data are limited about their prescribing of antiretrovirals (ARVs) for prevention, including non-occupational post-exposure prophylaxis (nPEP), pre-exposure prophylaxis (PrEP), and antiretroviral therapy (ART). We examined these practices to assess gaps. During April-August 2017, we conducted an online survey of PCPs in Atlanta, Baltimore, Baton Rouge, Miami, New Orleans, and Washington, DC to assess HIV-related knowledge, attitudes and practices. Adjusted prevalence ratios (aPR) and 95% confidence intervals (CI) were used to estimate correlates of nPEP, PrEP and ART prescribing practices. Adjusting for MSA and specialty, the weighted sample (n=820, 29.6% adjusted response rate) comprised 60.2% white and 59.4% females. PCPs reported ever prescribing nPEP (31.0%), PrEP (18.1%), and ART (27.2%). Prescribing nPEP was associated with nPEP familiarity (aPR=2.63, 95% CI 1.59, 4.35) and prescribing PrEP (aPR=3.57, 95% CI 2.78, 4.55). Prescribing PrEP was associated with PrEP familiarity (aPR=4.35, 95% CI 2.63, 7.14), prescribing nPEP (aPR=5.00, 95% CI 2.00, 12.50), and providing care for persons with HIV (aPR=1.56, 95% CI 1.06, 2.27). Prescribing ART was associated with nPEP familiarity (aPR=1.89, 95% CI 1.27, 2.78) and practicing in outpatient public practice versus hospital-based facilities (aPR=2.14 95% CI 1.51, 3.04), and inversely associated with collaborations involving specialists (aPR=0.60, 95% CI 0.42, 0.86). A minority of PCPs surveyed from the Southeast report ever prescribing ARVs for prevention. Future efforts should include enhancing HIV care coordination and developing strategies to increase use of biomedical tools. |
Laboratory testing of a cohort of commercially insured users of HIV preexposure prophylaxis in the United States, 2011-2015
Huang YA , Tao G , Samandari T , Hoover KW . J Infect Dis 2017 217 (4) 617-621 To ensure the health and safety of persons taking antiretroviral medication for HIV preexposure prophylaxis (PrEP), CDC guidelines recommend initial and follow-up laboratory testing. We assessed the rates of recommended testing using a commercial insurance claims database. Before taking PrEP, 45% of users were tested for HIV, 31% for creatinine, 55% for syphilis, 43% for chlamydia/gonorrhea, and 38% for hepatitis B. By 6 months after PrEP initiation, 38% were tested for HIV, 37% for creatinine, 49% for syphilis, and 39% for chlamydia/gonorrhea. Although laboratory testing was less frequent than recommended, testing rates increased over the study period. |
Incidence of hepatitis C virus infection in the Human Immunodeficiency Virus Outpatient Study Cohort, 2000-2013
Samandari T , Tedaldi E , Armon C , Hart R , Chmiel JS , Brooks JT , Buchacz K . Open Forum Infect Dis 2017 4 (2) ofx076 BACKGROUND: There are few recent studies of incident hepatitis C virus (HCV) infection among human immunodeficiency virus (HIV)-infected patients in the United States. METHODS: We studied HIV Outpatient Study (HOPS) participants seen in 9 HIV-specialty clinics who had ≥1 clinical encounter during 2000-2013 and ≥2 HCV-related tests, the first of which was a negative HCV antibody test (Ab). Hepatitis C virus incident cases were identified by first positive HCV Ab, viral load, or genotype. We assessed rates of incident HCV overall, by calendar intervals, and by demographic and HIV risk strata, and we explored risk factors for incident HCV using Cox proportional hazards models. RESULTS: The 1941 eligible patients (median age 40 years, 23% female, 61% men who had sex with men [MSM], and 3% persons who injected drugs [PWID]) experienced 102 (5.3%) incident HCV infections for an overall incidence of 1.07 (95% confidence interval [CI], 0.87-1.30) per 100 person-years (py). Hepatitis C virus incidence decreased from 1.83 in 2000-2003 to 0.88 in 2011-2013 (P = .024), with decreases observed (P < .05) among PWID and heterosexuals, but not among MSM. Overall, MSM comprised 59% of incident cases, and PWID were at most risk for incident HCV infection (adjusted hazard ratio [aHR] for PWID = 4.62 and 95% CI = 2.11-10.13; for MSM, aHR = 1.48 and 95% CI = 0.86-2.55 compared with heterosexuals). CONCLUSIONS: Among HIV-infected patients in care during 2000-2013, incidence of HCV infection exceeded 1 case per 100 py. Our findings support recommendations for annual HCV screenings for HIV-infected persons, including persons with only MSM risk, to enable HCV diagnosis and treatment for coinfected individuals. |
Antiretroviral drugs as the linchpin for prevention of HIV infections in the United States
Samandari T , Harris N , Cleveland JC , Purcell DW , McCray E . Am J Public Health 2017 107 (10) 1577-1579 Recent advances in the use of antiretroviral drugs for the prevention of HIV infection present a historic opportunity to better control the spread of the disease. Despite an estimated 18% decline in the number of annual HIV infections between 2008 and 2014 (http://bit.ly/2ftovat), there were approximately 38 000 new infections in 2014, 70% of which were among men who have sex with men (MSM). As a consequence of improved survival with antiretroviral therapy (ART), the number of persons living with HIV has increased to 1.1 million. However, all of these persons are a potential source of new infections to their partners, particularly the 15% who do not know that they are infected, as well as those who know their HIV status but have not achieved a suppressed viral load (i.e., as a result of ART). Each infected person incurs $402 000 in discounted lifetime costs.1 |
Effect of point-of-care CD4 cell count results on linkage to care and antiretroviral initiation during a home-based HIV testing campaign: a non-blinded, cluster-randomised trial
Desai MA , Okal DO , Rose CE , Ndivo R , Oyaro B , Otieno FO , Williams T , Chen RT , Zeh C , Samandari T . Lancet HIV 2017 4 (9) e393-e401 BACKGROUND: HIV disease staging with referral laboratory-based CD4 cell count testing is a key barrier to the initiation of antiretroviral treatment (ART). Point-of-care CD4 cell counts can improve linkage to HIV care among people living with HIV, but its effect has not been assessed with a randomised controlled trial in the context of home-based HIV counselling and testing (HBCT). METHODS: We did a two-arm, cluster-randomised, controlled efficacy trial in two districts of western Kenya with ongoing HBCT. Housing compounds were randomly assigned (1:1) to point-of-care CD4 cell counts (366 compounds with 417 participants) or standard-of-care (318 compounds with 353 participants) CD4 cell counts done at one of three referral laboratories serving the study catchment area. In each compound, we enrolled people with HIV not engaged in care in the previous 6 months. All participants received post-test counselling and referral for HIV care. Point-of-care test participants received additional counselling on the result, including ART eligibility if CD4 was less than 350 cells per muL, the cutoff in Kenyan guidelines. Participants were interviewed 6 months after enrolment to ascertain whether they sought HIV care, verified through chart reviews at 23 local clinics. The prevalence of loss to follow-up at 6 months (LTFU) was listed as the main outcome in the study protocol. We analysed linkage to care at 6 months (defined as 1-LTFU) as the primary outcome. All analyses were by intention to treat. This trial is registered at ClinicalTrials.gov, number NCT02515149. FINDINGS: We enrolled 770 participants between July 1, 2013, and Feb 28, 2014. 692 (90%) had verified linkage to care status and 78 (10%) were lost to follow-up. Of 371 participants in the point-of-care group, 215 (58%) had linked to care within 6 months versus 108 (34%) of 321 in the standard-of-care group (Cox proportional multivariable hazard ratio [HR] 2.14, 95% CI 1.67-2.74; log rank p<0.0001). INTERPRETATION: Point-of-care CD4 cell counts in a resource-limited HBCT setting doubled linkage to care and thereby improved ART initiation. Given the substantial economic and logistic hindrances to providing ART for all people with HIV in resource-limited settings in the near term, point of care CD4 cell counts might have a role in prioritising care and improving linkage to care. FUNDING: US Centers for Disease Control and Prevention. |
Analysis of false-negative HIV rapid tests performed on oral fluid in three international clinical research studies
Curlin ME , Gvetadze R , Leelawiwat W , Martin M , Rose C , Niska RW , Segolodi TM , Choopanya K , Tongtoyai J , Holtz TH , Samandari T , McNicholl JM . Clin Infect Dis 2017 64 (12) 1663-1669 Objective: The OraQuick Advance Rapid HIV-1/2 Test is a point-of-care test capable of detecting HIV-specific antibodies in blood and oral fluid. To understand test performance and factors contributing to false-negative (FN) results in longitudinal studies, we examined results of participants enrolled in the TDF2 study, the Bangkok Tenofovir Study, and the Bangkok MSM Cohort Study (BMCS), three separate clinical studies of high-risk, HIV-negative persons conducted in Botswana and Thailand. Design: Retrospective observational analysis. Methods: We compared oral fluid OraQuick (OFOQ) results among participants becoming HIV-infected to results obtained retrospectively using enzyme immunoassay and nucleic acid amplification tests on stored specimens. We categorized negative OFOQ results as true-negative or false-negative relative to NAAT and/or EIA, and determined the delay in OFOQ conversion relative to the estimated time of infection. We used generalized estimating equations to examine the association between FN results and participant, clinical and testing-site factors. Results: Two-hundred and thirty-three FN OFOQ results occurred in 80 of 287 seroconverting individuals. Estimated OFOQ conversion delay ranged from 14.5-547.5 (median 98.5) days. Delayed OFOQ conversion was associated with clinical site and test operator (p<0.05), pre-exposure prophylaxis (p=0.01), low plasma viral load (p<0.02) and time to kit expiration (p<0.01). Participant age, gender, and HIV subtype were not associated with FN results. Long OFOQ conversion delay time was associated with antiretroviral exposure and low PVL. Conclusions: Failure of OFOQ to detect HIV-1 infection was frequent, and multifactorial in origin. In longitudinal trials, negative oral fluid results should be confirmed by testing blood samples. |
Factors associated with the uptake of and adherence to HIV pre-exposure prophylaxis in people who have injected drugs: an observational, open-label extension of the Bangkok Tenofovir Study
Martin M , Vanichseni S , Suntharasamai P , Sangkum U , Mock PA , Chaipung B , Worrajittanon D , Leethochawalit M , Chiamwongpaet S , Kittimunkong S , Gvetadze RJ , McNicholl JM , Paxton LA , Curlin ME , Holtz TH , Samandari T , Choopanya K . Lancet HIV 2016 4 (2) e59-e66 BACKGROUND: Results of the randomised, double-blind, placebo-controlled Bangkok Tenofovir Study (BTS) showed that taking tenofovir daily as pre-exposure prophylaxis (PrEP) can reduce the risk of HIV infection by 49% in people who inject drugs. In an extension to the trial, participants were offered 1 year of open-label tenofovir. We aimed to examine the demographic characteristics, drug use, and risk behaviours associated with participants' uptake of and adherence to PrEP. METHODS: In this observational, open-label extension of the BTS (NCT00119106), non-pregnant, non-breastfeeding, HIV-negative BTS participants, all of whom were current or previous injecting drug users at the time of enrolment in the BTS, were offered daily oral tenofovir (300 mg) for 1 year at 17 Bangkok Metropolitan Administration drug-treatment clinics. Participant demographics, drug use, and risk behaviours were assessed at baseline and every 3 months using an audio computer-assisted self-interview. HIV testing was done monthly and serum creatinine was assessed every 3 months. We used logistic regression to examine factors associated with the decision to take daily tenofovir as PrEP, the decision to return for at least one PrEP follow-up visit, and greater than 90% adherence to PrEP. FINDINGS: Between Aug 1, 2013, and Aug 31, 2014, 1348 (58%) of the 2306 surviving BTS participants returned to the clinics, 33 of whom were excluded because they had HIV (n=27) or grade 2-4 creatinine results (n=6). 798 (61%) of the 1315 eligible participants chose to start open-label PrEP and were followed up for a median of 335 days (IQR 0-364). 339 (42%) participants completed 12 months of follow-up; 220 (28%) did not return for any follow-up visits. Participants who were 30 years or older (odds ratio [OR] 1.8, 95% CI 1.4-2.2; p<0.0001), injected heroin (OR 1.5, 1.1-2.1; p=0.007), or had been in prison (OR 1.7, 1.3-2.1; p<0.0001) during the randomised trial were more likely to choose PrEP than were those without these characteristics. Participants who reported injecting heroin or being in prison during the 3 months before open-label enrolment were more likely to return for at least one open-label follow-up visit than those who did not report injecting heroin (OR 3.0, 95 % CI 1.3-7.3; p=0.01) or being in prison (OR 2.3, 1.4-3.7; p=0.0007). Participants who injected midazolam or were in prison during open-label follow-up were more likely to be greater than 90% adherent than were those who did not inject midazolam (OR 2.2, 95% CI 1.2-4.3; p=0.02) or were not in prison (OR 4.7, 3.1-7.2; p<0.0001). One participant tested positive for HIV, yielding an HIV incidence of 2.1 (95% CI 0.05-11.7) per 1000 person-years. No serious adverse events related to tenofovir use were reported. INTERPRETATION: More than 60% of returning, eligible BTS participants started PrEP, which indicates that a substantial proportion of PWID who are knowledgeable about PrEP might be interested in taking it. Participants who had injected heroin or been in prison were more likely to choose to take PrEP, suggesting that participants based their decision to take PrEP, at least in part, on their perceived risk of incident HIV infection. FUNDING: US Centers for Disease Control and Prevention and the Bangkok Metropolitan Administration. |
HIV Infection Linked to Injection Use of Oxymorphone in Indiana, 2014-2015.
Peters PJ , Pontones P , Hoover KW , Patel MR , Galang RR , Shields J , Blosser SJ , Spiller MW , Combs B , Switzer WM , Conrad C , Gentry J , Khudyakov Y , Waterhouse D , Owen SM , Chapman E , Roseberry JC , McCants V , Weidle PJ , Broz D , Samandari T , Mermin J , Walthall J , Brooks JT , Duwve JM . N Engl J Med 2016 375 (3) 229-39 Background In January 2015, a total of 11 new diagnoses of human immunodeficiency virus (HIV) infection were reported in a small community in Indiana. We investigated the extent and cause of the outbreak and implemented control measures. Methods We identified an outbreak-related case as laboratory-confirmed HIV infection newly diagnosed after October 1, 2014, in a person who either resided in Scott County, Indiana, or was named by another case patient as a syringe-sharing or sexual partner. HIV polymerase (pol) sequences from case patients were phylogenetically analyzed, and potential risk factors associated with HIV infection were ascertained. Results From November 18, 2014, to November 1, 2015, HIV infection was diagnosed in 181 case patients. Most of these patients (87.8%) reported having injected the extended-release formulation of the prescription opioid oxymorphone, and 92.3% were coinfected with hepatitis C virus. Among 159 case patients who had an HIV type 1 pol gene sequence, 157 (98.7%) had sequences that were highly related, as determined by phylogenetic analyses. Contact tracing investigations led to the identification of 536 persons who were named as contacts of case patients; 468 of these contacts (87.3%) were located, assessed for risk, tested for HIV, and, if infected, linked to care. The number of times a contact was named as a syringe-sharing partner by a case patient was significantly associated with the risk of HIV infection (adjusted risk ratio for each time named, 1.9; P<0.001). In response to this outbreak, a public health emergency was declared on March 26, 2015, and a syringe-service program in Indiana was established for the first time. Conclusions Injection-drug use of extended-release oxymorphone within a network of persons who inject drugs in Indiana led to the introduction and rapid transmission of HIV. (Funded by the state government of Indiana and others.). |
Characteristics of women screened for a contraceptive intravaginal ring study in Kisumu, Kenya, 2014
McLellan-Lemal E , Gust DA , Gvetadze R , Furtado M , Otieno FO , Desai M , Zeh C , Samandari T , Nyagol B , Makanga EM . Res J Womens Health 2016 3 (1) BACKGROUND: HIV antiretroviral-based intravaginal rings with and without co-formulated contraception hold promise for increasing HIV prevention options for women. Acceptance of and ability to correctly and consistently use this technology may create challenges for future ring-based microbicide trials in settings where this technology has not been introduced. We examined baseline factors associated with enrolling in a contraceptive intravaginal ring study in Kisumu, Kenya and describe notional acceptability (willingness to switch to a contraceptive ring based solely on information received about it). METHODS: Demographic, psychosocial, and behavioral eligibility screening of women 18-34 years was undertaken. Testing for pregnancy, HIV, and other sexually transmitted infections (STIs) was also conducted. We compared enrollment status across groups of categorical predictors using prevalence ratios (PR) and 95% confidence interval (CI) estimates obtained from a log-binomial regression model. RESULTS: Out of 692 women pre-screened April to November 2014, 463 completed screening, and 302 women were enrolled. Approximately 97% of pre-screened women were willing to switch from their current contraceptive method to use the intravaginal ring exclusively for the 6-month intervention period. Pregnancy, HIV, and STI prevalence were 1.7%, 14.5%, and 70.4% respectively for the 463 women screened. Women 18-24 (PR=1.47, CI 1.15-1.88) were more likely to be enrolled than those 30-34 years of age, as were married/cohabitating women (PR=1.62, CI 1.22-2.16) compared to those separated, divorced, or widowed. In adjusted analyses, sexual debut at less than 17 years of age, one lifetime sexual partner, abnormal vaginal bleeding in the past 12 months, condomless vaginal or anal sex in the past 3 months, and not having a sexual partner of unknown HIV status in the past 3 months were predictive of enrollment. CONCLUSION: High notional acceptability suggests feasibility for contraceptive intravaginal ring use. Factors associated with ring use initiation and 6-month use will need to be assessed. |
Screening yield of HIV antigen/antibody combination and pooled HIV RNA testing for acute HIV infection in a high-prevalence population
Peters PJ , Westheimer E , Cohen S , Hightow-Weidman LB , Moss N , Tsoi B , Hall L , Fann C , Daskalakis DC , Beagle S , Patel P , Radix A , Foust E , Kohn RP , Marmorino J , Pandori M , Fu J , Samandari T , Gay CL . JAMA 2016 315 (7) 682-90 IMPORTANCE: Although acute HIV infection contributes disproportionately to onward HIV transmission, HIV testing has not routinely included screening for acute HIV infection. OBJECTIVE: To evaluate the performance of an HIV antigen/antibody (Ag/Ab) combination assay to detect acute HIV infection compared with pooled HIV RNA testing. DESIGN, SETTING, AND PARTICIPANTS: Multisite, prospective, within-individual comparison study conducted between September 2011 and October 2013 in 7 sexually transmitted infection clinics and 5 community-based programs in New York, California, and North Carolina. Participants were 12 years or older and seeking HIV testing, without known HIV infection. EXPOSURES: All participants with a negative rapid HIV test result were screened for acute HIV infection with an HIV Ag/Ab combination assay (index test) and pooled human immunodeficiency virus 1 (HIV-1) RNA testing. HIV RNA testing was the reference standard, with positive reference standard result defined as detectable HIV-1 RNA on an individual RNA test. MAIN OUTCOMES AND MEASURES: Number and proportion with acute HIV infections detected. RESULTS: Among 86,836 participants with complete test results (median age, 29 years; 75.0% men; 51.8% men who have sex with men), established HIV infection was diagnosed in 1158 participants (1.33%) and acute HIV infection was diagnosed in 168 participants (0.19%). Acute HIV infection was detected in 134 participants with HIV Ag/Ab combination testing (0.15% [95% CI, 0.13%-0.18%]; sensitivity, 79.8% [95% CI, 72.9%-85.6%]; specificity, 99.9% [95% CI, 99.9%-99.9%]; positive predictive value, 59.0% [95% CI, 52.3%-65.5%]) and in 164 participants with pooled HIV RNA testing (0.19% [95% CI, 0.16%-0.22%]; sensitivity, 97.6% [95% CI, 94.0%-99.4%]; specificity, 100% [95% CI, 100%-100%]; positive predictive value, 96.5% [95% CI, 92.5%-98.7%]; sensitivity comparison, P < .001). Overall HIV Ag/Ab combination testing detected 82% of acute HIV infections detectable by pooled HIV RNA testing. Compared with rapid HIV testing alone, HIV Ag/Ab combination testing increased the relative HIV diagnostic yield (both established and acute HIV infections) by 10.4% (95% CI, 8.8%-12.2%) and pooled HIV RNA testing increased the relative HIV diagnostic yield by 12.4% (95% CI, 10.7%-14.3%). CONCLUSIONS AND RELEVANCE: In a high-prevalence population, HIV screening using an HIV Ag/Ab combination assay following a negative rapid test detected 82% of acute HIV infections detectable by pooled HIV RNA testing, with a positive predictive value of 59%. Further research is needed to evaluate this strategy in lower-prevalence populations and in persons using preexposure prophylaxis for HIV prevention. |
Cost-Effectiveness of Antiretroviral Therapy and Isoniazid Prophylaxis to Reduce Tuberculosis and Death in People Living With HIV in Botswana
Smith T , Samandari T , Abimbola T , Marston B , Sangrujee N . J Acquir Immune Defic Syndr 2015 70 (3) e84-93 OBJECTIVE: In Botswana, a 36-month course of isoniazid treatment for latent tuberculosis (TB) infection (IPT) was superior to 6-month IPT in reducing TB and death in persons living with HIV (PLHIV) having positive tuberculin skin-tests (TST) but not in those with negative TST. We examined the cost-effectiveness of IPT in Botswana, where antiretroviral therapy (ART) is widely available. DESIGN: Using a decision-analytic model, we determined the incremental cost-effectiveness of strategies for reducing TB and death in 10,000 PLHIV over 36 months. METHODS: IPT for 6 months and provision of ART if CD4+ lymphocyte count <250 cells/muL (2011 Botswana policy) was compared with six alternative strategies that varied use of IPT, TST, and ART for CD4+ count thresholds, including CD4+ <350 and <500 cells/muL. RESULTS: 2011 Botswana policy was dominated by most other strategies. 36-month IPT for TST-positive PLHIV with ART for CD4+ <250 cells/muL resulted in 120 fewer TB cases for an additional cost of $1,612 per case averted and resulted in 80 fewer deaths for an additional $2,418 per death averted compared with provision of 6-month IPT to TST-positive PLHIV who received ART for CD4+ <250 cells muL, the next most effective strategy. Alternative strategies offered lower incremental effectiveness at higher cost. These findings remained consistent in sensitivity analyses. CONCLUSIONS: A strategy of treating PLHIV who have positive TST with 36-month IPT is more cost-effective for reducing both TB and death compared with providing IPT without a TST, providing only 6-month IPT, or expanding ART eligibility without IPT. |
Temporal trends in HIV-1 incidence and risk behaviours in men who have sex with men in Bangkok, Thailand, 2006-13: an observational study
van Griensven F , Holtz TH , Thienkrua W , Chonwattana W , Wimonsate W , Chaikummao S , Varangrat A , Chemnasiri T , Sukwicha W , Curlin ME , Samandari T , Chitwarakorn A , Mock PA . Lancet HIV 2015 2 (2) 64-70 BACKGROUND: HIV-1 incidence in men who have sex with men (MSM) is often difficult to estimate. We therefore assessed temporal trends in HIV-1 incidence and behavioural risk factors in MSM in Bangkok, Thailand, from 2006 to 2013. METHODS: In this observational study, we used data for clients attending the Silom Community Clinic for voluntary counselling and testing (VCT) services and from the Bangkok MSM Cohort Study (BMCS) to investigate trends in HIV incidence per 100 person-years per quarter in both cohorts. During VCT, basic demographic data were gathered at registration. However, no behavioural risk data were gathered. In the BMCS, we gathered demographic and behavioural data at baseline and at regular study visits using audio computer-assisted self-interviewing. Questions were included about potential risk factors such as drug use, sexual practices, and how often condoms were used. We also analysed behavioural risk factors in the BMCS cohort, using a restricted cubic spline function for time. FINDINGS: From 2006 to 2013, 8176 MSM came for VCT; 1999 (24%) clients were initially seronegative and returned for another test. 235 (12%) individuals seroconverted. The overall HIV-1 incidence was 55 per 100 person-years (95% CI 48-63), with an increasing trend (adjusted p=002). In the BMCS, 1372 people were seronegative at baseline; 1259 (92%) had more than one follow-up test and 238 (17%) seroconverted. The overall HIV-1 incidence was 53 per 100 person-years (95% CI 47-61), with an increase and then a decline (inverted U-shaped curve, p=00001). Individuals aged 21 years and younger were at significantly higher risk of HIV infection than were those aged 30 years and older in the in the VCT (rate ratio 229, 95% CI 188-278, p<00001) and BMCS cohorts (199, 150-265, p<00001). Overall, drug use (p=003), drug use to enhance sex (p=00006), use of drugs for erectile dysfunction (p<00001), and 100% condom use (p<00001) increased over time, whereas the proportion of individuals reporting receptive anal intercourse decreased (p=0004). INTERPRETATION: With a sustained high HIV-1 incidence and increasing drug use in MSM in Bangkok, we urgently need innovative and acceptable HIV prevention interventions, especially for young MSM. FUNDING: US Centers for Disease Control and Prevention. |
Tuberculosis incidence after 36 months' isoniazid prophylaxis in HIV-infected adults in Botswana: a posttrial observational analysis
Samandari T , Agizew TB , Nyirenda S , Tedla Z , Sibanda T , Mosimaneotsile B , Motsamai OI , Shang N , Rose CE , Shepherd J . AIDS 2015 29 (3) 351-9 OBJECTIVE: Thirty-six months of isoniazid preventive therapy (36IPT) was superior to 6 months of IPT (6IPT) in preventing tuberculosis (TB) among HIV-infected adults in Botswana. We assessed the posttrial durability of this benefit. DESIGN: A 36-month double-blind placebo controlled trial (1 : 1 randomization) with recruitment between November 2004 and July 2006 and observation until June 2011. METHODS: One thousand, nine hundred and ninety-five participants were followed in eight public health clinics. Twenty-four percent had a tuberculin skin test ≥5 mm (TST-positive). A minimum CD4 lymphocyte count was not required for enrolment. Antiretroviral therapy (ART) was provided in accordance with Botswana guidelines; 72% of participants retained by June 2011 had initiated ART. Multivariable analysis using Cox regression analysis included treatment arm, TST status, ART as a time-dependent variable and CD4 cell count at baseline and updated at 36 months. RESULTS: In the posttrial period, 2.13 and 2.14 per 100 person-years accumulated, whereas 0.93 and 1.13% TB incidence rates were observed in the 36IPT and 6IPT arms, respectively (P = 0.52). The crude hazard ratio of TB during the trial and posttrial was 0.57 [95% confidence intervals (CI) 0.33, 0.99] and 0.82 (95% CI 0.46, 1.49), and when restricted to TST-positive participants was 0.26 (95% CI 0.08, 0.80) and 0.40 (95% CI 0.15, 1.08), respectively. Multivariable analysis showed that ART use was associated with reduced death (adjusted hazard ratio 0.36, 95% CI 0.17-0.75) but not TB (0.92, 95% CI 0.55-1.53) in the posttrial period. CONCLUSION: The benefit of 36IPT for TB prevention declined posttrial in this cohort. Adjunctive measures are warranted to prevent TB among HIV-infected persons receiving long-term ART in TB-endemic settings. |
Increase in anti-tuberculosis drug resistance in Botswana: results from the fourth National Drug Resistance Survey
Menzies HJ , Moalosi G , Anisimova V , Gammino V , Sentle C , Bachhuber MA , Bile E , Radisowa K , Kachuwaire O , Basotli J , Maribe T , Makombe R , Shepherd J , Kim B , Samandari T , El-Halabi S , Chirenda J , Cain KP . Int J Tuberc Lung Dis 2014 18 (9) 1026-33 SETTING: Although approximately 0.5 million cases of multidrug-resistant tuberculosis (MDR-TB) occur globally each year, surveillance data are limited. Botswana is one of the few high TB burden countries to have carried out multiple anti-tuberculosis drug resistance surveys (in 1995-1996, 1999 and 2002). OBJECTIVE: In 2007-2008, we conducted the fourth national survey of anti-tuberculosis drug resistance in Botswana to assess anti-tuberculosis drug resistance, including trends over time. In the previous survey, 0.8% (95% CI 0.4-1.5) of new patients and 10.4% (95%CI 5.6-17.3) of previously treated patients had MDR-TB. DESIGN: During the survey period, eligible specimens from all new sputum-smear positive TB patients and from all TB patients with history of previous anti-tuberculosis treatment underwent mycobacterial culture and anti-tuberculosis drug susceptibility testing (DST). RESULTS: Of 924 new TB patients and 137 with previous anti-tuberculosis treatment with DST results, respectively 23 (2.5%, 95% CI 1.6-3.7) and 9 (6.6%, 95% CI 3.3-11.7) had MDR-TB. The proportion of new TB patients with MDR-TB has tripled in Botswana since the previous survey. CONCLUSION: Combatting drug-resistant TB will require the scale-up of MDR-TB diagnosis and treatment to prevent the transmission of MDR-TB and strengthening of general TB control to prevent the emergence of resistance. |
Investigation of HIV incidence rates in a high-risk, high-prevalence Kenyan population: potential lessons for intervention trials and programmatic strategies
Mdodo R , Gust D , Otieno FO , McLellan-Lemal E , Chen RT , Lebaron C , Hardnett F , Turner K , Ndivo R , Zeh C , Samandari T , Mills LA . J Int Assoc Provid AIDS Care 2013 15 (1) 42-50 Cost-effective HIV prevention programs should target persons at high risk of HIV acquisition. We conducted an observational HIV incidence cohort study in Kisumu, Kenya, where HIV prevalence is triple that of the national rate. We used referral and venue-sampling approaches to enroll HIV-negative persons for a 12-month observational cohort, August 2010 to September 2011, collected data using computer-assisted interviews, and performed HIV testing quarterly. Among 1292 eligible persons, 648 (50%) were excluded for HIV positivity and other reasons. Of the 644 enrollees, 52% were women who were significantly older than men (P < .01). In all, 7 persons seroconverted (incidence rate [IR] per 100 person-years = 1.11; 95% confidence interval [CI] 0.45-2.30), 6 were women; 5 (IR = 3.14; 95% CI 1.02-7.34) of whom were ≤25 years. Most new infections occurred in young women, an observation consistent with other findings in sub-Saharan Africa that women aged ≤25 years are an important population for HIV intervention trials in Africa. |
The proportions of people living with HIV in low and middle-income countries who test tuberculin skin test positive using either a greater or equal to 5 mm or a greater or equal to 10 mm cut-off: a systematic review
Kerkhoff AD , Gupta A , Samandari T , Lawn SD . BMC Infect Dis 2013 13 (1) 307 BACKGROUND: A positive tuberculin skin test (TST) is often defined by skin induration of >=10 mm in people who are HIV-seronegative. However, to increase sensitivity for detection of Mycobacterium tuberculosis infection in the context of impaired immune function, a revised cut-off of >=5 mm is used for people living with HIV infection. The incremental proportion of patients who are included by this revised definition and the association between this proportion and CD4+ cell count are unknown. METHODS: The literature was systematically reviewed to determine the proportion of people living with HIV (PLWH) without evidence of active tuberculosis in low and middle-income countries who tested TST-positive using cut-offs of >=5 mm and >=10 mm of induration. The difference in the proportion testing TST-positive using the two cut-off sizes was calculated for all eligible studies and was stratified by geographical region and CD4+ cell count. RESULTS: A total of 32 studies identified meeting criteria were identified, providing data on 10,971 PLWH from sub-Saharan Africa, Asia and the Americas. The median proportion of PLWH testing TST-positive using a cut-off of >=5 mm was 26.8% (IQR, 19.8-46.1%; range, 2.5-81.0%). Using a cut-off of >=10 mm, the median proportion of PLWH testing TST-positive was 19.6% (IQR, 13.7-36.8%; range 0--52.1%). The median difference in the proportion of PLWH testing TST-positive using the two cut-offs was 6.0% (IQR, 3.4-10.1%; range, 0--37.6%). Among those with CD4+ cell counts of <200, 200--499 and >=500 cells/muL, the proportion of positive tests defined by the >=5 mm cut-off that were between 5.0 and 9.9 mm in diameter was similar (12.5%, 12.9% and 10.5%, respectively). CONCLUSIONS: There is a small incremental yield in the proportion of PLWH who test TST-positive when using an induration cut-off size of >=5 mm compared to >=10 mm. This proportion was similar across the range of CD4+ cell strata, supporting the current standardization of this cut-off at all levels of immunodeficiency. |
Pregnancy outcomes in HIV-infected women receiving long-term isoniazid prophylaxis for tuberculosis and antiretroviral therapy
Taylor AW , Mosimaneotsile B , Mathebula U , Mathoma A , Moathlodi R , Theebetsile I , Samandari T . Infect Dis Obstet Gynecol 2013 2013 195637 OBJECTIVE: While 6- to 12-month courses of isoniazid for tuberculosis prevention are considered safe in pregnant women, the effects of longer-term isoniazid prophylaxis or isoniazid in combination with antiretroviral therapy (ART) are not established in human-immunodeficiency-virus-(HIV-) infected women who experience pregnancy during the course of therapy. DESIGN: Nested study of pregnancy outcomes among HIV-infected women participating in a placebo-controlled, TB-prevention trial using 36 months daily isoniazid. Pregnancy outcomes were collected by interview and record review. RESULTS: Among 196 pregnant women, 103 (52.6%) were exposed to isoniazid during pregnancy; all were exposed to antiretroviral drugs. Prior to pregnancy they had received a median of 341 days (range 1-1095) of isoniazid. We observed no isoniazid-associated hepatitis or other severe isoniazid-associated adverse events in the 103 women. Pregnancy outcomes were 132 term live births, 42 premature births, 11 stillbirths, 8 low birth weight, 6 spontaneous abortions, 4 neonatal deaths, and 1 congenital abnormality. In a multivariable model, neither isoniazid nor ART exposure during pregnancy was significantly associated with adverse pregnancy outcome (adjusted odds ratios 0.6, 95% CI: 0.3-1.1 and 1.8, 95% CI 0.9-3.6, resp.). CONCLUSIONS Long-term isoniazid prophylaxis was not associated with adverse pregnancy outcomes, such as preterm delivery, even in the context of ART exposure. |
Anti-tuberculosis treatment outcomes in HIV-infected adults exposed to isoniazid preventive therapy in Botswana
Sibanda T , Tedla Z , Nyirenda S , Agizew T , Marape M , Miranda AG , Reuter H , Johnson JL , Samandari T . Int J Tuberc Lung Dis 2013 17 (2) 178-85 SETTING: Eight public health clinics in Gaborone and Francistown, Botswana. OBJECTIVES: To describe the characteristics and outcomes of incident tuberculosis (TB) cases in human immunodeficiency virus (HIV) infected adults exposed to isoniazid preventive therapy (IPT) with access to antiretroviral and anti-tuberculosis treatment. DESIGN: In 1995 HIV-infected adults, TB disease was excluded before commencing IPT. During and after receipt of 6 or 36 months of IPT, symptomatic participants were evaluated using chest radiographs, sputum microscopy, cultures and drug susceptibility testing (DST). Incident TB cases received ≥6 months of anti-tuberculosis treatment. RESULTS: Seventy-five incident TB cases were identified among 619 symptomatic participants. The median duration of IPT in these cases was 6 months (range 1-35), and the median time to initiation of anti-tuberculosis treatment was 12 months after IPT cessation. Antiretroviral therapy (ART) was initiated before anti-tuberculosis treatment in 37 cases. Culture was positive in 43/58 (74%) TB cultures. DST was available for 38 cases, of which six (16%) were resistant to isoniazid (INH); 67/75 (89%) cases, including four with INH-monoresistant TB, completed anti-tuberculosis treatment or were cured. CONCLUSIONS: With prompt initiation of anti-tuberculosis treatment and access to ART, excellent outcomes were achieved in a public health setting in HIV-infected adults who developed TB disease. |
Persistence of long-term immunity to hepatitis B among adolescents immunized at birth
Chaves SS , Fischer G , Groeger J , Patel PR , Thompson ND , Teshale EH , Stevenson K , Yano VM , Armstrong GL , Samandari T , Kamili S , Drobeniuc J , Hu DJ . Vaccine 2012 30 (9) 1644-9 The long-term duration of recombinant hepatitis B vaccine-induced immunity among persons vaccinated starting at birth is still not well understood. Waning of vaccine-induced immunity could leave young adults at risk of hepatitis B virus infection due to behavioral or occupational exposures. We followed a cohort of children immunized starting at birth with a 3-dose regimen of recombinant hepatitis B vaccine (5mcg, 2.5mcg, 2.5mcg). They were challenged with a booster dose of the hepatitis B vaccine 10 and 15 years after vaccination to assess anamnestic response as a measure of persistence of protection. Among 108 participants who had lost protective antibody levels against hepatitis B, the majority (>70%) had an anamnestic response to the booster dose; response rates did not decline significantly between 10 and 15 years follow-up periods. A high antibody concentration following primary vaccination was independently associated with an anamnestic response later on in life. Nonetheless, approximately 20-30% of participants were unable to mount an immune response after boosting. Hepatitis B revaccination might be required for persons vaccinated starting at birth if opportunities for hepatitis B virus exposure exist. Future vaccine recommendations should be based on studies ascertaining protection against clinically significant disease. |
Risk factors for non-adherence and loss to follow-up in a three-year clinical trial in Botswana
Gust DA , Mosimaneotsile B , Mathebula U , Chingapane B , Gaul Z , Pals SL , Samandari T . PLoS One 2011 6 (4) e18435 BACKGROUND: Participant non-adherence and loss to follow-up can compromise the validity of clinical trial results. An assessment of these issues was made in a 3-year tuberculosis prevention trial among HIV-infected adults in Botswana. METHODS AND FINDINGS: Between 11/2004-07/2006, 1995 participants were enrolled at eight public health clinics. They returned monthly to receive bottles of medication and were expected to take daily tablets of isoniazid or placebo for three years. Non-adherence was defined as refusing tablet ingestion but agreeing to quarterly physical examinations. Loss to follow-up was defined as not having returned for appointments in ≥60 days. Between 10/2008-04/2009, survey interviews were conducted with 83 participants identified as lost to follow-up and 127 identified as non-adherent. As a comparison, 252 randomly selected adherent participants were also surveyed. Multivariate logistic regression analysis was used to identify associations with selected risk factors. Men had higher odds of being non-adherent (adjusted odds ratio (AOR), 2.24; 95% confidence interval [95%CI] 1.24-4.04) and lost to follow-up (AOR 3.08; 95%CI 1.50-6.33). Non-adherent participants had higher odds of reporting difficulties taking the regimen or not knowing if they had difficulties (AOR 3.40; 95%CI 1.75-6.60) and lower odds associated with each year of age (AOR 0.95; 95%CI 0.91-0.98), but other variables such as employment, distance from clinic, alcohol use, and understanding study requirements were not significantly different than controls. Among participants who were non-adherent or lost to follow-up, 40/210 (19.0%) reported that they stopped the medication because of work commitments and 33/210 (15.7%) said they thought they had completed the study. CONCLUSIONS: Men had higher odds of non-adherence and loss to follow-up than women. Potential interventions that might improve adherence in trial participants may include:targeting health education for men, reducing barriers, clarifying study expectations, educating employers about HIV/AIDS to help reduce stigma in the workplace, and encouraging employers to support employee health. TRIAL REGISTRATION: ClinicalTrials.gov NCT00164281. |
6-month versus 36-month isoniazid preventive treatment for tuberculosis in adults with HIV infection in Botswana: a randomised, double-blind, placebo-controlled trial
Samandari T , Agizew TB , Nyirenda S , Tedla Z , Sibanda T , Shang N , Mosimaneotsile B , Motsamai OI , Bozeman L , Davis MK , Talbot EA , Moeti TL , Moffat HJ , Kilmarx PH , Castro KG , Wells CD . Lancet 2011 377 (9777) 1588-98 BACKGROUND: In accordance with WHO guidelines, people with HIV infection in Botswana receive daily isoniazid preventive therapy against tuberculosis without obtaining a tuberculin skin test, but duration of prophylaxis is restricted to 6 months. We aimed to assess effectiveness of extended isoniazid therapy. METHODS: In our randomised, double-blind, placebo-controlled trial we enrolled adults infected with HIV aged 18 years or older at government HIV-care clinics in Botswana. Exclusion criteria included current illness such as cough and an abnormal chest radiograph without antecedent tuberculosis or pneumonia. Eligible individuals were randomly allocated (1:1) to receive 6 months' open-label isoniazid followed by 30 months' masked placebo (control group) or 6 months' open-label isoniazid followed by 30 months' masked isoniazid (continued isoniazid group) on the basis of a computer-generated randomisation list with permuted blocks of ten at each clinic. Antiretroviral therapy was provided if participants had CD4-positive lymphocyte counts of fewer than 200 cells per muL. We used Cox regression analysis and the log-rank test to compare incident tuberculosis in the groups. Cox regression models were used to estimate the effect of antiretroviral therapy. The trial is registered at ClinicalTrials.gov, number NCT00164281. FINDINGS: Between Nov 26, 2004, and July 3, 2009, we recorded 34 (3.4%) cases of incident tuberculosis in 989 participants allocated to the control group and 20 (2.0%) in 1006 allocated to the continued isoniazid group (incidence 1.26% per year vs 0.72%; hazard ratio 0.57, 95% CI 0.33-0.99, p=0.047). Tuberculosis incidence in those individuals receiving placebo escalated approximately 200 days after completion of open-label isoniazid. Participants who were tuberculin skin test positive (ie, ≥5 mm induration) at enrolment received a substantial benefit from continued isoniazid treatment (0.26, 0.09-0.80, p=0.02), whereas participants who were tuberculin skin test-negative received no significant benefit (0.75, 0.38-1.46, p=0.40). By study completion, 946 (47%) of 1995 participants had initiated antiretroviral therapy. Tuberculosis incidence was reduced by 50% in those receiving 360 days of antiretroviral therapy compared with participants receiving no antiretroviral therapy (adjusted hazard ratio 0.50, 95% CI 0.26-0.97). Severe adverse events and death were much the same in the control and continued isoniazid groups. INTERPRETATION: In a tuberculosis-endemic setting, 36 months' isoniazid prophylaxis was more effective for prevention of tuberculosis than was 6-month prophylaxis in individuals with HIV infection, and chiefly benefited those who were tuberculin skin test positive. FUNDING: US Centers for Disease Control and Prevention and US Agency for International Development. |
Costs and consequences of additional chest X-ray in a tuberculosis prevention program in Botswana
Samandari T , Bishai D , Luteijn M , Mosimaneotsile B , Motsamai O , Postma M , Hubben G . Am J Respir Crit Care Med 2010 183 (8) 1103-11 RATIONALE: Isoniazid preventive therapy (IPT) is effective in reducing the risk of tuberculosis (TB) in persons living with HIV (PLWH), however screening must exclude TB disease prior to initiating therapy. Symptom screening alone may be insufficient to exclude TB disease in PLWH because some PLWH with TB disease have no symptoms. The addition of chest radiography (CXR) may improve disease detection. OBJECTIVES: The objective of the present analysis was to compare the costs and effects of the addition of CXR to the symptom screening process against the costs and effects of symptom screening alone. METHODS: Using data from Botswana, a decision analytic model was used to compare a 'Symptom only' policy against a 'Symptom+CXR' policy. The outcomes of interest were cost, death, isoniazid- and multidrug-resistant TB in a hypothetical cohort of 10,000 PLWH. MEASUREMENTS AND MAIN RESULTS: A 'Symptom+CXR' policy prevented 16 isoniazid- and 0.3 multidrug-resistant TB cases, however due to attrition from the screening process, there were 98 excess cases of TB, 15 excess deaths and an additional cost of US$127,100. 'Symptom+CXR' policy reduced deaths only if attrition were close to zero, however in order to eliminate attrition the cost would be US$2.8 million per death averted. These findings did not change in best- and worst-case scenario analysis. CONCLUSIONS: In Botswana, a policy with symptom screening only preceding IPT initiation, prevents more TB and TB-related deaths, and uses fewer resources than a policy that uses both CXR and symptom screening. |
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