Last data update: Dec 09, 2024. (Total: 48320 publications since 2009)
Records 1-8 (of 8 Records) |
Query Trace: Singletary T[original query] |
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Notes from the field: Increases in imported malaria cases - three southern U.S. Border jurisdictions, 2023
Mitchell CL , Kennar A , Vasquez Y , Noris K , Williamson T , Mannell A , Taylor A , Ruberto I , Cullen TA , Singletary M , Shah S , Ocaranza H , Rodriguez Lainz A , Mace KE . MMWR Morb Mortal Wkly Rep 2024 73 (18) 417-419 Malaria is a severe and potentially fatal mosquitoborne disease caused by infection with Plasmodium spp. parasites. Although malaria is no longer endemic in the United States, imported infections are reported annually; the primary risk group has been U.S. residents traveling to areas where malaria is endemic (1). In 2023, sporadic locally acquired mosquito-transmitted malaria cases were reported in several U.S. states (2,3). This report describes increases in imported malaria cases in 2023 compared with 2022 in three public health jurisdictions along the U.S. southern border. |
Extended post-exposure protection against vaginal SHIV infection with tenofovir alafenamide fumarate/elvitegravir inserts in macaques
Makarova N , Singletary T , Peet MM , Mitchell J , Bachman S , Holder A , Dinh C , Lipscomb J , Agrahari V , Mendoza M , Pan Y , Heneine W , Clark MR , García-Lerma JG , Doncel GF , Smith JM . J Infect Dis 2023 Vaginal inserts that can be used on demand before or after sex may be a desirable HIV prevention option for women. We recently showed that inserts containing tenofovir alafenamide fumarate (TAF/20mg) and elvitegravir (EVG/16mg) were highly protective against repeated SHIV vaginal exposures when administered to macaques 4h before or after virus exposure (93% and 100%, respectively). Here, we show in the same macaque model that insert application 8h or 24h after exposure maintains high efficacy (94.4% and 77.2%, respectively). These data extend the protective window by TAF/EVG inserts and inform their clinical development for on-demand prophylaxis in women. |
Human rabies - Texas, 2021
Blackburn D , Minhaj FS , Al Hammoud R , Orciari L , Miller J , Maness T , Stewart J , Singletary B , Ledezma E , Ellsworth M , Carlo-Angleró A , Niezgoda M , Gigante CM , Rao AK , Satheshkumar PS , Heresi GP , Kieffer A , Wallace RM . MMWR Morb Mortal Wkly Rep 2022 71 (49) 1547-1549 In late August 2021, a boy aged 7 years was bitten by a bat while he was playing outside his apartment home in Medina County, Texas. He informed his parents; however, no rabies postexposure prophylaxis (PEP) was sought because there were no visible bite marks, and the family was unaware that contact with a bat, including in the absence of visible bite marks, might cause rabies. Approximately 2 months later, the child was hospitalized for altered mental status, seizures, and hypersalivation and ultimately received a diagnosis of rabies. Experimental therapies were attempted; however, the child died 22 days after symptom onset. Fifty-seven persons who met criteria for suspected or known exposure to infectious secretions in this case were advised to consult with a medical provider about the need for rabies PEP in accordance with Advisory Committee on Immunization Practices (ACIP) guidelines (1). Rabies, an acute, progressive neuroencephalitis, is nearly always fatal. Although dogs are the most common source of human rabies deaths worldwide and account for an estimated 59,000 annual cases of human rabies globally (2), bats are the most common source of domestically acquired rabies in the United States and have been implicated in 31 (81.6%) of 38 human infections since 2000 (3). Attempts to prevent death or poor neurologic outcomes once rabies symptoms develop have been largely unsuccessful (4). Administration of rabies PEP, comprising rabies immunoglobulin and a series of doses of rabies vaccine, is critical to preventing rabies after an exposure; enhanced public education about the risk posed by bats, and the availability of PEP to prevent rabies, is needed. |
Pharmacokinetics and efficacy of topical inserts containing tenofovir alafenamide fumarate and elvitegravir administered rectally in macaques
Makarova N , Singletary T , Peet MM , Mitchell J , Holder A , Dinh C , Agrahari V , Mendoza M , Pan Y , Heneine W , Clark MR , García-Lerma JG , Smith JM , Doncel GF . EBioMedicine 2022 86 104338 BACKGROUND: Topical on-demand forms for HIV pre-exposure prophylaxis (PrEP) may be a desirable alternative for people that prefer not to use daily PrEP. CONRAD has developed inserts containing tenofovir alafenamide (TAF) and elvitegravir (EVG) for on-demand vaginal or rectal pericoital use. We assessed the pharmacokinetics (PK) and pre-exposure efficacy of rectally applied TAF/EVG inserts in macaques. METHODS: PK was assessed in 12 pigtailed macaques. Tenofovir (TFV) and EVG levels were assayed in rectal biopsies and secretions, and tenofovir-diphosphate (TFV-DP) levels in biopsies and peripheral blood mononuclear cells (PBMC). Drug biodistribution was evaluated in 10 animals at necropsy 4 h post-dosing. For efficacy assessments, one or two TAF/EVG inserts were administered to macaques (n = 6) 4 h before repeated rectal SHIV162p3 challenges. FINDINGS: One TAF/EVG insert resulted in rapid and high EVG and TFV-DP in rectal tissue 4 h after application. Adding a second insert led to a 10-fold increase in EVG and TFV-DP in rectal tissue. Efficacy of one and two TAF/EVG inserts were 72.6% (CI 24.5%-92.6%) and 93.1% (CI 73.3%-99.2%), respectively. INTERPRETATION: Although high TFV-DP and EVG levels were observed with one rectal TAF/EVG insert, it only conferred partial protection from rectal SHIV challenges. Adding a second insert led to an increase in TFV and EVG in rectal tissues resulting in higher (>90%) efficacy. These results highlight the high efficacy of TAF/EVG inserts as topical on-demand rectal PrEP, as well as the need for appropriate drug coverage in the deep rectum and colon to achieve high protection. FUNDING: The work related to animal studies was funded by CDC intramural funds and an interagency agreement between CDC and USAID (USAID/CDC IAA AID-GH-T-15-00002). The work related to the insert formulation was funded by U.S. PEPFAR through USAID under a Cooperative Agreement (AID-OAA-A-14-00010) with CONRAD/Eastern Virginia Medical School. The findings and conclusions of this manuscript are those of the authors and do not necessarily represent the official views of the Centers for Disease Control and Prevention (CDC), USAID, President's Emergency Plan for AIDS Relief (PEPFAR), Eastern Virginia Medical School (EVMS), or the US government. |
Effects of gel volume on pharmacokinetics for vaginal and rectal applications of combination DuoGel-IQB4012, a dual chamber-dual drug HIV microbicide gel, in pigtailed macaques
Pereira LE , Singletary T , Martin A , Dinh CT , Deyounks F , Holder A , McNicholl J , Buckheit KW , Buckheit RWJr , Ham A , Katz DF , Smith JM . Drug Deliv Transl Res 2018 8 (5) 1180-1190 This study evaluated effects of differing gel volumes on pharmacokinetics (PK). IQB4012, a gel containing the non-nucleoside reverse transcriptase inhibitor IQP-0528 and tenofovir (TFV), was applied to the pigtailed macaque vagina and rectum. Vaginal gel volumes (1% loading of both drugs) were 0.5 or 1.5 ml; following wash-out, 1 or 4 ml of gel were then applied rectally. Blood, vaginal, and rectal fluids were collected at 0, 2, 4, and 24 h. Vaginal and rectal tissue biopsies were collected at 4 and 24 h. There were no statistically significant differences in concentrations for either drug between gel volumes within compartments at matched time points. After vaginal gel application, median IQP-0528 concentrations were ~ 10(4)-10(5) ng/g, 10(5)-10(6) ng/ml, and 10(3)-10(5) ng/ml in vaginal tissues, vaginal fluids, and rectal fluids, respectively (over 24 h). Median vaginal TFV concentrations were 1-2 logs lower than IQP-0528 levels at matched time points. After rectal gel application, median IQP-0528 and TFV concentrations in rectal fluids were ~ 10(3)-10(5) ng/ml and ~ 10(2)-10(3) ng/ml, respectively. Concentrations of both drugs sampled in rectal tissues were low (~ 10(1)-10(3) ng/g). For 1 ml gel, half of sampled rectal tissues had undetectable concentrations of either drug, and over half of sampled rectal fluids had undetectable TFV concentrations. These results indicate differences in drug delivery between the vaginal and rectal compartments, and that smaller vaginal gel volumes may not significantly compromise microbicide PK and prophylactic potential. However, effects of rectal gel volume on PK for both drugs were less definitive. |
An assessment of information exchange practices, challenges, and opportunities to support US disease surveillance in 3 states
Garcia MC , Garrett NY , Singletary V , Brown S , Hennessy-Burt T , Haney G , Link K , Tripp J , Mac Kenzie WR , Yoon P . J Public Health Manag Pract 2017 24 (6) 546-553 BACKGROUND: State and local public health agencies collect and use surveillance data to identify outbreaks, track cases, investigate causes, and implement measures to protect the public-s health through various surveillance systems and data exchange practices. PURPOSE: The purpose of this assessment was to better understand current practices at state and local public health agencies for collecting, managing, processing, reporting, and exchanging notifiable disease surveillance information. METHODS: Over an 18-month period (January 2014-June 2015), we evaluated the process of data exchange between surveillance systems, reporting burdens, and challenges within 3 states (California, Idaho, and Massachusetts) that were using 3 different reporting systems. RESULTS: All 3 states use a combination of paper-based and electronic information systems for managing and exchanging data on reportable conditions within the state. The flow of data from local jurisdictions to the state health departments varies considerably. When state and local information systems are not interoperable, manual duplicative data entry and other work-arounds are often required. The results of the assessment show the complexity of disease reporting at the state and local levels and the multiple systems, processes, and resources engaged in preparing, processing, and transmitting data that limit interoperability and decrease efficiency. CONCLUSIONS: Through this structured assessment, the Centers for Disease Control and Prevention (CDC) has a better understanding of the complexities for surveillance of using commercial off-the-shelf data systems (California and Massachusetts), and CDC-developed National Electronic Disease Surveillance System Base System. More efficient data exchange and use of data will help facilitate interoperability between National Notifiable Diseases Surveillance Systems. |
A multiplex assay for detection of SHIV plasma and mucosal IgG and IgA
Parker IK , Price KA , Singletary T , Srinivasan P , Smith JM , Curtis KA . J Immunol Methods 2017 450 34-40 Evaluating antibody maturation provides valuable data to characterize immune responses to HIV infection and can provide insight into biomedical intervention efficacy. It is important to develop assays that evaluate antibody maturation in both plasma and mucosal compartments. The nonhuman primate model provides a controlled system to collect temporal data that are integral to assessing intervention strategies. We report the development of a novel multiplex assay, based on the Bio-Plex platform, to evaluate plasma and mucosal IgG and IgA avidity and maturation against simian/human immunodeficiency virus (SHIV) in this controlled system. Vaginal mucosa and plasma samples were collected from a prior study evaluating the efficacy of a tenofovir disoproxil fumarate (TDF) intravaginal ring (IVR) against SHIVSF162P3 challenge in female pigtailed macaques. For validation of the multiplex assay, specimens from six SHIV-infected placebo animals and one TDF breakthrough animal were evaluated. For SHIV and HIV envelope analytes, antibody levels and avidity in both compartments continued to mature post-infection. Maturation of IgG and IgA levels was similar in each compartment, however, mucosal antibody levels tended to be more variable. This SHIV assay elucidates IgG/IgA antibody kinetics in the plasma and vaginal mucosa and will be a valuable tool in vaccine and other biomedical intervention studies in the nonhuman primate model. |
Pharmacokinetic and pharmacodynamic evaluation following vaginal application of IQB3002, a dual chamber microbicide gel containing the NNRTI IQP-0528 in rhesus macaques
Pereira LE , Mesquita PM , Ham A , Singletary T , Deyounks F , Martin A , McNicholl J , Buckheit KW , Buckheit RW Jr , Smith JM . Antimicrob Agents Chemother 2015 60 (3) 1393-400 We evaluated in vivo pharmacokinetics and used a complementary ex vivo co-culture assay to determine pharmacodynamics of IQB3002 gel containing 1% IQP-0528, a non-nucleoside reverse transcriptase inhibitor, in rhesus macaques (RM). Gel (1.5 ml) was applied vaginally to 6 SHIV+ female RM. Blood, vaginal and rectal fluids were collected at 0, 1, 2, and 4 hours. RM were euthanized at 4 hours, and vaginal, cervical, rectal, and regional lymph node tissues were harvested. Anti-HIV activity was evaluated ex vivo by co-culturing fresh or frozen vaginal tissue with activated human peripheral blood mononuclear cells (PBMCs), and measuring p24 levels for 10 days after HIV-1Ba-L challenge. Median levels of IQP-0528, determined using LC-MS methods, were between 104-105 ng/g in vaginal and cervical tissue, 103-104 ng/g in rectal tissues, and 105-107 ng/ml in vaginal fluids over the 4 hour period. Vaginal tissues protected co-cultured PBMCs from HIV-1 infection ex vivo, with a viral inhibition range of 81-100% in fresh and frozen tissues that were proximal, medial, and distal relative to the cervix. No viral inhibition was detected in untreated baseline tissues. Collectively, the observed median drug levels were 5-7 logs higher than the in vitro EC50 range (0.21 ng/ml -1.29 ng/ml), suggesting that 1.5 ml of gel delivers IQP-0528 throughout the RM vaginal compartment at levels that are highly inhibitory to HIV-1. Importantly, anti-viral activity was observed in both fresh and frozen vaginal tissues, broadening the scope of the ex vivo co-culture model for future NNRTI efficacy studies. |
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