Timothy J Whitman

Uniformed Services University of the Health Sciences, 베서스다, Maryland, United States

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Publications (40)

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    Full-text Article · Mar 2016 · MSMR
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    [Show abstract] [Hide abstract] ABSTRACT: Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice.
    Full-text Article · Mar 2015 · PLoS Medicine
  • Article · Nov 2014
  • Kerry Wilson · Charles Magee · Timothy Whitman · [...] · Joshua Hartzell
    [Show abstract] [Hide abstract] ABSTRACT: Background: The FDA recently approved tenofovir/emtricitabine as pre-exposure prophylaxis (PrEP) to prevent acquisition of HIV among adults. The CDC established guidance on prescribing PrEP. However, there is a paucity of data on how providers should implement PrEP into clinical practice, provider knowledge related to PrEP, and its cost-effectiveness. Methods: A voluntary, anonymous survey was conducted to evaluate the current knowledge, attitudes, and perceptions of PrEP among two groups of primarily infectious disease providers. The link to the 34-question survey was emailed to both the Greater Washington Infectious Disease Society (GWIDS) and the Armed Forces Infectious Disease Society (AFIDS). This survey assessed provider demographics and the volume of HIV-infected patients in their practice in addition to their knowledge, prescribing patterns, and opinions regarding PrEP. Results: There were 105 responses – 20 (19%) were members of GWIDS, 58 (55%) were members of AFIDS, and 27 (25.7%) were part of both groups. All were physicians, and 94% were adult infectious disease specialists. The majority (60%) of knowledge questions were answered incorrectly. Of the respondents, 36 (34.3%) spent >25% of their time in HIV care. Those who spent >25% of their time in HIV care had a significantly higher percentage of correct answers in the knowledge component of the survey. Sixty-two (67%) respondents felt that the current literature supports the use of PrEP, 12 (13%) did not think the literature supports its use, and 18 (19.5%) were undecided. When asked whether the cost of PrEP was considered justifiable, only 23 (25%) said yes, while 35 (38%) said no and 34 (37%) were undecided. Conclusion: There is a significant amount of uncertainty that remains regarding the use of PrEP. This survey demonstrates that knowledge related to the use of PrEP is lacking and suggests training is warranted to ensure providers become familiar with CDC guidance. Given the lack of knowledge amongst providers who spent <25% of their time caring for HIV patients, organizations should consider restricting its use to providers who spend >25% of their time caring for HIV patients. Only a quarter of surveyed providers feel the cost is justified. Further research in this area is necessary to explore options for more cost effective methods of HIV prevention.
    Conference Paper · Oct 2014
  • [Show abstract] [Hide abstract] ABSTRACT: Background: The pre-travel counseling visit represents an ideal opportunity for updating routine and destination specific immunizations. The American College of Immunization Practices (ACIP) recommends pneumococcal vaccination (PPSV) for adults ≥ 65 years and Zostavax in those ≥ 60 years. Recent updates also recommend Hepatitis B vaccination for diabetics. To examine coverage and factors associated with the failure to address routine adult vaccinations listed above, we analyzed data collected in the TravMil study at the pre-travel visit. Methods: The TravMil cohort is comprised of DoD beneficiaries evaluated pre-travel at 3 military travel clinics (Walter Reed National Military Medical Center (WRNMMC), National Naval Medical Center San-Diego (NMCSD), and Naval Medical Center Portsmouth (NMCP)). Vaccination status and vaccine prescriptions were evaluated. Multivariate Poisson regression with robust error variance was used to examine factors associated with failure to immunize adults who met criteria for immunization with PPSV, Zostavax, and Hepatitis B. Results: Vaccine Status Overall WRNMMC NMCP NMCSD Hepatitis B in Diabetics n=86 n=8 n=29 n=49 Up to date 26(30.2) 5(62.5) 5(17.2) 16(32.7) Administered at pre-travel visit 14(16.3) 1(7.1) 9(31.0) 4(8.2) PPSV in adults ≥65 n=352 n=39 n=97 n=216 Up to date 241(68.5) 29(74.4) 59(60.8) 153(70.8) Administered at pre-travel visit 72(20.5) 9(23.1) 22(22.7) 41(19.0) Zostavax in adults ≥60 n=477 n=54 n=139 n=284 Up to date 301(63.1) 39(72.2) 72(51.8) 190(66.9) Administered at pre-travel visit 41(8.6) 5(9.3) 3(2.2) 33(11.6) Non-white race [RR: 1.42 (1.04-1.92)] was associated with a failure to vaccinate with Zostavax and/or PPSV, as was evaluation at NMCP [Ref WRNMMC; RR 2.46 (1.43-4.24)]. Female diabetics were less likely to receive Hepatitis B vaccination [RR: 1.60 (1.08-2.39)]. Conclusion: Even in a setting with free access to care and vaccinations, significant variability in coverage of recommended vaccines was noted by race, gender and clinic site. Factors associated with these differences need to be studied further.
    Conference Paper · Oct 2014
  • Mackenzie K Morgan · Timothy J Whitman · Jeffrey I Cohen · [...] · Timothy H Burgess
    Article · Jul 2014 · Clinical Infectious Diseases
  • Dennis C Drinkwater · Jan Davidson-Moncada · Emily Heckendorn · [...] · Timothy J Whitman
    Article · Mar 2014 · Clinical Infectious Diseases
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    [Show abstract] [Hide abstract] ABSTRACT: Background. Treatment guidelines recommend the use of a single dose of benzathine penicillin G (BPG) for treating early syphilis in human immunodeficiency virus (HIV)-infected persons. However, data supporting this recommendation are limited. We examined the efficacy of single-dose BPG in the US Military HIV Natural History Study. Methods. Subjects were included if they met serologic criteria for syphilis (ie, a positive nontreponemal test [NTr] confirmed by treponemal testing). Response to treatment was assessed at 13 months and was defined by a ≥4-fold decline in NTr titer. Multivariate Cox proportional hazard regression models were utilized to examine factors associated with treatment response. Results. Three hundred fifty subjects (99% male) contributed 478 cases. Three hundred ninety-three cases were treated exclusively with BPG (141 with 1 dose of BPG). Treatment response was the same among those receiving 1 or >1 dose of BPG (92%). In a multivariate analysis, older age (hazard ratio [HR], 0.82 per 10-year increase; 95% confidence interval [CI], .73–.93) was associated with delayed response to treatment. Higher pretreatment titers (reference NTr titer <1:64; HR, 1.94 [95% CI, 1.58–2.39]) and CD4 counts (HR, 1.07 for every 100-cell increase [95% CI, 1.01–1.12]) were associated with a faster response to treatment. Response was not affected by the number of BPG doses received (reference, 1 dose of BPG; HR, 1.11 [95% CI, .89–1.4]). Conclusions. In this cohort, additional BPG doses did not affect treatment response. Our data support the current recommendations for the use of a single dose of BPG to treat HIV-infected persons with early syphilis.
    Full-text Article · Jan 2014 · Clinical Infectious Diseases
  • [Show abstract] [Hide abstract] ABSTRACT: Background: Current US treatment guidelines recommend one dose of benzathine penicillin (BPN), for the treatment of early syphilis, regardless of HIV serostatus. Data supporting the use of this regimen in HIV-infected persons are limited. To assess the adequacy of these recommendations, we examined syphilis treatment responses and factors associated with response in the U.S. Military HIV Natural History Study [NHS], a well-characterized cohort of HIV-infected DoD beneficiaries. Methods: NHS subjects with early syphilis were included, if they met serologic criteria for syphilis [i.e. a positive non-treponemal (NTr) test confirmed by treponemal (Tr) testing], had treatment documented in the database, and had follow up NTr titers drawn within 12 months of treatment. We defined syphilis episodes as being early if the subject had a negative NTr test in the 365 days prior to their positive NTr test. Response to treatment was assessed at 12 months. Serologic response was defined as a ≥4-fold decline in NTr titer following treatment. GEE logistic regression models were utilized to examine factors associated with response to treatment. Results: 418 subjects [99% male, 63% African American, 24% Caucasian] experienced 604 episodes of early syphilis. 404 [67%] episodes had treatment and follow up titers recorded, in the NHS database, and are included in this analysis. 326 [81%] episodes were treated with a BPN containing regimen [121 [30%] with 1 dose, and 205 (51%) with > 1 dose]. 78 [19%] episodes were treated with a non-penicillin containing regimen. Overall, 91% of all early episodes responded to treatment [1 dose BPN-88%, >1 dose BPN-93%]. In a multivariate analysis, adjusted for age, race, antiretroviral use, HIV viral load, CD4 count and baseline NTr titers, serologic response was not affected by the number of BPN doses received [Ref: single dose of BPN; Odds Ratio [OR]: 1.60 (0.6, 4.0)]. However, having a higher CD4 count at episode diagnosis [OR per 100 cell increase: 1.41 (1.1, 1.8)] was associated with a greater likelihood of response at 12 months. Conclusion: In this cohort serologic failure to syphilis treatment was uncommon and the number of BPN doses did not impact treatment response. Our data support the current recommendations for the use of a single dose of BPN to treat HIV-infected persons with early syphilis.
    Conference Paper · Oct 2013
  • [Show abstract] [Hide abstract] ABSTRACT: Background. USA300 methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of skin and soft-tissue infection (SSTI) in military personnel. USA300 MRSA has emerged as an important cause of healthcare-associated bloodstream infection (BSI) in metropolitan centers. Objective. To determine the prevalence, risk factors, and patient outcomes associated with USA300 MRSA BSI in military tertiary medical centers. Design. Retrospective case-control study. Patients. Patients admitted during the period 2001-2009 with MRSA BSI. Setting. Walter Reed Army Medical Center (Washington, DC) and National Naval Medical Center (Bethesda, MD) tertiary medical centers with 500 inpatient beds combined, which provide care to active duty service members and military beneficiaries. Methods. After identifying patients with MRSA BSI, we collected epidemiological data from electronic medical records and characterized bacterial isolates using pulsed-field gel electrophoresis (PFGE). Results. A total of 245 MRSA BSI cases were identified, and 151 isolates were available for analysis. Epidemiological characteristics for the 151 patients with available isolates included the following: mean age, 61 years; male sex, 70%; white race, 62%; and combat-wounded service members, 11%. The crude in-hospital mortality rate was 17%. PFGE demonstrated that 30 (20%) of 151 MRSA BSI cases with isolates available for analysis were due to USA300, and 27 (87%) of these 30 cases were healthcare-associated infection. USA300 was associated with a significantly increasing proportion of MRSA BSI when examined over sequential time periods: 2 (4%) of 51 isolates during 2001-2003, 9 (19%) of 47 isolates during 2004-2006, and 19 (36%) of 53 isolates during 2007-2009 ([Formula: see text]). Conclusion. USA300 MRSA is emerging as a cause of healthcare-associated BSI in tertiary military medical centers.
    Article · Apr 2013 · Infection Control and Hospital Epidemiology
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    Full-text Dataset · Jan 2013
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    [Show abstract] [Hide abstract] ABSTRACT: The Department of Defense (DoD) and the Department of Veterans Affairs (VA) provide comprehensive HIV treatment and care to their beneficiaries with open access and few costs to the patient. Individuals who receive HIV care in the VA have higher rates of substance abuse, homelessness and unemployment than individuals who receive HIV care in the DoD. A comparison between individuals receiving HIV treatment and care from the DoD and the VA provides an opportunity to explore the impact of individual-level characteristics on clinical outcomes within two healthcare systems that are optimized for clinic retention and medication adherence. Data were collected on 1065 patients from the HIV Atlanta VA Cohort Study (HAVACS) and 1199 patients from the US Military HIV Natural History Study (NHS). Patients were eligible if they had an HIV diagnosis and began HAART between January 1, 1996 and June 30, 2010. The analysis examined the survival from HAART initiation to all-cause mortality or an AIDS event. Although there was substantial between-cohort heterogeneity and the 12-year survival of participants in NHS was significantly higher than in HAVACS in crude analyses, this survival disparity was reduced from 21.5% to 1.6% (mortality only) and 26.8% to 4.1% (combined mortality or AIDS) when controlling for clinical and demographic variables. We assessed the clinical outcomes for individuals with HIV from two very similar government-sponsored healthcare systems that reduced or eliminated many barriers associated with accessing treatment and care. After controlling for clinical and demographic variables, both 12-year survival and AIDS-free survival rates were similar for the two study cohorts who have open access to care and medication despite dramatic differences in socioeconomic and behavioral characteristics.
    Full-text Article · Jan 2013 · PLoS ONE
  • [Show abstract] [Hide abstract] ABSTRACT: A cluster-randomized trial evaluating the effectiveness of chlorhexidine gluconate-impregnated wipes against skin and soft tissue infections (SSTIs) and colonization with methicillin-resistant Staphylococcus aureus (MRSA) was conducted among military recruits attending Officer Candidate School at Marine Corps Base Quantico, Virginia. Participants were instructed to use the wipes thrice weekly and were monitored daily for SSTI. Surveys assessed frequency of wipe use as well as knowledge and attitudes regarding MRSA SSTI. Use of chlorhexidine gluconate-impregnated wipes failed to prevent SSTI; however, study adherence was moderate. Adherence with the study regimen (defined as use of > or = 50% of the wipes) was 65% at week 2 and declined to 49% by week 6. Adherence was approximately 59% in the first two classes and declined in later classes. One-third felt that use of the wipes was disruptive. Participants were knowledgeable about MRSA SSTI prevention measures. However, only 53% agreed that MRSA commonly causes skin infections in military training facilities. Understanding adherence and its determinants is needed to optimize prevention strategies that require self-administration. Future efforts should address barriers to adherence with prevention strategies in recruit training settings.
    Article · Nov 2012 · Military medicine
  • Article · Nov 2012 · Clinical Infectious Diseases
  • Britta Babel · Timothy Whitman · Lindsay Stevenson
    [Show abstract] [Hide abstract] ABSTRACT: Background: Fosfomycin is an older antibiotic, recently recommended as first-line therapy for uncomplicated cystitis. International studies have reported that fosfomycin possesses good activity against common urinary pathogens, but recent data from U.S. hospitals are sparse. In this project, fosfomycin susceptibility data is reported for urinary pathogens from a U.S. hospital. Methods: 149 non-duplicative, clinically significant, isolates recovered from urinary clinical samples were tested by disk diffusion methods described by the Clinical and Laboratory Standards Institute (CLSI). Interpretive criteria for susceptibility were based on CLSI criteria for E. coli (for gram-negative bacteria) and E. faecalis (for gram-positive bacteria). Results: For bacterial species with at least 4 tested isolates, the % susceptible was: E. coli (92%), K. pneumoniae (75%), P. mirabilis (89%), P. aeruginosa (50%), C. koseri (75%), E. cloacae (75%) and E. faecalis (100%). Overall, 90% of urinary pathogens were susceptible to fosfomycin. Conclusion: Similar to results published in non-U.S. hospitals, fosfomycin appears to possess good in vitro activity against common urinary pathogens. However, despite minimal use of fosfomycin at our institution, non-susceptible isolates were detected in almost 10% of E. coli, which may increase in parallel with expanded use of fosfomycin. Routine testing of urinary clinical isolates for fosfomycin susceptibility is suggested to aid clinical decision-making.
    Conference Paper · Oct 2012
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    Full-text Article · Oct 2012 · Infection Control and Hospital Epidemiology
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    Timothy J Whitman · Carey D Schlett · Greg A Grandits · [...] · David R Tribble
    [Show abstract] [Hide abstract] ABSTRACT: Methicillin-resistant Staphylococcus aureus (MRSA) pulsed-field type (PFT) USA300 causes skin and soft tissue infections in military recruits and invasive disease in hospitals. Chlorhexidine gluconate (CHG) is used to reduce MRSA colonization and infection. The impact of CHG on the molecular epidemiology of MRSA is not known. To evaluate the impact of 2% CHG-impregnated cloths on the molecular epidemiology of MRSA colonization. Cluster-randomized, double-blind, controlled trial. Marine Officer Candidate School, Quantico, Virginia, in 2007. Military recruits. Thrice-weekly application of CHG-impregnated or control (Comfort Bath; Sage) cloths over the entire body. Baseline and serial (every 2 weeks) nasal and/or axillary swab samples were assessed for MRSA colonization. Molecular analysis was performed with pulsed-field gel electrophoresis. During training, 77 subjects (4.9%) acquired MRSA, 26 (3.3%) in the CHG group and 51 (6.5%) in the control group (P=.004). When analyzed for PFT, 24 subjects (3.1%) in the control group but only 6 subjects (0.8%) in the CHG group (P=.001) had USA300. Of the 167 colonizing isolates recovered from 77 subjects, 99 were recovered from the control group, including USA300 (40.4%), USA800 (38.4%), USA1000 (12.1%), and USA100 (6.1%), and 68 were recovered from the CHG group, including USA800 (51.5%), USA100 (23.5%), and USA300 (13.2%). CHG decreased the transmission of MRSA--more specifically, USA300--among military recruits. In addition, USA300 and USA800 outcompeted other MRSA PFTs at incident colonization. Future studies should evaluate the broad-based use of CHG to decrease transmission of USA300 in hospital settings.
    Full-text Article · Aug 2012 · Infection Control and Hospital Epidemiology
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    [Show abstract] [Hide abstract] ABSTRACT: Immunoglobulin (Ig)G levels are important for antibody vaccine responses and IgG subclass deficiencies have been associated with severe 2009 influenza A (H1N1) infections. Studies have demonstrated variations in immune responses to the H1N1 vaccine, but the aetiology of this is unknown. We determined the associations between pre-vaccination overall and influenza-specific IgG subclass levels and 2009 H1N1-specific antibody responses post-vaccination (robust versus poor at day 28) stratified by human immunodeficiency virus (HIV) status. Logistic regression models were utilized to evaluate whether pre-vaccination IgG subclass levels were associated with the antibody response generated post-vaccination. We evaluated 48 participants as part of a clinical study who were stratified by robust versus poor post-vaccination immune responses. Participants had a median age of 35 years; 92% were male and 44% were Caucasian. HIV-infected adults had a median CD4 count of 669 cells/mm(3) , and 79% were receiving highly active anti-retroviral therapy. HIV-infected participants were more likely to have IgG2 deficiency (<240 mg/dl) than HIV-uninfected individuals (62% versus 4%, P < 0·001). No association of pre-vaccination IgG subclass levels (total or influenza-specific) and the antibody response generated by HIN1 vaccination in either group was found. In summary, pre-vaccination IgG subclass levels did not correlate with the ability to develop robust antibody responses to the 2009 influenza A (H1N1) monovalent vaccine. IgG2 deficiencies were common among HIV-infected individuals but did not correlate with poor influenza vaccine responses. Further investigations into the aetiology of disparate vaccine responses are needed.
    Full-text Article · Apr 2012 · Clinical & Experimental Immunology
  • Timothy Whitman · Carey Schlett · Greg Grandits · [...] · David Tribble
    [Show abstract] [Hide abstract] ABSTRACT: Background: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) causes skin and soft tissue infections (SSTI) in military recruits. Molecular methods such as pulsed-field gel electrophoresis (PFGE) characterize specific CA-MRSA types among isolates associated with invasive disease vs. colonization. As colonization can precede SSTI, insight into the longitudinal molecular epidemiology of colonization is important for disease prevention. Methods: A cluster-randomized, double-blind, controlled trial comparing the effectiveness of thrice-weekly chlorhexidine (CHG) cloths with control (Comfort Bath) in SSTI prevention was conducted in military recruits. Baseline and serial nasal/axillary swabs assessed for CA-MRSA colonization. Isolates were typed by PFGE. Results: Of the 1562 subjects enrolled, 32 (2.0%) were colonized with CA-MRSA at baseline, primarily with PFGE types USA800 (31%), USA100 (25%), USA1000 (16%), and USA300 (13%). After 10 weeks, the CHG group had 68 follow-up CA-MRSA colonization episodes which included types USA800 (51.5%), USA100 (23.5%), USA300 (13.2%). In contrast, the control group had 99 CA-MRSA colonization episodes which included types USA300 (40.4%), USA800 (38.4%), USA1000 (12.1%), and USA100 (6.1%). The mean cumulative incidence of USA300 colonization was lower in the CHG group than in the control group (0.9% vs. 3.6%, [P= 0.058]). Conclusion: Use of CHG caused a trend towards decreased acquisition of CA-MRSA type USA300 in military recruits. Furthermore, increased colonization with less virulent types, namely USA800, was observed over time. Future studies should evaluate why colonization dynamics, and the impact of CHG on molecular epidemiology, varies by CA-MRSA type.
    Conference Paper · Oct 2011
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    [Show abstract] [Hide abstract] ABSTRACT: Despite advances in resuscitation and surgical management of combat wounds, infection remains a concerning and potentially preventable complication of combat-related injuries. Interventions currently used to prevent these infections have not been either clearly defined or subjected to rigorous clinical trials. Current infection prevention measures and wound management practices are derived from retrospective review of wartime experiences, from civilian trauma data, and from in vitro and animal data. This update to the guidelines published in 2008 incorporates evidence that has become available since 2007. These guidelines focus on care provided within hours to days of injury, chiefly within the combat zone, to those combat-injured patients with open wounds or burns. New in this update are a consolidation of antimicrobial agent recommendations to a backbone of high-dose cefazolin with or without metronidazole for most postinjury indications and recommendations for redosing of antimicrobial agents, for use of negative pressure wound therapy, and for oxygen supplementation in flight.
    Full-text Article · Aug 2011 · The Journal of trauma