Michael L. Landrum

Clinical Outcomes of Elite Controllers, Viremic Controllers, and Long-Term Nonprogressors in the US Department of Defense HIV Natural History Study

Durable control of human immunodeficiency virus (HIV) replication and lack of disease progression in the absence of antiretroviral therapy were studied in a military cohort of 4586 subjects. We examined groups of elite controllers (ie, subjects with plasma HIV RNA levels of <50 copies/mL; prevalence, 0.55% [95% confidence interval {CI}, 0.35%-0.80%]), viremic controllers (ie, subjects with plasma HIV RNA levels of 50-2000 copies/mL; prevalence, 3.34% [95% CI, 2.83%-3.91%]), and subjects with a lack of disease progression (ie, long-term nonprogressors [LTNPs]) through 7 years of follow-up (LTNP7s; prevalence, 3.32% [95% CI, 2.70%-4.01%]) or 10 years of follow-up (LTNP10s; prevalence, 2.04% [95% CI, 1.52%-2.68%]). For elite and viremic controllers, spontaneous virologic control was established early and was typically observed when the initial viral load measurement was obtained within 1 year of estimated seroconversion. Elite controllers had favorable time to development of AIDS (P=.048), a CD4 cell count of 350 cells/microL (P= .009), and more-stable CD4 cell trends, compared with viremic controllers. LTNPs defined by 10-year versus 7-year criteria had a longer survival time (P=.001), even after adjustment for differing periods of invulnerability (P= .042). Definitions of controllers and LTNPs describe distinct populations whose differing clinical outcomes improve with the stringency of criteria, underscoring the need for comparability between study populations.

Epidemiology of Staphylococcus aureus blood and skin and soft tissue infections in the US military health system, 2005-2010.

CONTEXT Rates of hospital-onset methicillin-resistant Staphylococcus aureus (MRSA) infections are reported as decreasing, but recent rates of community-onset S. aureus infections are less known. OBJECTIVES To characterize the overall and annual incidence rates of community-onset and hospital-onset S. aureus bacteremia and skin and soft tissue infections (SSTIs) in a national health care system and to evaluate trends in the incidence rates of S. aureus bacteremia and SSTIs and the proportion due to MRSA. DESIGN, SETTING, AND PARTICIPANTS Observational study of all Department of Defense TRICARE beneficiaries from January 2005 through December 2010. Medical record databases were used to identify and classify all annual first-positive S. aureus blood and wound or abscess cultures as methicillin-susceptible S. aureus or MRSA, and as community-onset or hospital-onset infections (isolates collected >3 days after hospital admission). MAIN OUTCOME MEASURES Unadjusted incidence rates per 100,000 person-years of observation, the proportion of infections that was due to MRSA, and annual trends for 2005 through 2010 (examined using the Spearman rank correlation test or the Mantel-Haenszel χ2 test for linear trend). RESULTS During 56 million person-years (nonactive duty: 47 million person-years; active duty: 9 million person-years), there were 2643 blood and 80,281 wound or abscess annual first-positive S. aureus cultures. Annual incidence rates varied from 3.6 to 6.0 per 100,000 person-years for S. aureus bacteremia and 122.7 to 168.9 per 100,000 person-years for S. aureus SSTIs. The annual incidence rates for community-onset MRSA bacteremia decreased from 1.7 per 100,000 person-years (95% CI, 1.5-2.0 per 100,000 person-years) in 2005 to 1.2 per 100,000 person-years (95% CI, 0.9-1.4 per 100,000 person-years) in 2010 (P = .005 for trend). The annual incidence rates for hospital-onset MRSA bacteremia also decreased from 0.7 per 100,000 person-years (95% CI, 0.6-0.9 per 100,000 person-years) in 2005 to 0.4 per 100,000 person-years (95% CI, 0.3-0.5 per 100,000 person-years) in 2010 (P = .005 for trend). Concurrently, the proportion of community-onset SSTI due to MRSA peaked at 62% in 2006 before decreasing annually to 52% in 2010 (P < .001 for trend). CONCLUSION In the Department of Defense population consisting of men and women of all ages from across the United States, the rates of both community-onset and hospital-onset MRSA bacteremia decreased in parallel, while the proportion of community-onset SSTIs due to MRSA has more recently declined.

Invasive mold infections following combat-related injuries.

BACKGROUND Major advances in combat casualty care have led to increased survival of patients with complex extremity trauma. Invasive fungal wound infections (IFIs) are an uncommon, but increasingly recognized, complication following trauma that require greater understanding of risk factors and clinical findings to reduce morbidity. METHODS The patient population includes US military personnel injured during combat from June 2009 through December 2010. Case definition required wound necrosis on successive debridements with IFI evidence by histopathology and/or microbiology (Candida spp excluded). Case finding and data collected through the Trauma Infectious Disease Outcomes Study utilized trauma registry, hospital records or operative reports, and pathologist review of histopathology specimens. RESULTS A total of 37 cases were identified: proven (angioinvasion, n=20), probable (nonvascular tissue invasion, n=4), and possible (positive fungal culture without histopathological evidence, n=13). In the last quarter surveyed, rates reached 3.5% of trauma admissions. Common findings include blast injury (100%) during foot patrol (92%) occurring in southern Afghanistan (94%) with lower extremity amputation (80%) and large volume blood transfusion (97.2%). Mold isolates were recovered in 83% of cases (order Mucorales, n=16; Aspergillus spp, n=16; Fusarium spp, n=9), commonly with multiple mold species among infected wounds (28%). Clinical outcomes included 3 related deaths (8.1%), frequent debridements (median, 11 cases), and amputation revisions (58%). CONCLUSIONS IFIs are an emerging trauma-related infection leading to significant morbidity. Early identification, using common characteristics of patient injury profile and tissue-based diagnosis, should be accompanied by aggressive surgical and antifungal therapy (liposomal amphotericin B and a broad-spectrum triazole pending mycology results) among patients with suspicious wounds.

Hepatitis B Virus Coinfection Negatively Impacts HIV Outcomes in HIV Seroconverters

BACKGROUND Understanding the impact of hepatitis B virus (HBV) in human immunodeficiency virus (HIV) coinfection has been limited by heterogeneity of HIV disease. We evaluated HBV coinfection and HIV-related disease progression in a cohort of HIV seroconverters. METHODS Participants with HIV diagnosis seroconversion window of ≤ 3 years and serologically confirmed HBV infection (HB) status were classified at baseline into 4 HB groups. The risk of clinical AIDS/death in HIV seroconverters was calculated by HB status. RESULTS Of 2352 HIV seroconverters, 474 (20%) had resolved HB, 82 (3%) had isolated total antibody to hepatitis B core antigen (HBcAb), and 64 (3%) had chronic HB. Unadjusted rates (95% confidence intervals [CIs]) of clinical AIDS/death for the HB-negative, resolved HB, isolated HBcAb, and chronic HB groups were 2.43 (2.15-2.71); 3.27 (2.71-3.84); 3.75 (2.25-5.25); and 5.41 (3.41-7.42), respectively. The multivariable risk of clinical AIDS/death was significantly higher in the chronic HB group compared to the HB-negative group (hazard ratio [HR], 1.80; 95% CI, 1.20-2.69); while the HRs were increased but nonsignificant for those with resolved HB (HR, 1.17; 95% CI, .94-1.46) and isolated HBcAb (HR, 1.14; 95% CI, .75-1.75). CONCLUSIONS HBV coinfection has a significant impact on HIV outcomes. The hazard for an AIDS or death event is almost double for those with chronic HB compared, with HIV-monoinfected persons.

Infection-associated clinical outcomes in hospitalized medical evacuees after traumatic injury: trauma infectious disease outcome study.

Infections have long been known to complicate care in patients following traumatic injury frequently leading to excess morbidity and mortality.1, 2 In no setting is this more well-recognized than the challenging environment of combat casualty care. During the current military conflicts in Iraq and Afghanistan, Operations Iraqi and Enduring Freedom (OIF/OEF), major advances resulting in increased survival among wounded personnel have been observed. These include enhanced training of medics, forward deployment of surgical assets, rapid medical evacuation, and improvements in body armor.3–5 The significant advances leading to survival are coupled with major challenges in care due to the extensive nature of the injuries, profound bone and soft tissue disruption, and extensive wound contamination.6, 7 In addition, the rapid transit of these patients through multiple echelons of medical care places significant obstacles on infection control in an era of increasing risk due to hospital-associated multidrug resistant (MDRO) organisms.8, 9 The U.S. Department of Defense (DoD) has implemented a range of measures to improve combat casualty care and mitigate risk of infectious complications. A Joint Theater Trauma System and Joint Theater Trauma Registry (JTTR) have been developed to benchmark metrics and to provide a timely assessment of performance improvement interventions.5, 10, 11 Efforts to prevent infection include the development of guidelines for the prevention of infection related to combat injuries through comprehensive review of current evidence and consensus review by military and civilian experts in trauma, infectious disease, infection control, preventive medicine, and surgical specialties.12 In addition, standardized infection control measures across echelons of care accompanied by enhanced MDRO surveillance and serial evaluation have also been implemented.13, 14 Despite the growing literature describing infectious complications of combat-related trauma, there is still a lack of prospectively collected standardized infection data that includes specific therapy, microbiological findings and clinical outcomes across treatment facilities. This report describes the initial data and current status of an ongoing 5-year prospective observational cohort study of infectious complications associated with traumatic injury sustained during deployment, the DoD-Department of Veterans Affairs (VA) Trauma Infectious Disease Outcomes Study (TIDOS).

A randomized clinical trial comparing revaccination with pneumococcal conjugate vaccine to polysaccharide vaccine among HIV-infected adults

BACKGROUND The risk of pneumococcal disease persists, and antibody responses to revaccination with the 23-valent polysaccharide vaccine (PPV) are low among human immunodeficiency virus (HIV)-infected adults. We determined whether revaccination with the 7-valent pneumococcal conjugate vaccine (PCV) would enhance these responses. METHODS In a randomized clinical trial, we compared the immunogenicity of revaccination with PCV ( n = 131) or PPV (n = 73) among HIV-infected adults (median CD4 cell count, 533 cells/mm(3)) who had been vaccinated with PPV 3-8 years earlier. HIV-uninfected adults (n = 25) without prior pneumococcal vaccination received 1 dose of PCV. A positive response was defined as a >or=2-fold increase (from baseline to day 60) in capsule-specific immunoglobulin G, with a postvaccination level >or=1000 ng/mL for at least 2 of the 4 serotypes. RESULTS HIV-infected persons demonstrated a higher frequency of positive antibody responses to PCV than to PPV (57% vs 36%) (P = .004) and greater mean changes in the immunoglobulin G concentration from baseline to day 60 for serotypes 4, 9V, and 19F (P < .05, for all), but not for serotype 14. However, by day 180, both outcomes were similar. Responses to PCV were greater in frequency and magnitude for all serotypes in HIV-uninfected adults, compared with those in HIV-infected adults. CONCLUSIONS Among persons with HIV infection, revaccination with PCV was only transiently more immunogenic than PPV, and responses were inferior to those in HIV-uninfected subjects with primary vaccination. Pneumococcal vaccines with more robust and sustained immunogenicity are needed for HIV-infected adults. Clinical trial registration. ClinicalTrials.gov identifier NCT00622843.

HIV-1 Disease-Influencing Effects Associated with ZNRD1, HCP5 and HLA-C Alleles Are Attributable Mainly to Either HLA-A10 or HLA-B*57 Alleles

A recent genome-wide association study (GWAS) suggested that polymorphisms in or around the genes HCP5, HLA-C and ZNRD1 confer restriction against HIV-1 viral replication or disease progression. Here, we also find that these alleles are associated with different aspects of HIV disease, albeit mainly in European Americans. Additionally, we offer that because the GWAS cohort was a subset of HIV-positive individuals, selected based in part on having a low viral load, the observed associations for viral load are magnified compared with those we detect in a large well-characterized prospective natural history cohort of HIV-1-infected persons. We also find that because of linkage disequilibrium (LD) patterns, the dominant viral load- and disease-influencing associations for the ZNRD1 or HLA-C and HCP5 alleles are apparent mainly when these alleles are present in HLA-A10- or HLA-B*57-containing haplotypes, respectively. ZNRD1 alleles lacking HLA-A10 did not confer disease protection whereas ZNRD1-A10 haplotypes did. When examined in isolation, the HCP5-G allele associates with a slow disease course and lower viral loads. However, in multivariate models, after partitioning out the protective effects of B*57, the HCP5-G allele associates with disease-acceleration and enhanced viral replication; these associations for HCP5-G are otherwise obscured because of the very strong LD between this allele and a subset of protective B*57 alleles. Furthermore, HCP5 and HLA-C alleles stratify B*57-containing genotypes into those that associate with either striking disease retardation or progressive disease, providing one explanation for the long-standing conundrum of why some HLA-B*57-carrying individuals are long-term non-progressors, whereas others exhibit progressive disease. Collectively, these data generally underscore the strong dependence of genotype-phenotype relationships upon cohort design, phenotype selection, LD patterns and populations studied. They specifically demonstrate that the influence of ZNRD1 alleles on disease progression rates are attributable to HLA-A10, help clarify the relationship between the HCP5, HLA-C and HLA-B*57 alleles, and reaffirm a critical role of HLA-B*57 alleles in HIV disease. Furthermore, as the protective B*57-containing genotypes convey striking salutary effects independent of their strong impact on viral control, it is conceivable that T cell-based therapeutic vaccine strategies aimed at reducing viral loads may be inadequate for limiting AIDS progression, raising the potential need for complementary strategies that target viral load-independent determinants of pathogenesis.

Outcomes of highly active antiretroviral therapy in the context of universal access to healthcare: the U.S. Military HIV Natural History Study

BackgroundTo examine the outcomes of highly-active antiretroviral therapy (HAART) for individuals with free access to healthcare, we evaluated 2327 patients in a cohort study composed of military personnel and beneficiaries with HIV infection who initiated HAART from 1996 to the end of 2007.MethodsOutcomes analyzed were virologic suppression (VS) and failure (VF), CD4 count changes, AIDS and death. VF was defined as never suppressing or having at least one rebound event. Multivariate (MV) analyses stratified by the HAART initiation year (before or after 2000) were performed to identify risk factors associated with these outcomes.ResultsAmong patients who started HAART after 2000, 81% had VS at 1 year (N = 1,759), 85% at 5 years (N = 1,061), and 82% at 8 years (N = 735). Five years post-HAART, the median CD4 increase was 247 cells/ml and 34% experienced VF. AIDS and mortality rates at 5 years were 2% and 0.3%, respectively. In a MV model adjusted for known risk factors associated with treatment response, being on active duty (versus retired) at HAART initiation was associated with a decreased risk of AIDS (HR = 0.6, 95% CI 0.4-1.0) and mortality (0.6, 0.3-0.9), an increased probability of CD4 increase ≥ 50% (1.2, 1.0-1.4), but was not significant for VF.ConclusionsIn this observational cohort, VS rates approach those described in clinical trials. Initiating HAART on active duty was associated with even better outcomes. These findings support the notion that free access to healthcare likely improves the response to HAART thereby reducing HIV-related morbidity and mortality.

Trends and Causes of Hospitalizations among HIV-Infected Persons during the Late HAART Era: What is the Impact of CD4 Counts and HAART Use?

Background:Declining rates of hospitalizations occurred shortly after the availability of highly active antiretroviral therapy (HAART). However, trends in the late HAART era are less defined, and data on the impact of CD4 counts and HAART use on hospitalizations are needed. Methods:We evaluated hospitalization rates from 1999 to 2007 among HIV-infected persons enrolled in a large US military cohort. Poisson regression was used to compare hospitalization rates per year and to examine factors associated with hospitalization. Results:Of the 2429 participants, 822 (34%) were hospitalized at least once with 1770 separate hospital admissions. The rate of hospitalizations (137 per 1000 person-years) was constant over the study period [relative rate (RR) 1.00 per year change, 95% confidence interval: 0.98 to 1.02]. The hospitalization rates due to skin infections (RR: 1.50, P = 0.02), methicillin-resistant staphylococcus aureus (RR: 3.19, P = 0.03), liver disease (RR: 1.71, P = 0.04), and surgery (RR: 1.17, P = 0.04) significantly increased over time, whereas psychological causes (RR: 0.60, P < 0.01) and trauma (RR: 0.54, P < 0.01) decreased. In the multivariate model, higher nadir CD4 (RR: 0.92 per 50 cells, P < 0.01) and higher proximal CD4 counts (RR of 0.71 for 350-499 vs. <350 cells/mm3 and RR 0.67 for ≥500 vs. <350 cells/mm3, both P < 0.01) were associated with lower risk of hospitalization. Risk of hospitalization was constant for proximal CD4 levels above 350 (RR: 0.94 P = 0.51, CD4 ≥500 vs. 350-499). HAART was associated with a reduced risk of hospitalization among those with a CD4 <350 (RR: 0.72, P = 0.02) but had smaller estimated and nonsignificant effects at higher CD4 levels (RR: 0.81, P = 0.33 and 1.06, P = 0.71 for CD4 350-499 and ≥500, respectively). Conclusions:Hospitalizations continue to occur at high rates among HIV-infected persons with increasing rates for skin infections, methicillin-resistant staphylococcus aureus, liver disease, and surgeries. Factors associated with a reduced risk of hospitalization include CD4 counts >350 cells per cubic millimeter and HAART use among patients with a CD4 count <350 cells per cubic millimeter.

Hepatitis B vaccine responses in a large U.S. military cohort of HIV-infected individuals: Another benefit of HAART in those with preserved CD4 count

The influence of highly active antiretroviral therapy (HAART) upon hepatitis B virus (HBV) vaccine responses in HIV-infected individuals is unclear. After classification of vaccinees as non-responders (HBsAb <10IU/L) or responders (HBsAb >or=10IU/L) in our HIV cohort, multivariate logistic regression was used to assess factors associated with subsequent vaccine response. Of 626 participants vaccinated from 1988 to 2005, 217 (35%) were vaccine responders. Receipt of >or=3 doses of vaccine (OR 1.83, 95% CI 1.24-2.70), higher CD4 count at vaccination (OR 1.09, 95% CI 1.05-1.13 per 50 cells/microl increase), and use of HAART (OR 2.37, 95% CI 1.56-3.62) were all associated with increased likelihood of developing a response. However, only 49% of those on HAART at last vaccination responded, and 62% of those on HAART, with CD4 count >or=350, and HIV RNA <400 copies/mL responded. Compared to those on HAART with CD4 count >or=350, those not on HAART with CD4 count >or=350 had significantly reduced odds of developing a vaccine response (OR 0.47, 95% CI 0.30-0.70). While HAART use concurrent with HBV immunization was associated with increased probability of responding to the vaccine, the response rate was low for those on HAART. These data provide additional evidence of HAART benefits, even in those with higher CD4 counts, but also highlight the need for improving HBV vaccine immunogenicity.