Journal Club
In this feature, a panel of IDSA members identifies and critiques important new studies in the current literature that have a significant impact on the practice of infectious diseases medicine.
- Taking It to Heart: Estimating Excess Heart Age in People Living with HIV
- Presentation and Outcome of Cryptococcal Infection According to Predisposing Illness
- What’s the Real Relationship Between Finding S. aureus in the Urine and Bacteremia?
Click here for the previous edition of Journal Club. For a review of other recent research in the infectious diseases literature, see “In the Literature,” by Stanley Deresinski, MD, FIDSA, in each issue of Clinical Infectious Diseases.
Taking It to Heart: Estimating Excess Heart Age in People Living with HIV
Reviewed by Erica Kaufman West, MD
Cardiovascular disease tools, like the Framingham Risk Score, can be helpful for primary care providers in estimating a patient’s individual risk for heart disease. Unfortunately, these tools underestimate the risk in people living with HIV (PLWH). The authors of an article recently published in AIDS used two heart age calculators, a cholesterol-based and a Body Mass Index-based model. There was no significant difference between the two.
Over 3,000 patients’ data were analyzed over an 8-year period. Participants had to have at least two visits, were between ages 30-74, were not pregnant, and had no known coronary artery disease (CAD) or CAD equivalents. While the mean chronological age for men was 49.3 and women was 49.1, the greatest excess heart age was for PLWH who were 50-59, as the excess heart age was 13.7 years for men and 16.4 years for women. By comparison, the general population’s excess heart age for men is 7.8 years and 5.4 years for women. Importantly, more than half of all participants had at least a 10-year excess heart age, and HIV-positive women were consistently at higher heart ages than men.
The cardiovascular literature has recognized this as well, with a recent article looking specifically at PLWH and taking into account things like viral suppression, hepatitis C virus coinfection, nadir CD4 count, and other pro-inflammatory states. This is a welcome addition for providers who do primary care for HIV-positive patients. HIV primary care providers should talk to their patients about their excess heart age and develop a targeted approach based on this age.
(Thompson-Paul et al. AIDS. 2019;33(12):1935–1942.)
Presentation and Outcome of Cryptococcal Infection According to Predisposing Illness
Reviewed by Zeina A. Kanafani, MD, MS, FIDSA
Infection with Cryptococcus neoformans has been traditionally associated with HIV infection. Recently, however, an increasing number of cases have been reported in other patient populations, namely transplant recipients and non-HIV nontransplant (NHNT) patients.
In a retrospective cohort study reported in the American Journal of Medicine, the investigators studied the clinical manifestations, treatment, and outcomes of patients diagnosed with cryptococcosis by comparing three patient populations: people living with HIV (n = 105; 35 percent), transplant patients (n = 41; 13 percent), and NHNT patients (n = 158; 52 percent).
Patients in the NHNT arm were older, with a mean age of 60.5 years, compared to those in the HIV arm (40.0 years) and the transplant arm (53.0 years). Whereas in the HIV group there was a predominance of central nervous system (CNS) infection (68 percent), with pulmonary infections constituting 10 percent of cases, the NHNT group had an equal distribution of CNS and pulmonary infections (39 percent and 38 percent, respectively). NHNT patients were also less likely to have disseminated disease and a positive serum cryptococcal antigen. The median duration of symptoms in the NHNT group was 19.0 days compared to 14.0 days in the HIV and transplant group (P = 0.036). In addition, there was a delay in diagnosis by one day in the NHNT and transplant patients compared to HIV patients.
The mortality at 90 days was 41.1 percent in NHNT patients compared to 15.2 percent in HIV patients and 12.2 percent in transplant patients (P < 0.001). This amounted to a 3.3-fold increase in the risk of death at 90 days for NHNT vs. HIV patients. Predictors of mortality in NHNT patients included end-stage liver disease (hazard ratio [HZ] 5.7; 95 percent confidence interval [CI], 3.4-9.7), not receiving treatment (HZ 4.5; 95 percent CI, 2.9-7.1), and presence of disseminated disease (HZ 2.3; 95 percent CI, 1.2-4.4).
Based on the above findings, the authors highlighted the importance of recognizing this shift in the epidemiology, manifestations, and outcomes of cryptococcosis in the non-HIV population.
(Hevey et al. Am J Med. 2019;132(8):977–983.e1.)
What’s the Real Relationship Between Finding S. aureus in the Urine and Bacteremia?
By Christopher J. Graber, MD MPH FIDSA
A common teaching in infectious diseases is to consider occult bacteremia whenever Staphylococcus aureus bacteriuria (SABU) occurs, but how frequently and under what circumstances this happens is unclear. A recent study published in Clinical Infectious Diseases attempted to answer this question by analyzing all urine cultures positive for S. aureus from 2010-2013 in a centralized laboratory for the province of Calgary in Canada. Presence of S. aureus bacteremia (SAB) was ascertained 3 months prior to and following each positive urine culture.
Of 875,587 urine cultures collected, 3,739 (0.4 percent) were positive for S. aureus bacteriuria (SABU); 2,540 cultures from 2,054 patients were included in the analysis. SAB was present in 175 SABU episodes (6.9 percent). Compared to SABU alone, SABU+SAB was more commonly seen with younger age, male gender, recent urinary procedures, and pure urine culture positivity; the most common sources of bacteremia were osteomyelitis of the spine or pelvis (23 percent) and endocarditis (11 percent). Having SAB diagnosed greater than 48 hours after SABU was associated with mortality (odds ratio 8.87, P < .001). Patients with SABU alone were more likely to be from a nursing home or have dementia and have recurrent or persistent SABU, methicillin-resistant S. aureus, and higher urine white blood cell counts.
This study suggests that while SAB is somewhat uncommon in the setting of SABU, certain risk factors are associated with its presence and early recognition may be important.
(Stokes et al. Clin Infect Dis. 2019;69(6):963-9.)