Impact of deceased organ donor marijuana use on donor culture positivity and solid organ transplant recipient outcomes.

With the increasing prevalence of marijuana use in the US, many deceased organ donors have a history of marijuana use, raising concerns about infectious risks to transplant recipients. We performed a multicenter retrospective cohort study in which exposed donors were those with recent marijuana use (in the prior 12 months) and unexposed donors were those with no recent marijuana use. Primary outcomes included the following: (1) positive donor cultures for bacteria or fungi, (2) recipient infection due to bacteria or fungi within 3 months posttransplant, and (3) recipient graft failure or death within 12 months posttransplant. Multivariable regression was used to evaluate the relationship between donor marijuana use and each outcome. A total of 658 recipients who received organs from 394 donors were included. Recent marijuana use was not associated with donor culture positivity (aOR: 0.84, 95% CI: 0.39-1.81, P = .65), recipient infection (aHR: 1.02, 95% CI: 0.76-1.38, P = .90), or recipient graft failure or death (aHR: 1.65, 95% CI: 0.90-3.02, P = .11). Our data suggest that organs from donors with a history of recent marijuana use do not pose significant infectious risks in the early posttransplant period.

Impact of donor multidrug-resistant organisms on solid organ transplant recipient outcomes.

BACKGROUND: The impact of donor colonization or infection with multidrug-resistant organisms (MDROs) on solid organ transplant (SOT) recipient outcomes remains uncertain. We thus evaluated the association between donor MDROs and risk of posttransplant infection, graft failure, and mortality. METHODS: A multicenter retrospective cohort study was performed. All SOT recipients with a local deceased donor were included. The cohort was divided into three exposure groups: recipients whose donors had (1) an MDRO, (2) a non-MDRO bacterial or candidal organism, or (3) no growth on cultures. The primary outcomes were (1) bacterial or invasive candidal infection within 3 months and (2) graft failure or death within 12 months posttransplant. Mixed effect multivariable frailty models were developed to evaluate each association. RESULTS: Of 658 total SOT recipients, 93 (14%) had a donor with an MDRO, 477 (73%) had a donor with a non-MDRO organism, and 88 (13%) had a donor with no organisms on culture. On multivariable analyses, donor MDROs were associated with a significantly increased hazard of infection compared to those with negative donor cultures (adjust hazard ratio [aHR] 1.63, 95% CI 1.01-2.62, p = .04) but were not associated with graft failure or death (aHR 0.45, 95% CI 0.15-1.36, p = .16). CONCLUSIONS: MDROs on donor culture increase the risk of early posttransplant infection but do not appear to affect long-term graft or recipient survival, suggesting organ donors with MDROs on culture may be safely utilized. Future studies aimed at reducing early posttransplant infections associated with donor MDROs are needed.

Impact of deceased organ donor injection drug use on donor culture positivity and recipient outcomes.

BACKGROUND: Due to the ongoing opioid epidemic in the United States, deceased organ donors increasingly have a history of injection drug use (IDU), raising concerns about infectious risks to solid organ transplant (SOT) recipients. We sought to determine how recent IDU among deceased organ donors impacted donor culture results and recipient outcomes. METHODS: A retrospective cohort study was performed at three transplant centers. Exposed donors were those with "recent IDU" (in the prior 12 months). Primary outcomes included (1) positive donor cultures for bacteria or Candida species, (2) recipient bacterial or Candida infection within 3 months posttransplant, and (3) recipient graft failure or death within 12 months posttransplant. Mixed effects multivariable regression models were used to evaluate the relationship between recent donor IDU and each outcome. RESULTS: A total of 658 SOT recipients who received organs from 394 donors were included. Sixty-six (17%) donors had a history of recent IDU. Recent IDU in donors was associated with a significantly increased odds of donor culture positivity (aOR 3.65, 95% CI 1.06-12.60, p = .04) but was not associated with SOT recipient infection (aHR 0.98, 95% CI 0.71-1.36, p = .92) or graft failure or death (aHR 0.67, 95% CI 0.29-1.51, p = .33). CONCLUSION: Donors with recent IDU are more likely to have positive cultures, but their recipients' outcomes are unaffected, suggesting organs from donors with recent IDU may be safely utilized.

Antibiotic Utilization in Deceased Organ Donors.

Antibiotic use in deceased organ donors has not been previously described. In a retrospective cohort of 440 donors, we found 427 (97%) received at least one antibiotic course, 312 (71%) received broad-spectrum antibiotics, and 61 (14%) received potentially redundant antibiotics during their terminal hospitalization, suggesting a need for stewardship.

Impact of deceased donor multidrug-resistant bacterial organisms on organ utilization.

The extent to which donor multidrug-resistant organisms (MDROs) affect organ utilization remains unclear. We performed a retrospective cohort study at 4 transplant centers between 2015 and 2016 to evaluate this question. All deceased donors who donated at least one organ were included. Exposed donors had at least one MDRO on culture. Unexposed donors had no MDRO-positive cultures. Only cultures obtained during the donor's terminal hospitalization were evaluated. Multivariable regression was used to determine the association between donor MDRO and (1) number of organs transplanted per donor and (2) the match run at which each organ was accepted. Subsequently, we restricted the analysis to donors with MDR-Gram-negative (GN) organisms. Of 440 total donors, 29 (7%) donors grew MDROs and 7 (2%) grew MDR-GNs. There was no significant association between donor MDRO and either measure of organ utilization. However, donor MDR-GNs were associated with a significant reduction in the number of organs transplanted per donor (incidence rate ratio 0.43, 95% confidence interval [CI] 0.39-0.48, P < .01), and organs were accepted significantly further down the match list (relative count 5.08, 95% CI 1.64-15.68, P = .01). Though donor MDR-GNs were infrequent in our study, their growing prevalence could meaningfully reduce the donor pool over time.

Risk factors for multidrug-resistant organisms among deceased organ donors.

Donor infection or colonization with a multidrug-resistant organism (MDRO) affects organ utilization and recipient antibiotic management. Approaches to identifying donors at risk of carrying MDROs are unknown. We sought to determine the risk factors for MDROs among transplant donors. A multicenter retrospective cohort study was conducted at four transplant centers between 2015 and 2016. All deceased donors who donated at least one organ were included. Cultures obtained during the donor's terminal hospitalization and organ procurement were evaluated. The primary outcome was isolation of an MDRO on culture. Multivariable Cox regression was used to determine risk factors associated with time to donor MDRO. Of 440 total donors, 64 (15%) donors grew an MDRO on culture. Predictors of an MDRO on donor culture included hepatitis C viremia (hazard ratio [HR] 4.09, 95% confidence interval [CI] 1.71-9.78, P = .002), need for dialysis (HR 4.59, 95% CI 1.09-19.21, P = .037), prior hematopoietic cell transplant (HR 7.57, 95% CI 1.03-55.75, P = .047), and exposure to antibiotics with a narrow gram-negative spectrum (HR 1.13, 95% CI 1.00-1.27, P = .045). This is the first study to determine risk factors for MDROs among deceased donors and will be important for risk stratifying potential donors and informing transplant recipient prophylaxis.

Ceftolozane-Tazobactam for the Treatment of Multidrug-Resistant Pseudomonas aeruginosa Infections: A Multicenter Study.

BACKGROUND: Multidrug-resistant Pseudomonas aeruginosa infections remain common in hospitals worldwide. We investigated the outcomes associated with the use of ceftolozane-tazobactam for the treatment of these infections. METHODS: Data were collected retrospectively from 20 hospitals across the United States about adults who received ceftolozane-tazobactam for the treatment of multidrug-resistant P aeruginosa infections of any source for at least 24 hours. The primary outcome was a composite of 30-day and inpatient mortality, and secondary outcomes were clinical success and microbiological cure. Multivariable regression analysis was conducted to determine factors associated with outcomes. RESULTS: Two-hundred five patients were included in the study. Severe illness and high degrees of comorbidity were common, with median Acute Physiology and Chronic Health Evaluation (APACHE) II scores of 19 (interquartile range [IQR], 11-24) and median Charlson Comorbidity Indexes of 4 (IQR, 3-6). Delayed initiation of ceftolozane-tazobactam was common with therapy started a median of 9 days after culture collection. Fifty-nine percent of patients had pneumonia. On susceptibility testing, 125 of 139 (89.9%) isolates were susceptible to ceftolozane-tazobactam. Mortality occurred in 39 patients (19%); clinical success and microbiological cure were 151 (73.7%) and 145 (70.7%), respectively. On multivariable regression analysis, starting ceftolozane-tazobactam within 4 days of culture collection was associated with survival (adjusted odds ratio [OR], 5.55; 95% confidence interval [CI], 2.14-14.40), clinical success (adjusted OR, 2.93; 95% CI, 1.40-6.10), and microbiological cure (adjusted OR, 2.59; 95% CI, 1.24-5.38). CONCLUSIONS: Ceftolozane-tazobactam appeared to be effective in the treatment of multidrug-resistant P aeruginosa infections, particularly when initiated early after the onset of infection.