Invasive Fungal Infections in Inpatient Solid Organ Transplant Recipients With COVID-19: A Multicenter Retrospective Cohort.

BACKGROUND: The prevalence and outcomes of COVID-19-associated invasive fungal infections (CAIFIs) in solid organ transplant recipients (SOTRs) remain poorly understood. METHODS: A retrospective cohort study of SOTRs with COVID-19 admitted to 5 hospitals within Johns Hopkins Medicine was performed between March 2020 and March 2022. Cox regression multilevel mixed-effects ordinal logistic regression was used. RESULTS: In the cohort of 276 SOTRs, 22 (8%) developed IFIs. The prevalence of CAIFIs was highest in lung transplant recipients (20%), followed by recipients of heart (2/28; 7.1%), liver (3/46; 6.5%), and kidney (7/149; 4.7%) transplants. In the overall cohort, only 42 of 276 SOTRs (15.2%) required mechanical ventilation; these included 11 of 22 SOTRs (50%) of the CAIFI group and 31 of 254 SOTRs (12.2%) of the no-CAIFI group. Compared with those without IFIs, SOTs with IFIs had worse outcomes and required more advanced life support (high-flow oxygen, vasopressor, and dialysis). SOTRs with CAIFIs had higher 1-y death-censored allograft failure (hazard ratio 1.6 5.1 16.4 , P  = 0.006) and 1-y mortality adjusting for oxygen requirement (adjusted hazard ratio 1.1 2.4 5.1 , P  < 0.001), compared with SOTRs without CAIFIs. CONCLUSIONS: The prevalence of CAIFIs in inpatient SOTRs with COVID-19 is substantial. Clinicians should be alert to the possibility of CAIFIs in SOTRs with COVID-19, particularly those requiring supplemental oxygen, regardless of their intubation status.

Needs assessment of a pythiosis continuing professional development program.

BACKGROUND: Pythiosis is a rare disease with high mortality, with over 94% of cases reported from Thailand and India. Prompt diagnosis and surgery improves patient outcomes. Therefore, continuing professional development (CPD) is essential for early recognition. However, a needs assessment related to a pythiosis CPD program has not been performed. OBJECTIVES: We conducted a needs assessment to develop a pythiosis CPD program. PATIENTS/METHODS: We conducted a survey study with 267 King Chulalongkorn Memorial Hospital residents (141 internal medicine (IM) residents and 126 surgery residents). A 30-item survey consisting of a knowledge assessment, demographic section, and an attitudes portion was distributed both electronically and via paper. The data was analyzed with descriptive and inferential statistics. RESULTS: Sixty-seven percent completed the survey (110/141 IM residents, 70/126 surgery residents). The mean score [95% confidence interval] on the knowledge assessment was 41.67% [39.64%-43.69%] across all objectives. The three domains with the highest scores were pythiosis risk factors (67.22% correct), microbiologic characteristics (50.83%), and radiographic interpretation (50.56%). The three domains with the lowest scores were laboratory investigation (15.00%), epidemiology (29.17%), and symptomatology (30.83%). Most participants noted that the program should be online with both synchronous and asynchronous sessions, with a preferred length of 60-90 minutes per session. CONCLUSION: The pythiosis CPD program should emphasize education regarding symptomatology, laboratory investigation, and epidemiology, all of which are critical for the early detection of pythiosis to decrease mortality from this devastating disease. Most respondents felt this program was necessary and should be implemented in a virtual blended format.

Attenuated immunogenicity of SARS-CoV-2 vaccines and risk factors in stem cell transplant recipients: a meta-analysis.

Immunogenicity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination is diminished in hematopoietic stem cell transplant (HSCT) recipients. To summarize current evidence and identify risk factors for attenuated responses, 5 electronic databases were searched since database inceptions through 12 January 2023 for studies reporting humoral and/or cellular immunogenicity of SARS-CoV-2 vaccination in the HSCT population. Using descriptive statistics and random-effects models, extracted numbers of responders and pooled odds ratios (pORs) with 95% confidence intervals (CIs) for risk factors of negative immune responses were analyzed (PROSPERO: CRD42021277109). From 61 studies with 5906 HSCT recipients, after 1, 2, and 3 doses of messenger RNA (mRNA) SARS-CoV-2 vaccines, the mean antispike antibody seropositivity rates (95% CI) were 38% (19-62), 81% (77-84), and 80% (75-84); neutralizing antibody seropositivity rates were 52% (40-64), 71% (54-83), and 78% (61-89); and cellular immune response rates were 52% (39-64), 66% (51-79), and 72% (52-86). After 2 vaccine doses, risk factors (pOR; 95% CI) associated with antispike seronegativity were male recipients (0.63; 0.49-0.83), recent rituximab exposure (0.09; 0.03-0.21), haploidentical allografts (0.46; 0.22-0.95), <24 months from HSCT (0.25; 0.07-0.89), lymphopenia (0.18; 0.13-0.24), hypogammaglobulinemia (0.23; 0.10-0.55), concomitant chemotherapy (0.48; 0.29-0.78) and immunosuppression (0.18; 0.13-0.25). Complete remission of underlying hematologic malignancy (2.55; 1.05-6.17) and myeloablative conditioning (1.72; 1.30-2.28) compared with reduced-intensity conditioning were associated with antispike seropositivity. Ongoing immunosuppression (0.31; 0.10-0.99) was associated with poor cellular immunogenicity. In conclusion, attenuated humoral and cellular immune responses to mRNA SARS-CoV-2 vaccination are associated with several risk factors among HSCT recipients. Optimizing individualized vaccination and developing alternative COVID-19 prevention strategies are warranted.

Ribavirin treatment for respiratory syncytial virus infection in patients with haematologic malignancy and haematopoietic stem cell transplant recipients: a systematic review and meta-analysis.

BACKGROUND: Ribavirin use for respiratory syncytial virus (RSV) infection in patients with haematologic malignancies (HM) and haematopoietic stem cell transplant (HSCT) recipients remains controversial. OBJECTIVES: To summarize the current evidence of ribavirin treatment in association with mortality and progression to lower respiratory tract infection (LRTI) among patients with HM/HSCT with RSV infection. DATA SOURCES: MEDLINE, Embase, and the Institute for Scientific Information Web of Science. STUDY ELIGIBILITY CRITERIA: Randomized controlled trials and observational studies investigating the effects of ribavirin, compared with treatment without ribavirin, for RSV infection. PARTICIPANTS: Patients with HM/HSCT. INTERVENTIONS: Ribavirin versus no ribavirin. ASSESSMENT OF RISK OF BIAS: The risk of bias in non-randomized studies of exposure (ROBIN-E). METHODS OF DATA SYNTHESIS: The random-effects model was used to calculate the pooled OR (pOR) with 95% CI for the pooled effect estimates of ribavirin benefits. Grading of recommendation assessment, development, and evaluation was used to evaluate the certainty of evidence. RESULTS: One randomized controlled trial and 14 observational studies were included, representing 1125 patients with HM/HSCT. Ribavirin use was not associated with lower all-cause or RSV-associated mortality with pORs [95% CI] of 0.81 [0.40, 1.66], I2 = 55% (low certainty of evidence) and 0.48 [0.11, 2.15], I2 = 64% (very low certainty of evidence), respectively. In subgroup analyses, ribavirin use was associated with lower mortality in patients with HM/HSCT with LRTI with pOR [95% CI] of 0.19 [0.07, 0.51], I2 = 0% (moderate certainty of evidence). In subgroup analyses among studies providing adjusted OR, ribavirin use was associated with lower all-cause mortality with pOR of 0.41 [0.23, 0.74], I2 = 0% (moderate certainty of evidence). In addition, aerosolized ribavirin was associated with lower progression to LRTI with pOR [95% CI] of 0.27 [0.09, 0.80], I2 = 71% (low certainty of evidence). CONCLUSIONS: Ribavirin may be a reasonable option to treat RSV in patients with HM/HSCT in the absence of other effective antiviral agents.

Prevalence of Ocular Candidiasis and Candida Endophthalmitis in Patients With Candidemia: A Systematic Review and Meta-Analysis.

BACKGROUND: Infectious diseases and ophthalmology professional societies have disagreed regarding ocular screening in patients with candidemia. We aimed to summarize the current evidence on the prevalence of ocular candidiasis (OC) and Candida endophthalmitis (CE) according to the standardized definitions. METHODS: A literature search was conducted from the inception date through 16 October 2022 using PubMed, Embase, and SCOPUS. Pooled prevalence of ocular complications was derived from generalized linear mixed models (PROSPERO CRD42022326610). RESULTS: A total of 70 and 35 studies were included in the meta-analysis for OC and concordant CE (chorioretinitis with vitreous involvement), respectively. This study represented 8599 patients with candidemia who underwent ophthalmologic examination. Pooled prevalences (95% CI) of OC, overall CE, concordant CE, and discordant CE were 10.7% (8.4-13.5%), 3.1% (2.1-4.5%), 1.8% (1.3-2.6%), and 7.4% (4.5-12%) of patients screened, respectively. Studies from Asian countries had significantly higher concordant CE prevalence (95% CI) of patients screened (3.6%; 2.9-4.6%) compared with studies from European countries (1.4%; .4-5%) and American countries (1.4%; .9-2.2%) (P <.01). Presence of total parenteral nutrition and Candida albicans was associated with CE, with pooled odds ratios (95% CI) of 6.92 (3.58-13.36) and 3.02 (1.67-5.46), respectively. CONCLUSIONS: Prevalence of concordant CE overall and among Asian countries was 2 and 4 times higher than the prevalence previously reported by the American Academy of Ophthalmology (AAO) of <0.9%, respectively. There is an urgent need to study optimal screening protocols and to establish joint recommendations by the Infectious Diseases Society of America and AAO.

Immunogenicity of SARS-CoV-2 vaccines in patients with multiple myeloma: a systematic review and meta-analysis.

Patients with multiple myeloma (MM) have a diminished immune response to coronavirus disease 2019 (COVID-19) vaccines. Risk factors for an impaired immune response are yet to be determined. We aimed to summarize the COVID-19 vaccine immunogenicity and to identify factors that influence the humoral immune response in patients with MM. Two reviewers independently conducted a literature search in MEDLINE, Embase, ISI Web of Science, Cochrane library, and Clinicaltrials.gov from existence until 24 May 24 2022. (PROSPERO: CRD42021277005). A total of 15 studies were included in the systematic review and 5 were included in the meta-analysis. The average rate (range) of positive functional T-lymphocyte response was 44.2% (34.2%-48.5%) after 2 doses of messenger RNA (mRNA) COVID-19 vaccines. The average antispike antibody response rates (range) were 42.7% (20.8%-88.5%) and 78.2% (55.8%-94.2%) after 1 and 2 doses of mRNA COVID-19 vaccines, respectively. The average neutralizing antibody response rates (range) were 25% (1 study) and 62.7% (53.3%-68.6%) after 1 and 2 doses of mRNA COVID-19 vaccines, respectively. Patients with high-risk cytogenetics or receiving anti-CD38 therapy were less likely to have a humoral immune response with pooled odds ratios of 0.36 (95% confidence interval [95% CI], 0.18, 0.69), I2 = 0% and 0.42 (95% CI, 0.22, 0.79), I2 = 14%, respectively. Patients who were not on active MM treatment were more likely to respond with pooled odds ratio of 2.42 (95% CI, 1.10, 5.33), I2 = 7%. Patients with MM had low rates of humoral and cellular immune responses to the mRNA COVID-19 vaccines. Further studies are needed to determine the optimal doses of vaccines and evaluate the use of monoclonal antibodies for pre-exposure prophylaxis in this population.

Impact of SARS-CoV-2 infection on the profiles and responses of innate immune cells after recovery.

BACKGROUNDS: SARS-CoV-2 infection results in a broad spectrum of clinical outcomes, ranging from asymptomatic to severe symptoms and death. Most COVID-19 pathogenesis is associated with hyperinflammatory conditions driven primarily by myeloid cell lineages. The long-term effects of SARS-CoV-2 infection post recovery include various symptoms. METHODS: We performed a longitudinal study of the innate immune profiles 1 and 3 months after recovery in the Thai cohort by comparing patients with mild, moderate, and severe clinical symptoms using peripheral blood mononuclear cells (n = 62). RESULTS: Significant increases in the frequencies of monocytes compared to controls and NK cells compared to mild and moderate patients were observed in severe patients 1-3 months post recovery. Increased polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) were observed in all recovered patients, even after 3 months. Increased IL-6 and TNFα levels in monocytes were observed 1 month after recovery in response to lipopolysaccharide (LPS) stimulation, while decreased CD86 and HLA-DR levels were observed regardless of stimulation. A multiplex analysis of serum cytokines performed at 1 month revealed that most innate cytokines, except for TNFα, IL4/IL-13 (Th2) and IFNγ (Th1), were elevated in recovered patients in a severity-dependent manner. Finally, the myelopoiesis cytokines G-CSF and GM-CSF were higher in all patient groups. Increased monocytes and IL-6- and TNFα-producing cells were significantly associated with long COVID-19 symptoms. CONCLUSIONS: These results reveal that COVID-19 infection influences the frequencies and functions of innate immune cells for up to 3 months after recovery, which may potentially lead to some of the long COVID symptoms.

Immunogenicity and reactogenicity after booster dose with AZD1222 via intradermal route among adult who had received CoronaVac.

BACKGROUND: Currently, booster dose is needed after 2 doses of non-live COVID-19 vaccine. With limited resources and shortage of COVID-19 vaccines, intradermal(ID) administration might be a potential dose-sparing strategy. OBJECTIVE: To determine immunologic response and reactogenicity of ID ChAdOx1 nCoV-19 vaccine (AZD1222,Oxford/AstraZeneca) as a booster dose after completion of 2-dose CoronaVac(SV) in healthy adult. METHODS: This is a prospective cohort study of adult aged 18-59 years who received 2-dose SV at 14-35 days apart for more than 2 months. Participants received ID AZD1222 at fractional low dose(1×1010 viral particles,0.1 ml). Antibody responses were evaluated by surrogate virus neutralization test(sVNT) against delta variant and wild type, and anti-spike-receptor-binding-domain immunoglobulin G(anti-S-RBD IgG) at prior, day14, 28, 90, and 180 post booster. Solicited reactogenicity was collected for 7 days post-booster. Primary endpoint was the differences of sVNT against delta strain ≥ 80% inhibition at day14 and 90 compared with the parallel cohort study of 0.5-ml intramuscular(IM) route. RESULTS: From August2021, 100 adults with median age of 46 years(IQR 41-52) participated. Prior to booster, geometric mean(GM) of sVNT against delta strain was 22.4% inhibition(95 %CI 18.7-26.9) and of anti-S-RBD IgG was 109.3 BAU/ml(95.4-125.1). Post ID booster, GMs of sVNT against delta strain were 95.5% inhibition (95%CI 94.2-96.8) at day14, 73.1% inhibition (66.7-80.2) at day90, and 22.7% inhibition (14.9-34.6) at day180. The differences of proportion of participants achieving sVNT against delta strain ≥ 80% inhibition in ID recipients versus IM were + 4.2% (95 %CI -2.0to10.5) at day14, and -37.3%(-54.2to-20.3) at day90. Anti-S-RBD IgG GMs were 2037.1 BAU/ml (95%CI 1770.9-2343.2) at day14 and 744.6 BAU/ml(650.1-852.9) at day90, respectively. Geometric mean ratios(GMRs) of anti-S-RBD IgG were 0.99(0.83-1.20) at day14, and 0.82(0.66-1.02) at day90. Only 18% reported feverish, compared with 37% of IM (p = 0.003). Common reactogenicity was erythema at injection site(53%) while 7% reported blister. CONCLUSION: Low-dose ID AZD1222 booster enhanced lower neutralizing antibodies at 3 months compared with IM route. Less systemic reactogenicity occurred, but higher local reactogenicity.

Immunogenicity and Risk Factors Associated With Poor Humoral Immune Response of SARS-CoV-2 Vaccines in Recipients of Solid Organ Transplant: A Systematic Review and Meta-Analysis.

Importance: Recipients of solid organ transplant (SOT) experience decreased immunogenicity after COVID-19 vaccination. Objective: To summarize current evidence on vaccine responses and identify risk factors for diminished humoral immune response in recipients of SOT. Data Sources: A literature search was conducted from existence of database through December 15, 2021, using MEDLINE, Embase, Web of Science, Cochrane Library, and ClinicalTrials.gov. Study Selection: Studies reporting humoral immune response of the COVID-19 vaccines in recipients of SOT were reviewed. Data Extraction and Synthesis: Two reviewers independently extracted data from each eligible study. Descriptive statistics and a random-effects model were used. This report was prepared following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. Data were analyzed from December 2021 to February 2022. Main Outcomes and Measures: The total numbers of positive immune responses and percentage across each vaccine platform were recorded. Pooled odds ratios (pORs) with 95% CIs were used to calculate the pooled effect estimates of risk factors for poor antibody response. Results: A total of 83 studies were included for the systematic review, and 29 studies were included in the meta-analysis, representing 11 713 recipients of SOT. The weighted mean (range) of total positive humoral response for antispike antibodies after receipt of mRNA COVID-19 vaccine was 10.4% (0%-37.9%) for 1 dose, 44.9% (0%-79.1%) for 2 doses, and 63.1% (49.1%-69.1%) for 3 doses. In 2 studies, 50% of recipients of SOT with no or minimal antibody response after 3 doses of mRNA COVID-19 vaccine mounted an antibody response after a fourth dose. Among the factors associated with poor antibody response were older age (mean [SE] age difference between responders and nonresponders, 3.94 [1.1] years), deceased donor status (pOR, 0.66 [95% CI, 0.53-0.83]; I2 = 0%), antimetabolite use (pOR, 0.21 [95% CI, 0.14-0.29]; I2 = 70%), recent rituximab exposure (pOR, 0.21 [95% CI, 0.07-0.61]; I2 = 0%), and recent antithymocyte globulin exposure (pOR, 0.32 [95% CI, 0.15-0.71]; I2 = 0%). Conclusions and Relevance: In this systematic review and meta-analysis, the rates of positive antibody response in solid organ transplant recipients remained low despite multiple doses of mRNA vaccines. These findings suggest that more efforts are needed to modulate the risk factors associated with reduced humoral responses and to study monoclonal antibody prophylaxis among recipients of SOT who are at high risk of diminished humoral response.

The association of cytomegalovirus infection and cytomegalovirus serostatus with invasive fungal infections in allogeneic haematopoietic stem cell transplant recipients: a systematic review and meta-analysis.

BACKGROUND: In allogeneic haematopoietic stem cell transplant (allo-HSCT) recipients, the inter-relationship between post-transplant cytomegalovirus (CMV) and subsequent invasive fungal infections (IFIs) is conflicting and the association of CMV serostatus with IFIs has not been evaluated. OBJECTIVES: To determine the relationship between CMV infection/serostatus and IFIs in allo-HSCT populations. DATA SOURCES: A systematic literature search was conducted from existence until 11 July 2021 using Medline, Embase and ISI Web of Science databases. STUDY ELIGIBILITY CRITERIA: Cross-sectional, prospective cohort, retrospective cohort and case-control studies that reported allo-HSCT recipients with CMV and without CMV who developed or did not develop IFIs after CMV infection. PARTICIPANTS: Allo-HSCT recipients. INTERVENTIONS: Not applicable. METHODS: A systematic search, screening, data extracting and assessing study quality were independently conducted by two reviewers. The Newcastle-Ottawa scale was used to assess risk of bias. data were analysed using the pooled effect estimates of a random-effects model. RESULTS: A total of 18 and 12 studies were included for systematic review and meta-analysis, respectively. Post-transplant CMV infection significantly increased the risk of IFIs with a pooled hazard ratio (pHR) of 2.58 (1.78, 3.74), I2 = 75%. Further subgroup analyses by timing of IFIs, CMV definitions, study continents, study design and adjustment of effect estimates showed that post-transplant CMV infection consistently increased the risk of subsequent IFIs. High-risk CMV serostatus (D-/R+) increased the risk of IFIs with a pooled odds ratio (OR) of 1.33 (1.04, 1.71), I2 = 0%, but low-risk CMV serostatus (D-/R-) decreased the risk of IFIs with a pOR of 0.69 (0.55, 0.87), I2 = 0%. CONCLUSIONS: Post-transplant CMV infection and high-risk CMV serostatus increased the risk of IFIs, but low-risk CMV serostatus decreased risk of IFIs among allo-HSCT recipients. Further studies are needed to identify at-risk allo-HSCT recipients as well as to focus on fungal diagnostics and prophylaxis to prevent this fungal-after-viral phenomenon.

Does Post-Transplant Cytomegalovirus Increase the Risk of Invasive Aspergillosis in Solid Organ Transplant Recipients? A Systematic Review and Meta-Analysis.

BACKGROUND: Cytomegalovirus (CMV) and invasive aspergillosis (IA) cause high morbidity and mortality in solid organ transplant (SOT) recipients. There are conflicting data with respect to the impact of CMV on IA development in SOT recipients. METHODS: A literature search was conducted from existence through to 2 April 2021 using MEDLINE, Embase, and ISI Web of Science databases. This review contained observational studies including cross-sectional, prospective cohort, retrospective cohort, and case-control studies that reported SOT recipients with post-transplant CMV (exposure) and without post-transplant CMV (non-exposure) who developed or did not develop subsequent IA. A random-effects model was used to calculate the pooled effect estimate. RESULTS: A total of 16 studies were included for systematic review and meta-analysis. There were 5437 SOT patients included in the study, with 449 SOT recipients developing post-transplant IA. Post-transplant CMV significantly increased the risk of subsequent IA with pORs of 3.31 (2.34, 4.69), I2 = 30%. Subgroup analyses showed that CMV increased the risk of IA development regardless of the study period (before and after 2003), types of organ transplantation (intra-thoracic and intra-abdominal transplantation), and timing after transplant (early vs. late IA development). Further analyses by CMV definitions showed CMV disease/syndrome increased the risk of IA development, but asymptomatic CMV viremia/infection did not increase the risk of IA. Conclusions: Post-transplant CMV, particularly CMV disease/syndrome, significantly increased the risks of IA, which highlights the importance of CMV prevention strategies in SOT recipients. Further studies are needed to understand the impact of programmatic fungal surveillance or antifungal prophylaxis to prevent this fungal-after-viral phenomenon.

Clinical Outcomes of Radical Surgery and Antimicrobial Agents in Vascular Pythiosis: A Multicenter Prospective Study.

Vascular pythiosis is a rare, neglected, life-threatening disease with mortality of 100% in patients with incomplete surgical resection or patients with persistently elevated serum ß-d-glucan (BDG). The study was conducted to understand the clinical outcomes of new treatment protocols and potential use of erythrocyte sedimentation rate (ESR) and c-reactive protein (CRP) as alternative monitoring tools, given recent favorable minimum inhibitory concentrations (MICs) of antibacterial agents and prohibitive cost of serum BDG in Thailand. A prospective cohort study of patients with vascular pythiosis was conducted between February 2019 and August 2020. After diagnosis, patients were followed at 0.5, 1, 1.5, 3, and 6 months. Descriptive statistics, Spearman's correlation coefficient, and general linear model for longitudinal data were used. Amongst the cohort of ten vascular pythiosis patients, four had residual disease after surgery. Among four with residual disease, one developed disseminated disease and died, one developed relapse disease requiring surgery, and two were successfully managed with antimicrobial agents. The spearman's correlation coefficients between BDG and ESR, and between BDG and CRP in patients without relapse or disseminated disease were 0.65 and 0.60, respectively. Tetracyclines and macrolides had most favorable minimum inhibitory concentrations and synergistic effects were observed in combinations of these two antibiotic classes. Adjunctive use of azithromycin and doxycycline preliminarily improved survival in vascular pythiosis patients with residual disease. Further studies are needed to understand the trends of ESR and CRP in this population.

In Vitro Susceptibility of Thai Pythium insidiosum Isolates to Antibacterial Agents.

Human pythiosis is a life-threatening human disease caused by Pythium insidiosum In Thailand, vascular pythiosis is the most common form and carries a mortality rate of 10 to 40%, despite aggressive treatment with radical surgery, antifungal agents, and immunotherapy. Itraconazole and terbinafine have been the mainstay of treatment, until recently, based on case report data showing potential synergistic effects against Brazilian P. insidiosum isolates. However, the synergistic effects of itraconazole and terbinafine against Thai P. insidiosum isolates were not observed. This study tested the in vitro susceptibilities of 27 Thai human P. insidiosum isolates (clade II, n = 17; clade IV, n = 10), 12 Thai environmental P. insidiosum isolates (clade II, n = 4; clade IV, n = 8), and 11 non-Thai animal P. insidiosum isolates (clade I, n = 9; clade II, n = 2) to antibiotics in eight antibacterial classes to evaluate alternative effective treatments. Tetracycline and macrolide antibiotics demonstrated in vitro activity against Thai P. insidiosum isolates, with doxycycline MICs (1 to 16 µg/ml), minocycline MICs (1 to 4 µg/ml), tigecycline MICs (1 to 4 µg/ml), azithromycin MICs (1 to 16 µg/ml), and clarithromycin MICs (0.125 to 8 µg/ml) being the lowest, on average. Synergistic effects of tetracyclines and macrolides were also observed.

Adjunctive antibacterial agents as a salvage therapy in relapsed vascular pythiosis patients.

Human vascular pythiosis is a life-threatening condition caused by Pythium insidiosum. Patients with unresectable intra-abdominal artery involvement have not previously survived, despite being treated with antifungal agents and immunotherapy. We report two novel cases of intra-abdominal pythiosis in patients for whom surgery could not be performed, who were successfully treated with adjunctive antibacterial agents.

Clinical outcomes in ocular pythiosis patients treated with a combination therapy protocol in Thailand: A prospective study.

Ocular pythiosis is the second most common form of human pythiosis, and the rates of evisceration/enucleation in Thailand are 55-79%. This prospective study was conducted to evaluate treatment outcomes of the combination therapy protocol and the potential use of serum (1→3)-ß-glucan (BG) and Pythium insidiosum-specific antibody (Pi-Ab) as an aid to diagnosis and monitoring of ocular pythiosis. Thirty patients were enrolled in the study and 14 (non-globe salvage) required evisceration/enucleation. The globe salvage group was significantly younger, and first ocular surgeries were performed significantly sooner than in the non-globe salvage group. Serum BG and Pi-Ab levels were similar among the 2 groups over time. In vitro susceptibility testing of antifungal agents revealed relatively high minimum inhibitory concentrations and lack of synergistic effect. Serum BG and Pi-Ab would not be useful in diagnosis and monitoring of ocular pythiosis. Until effective antimicrobial agents are discovered, ocular surgeries are still the mainstay therapy in Thailand.