Browsing by Author "Williams, Darlisha A."
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Item Evaluation of an Aspergillus IgG/IgM lateral flow assay for serodiagnosis of fungal asthma in Uganda(Plos one, 2019) Kwizera, Richard; Cresswell, Fiona V.; Mugumya, Gerald; Okirwoth, Micheal; Kagimu, Enock; Bangdiwala, Ananta S.; Williams, Darlisha A.; Rhein, Joshua; Boulware, David R.; Meya, David B.The diagnostic utility of the Mycobacteria tuberculosis lipoarabinomannan (TB-LAM) antigen lateral flow assay on cerebrospinal fluid (CSF) for the diagnosis of tuberculous meningitis (TBM) has not been extensively studied and the few published studies have conflicting results. Lumbar CSF from 59 HIV-positive patients with suspected TBM was tested with TB-LAM and Xpert MTB/Rif Ultra. The diagnostic performance of CSF TB-LAM was compared to positive CSF Xpert MTB/Rif Ultra (definite TBM) and a composite reference of probable or definite TBM according to the uniform case definition. Of 59 subjects, 12 (20%) had definite TBM and five (9%) had probable TBM. With reference to definite TBM, CSF TB-LAM assay had a diagnostic sensitivity of 33% and specificity of 96%. When compared to a composite reference of definite or probable TBM, the sensitivity was 24% and specificity was 95%. There were two false positive tests with TB-LAM (3+ grade). In-hospital mortality in CSF TB-LAM positive patients was 17% compared to 0% in those with definite TBM by Xpert MTB/Rif Ultra but negative LAM. Lumbar CSF TB-LAM has a poor performance in diagnosing TBM. Both urine TB-LAM and Xpert Ultra should be further investigated in the diagnosis of TBM.Item Evaluation of Fingerstick Cryptococcal Antigen Lateral Flow Assay in HIV-Infected Persons : A Diagnostic Accuracy Study(Clinical Infectious Diseases, 2015) Williams, Darlisha A.; Kiiza, Tadeo; Kwizera, Richard; Kiggundu, Reuben; Velamakanni, Sruti; Meya, David B.; Rhein, Joshua; Boulware, David R.Cryptococcus neoformans is the most common cause of adult meningitis in sub-Saharan Africa. The cryptococcal antigen (CRAG) lateral flow assay (LFA) has simplified diagnosis as a point-of-care test approved for serum or cerebrospinal fluid (CSF). We evaluated the accuracy of the CRAG LFA using fingerstick whole blood compared with serum/plasma and CSF for diagnosing meningitis. Methods. From August 2013 to August 2014, CRAG LFA (IMMY, Norman, Oklahoma) tests were performed on fingerstick whole blood, plasma/serum, and CSF in 207 HIV-infected adults with suspected meningitis in Kampala, Uganda. Venous blood was also collected and centrifuged to obtain serum and/or plasma. CSF was tested after lumbar puncture. Results. Of 207 participants, 149 (72%) had fingerstick CRAG-positive results. There was 100% agreement between fingerstick whole blood and serum/plasma. Of the 149 fingerstick CRAG-positive participants, 138 (93%) had evidence of cryptococcal meningitis with a positive CSF CRAG. Eleven participants (5%) had isolated cryptococcal antigenemia with a negative CSF CRAG and culture, of whom 8 had CSF abnormalities (n = 3 lymphocytic pleocytosis, n = 5 elevated protein, n = 4 increased opening pressure). No persons with cryptococcal meningitis had negative fingersticks. Conclusions. The 100% agreement between whole blood, serum, and plasma CRAG LFA results demonstrates that fingerstick CRAG is a reliable bedside diagnostic test. Using point-of-care CRAG testing simplifies screening large numbers of patients and enables physicians to prioritize on whom to measure CSF opening pressure using manometers.Item Evaluation of Fingerstick Cryptococcal Antigen Lateral Flow Assay in HIV-Infected Persons: A Diagnostic Accuracy Study(Clinical Infectious Diseases, 2015) Williams, Darlisha A.; Kiiza, Tadeo; Kwizera, Richard; Kiggundu, Reuben; Velamakanni, Sruti; Meya, David B.; Rhein, Joshua; Boulware, David R.Cryptococcus neoformans is the most common cause of adult meningitis in sub-Saharan Africa. The cryptococcal antigen (CRAG) lateral flow assay (LFA) has simplified diagnosis as a point-of-care test approved for serum or cerebrospinal fluid (CSF). We evaluated the accuracy of the CRAG LFA using fingerstick whole blood compared with serum/plasma and CSF for diagnosing meningitis.From August 2013 to August 2014, CRAG LFA (IMMY, Norman, Oklahoma) tests were performed on fingerstick whole blood, plasma/serum, and CSF in 207 HIV-infected adults with suspected meningitis in Kampala, Uganda. Venous blood was also collected and centrifuged to obtain serum and/or plasma. CSF was tested after lumbar puncture.Of 207 participants, 149 (72%) had fingerstick CRAG-positive results. There was 100% agreement between fingerstick whole blood and serum/plasma. Of the 149 fingerstick CRAG-positive participants, 138 (93%) had evidence of cryptococcal meningitis with a positive CSF CRAG. Eleven participants (5%) had isolated cryptococcal antigenemia with a negative CSF CRAG and culture, of whom 8 had CSF abnormalities (n = 3 lymphocytic pleocytosis, n = 5 elevated protein, n = 4 increased opening pressure). No persons with cryptococcal meningitis had negative fingersticks.The 100% agreement between whole blood, serum, and plasma CRAG LFA results demonstrates that fingerstick CRAG is a reliable bedside diagnostic test. Using point-of-care CRAG testing simplifies screening large numbers of patients and enables physicians to prioritize on whom to measure CSF opening pressure using manometers.Item Evaluation of the Diagnostic Performance of a Semiquantitative Cryptococcal Antigen Point-of-Care Assay among HIV-Infected Persons with Cryptococcal Meningitis(Journal of clinical microbiology, 2021) Tadeo, Kiiza Kandole; Nimwesiga, Audrey; Kwizera, Richard; Apeduno, Lucy; Martyn, Emily; Okirwoth, Michael; Nalintya, Elizabeth; Rajasingham, Radha; Williams, Darlisha A.; Rhein, Joshua; Meya, David B.; Kafufu, Bosco; Boulware, David R.; Skippera, Caleb P.A newly developed cryptococcal antigen (CrAg) semiquantitative (SQ) lateral flow assay (LFA) provides a semiquantitative result in a rapid one-step test instead of performing serial dilutions to determine CrAg titer. We prospectively compared the diagnostic performance of the CrAgSQ assay (IMMY) with the CrAg LFA (IMMY) on cerebrospinal fluid (CSF) samples collected from persons with HIV-associated meningitis. The CrAgSQ grades (1+ to 5+) were compared with CrAg LFA titers and quantitative CSF fungal cultures. Among 87 participants screened for HIV-associated meningitis, 60 had cryptococcal meningitis (59 CrAg positive [CrAg+] by LFA and 1 false negative due to prozone with CrAg LFA titer of 1:1,310,000 and culture positivity), and 27 had no cryptococcal meningitis by CrAg LFA or culture. The CrAgSQ on CSF had 100% (60/60) sensitivity and 100% specificity (27/27). CSF CrAg titers ranged from 1:5 to 1:42 million. CrAgSQ grades of 1+, 2+, 3+, 4+, and 5+ corresponded to median CrAg LFA titers of 1:<10, 1:60, 1:7,680, 1:81,920, and 1:1,474,000, respectively. CSF CrAgSQ grades 3+ or higher were always CSF culture positive. Mortality at 14 days for those with low CrAgSQ grade (1+ to 3+) was 5% (1/22) versus 21% (8/38) with high CrAgSQ grades (4+ to 5+) (P = 0.084). The CrAgSQ demonstrates excellent diagnostic performance, maintaining both the sensitivity and specificity of the CrAg LFA, and counters false-negative prozone effects. The CrAgSQ assay reading is more complex but does provide useful clinical information about disease burden and probability of culture positivity in a single rapid diagnostic test.Item Evaluation of the Dynamiker Cryptococcal Antigen Lateral Flow Assay for the Diagnosis of HIV-Associated Cryptococcosis(Journal of clinical microbiology, 2021) Kwizera, Richard; Omali, Denis; Tade, Kiiza; Kasibante, John; Rutakingirwa, Morris K.; Kagimu, Enock; Ssebambulidde, Kenneth; Williams, Darlisha A.; Rhein, Joshua; Boulware, David; Meya, David B.Cryptococcal meningitis is a leading cause of meningitis in sub-Saharan Africa. Given the need for rapid point-of-care testing, we evaluated the diagnostic performance of the Dynamiker cryptococcal antigen (CrAg) lateral flow assay (LFA). We assessed the diagnostic performance of the Dynamiker CrAg LFA compared to the IMMY CrAg LFA as the reference standard. We tested 150 serum, 115 plasma, and 100 cerebrospinal fluid (CSF) samples from HIV patients with symptomatic meningitis and 113 serum samples from patients with suspected asymptomatic cryptococcal antigenemia. Compared to the IMMY CrAg LFA, sensitivity of Dynamiker CrAg LFA was 98% in serum, 100% in plasma, 100% in CSF from symptomatic patients and 96% in serum from asymptomatic patients. Specificity was 66% in serum, 61% in plasma, and 91% in CSF from symptomatic patients, and 86% in serum from asymptomatic patients. The positive predictive value was 85% in serum, 82% in plasma, and 96% in CSF from symptomatic patients, and 69% in serum from asymptomatic patients. The negative predictive value was 94% in serum, 100% in plasma, and 100% in CSF from symptomatic patients, and 99% in serum from asymptomatic patients. The interassay reproducibility was 100% across the four sample types with no observed discordant results when Dynamiker CrAg LFA was tested in duplicate. However, a high number of false positives were observed on serum of symptomatic patients (11%), serum of asymptomatic patients (11%) and plasma of symptomatic patients (14%). The Dynamiker CrAg LFA had excellent sensitivity but poor specificity, particularly when tested on serum and plasma.Item Human Immune Response Varies by the Degree of Relative Cryptococcal Antigen Shedding(Oxford University Press, 2016) Boulware, David R.; Hohenberg, Maximilian von; Rhein, Joshua; Akampurira, Andrew; Williams, Darlisha A.; Taseera, Kabanda; McDonald, Tami; Muzoora, Conrad; Meya, David B.; Hullsiek, Katherine Huppler; For the Cryptococcal Optimal ART Timing (COAT) Trial TeamCerebrospinal fluid (CSF) cryptococcal glucuronoxylomannan antigen (CrAg) titers generally correlate with quantitative fungal culture burden; however, correlation is not precise. Some patients have higher CrAg titers with lower fungal burdens and vice versa. We hypothesized that the relative discordancy between CrAg titer and quantitative culture burden reflects the relative degree of CrAg shedding by Cryptococcus neoformans and is associated with human immune responses.One hundred ninety human immunodeficiency virus-infected individuals with cryptococcal meningitis were enrolled in Uganda and South Africa. We compared initial CSF CrAg titers relative to their CSF quantitative cultures to determine low (n = 58), intermediate (n = 68), or high (n = 64) CrAg shedders. We compared cytokines measured by Luminex multiplex assay on cryopreserved CSF and 10-week mortality across shedding groups using linear and logistic regression and distribution of genotypes by multilocus sequence typing.The relative degree of CrAg shedding was positively associated with increasing CSF levels of the following: interleukin (IL)-6, IL-7, IL-8, and tumor necrosis factor-α (each P < 0.01), which are all secreted by antigen-presenting cells and negatively associated with vascular endothelial growth factor (P = .01). In addition, IL-5, IL-13, granulocyte colony-stimulating factor, and macrophage chemotactic protein were decreased in low-CrAg shedders compared with intermediate shedders (each P ≤ .01). Type 1 T-helper cells (Th1) cytokine responses and 10-week mortality did not differ between the shedding groups. Cryptococcal genotypes were equally distributed across shedding groups.Discordancy between CrAg shedding and expected shedding based on quantitative fungal burden is associated with detectable immunologic differences in CSF, primarily among secreted cytokines and chemokines produced by antigen-presenting cells and Th2.Item Management of Amphotericin-Induced Phlebitis among HIV Patients with Cryptococcal Meningitis in a Resource Limited Setting: A Prospective Cohort Study(BMC infectious diseases, 2019) Ahimbisibwe, Cynthia; Kwizera, Richard; Ndyetukira, Jane Frances; Kugonza, Florence; Hullsiek, Kathy Huppler; Williams, Darlisha A.; Rhein, Joshua; Boulware, David R.; Meya, David B.Amphotericin-induced phlebitis is a common infusion-related reaction in patients managed for cryptococcal meningitis. High-quality nursing care is critical component to successful cryptococcosis treatment. We highlight the magnitude and main approaches in the management of amphotericin-induced phlebitis and the challenges faced in resource-limited settings. We prospectively determined the incidence of amphotericin-induced phlebitis during clinical trials in Kampala, Uganda from 2013 to 2018. We relate practical strategies and challenges faced in clinical management of phlebitis. Overall, 696 participants were diagnosed with HIV-related cryptococcal meningitis. Participants received 7–14 doses of intravenous (IV) amphotericin B deoxycholate 0.7–1.0 mg/kg/day for induction therapy through peripheral IV lines at a concentration of 0.1 mg/mL in 5% dextrose. Overall, 18% (125/696) developed amphotericin-induced phlebitis. We used four strategies to minimize/prevent the occurrence of phlebitis. First, after every dose of amphotericin, we gave one liter of intravenous normal saline. Second, we rotated IV catheters every three days. Third, we infused IV amphotericin over 4 h. Finally, early ambulation was encouraged to minimize phlebitis. To alleviate phlebitis symptoms, warm compresses were used. In severe cases, treatment included topical diclofenac gel and oral anti-inflammatory medicines. Antibiotics were used only when definite signs of infection developed. Patient/caregivers’ education was vital in implementing these management strategies. Major challenges included implementing these interventions in participants with altered mental status and limited access to topical and oral anti-inflammatory medicines in resource-limited settings. Amphotericin-induced phlebitis is common with amphotericin, yet phlebitis is a preventable complication even in resource-limited settings.Item Performance of Lipoarabinomannan Assay using Cerebrospinal fluid for the diagnosis of Tuberculous meningitis among HIV patients(Wellcome open research, 2019) Kwizera, Richard; Cresswell, Fiona V.; Mugumya, Gerald; Okirwoth, Micheal; Kagimu, Enock; Bangdiwala, Ananta S.; Williams, Darlisha A.; Rhein, Joshua; Boulware, David R.; Meya, David B.The diagnostic utility of the Mycobacteria tuberculosis lipoarabinomannan (TB-LAM) antigen lateral flow assay on cerebrospinal fluid (CSF) for the diagnosis of tuberculous meningitis (TBM) has not been extensively studied and the few published studies have conflicting results.Lumbar CSF from 59 HIV-positive patients with suspected TBM was tested with TB-LAM and Xpert MTB/Rif Ultra. The diagnostic performance of CSF TB-LAM was compared to positive CSF Xpert MTB/Rif Ultra (definite TBM) and a composite reference of probable or definite TBM according to the uniform case definition. Of 59 subjects, 12 (20%) had definite TBM and five (9%) had probable TBM. With reference to definite TBM, CSF TB-LAM assay had a diagnostic sensitivity of 33% and specificity of 96%. When compared to a composite reference of definite or probable TBM, the sensitivity was 24% and specificity was 95%. There were two false positive tests with TB-LAM (3+ grade). In-hospital mortality in CSF TB-LAM positive patients was 17% compared to 0% in those with definite TBM by Xpert MTB/Rif Ultra but negative LAM.Lumbar CSF TB-LAM has a poor performance in diagnosing TBM. Both urine TB-LAM and Xpert Ultra should be further investigated in the diagnosis of TBM.Item Symptomatic Cryptococcal Antigenemia Presenting as Early Cryptococcal Meningitis With Negative Cerebral Spinal Fluid Analysis(Clinical infectious diseases, 2019) Ssebambulidde, Kenneth; Kwizera, Richard; Kandole, Tadeo Kiiza; Tugume, Lillian; Kiggundu, Reuben; Mpoza, Edward; Nuwagira, Edwin; Williams, Darlisha A.; Lofgren, Sarah M.; Abassi, Mahsa; Musubire, Abdu K.; Cresswell, Fiona V.; Muzoora, Conrad; Boulware, David R.; Meya, David B.; for the Adjunctive Sertraline for Treatment of HIV-associated Cryptococcal Meningitis TeamIndividuals with cryptococcal antigenemia are at high risk of developing cryptococcal meningitis if untreated. The progression and timing from asymptomatic infection to cryptococcal meningitis is unclear. We describe a subpopulation of individuals with neurologic symptomatic cryptococcal antigenemia but negative cerebral spinal fluid (CSF) studies.We evaluated 1201 human immunodeficiency virus–seropositive individuals hospitalized with suspected meningitis in Kampala and Mbarara, Uganda. Baseline characteristics and clinical outcomes of participants with neurologic–symptomatic cryptococcal antigenemia and negative CSF cryptococcal antigen (CrAg) were compared to participants with confirmed CSF CrAg+ cryptococcal meningitis. Additional CSF testing included microscopy, fungal culture, bacterial culture, tuberculosis culture, multiplex FilmArray polymerase chain reaction (PCR; Biofire), and Xpert MTB/Rif.We found 56% (671/1201) of participants had confirmed CSF CrAg+ cryptococcal meningitis and 4% (54/1201) had neurologic symptomatic cryptococcal antigenemia with negative CSF CrAg. Of those with negative CSF CrAg, 9% (5/54) had Cryptococcus isolated on CSF culture (n = 3) or PCR (n = 2) and 11% (6/54) had confirmed tuberculous meningitis. CSF CrAg-negative patients had lower proportions with CSF pleocytosis (16% vs 26% with ≥5 white cells/μL) and CSF opening pressure >200 mmH2O (16% vs 71%) compared with CSF CrAg-positive patients. No cases of bacterial or viral meningitis were detected by CSF PCR or culture. In-hospital mortality was similar between symptomatic cryptococcal antigenemia (32%) and cryptococcal meningitis (31%; P = .91).Cryptococcal antigenemia with meningitis symptoms was the third most common meningitis etiology. We postulate this is early cryptococcal meningoencephalitis. Fluconazole monotherapy was suboptimal despite Cryptococcus-negative CSF. Further studies are warranted to understand the clinical course and optimal management of this distinct entity.Item Tuberculosis in HIV-Associated Cryptococcal Meningitis is Associated with an Increased Risk of Death(Journal of Clinical Medicine, 2020) Rutakingirwa, Morris K.; Cresswell, Fiona V.; Kwizera, Richard; Ssebambulidde, Kenneth; Kagimu, Enock; Nuwagira, Edwin; Tugume, Lillian; Mpoza, Edward; Dobbin, Joanna; Williams, Darlisha A.; Muzoora, Conrad; Meya, David B.; Boulware, David R.; Hullsiek, Kathy H.; Rhein, Joshuauberculosis (TB) and cryptococcal meningitis are leading causes of morbidity and mortality in advanced HIV disease. Data are limited on TB co-infection among individuals with cryptococcal meningitis. We performed a retrospective analysis of HIV-infected participants with cryptococcal meningitis from 2010–2017. Baseline demographics were compared between three groups: ‘prevalent TB’ if TB treated >14 days prior to cryptococcal meningitis diagnosis, ‘concurrent TB’ if TB treated ± 14 days from diagnosis, or ‘No TB at baseline’. We used time-updated proportional-hazards regression models to assess TB diagnosis as a risk for death. Of 870 participants with cryptococcal meningitis, 50 (6%) had prevalent TB, 67 (8%) had concurrent TB, and 753 (86%) had no baseline TB. Among participants without baseline TB, 67 (9%) were diagnosed with incident TB (after >14 days), with a median time to TB incidence of 41 days (IQR, 22–69). The 18-week mortality was 50% (25/50) in prevalent TB, 46% (31/67) in concurrent TB, and 45% (341/753) in the no TB group (p = 0.81). However, TB co-infection was associated with an increased hazard of death (HR = 1.75; 95% CI, 1.33–2.32; p < 0.001) in a time-updated model. TB is commonly diagnosed in cryptococcal meningitis, and the increased mortality associated with co-infection is a public health concern.Item Xpert MTB/RIF Ultra for the Diagnosis of HIV-associated Tuberculous Meningitis: A Prospective Validation Study(The Lancet infectious diseases, 2020) Cresswell, Fiona V.; Tugume, Lillian; Kwizera, Richard; Bangdiwala, Ananta S.; Musubire, Abdu K.; Rutakingirwa, Morris; Kagimu, Enock; Nuwagira, Edwin; Mpoza, Edward; Rhein, Joshua; Williams, Darlisha A.; Muzoora, Conrad; Grint, Daniel; Elliott, Alison M.; Meya, David B.; Boulware, David R.; on behalf of the ASTRO-CM teamTuberculous meningitis accounts for 1–5% of tuberculosis cases. Diagnostic delay contributes to poor outcomes. We evaluated the performance of the new Xpert MTB/RIF Ultra (Xpert Ultra) for tuberculous meningitis diagnosis. In this prospective validation study, we tested the cerebrospinal fluid (CSF) of adults presenting with suspected meningitis (ie, headache or altered mental status with clinical signs of meningism) to the Mulago National Referral Hospital and Mbarara Regional Referral Hospital in Uganda. We centrifuged the CSF, resuspended the cell pellet in 2 mL CSF, and tested 0·5 mL aliquots with Xpert Ultra, Xpert MTB/RIF (Xpert), and mycobacterial growth indicator tube (MGIT) culture. We quantified diagnostic performance against the uniform case definition of probable or definite tuberculous meningitis and a composite microbiological reference standard. From Nov 25, 2016, to Jan 24, 2019, we screened 466 adults with suspected meningitis and tested 204 for tuberculous meningitis. Uniform clinical case definition classified 51 participants as having probable or definite tuberculous meningitis. Against this uniform case definition, Xpert Ultra had 76·5% sensitivity (95% CI 62·5–87·2; 39 of 51 patients) and a negative predictive value of 92·7% (87·6–96·2; 153 of 165), compared with 55·6% sensitivity (44·0–70·4; 25 of 45; p=0·0010) and a negative predictive value of 85·8% (78·9–91·1; 121 of 141) for Xpert and 61·4% sensitivity (45·5–75·6; 27 of 44; p=0·020) and negative predictive value of 85·2% (77·4–91·1; 98 of 115) for MGIT culture. Against the composite microbiological reference standard, Xpert Ultra had sensitivity of 92·9% (80·5–98·5; 39 of 42), higher than Xpert at 65·8% (48·6–80·4; 25 of 38; p=0·0063) and MGIT culture at 72·2% (55·9–86·2; 27 of 37; p=0·092). Xpert Ultra detected nine tuberculous meningitis cases missed by Xpert and MGIT culture. Xpert Ultra detected tuberculous meningitis with higher sensitivity than Xpert and MGIT culture in this HIV-positive population. However, with a negative predictive value of 93%, Xpert Ultra cannot be used as a rule-out test. Clinical judgment and novel highly sensitive point-of-care tests are still required.