Browsing by Author "Kagimu, Enock"

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    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.
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    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.
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    High-Dose Oral and Intravenous Rifampicin for the Treatment of Tuberculous Meningitis in Predominantly Human Immunodeficiency Virus (HIV)-Positive Ugandan Adults: A Phase II Open-Label Randomized Controlled Trial
    (Clinical Infectious Diseases, 2021) Cresswell, Fiona V.; Meya, David B.; Kagimu, Enock; Grint, Daniel; Brake, Lindsey te; Kasibante, John; Martyn, Emily; Rutakingirwa, Morris; Quinn, Carson M.; Okirwoth, Micheal; Tugume, Lillian; Ssembambulidde, Kenneth; Musubire, Abdu K.; Bangdiwala, Ananta S.; Buzibye, Allan; Muzoora, Conrad; Svensson, Elin M.; Aarnoutse, Rob; Boulware, David R.; Elliott, Alison M.
    High-dose rifampicin may improve outcomes of tuberculous meningitis (TBM). Little safety or pharmacokinetic (PK) data exist on high-dose rifampicin in human immunodeficiency virus (HIV) coinfection, and no cerebrospinal fluid (CSF) PK data exist from Africa. We hypothesized that high-dose rifampicin would increase serum and CSF concentrations without excess toxicity. Methods. In this phase II open-label trial, Ugandan adults with suspected TBM were randomized to standard-of-care control (PO-10, rifampicin 10 mg/kg/day), intravenous rifampicin (IV-20, 20 mg/kg/day), or high-dose oral rifampicin (PO-35, 35 mg/kg/ day). We performed PK sampling on days 2 and 14. The primary outcomes were total exposure (AUC0–24), maximum concentration (Cmax), CSF concentration, and grade 3–5 adverse events. Results. We enrolled 61 adults, 92% were living with HIV, median CD4 count was 50 cells/μL (interquartile range [IQR] 46–56). On day 2, geometric mean plasma AUC0–24hr was 42.9·h mg/L with standard-of-care 10 mg/kg dosing, 249·h mg/L for IV-20 and 327·h mg/L for PO-35 (P < .001). In CSF, standard of care achieved undetectable rifampicin concentration in 56% of participants and geometric mean AUC0–24hr 0.27 mg/L, compared with 1.74 mg/L (95% confidence interval [CI] 1.2–2.5) for IV-20 and 2.17 mg/L (1.6–2.9) for PO-35 regimens (P < .001). Achieving CSF concentrations above rifampicin minimal inhibitory concentration (MIC) occurred in 11% (2/18) of standard-of-care, 93% (14/15) of IV-20, and 95% (18/19) of PO-35 participants. Higher serum and CSF levels were sustained at day 14. Adverse events did not differ by dose (P = .34). Conclusions. Current international guidelines result in sub-therapeutic CSF rifampicin concentration for 89% of Ugandan TBM patients. High-dose intravenous and oral rifampicin were safe and respectively resulted in exposures ~6- and ~8-fold higher than standard of care, and CSF levels above the MIC.
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    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.
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    Therapeutic Lumbar Punctures in HIV-associated Cryptococcal Meningitis: should opening pressure direct management?
    (In Open Forum Infectious Diseases., 2022) Kagimu, Enock; Engen, Nicole; Ssebambulidde, Kenneth; Kasibante, John; Kiiza, Tadeo K; Mpoza, Edward; L., Lillian Tugume; Nuwagira, Edwin; Nsangi, Laura; Meya, David B.; Rhein, Joshua; Abassi, Mahsa; Musubire, Abdu K.
    Increased intracranial pressure (ICP) frequently complicates cryptococcal meningitis. Therapeutic lumbar punctures (LPs) have acute survival benefits in the first week, and we sought to understand the longer-term survival impact of therapeutic LPs. We prospectively enrolled HIV-seropositive adults with cryptococcal meningitis from 2013 to 2017 in Uganda. CSF opening pressure was measured at diagnosis. Therapeutic LPs were scheduled on days 3, 7, 10, 14, and performed additionally as clinically indicated. We assessed the association between clinical characteristics, CSF parameters, and 14- and 30-day mortality by baseline ICP. We also assessed 30-day mortality by number of follow-up therapeutic LPs performed within 7 days.
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    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, Joshua
    uberculosis (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.
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    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 team
    Tuberculous 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.