Elevated Aspergillus-specific antibody levels among HIV infected Ugandans with pulmonary tuberculosis.

BACKGROUND: The incidence of tuberculosis (TB) is high among human immunodeficiency virus (HIV) infected Ugandans. Recent evidence suggests that Chronic Pulmonary Aspergillosis and Aspergillus sensitisation might be responsible for significant mortality in patients treated for tuberculosis in Uganda. METHODS: We retrieved and tested paired serum aliquots for 101 HIV-TB co-infected patients at the beginning and week 24 of TB treatment. We tested samples for Aspergillus-specific immunoglobulin G (IgG) and immunoglobulin E (IgE) using ImmunoCAP®; and Aspergillus-specific IgG and total serum IgE using Immulite® immunoassays. We compared antibody levels between baseline and week 24, relating them to selected baseline characteristics. RESULTS: 10% of the patients had elevated Aspergillus-specific IgE (Aspergillus sensitization) and Aspergillus-specific IgG antibodies were elevated in 9% of the patients at the end of TB treatment. There was a significant fall in the Aspergillus-specific IgG antibody levels between baseline and week 24 (P = 0.02). Patients with cluster of differentiation 4 (CD4) T-cell count <100 cells/μl and those who were not on anti-retroviral therapy at baseline had more elevated Aspergillus-specific IgG antibodies (P = 0.01, P = 0.03). The ImmunoCAP® Aspergillus-specific IgG antibody titres were higher at week 24 than baseline with more positives at week 24; even though the difference in means was small. However, this difference was statistically significant (P = 0.02). Pulmonary infiltrates were the commonest x-ray abnormality and only 5% of the patients had pulmonary cavities on chest x-ray at week 24. CONCLUSION: These results suggest that Aspergillus infection may complicate active pulmonary TB and further studies including fungal culture and thoracic imaging may now be indicated to measure the prevalence of pulmonary aspergillosis complicating tuberculosis. TRIAL REGISTRATION: The SOUTH trial was registered prospectively. ClinicalTrials.gov Identifier: NCT01782950 ; Registration date: 4th February 2013; Last verified: 13th April 2015

Treatment of Histoplasmosis

Histoplasmosis, caused by the thermally dimorphic fungus Histoplasma capsulatum, is an uncommon multisystem disease with a global distribution. The spectrum of clinical manifestations ranges from an asymptomatic or minimally symptomatic acute pulmonary disease following inhalation of a large inoculum of Histoplasma microconidia to chronic pulmonary disease in patients with underlying structural lung disease. It also extends to acute progressive disseminated disease in patients with severe immunodeficiency. Generally, antifungal therapy is indicated for patients with progressive acute pulmonary histoplasmosis, chronic pulmonary histoplasmosis and acute progressive disseminated histoplasmosis. In immunocompetent patients, acute pulmonary histoplasmosis may be a self-limiting disease without the need for systemic antifungal therapy. Oral triazole antifungal drugs alone are recommended for less severe disease. However, moderate-to-severe acute pulmonary histoplasmosis requires intravenous amphotericin B therapy for at least 1–2 weeks followed by oral itraconazole for at least 12 weeks. For acute progressive disseminated histoplasmosis, intravenous amphotericin B therapy is given for at least 2 weeks (4–6 weeks if meningeal involvement) or until a patient can tolerate oral therapy, followed by oral itraconazole (or an alternative triazole) for at least 12 months. Chronic cavitary pulmonary histoplasmosis is treated with oral itraconazole for 1–2 years. There is insufficient evidence to support the use of isavuconazole or the echinocandins for the treatment of histoplasmosis

Prevalence of Aspergillus fumigatus skin positivity in adults without an apparent/known atopic disease in Uganda.

BACKGROUND: Skin prick testing (SPT) is an important investigation in the evaluation of allergy to fungal pathogens. However, the background sensitivity to fungal allergens among healthy people in Uganda is unknown. Our aim was to assess the background prevalence of Aspergillus fumigatus SPT positivity in apparently healthy adults without known atopic disease in Uganda. METHODS: For this pilot study, we recruited 50 healthy volunteers using convenience sampling, 56% of whom were health workers. We performed the SPT for A. fumigatus according to manufacturer's instructions. A wheal diameter of ⩾3 mm was considered positive. RESULTS: The prevalence of A. fumigatus skin positivity was 60% (30/50). Participants with a positive A. fumigatus SPT were significantly younger than those with a negative result [median age (years): 28 versus 35; p = 0.005]. CONCLUSION: There is a high skin positivity against A. fumigatus among non-atopic healthy Ugandan adults. There is an urgent need to establish a normal wheal cut-off value for this population. SPT alone may be an unreliable test for the diagnosis of A. fumigatus associated allergic syndromes. More studies are needed to define the prevalence of A. fumigatus skin positivity among non-atopic healthy population in Africa

Performance of Lipoarabinomannan Assay using Cerebrospinal fluid for the diagnosis of Tuberculous meningitis among HIV patients.

Background: 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. Methods: 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.  Results: 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. Conclusions: 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

Skin prick reactivity among asthmatics in East Africa

Background: The burden of asthma in Africa is high, and yet the disease is not universally prioritised. Data on allergic asthma and its impact on asthma morbidity are limited in Africa. Our aim was to describe the distribution of skin prick positivity among asthmatics in Eastern Africa. Methods: From August 2016 to May 2018, 1671 asthmatic patients were enrolled from Uganda, Kenya, and Ethiopia as part of the African Severe Asthma Program clinical study. Skin prick testing was performed at baseline using a panel of 12 allergens, and factors associated with skin prick reactivity determined. Results: Of the 1, 671 patients recruited, 71% were female with a median age of 40 years, 93.6% were aged >15 years and the patterns of asthma symptom frequency was intermittent in 2.9%, mild persistent in 19.9%, moderate persistent in 42.6% and severe persistent in 34.6% at baseline. Self-reported triggers, were dust (92%), cold weather (89%), upper respiratory infections (84%), strong smells (79%) and exposure to tobacco (78%). The majority (90%) of the participants had at least 1 positive allergen reaction, with 0.9% participants reacting to all the 12 allergens. Participants commonly reacted to house dust mites (66%), Blomia tropicalis (62%), and the German cockroach (52%). Patients sensitized to more allergens (>2) had significantly reduced lung function (FEV ≤ 80%; p = 0.001) and were more likely to visit the emergency department due to asthma (p = 0.012). There was no significant relationship between number of allergens and measures of asthma control, quality of life, and other clinical outcomes. Only the country of origin was independently associated with atopy among African asthmatics. Conclusion: There is a high prevalence of skin prick positivity among East African patients with asthma, with the commonest allergen being house dust mite. Skin reactivity did not correlate well with asthma severity and poor asthma control. The relation between atopy, measured through skin prick testing, and measures of asthma control among asthma patients in Eastern Africa is unclear and needs further study. Trial registration: The ASAP study was registered prospectively. ClinicalTrials.gov Identifier: NCT03065920; Registration date: February 28, 2017; Last verified: February 28, 2017

Building clinical pharmacology laboratory capacity in low- and middle-income countries: Experience from Uganda

BACKGROUND Research and clinical use of clinical pharmacology laboratories are limited in low- and middle-income countries. We describe our experience in building and sustaining laboratory capacity for clinical pharmacology at the Infectious Diseases Institute, Kampala, Uganda. INTERVENTION Existing laboratory infrastructure was repurposed, and new equipment was acquired. Laboratory personnel were hired and trained to optimise, validate, and develop in-house methods for testing antiretroviral, anti-tuberculosis and other drugs, including 10 high-performance liquid chromatography methods and four mass spectrometry methods. We reviewed all research collaborations and projects for which samples were assayed in the laboratory from January 2006 to November 2020. We assessed laboratory staff mentorship from collaborative relationships and the contribution of research projects towards human resource development, assay development, and equipment and maintenance costs. We further assessed the quality of testing and use of the laboratory for research and clinical care. LESSONS LEARNT Fourteen years post inception, the clinical pharmacology laboratory had contributed significantly to the overall research output at the institute by supporting 26 pharmacokinetic studies. The laboratory has actively participated in an international external quality assurance programme for the last four years. For clinical care, a therapeutic drug monitoring service is accessible to patients living with HIV at the Adult Infectious Diseases clinic in Kampala, Uganda. RECOMMENDATIONS Driven primarily by research projects, clinical pharmacology laboratory capacity was successfully established in Uganda, resulting in sustained research output and clinical support. Strategies implemented in building capacity for this laboratory may guide similar processes in other low- and middle-income countries

Evaluation of an Aspergillus IgG/IgM lateral flow assay for serodiagnosis of fungal asthma in Uganda

Background: Diagnosis of fungal allergies in asthma remains problematic in low-and middle-income countries due to non-availability of point-of-care testing. In this study, we aimed to evaluate the performance of an Aspergillus immunochromatographic technology (ICT) IgG/M lateral flow device (LFD) for the serological diagnosis of allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitisation (SAFS) among Ugandan adult asthmatics. Methods: 374 adult (aged ≥18years) asthmatics in the African Severe Asthma Program study, Ugandan site constituted the study population. ABPA and SAFS were diagnosed according to standard criteria. Asthmatics who did not meet the above criteria constituted a control group. The LFD tests were performed and read according to manufacturer’s instructions. Results: ABPA was found in 12/374 (3.2%) and SAFS in 60/374 (16%) participants. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the Aspergillus ICT for the diagnosis of ABPA were 0.0%, 96.4%, 0.0% and 96.7% respectively, and for SAFS 6.7%, 97.1%, 30.8% and 84.5% respectively. False positive and negative rates were 3.5% and 3.2% for ABPA and 2.4% and 14.9% for SAFS, respectively. Patients with a positive LFD significantly had higher median Aspergillus fumigatus-specific IgE levels compared to those with negative LFD (median: 0.06 kUA/l VS 0.03 kUA/L, P = 0.011). Conclusion: The Aspergillus ICT IgG/M LFD had a poor diagnostic performance for the diagnosis of both ABPA and SAFS. Its greatest value may be in distinguishing chronic and allergic aspergillosis in Africa

Xpert MTB/RIF Ultra for the diagnosis of HIV-associated tuberculous meningitis: a prospective validation study.

INTRODUCTION: 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. METHODS: 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. FINDINGS: 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. INTERPRETATION: 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. FUNDING: Wellcome Trust, National Institute of Health, National Institute of Neurologic Diseases and Stroke, Fogarty International Center, and National Institute of Allergy and Infectious Diseases

COVID-19 and the HIV care continuum in Uganda: minimising collateral damage

The novel coronavirus, SARS-CoV-2, has spread across the world within months of its first description in Wuhan, China in December 2019, resulting in an unprecedented global health emergency. Whilst Europe and North America are the current epicentres of infection, the global health community are preparing for the potential effects of this new disease on the African continent. Modelling studies predict that factors such as a youthful and rural population may be protective in mitigating the spread of COVID-19 in the World Health Organisation (WHO) African Region, however, with 220 million infections and 4.6 million hospitalisations predicted in the first year of the pandemic alone, fragile health systems could still be placed under significant strain. Furthermore, subsequent disruptions to the provision of services for people living with HIV, or at risk of acquiring HIV, are predicted to lead to an extra 500,000 adult HIV deaths and a 2-fold increase in mother to child transmission of HIV in sub-Saharan Africa in 2020-2021. Ignoring these predictions may have severe consequences and we risk �stepping back in time� in AIDS-related deaths to numbers seen over a decade ago. Reflecting on our current experience of the COVID-19 pandemic in Uganda, we explore the potential impact of public health measures implemented to mitigate spread of COVID-19 on the HIV care continuum, and suggest areas of focus for HIV services, policy makers and governments to urgently address in order to minimise the collateral damage

Invasive Fungal Diseases in Africa: A Critical Literature Review

Invasive fungal diseases (IFDs) are of huge concern in resource-limited settings, particularly in Africa, due to the unavailability of diagnostic armamentarium for IFDs, thus making definitive diagnosis challenging. IFDs have non-specific systemic manifestations overlapping with more frequent illnesses, such as tuberculosis, HIV, and HIV-related opportunistic infections and malignancies. Consequently, IFDs are often undiagnosed or misdiagnosed. We critically reviewed the available literature on IFDs in Africa to provide a better understanding of their epidemiology, disease burden to guide future research and interventions. Cryptococcosis is the most encountered IFD in Africa, accounting for most of the HIV-related deaths in sub-Saharan Africa. Invasive aspergillosis, though somewhat underdiagnosed and/or misdiagnosed as tuberculosis, is increasingly being reported with a similar predilection towards people living with HIV. More cases of histoplasmosis are also being reported with recent epidemiological studies, particularly from Western Africa, showing high prevalence rates amongst presumptive tuberculosis patients and patients living with HIV. The burden of pneumocystis pneumonia has reduced significantly probably due to increased uptake of anti-retroviral therapy among people living with HIV both in Africa, and globally. Mucormycosis, talaromycosis, emergomycosis, blastomycosis, and coccidiomycosis have also been reported but with very few studies from the literature. The emergence of resistance to most of the available antifungal drugs in Africa is yet of huge concern as reported in other regions. IFDs in Africa is much more common than it appears and contributes significantly to morbidity and mortality. Huge investment is needed to drive awareness and fungi related research especially in diagnostics and antifungal therapy