Bio

Dr. Diana Marangu-Boore MBChB, MMed, MPH, MPhil, PhD

Diana is a Paediatrician, Pulmonologist and Lecturer in the Department of Paediatrics and Child Health. She is passionate about improving respiratory health in children, nationally, regionally and globally.

Publications


2022

Verwey, C, Gray DM, Dangor Z, Ferrand RA, Ayuk AC, Marangu D, Kwarteng Owusu S, Mapani MK, Goga A, Masekela R.  2022.  Bronchiectasis in African children: Challenges and barriers to care., 2022. Frontiers in pediatrics. 10:954608. Abstract

Bronchiectasis (BE) is a chronic condition affecting the bronchial tree. It is characterized by the dilatation of large and medium-sized airways, secondary to damage of the underlying bronchial wall structural elements and accompanied by the clinical picture of recurrent or persistent cough. Despite an increased awareness of childhood BE, there is still a paucity of data on the epidemiology, pathophysiological phenotypes, diagnosis, management, and outcomes in Africa where the prevalence is mostly unmeasured, and likely to be higher than high-income countries. Diagnostic pathways and management principles have largely been extrapolated from approaches in adults and children in high-income countries or from data in children with cystic fibrosis. Here we provide an overview of pediatric BE in Africa, highlighting risk factors, diagnostic and management challenges, need for a global approach to addressing key research gaps, and recommendations for practitioners working in Africa.

Beydon, N, Ferkol T, Harris AL, Colas M, Davis SD, Haarman E, Hogg C, Kilbride E, Kouis P, Kuehni CE, Latzin P, Marangu D, Marthin J, Nielsen KG, Robinson P, Rumman N, Rutter M, Walker W, Lucas JS.  2022.  An international survey on nasal nitric oxide measurement practices for the diagnosis of primary ciliary dyskinesia., 2022 Apr. ERJ open research. 8(2) Abstract

Nasal nitric oxide (nNO) measurements are used in the assessment of patients suspected of having primary ciliary dyskinesia (PCD), but recommendations for performing such measurements have not focused on children and do not include all current practices. To guide the development of a European Respiratory Society-supported technical standard for nNO measurement in children, an international online survey was conducted to better understand current measurement practices among providers involved in PCD diagnostics. 78 professionals responded, representing 65 centres across 18 countries, mainly in Europe and North America. Nearly all centres measured nNO in children and more than half performed measurements before 5 years of age. The test was often postponed in children with signs of acute airway infection. In Europe, the electrochemical technique was more frequently used than chemiluminescence. A similar proportion of centres performed measurements during exhalation against a resistance (49 out of 65) or during tidal breathing (50 out of 65); 15 centres used only exhalation against a resistance and 15 used only tidal breathing. The cut-off values used to discriminate PCD were consistent across centres using chemiluminescence analysers; these centres reported results as an output (nL·min). Cut-off values were highly variable across centres using electrochemical devices, and nNO concentrations were typically reported as ppb. This survey is the first to determine real-world use of nNO measurements globally and revealed remarkable variability in methodology, equipment and interpretation. These findings will help standardise methods and training.

2021

Oreskovic, A, Panpradist N, Marangu D, Ngwane WM, Magcaba ZP, Ngcobo S, Ngcobo Z, Horne DJ, Wilson DPK, Shapiro AE, Drain PK, Lutz BR.  2021.  Diagnosing Pulmonary Tuberculosis by Using Sequence-Specific Purification of Urine Cell-Free DNA., 2021 07 19. Journal of clinical microbiology. 59(8):e0007421. Abstract

Transrenal urine cell-free DNA (cfDNA) is a promising tuberculosis (TB) biomarker, but is challenging to detect because of the short length (<100 bp) and low concentration of TB-specific fragments. We aimed to improve the diagnostic sensitivity of TB urine cfDNA by increasing recovery of short fragments during sample preparation. We developed a highly sensitive sequence-specific purification method that uses hybridization probes immobilized on magnetic beads to capture short TB cfDNA (50 bp) with 91.8% average efficiency. Combined with short-target PCR, the assay limit of detection was ≤5 copies of cfDNA in 10 ml urine. In a clinical cohort study in South Africa, our urine cfDNA assay had 83.7% sensitivity (95% CI: 71.0 to 91.5%) and 100% specificity (95% CI: 86.2 to 100%) for diagnosis of active pulmonary TB when using sputum Xpert MTB/RIF as the reference standard. The detected cfDNA concentration was 0.14 to 2,804 copies/ml (median 14.6 copies/ml) and was inversely correlated with CD4 count and days to culture positivity. Sensitivity was nonsignificantly higher in HIV-positive (88.2%) compared to HIV-negative patients (73.3%), and was not dependent on CD4 count. Sensitivity remained high in sputum smear-negative (76.0%) and urine lipoarabinomannan (LAM)-negative (76.5%) patients. With improved sample preparation, urine cfDNA is a viable biomarker for TB diagnosis. Our assay has the highest reported accuracy of any TB urine cfDNA test to date and has the potential to enable rapid non-sputum-based TB diagnosis across key underserved patient populations.

Golden, L, Chaya S, Reichmuth K, Visagie A, Ayuk A, Kwarteng Owusu S, Marangu D, Affendi N, Lakhan A, Gray D, Vanker A, Zar H, Zampoli M.  2021.  Aetiology and presentation of childhood pleural infections in the post-pneumococcal conjugate vaccine era in South Africa., 2021. African journal of thoracic and critical care medicine. 27(4) Abstract

Complications of respiratory infections including pleural effusion (PE) are associated with a high morbidity. Differentiating between PE caused by (Mtb) infection and other bacterial infections in endemic areas is difficult in children, thus, impacting treatment.

2020

Chang, J-WR, Akemokwe FM, Marangu DM, Chisunkha B, Irekpita E, Obasikene G, Kagima JW, Obonyo CO.  2020.  Obstructive Sleep Apnea Awareness among Primary Care Physicians in Africa., 2020 01. Annals of the American Thoracic Society. 17(1):98-106. Abstract

Obstructive sleep apnea (OSA) is a significant health problem among adults and children globally, resulting in decreased quality of life and increased costs of healthcare. For optimal clinical care, primary care physicians should be familiar with OSA and confident in their ability to screen, diagnose, and manage this condition. To assess the knowledge, attitudes, and practices of primary care physicians in Kenya, Nigeria, and South Africa regarding OSA in adults and children. We conducted a multicenter cross-sectional survey in Kenya (Nairobi), Nigeria (Edo State), and South Africa (Cape Town) between April 2016 and July 2017. At least 40 participants were randomly selected from a register of primary care physicians at each site. Potential participants were contacted to receive online/paper-based, validated OSA Knowledge and Attitudes (OSAKA) and OSAKA in Children (OSAKA-KIDS) questionnaires related to adults and children, respectively. The median percentage knowledge scores and proportions of favorable attitude were computed and current diagnostic and referral practices were documented. The median OSAKA knowledge scores were 83.3% (interquartile range [IQR], 77.8-88.9), 66.7% (IQR, 55.6-77.8), and 61.1% (IQR, 55.6-77.8) among South African, Kenyan, and Nigerian physicians, respectively. For OSAKA-KIDS, the median knowledge scores were 61.1% (IQR, 50.0-72.2), 64.2% (IQR, 35.3-93.2), and 58.3% (IQR, 44.4-66.7) among South African, Kenyan, and Nigerian physicians, respectively. Most physicians (90-94%) considered adult and pediatric OSA very/extremely important. Fewer physicians agreed/strongly agreed that they were confident about OSA diagnosis (55%), management (25%), and continuous positive airway pressure (18%) use in adults. Even fewer physicians agreed/strongly agreed that they were confident about pediatric OSA diagnosis (35%), management (21%), and continuous positive airway pressure use (18%). South African physicians mainly prescribed polysomnography (51%) and overnight oximetry (22%), whereas 49% of Nigerian physicians and 65% of Kenyan physicians commonly requested lateral cervical radiography. Primary care physicians in South Africa, Nigeria, and Kenya considered OSA to be important but had modest knowledge about OSA in adults and children, and had a low perceived confidence in adult and pediatric management. Focused educational interventions during undergraduate training and continuing professional development programs may improve primary physicians' knowledge about OSA and its diagnosis and management.

2019

Marangu, D, Zar HJ.  2019.  Childhood pneumonia in low-and-middle-income countries: An update., 2019 Nov. Paediatric respiratory reviews. 32:3-9. Abstract

To review epidemiology, aetiology and management of childhood pneumonia in low-and-middle-income countries.

Mwangi, PM, Dalton Wamalwa, Marangu D, Obimbo EM, Ng'ang'a M.  2019.  Implementation of Isoniazid Preventive Therapy Among HIV-Infected Children at Health Facilities in Nairobi County, Kenya: A Cross-Sectional Study., 2019. The East African health research journal. 3(2):141-150. Abstract

HIV is the strongest risk factor for developing tuberculosis (TB) among people with latent or new infection. Isoniazid preventive therapy (IPT) reduces the risk of active TB among people living with HIV by up to 62%. Despite evidence that IPT is safe and efficacious, its provision remains low globally. The current study aimed at documenting IPT uptake, adherence, and completion rates, as well as the correlates of IPT uptake among HIV-infected children in Kenya. The study also assessed the knowledge, attitude, and practices of health-care workers (HCWs) with regard to IPT.

Katz, MA, Marangu D, Attia EF, Bauwens J, Bont LJ, Bulatovic A, Crane J, Doroshenko A, Ebruke BE, Edwards KM, Fortuna L, Jagelaviciene A, Joshi J, Kemp J, Kovacs S, Lambach P, Lewis KDC, Ortiz JR, Simões EAF, Turner P, Tagbo BN, Vaishnavi V, Bonhoeffer J.  2019.  Acute wheeze in the pediatric population: Case definition & guidelines for data collection, analysis, and presentation of immunization safety data., 2019 01 07. Vaccine. 37(2):392-399.
Marangu, D, Gray D, Vanker A, Zampoli M.  2019.  Exogenous lipoid pneumonia in children: A systematic review., 2019 Jan 20. Paediatric respiratory reviews. Abstract

To describe the clinical-radiological-pathological characteristics and treatment outcomes of children with suspected exogenous lipoid pneumonia (ELP).

2018

Andreieva, IO, Konstantynovska O, Midulla F, Marangu D, Mchedlishvili N.  2018.  Summer schools of adult and paediatric respiratory medicine: course report., 2018 Mar. Breathe (Sheffield, England). 14(1):9-12. Abstract
Marangu, D, Pillay K, Banderker E, Gray D, Vanker A, Zampoli M.  2018.  Exogenous lipoid pneumonia: an important cause of interstitial lung disease in infants., 2018 Oct. Respirology case reports. 6(7):e00356. Abstract

Exogenous lipoid pneumonia (ELP), an important cause of interstitial lung disease, often goes unrecognized. We conducted a retrospective study of children with histologically confirmed ELP at Red Cross Children's Hospital, South Africa. Twelve children of Zimbabwean heritage aged 2.1-10.8 months were identified between 2012 and 2017. Repeated oral administration of plant-based oil for cultural reasons was reported by 10 of 11 caregivers. Cough (12/12), tachypnoea (11/12), hypoxia (9/12), and diffuse alveolar infiltrates on chest radiography (12/12) were common at presentation. Chest computed tomography revealed ground-glass opacification with lower zone predominance (9/9) and interlobular septal thickening (8/9). Bronchoalveolar lavage specimens appeared cloudy/milky, with abundant lipid-laden macrophages and extracellular lipid on Oil-Red-O staining (12/12), with polymicrobial (6/12) and Mycobacterium abscessus (2/12) co-infection. Antibiotics, systemic corticosteroids, and therapeutic lavage were interventions in all eight and five patients, respectively. Clinicians should consider ELP in children with non-resolving pneumonia in settings with similar practices.

2017

Marangu, D, Mwaniki H, Nduku S, Maleche-Obimbo E, Jaoko W, Babigumira J, John-Stewart G, Rao D.  2017.  Stakeholder perspectives for optimization of tuberculosis contact investigation in a high-burden setting., 2017. PloS one. 12(9):e0183749. Abstract

Optimal tuberculosis contact investigation impacts TB prevention, timely case finding and linkage to care, however data on routine implementation in high burden contexts is limited.

Marangu, D, Mwaniki H, Nduku S, Maleche-Obimbo E, Jaoko W, Babigumira J, John-Stewart G, Rao D.  2017.  ADAPTING A STIGMA SCALE FOR ASSESSMENT OF TUBERCULOSIS-RELATED STIGMA AMONG ENGLISH/SWAHILI-SPEAKING PATIENTS IN AN AFRICAN SETTING., 2017 Nov. Stigma and health. 2(4):326. Abstract

To adapt a validated instrument that quantitatively measures stigma among English/Swahili speaking TB (tuberculosis) patients in Kenya, a high burden TB country.

2016

Russ, CM, Ganapathi L, Marangu D, Silverman M, Kija E, Bakeera-Kitaka S, Laving A.  2016.  Perspectives of host faculty and trainees on international visiting faculty to paediatric academic departments in East Africa., 2016. BMJ global health. 1(3):e000097. Abstract

Investments in faculty exchanges to build physician workforce capacity are increasing. Little attention has been paid to the expectations of host institution faculty and trainees. This prospective qualitative research study explored faculty and resident perspectives about guest faculty in paediatric departments in East Africa, asking (1) What are the benefits and challenges of hosting guest faculty, (2) What factors influence the effectiveness of faculty visits and (3) How do host institutions prepare for faculty visits?

2015

Marangu, D, Devine B, John-Stewart G.  2015.  Diagnostic accuracy of nucleic acid amplification tests in urine for pulmonary tuberculosis: a meta-analysis., 2015 Nov. The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease. 19(11):1339-47. Abstract

To determine the diagnostic accuracy of tuberculosis (TB) nucleic acid amplification tests (NAATs) in urine samples for individuals with active pulmonary tuberculosis (PTB).

Marangu, D, Kovacs S, Walson J, Bonhoeffer J, Ortiz JR, John-Stewart G, Horne DJ.  2015.  Wheeze as an adverse event in pediatric vaccine and drug randomized controlled trials: A systematic review., 2015 Oct 5. Vaccine. 33(41):5333-41. Abstract

Wheeze is an important sign indicating a potentially severe adverse event in vaccine and drug trials, particularly in children. However, there are currently no consensus definitions of wheeze or associated respiratory compromise in randomized controlled trials (RCTs).

2014

Marangu, D, Jowi C, Aswani J, Wambani S, Ruth Nduati.  2014.  Prevalence and associated factors of pulmonary hypertension in Kenyan children with adenoid or adenotonsillar hypertrophy., 2014 Aug. International journal of pediatric otorhinolaryngology. 78(8):1381-6. Abstract

Adenotonsillar hypertrophy is a common condition in childhood, whose serious complications of pulmonary hypertension and cor pulmonale are devastating but local prevalence is unknown. This study determined the prevalence and associated factors of pulmonary hypertension in children with adenoid or adenotonsillar hypertrophy at Kenyatta National Hospital, Kenya.

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