Letter to the editor 1: Predictors of oesophageal candidiasis in persons with or without HIV infection

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Letter to the editor 1: Predictors of oesophageal candidiasis in persons with or without HIV infection

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Surface diffusion induced by low-energy bombardment with He ions: an exchange mechanism

The radiation-induced surface diffusion of molybdenum adatoms was studied using molecular dynamics simulations based on a many-body tight-binding potential interpolated to the short-range repulsive screened Coulombic interactions. It was shown that the He ion impact is accompanied by an extensive surface mobility of Mo atoms. The long radiation-induced atomic jumps, spanning more than a nearest-neighbor distance, were revealed on the {110} terrace. The radiation induced exchange of Mo atoms colliding with Mo {110} surface was found in our mathematical simulations: there were observed exchange processes in which the radiation excited atom entered the surface and another surface atom emerged nearby. These results of MD simulations appear to be the first observation of exchange events in radiation-induced surface diffusion.Радіаційно-індукована поверхнева дифузія адатомів молібдену була вивчена за допомогою моделювання методом молекулярної динаміки, що базується на багаточастковому потенціалі жорсткого зв'язку з інтерполяцією короткодіючого відштовхування екранованою кулонівською взаємодією. Було показано, що бомбардування іонами Не супроводжується великою поверхневою рухливістю атомів Мо. Довгі радіаційно-індуковані атомні стрибки, що охоплюють відстані більш, ніж найближчі міжатомні, були виявлені на {110} терасах. Радіаційно-індукований обмін атомів Мо, що стикаються з поверхнею Мо {110}, був виявлений в нашому математичному моделюванні: спостерігалися обмінні процеси, в яких радіаційно-збуджений атом проникав у поверхневий шар, а поблизу виходив на поверхню інший атом. Ці результати моделювання являють собою перше спостереження обмінних ефектів у радіаційно-індукованій поверхневій дифузії.Радиационно-индуцированная поверхностная диффузия адатомов молибдена была изучена с помощью моделирования методом молекулярной динамики, основанном на многочастичном потенциале жесткой связи с интерполяцией короткодействующего отталкивания экранированным кулоновским взаимодействием. Было показано, что бомбардировка ионами Не сопровождается обширной поверхностной подвижностью атомов Мо. Длинные радиационно-индуцированные атомные скачки, охватывающие расстояния более чем ближайшие межатомные, были выявлены на {110} террасах. Радиационно-индуцированный обмен атомов Мо, сталкивающихся с поверхностью Мо {110}, был обнаружен в нашем математическом моделировании: наблюдались обменные процессы, в которых радиационно-возбужденный атом проникал в поверхностный слой, а поблизости выходил на поверхность другой атом. Эти результаты моделирования представляют собой первое наблюдение обменных эффектов в радиационно-индуцированной поверхностной диффузии

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

Cardiovascular risk factors among people with drug-resistant tuberculosis in Uganda

This work was funded by the National Institute for Health Research through the Royal Society of Tropical Medicine and Hygiene.Background Tuberculosis (TB) and its risk factors are independently associated with cardiovascular disease (CVD). We determined the prevalence and associations of CVD risk factors among people with drug-resistant tuberculosis (DRTB) in Uganda. Methods In this cross-sectional study, we enrolled people with microbiologically confirmed DRTB at four treatment sites in Uganda between July to December 2021. The studied CVD risk factors were any history of cigarette smoking, diabetes mellitus (DM) hypertension, high body mass index (BMI), central obesity and dyslipidaemia. We used modified Poisson regression models with robust standard errors to determine factors independently associated with each of dyslipidaemia, hypertension, and central obesity. Results Among 212 participants, 118 (55.7%) had HIV. Overall, 196 (92.5%, 95% confidence interval (CI) 88.0-95.3) had ≥ 1 CVD risk factor. The prevalence; 95% CI of individual CVD risk factors was: dyslipidaemia (62.5%; 55.4–69.1), hypertension (40.6%; 33.8–47.9), central obesity (39.3%; 32.9–46.1), smoking (36.3%; 30.1–43.1), high BMI (8.0%; 5.0–12.8) and DM (6.5%; 3.7–11.1). Dyslipidaemia was associated with an increase in glycated haemoglobin (adjusted prevalence ratio (aPR) 1.14, 95%CI 1.06–1.22). Hypertension was associated with rural residence (aPR 1.89, 95% CI 1.14–3.14) and previous history of smoking (aPR 0.46, 95% CI 0.21–0.98). Central obesity was associated with increasing age (aPR 1.02, 95%CI 1.00–1.03), and elevated diastolic blood pressure (aPR 1.03 95%CI 1.00–1.06). Conclusion There is a high prevalence of CVD risk factors among people with DRTB in Uganda, of which dyslipidaemia is the commonest. We recommend integrated services for identification and management of CVD risk factors in DRTB.Publisher PDFPeer reviewe

Gender differences among patients with drug resistant tuberculosis and HIV co-infection in Uganda: a countrywide retrospective cohort study

Background Gender differences among patients with drug resistant tuberculosis (DRTB) and HIV co-infection could affect treatment outcomes. We compared characteristics and treatment outcomes of DRTB/HIV co-infected men and women in Uganda. Methods We conducted a retrospective chart review of patients with DRTB from 16 treatment sites in Uganda. Eligible patients were aged ≥ 18 years, had confirmed DRTB, HIV co-infection and a treatment outcome registered between 2013 and 2019. We compared socio-demographic and clinical characteristics and tuberculosis treatment outcomes between men and women. Potential predictors of mortality were determined by cox proportional hazard regression analysis that controlled for gender. Statistical significance was set at p < 0.05. Results Of 666 DRTB/HIV co-infected patients, 401 (60.2%) were men. The median (IQR) age of men and women was 37.0 (13.0) and 34.0 (13.0) years respectively (p < 0.001). Men were significantly more likely to be on tenofovir-based antiretroviral therapy (ART), high-dose isoniazid-containing DRTB regimen and to have history of cigarette or alcohol use. They were also more likely to have multi-drug resistant TB, isoniazid and streptomycin resistance and had higher creatinine, aspartate and gamma-glutamyl aminotransferase and total bilirubin levels. Conversely, women were more likely to be unemployed, unmarried, receive treatment from the national referral hospital and to have anemia, a capreomycin-containing DRTB regimen and zidovudine-based ART. Treatment success was observed among 437 (65.6%) and did not differ between the genders. However, mortality was higher among men than women (25.7% vs. 18.5%, p = 0.030) and men had a shorter mean (standard error) survival time (16.8 (0.42) vs. 19.0 (0.46) months), Log Rank test (p = 0.046). Predictors of mortality, after adjusting for gender, were cigarette smoking (aHR = 4.87, 95% CI 1.28–18.58, p = 0.020), an increase in alanine aminotransferase levels (aHR = 1.05, 95% CI 1.02–1.07, p < 0.001), and history of ART default (aHR = 3.86, 95% CI 1.31–11.37, p = 0.014) while a higher baseline CD4 count was associated with lower mortality (aHR = 0.94, 95% CI 0.89–0.99, p = 0.013 for every 10 cells/mm3 increment). Conclusion Mortality was higher among men than women with DRTB/HIV co-infection which could be explained by several sociodemographic and clinical differences.Funding for this research was obtained from the East African Public Health Laboratory Networking (EAPHLN) Project, Uganda under the Ministry of Health, which was supported by the World Bank. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript