Facilitators and barriers to TB care during the COVID-19 pandemic.

BACKGROUND: Knowledge about factors influencing access and adherence to TB care, and on the impact of the COVID-19 pandemic on TB care in resource-restricted settings is scarce. We conducted this study in Atsimo-Andrefana, a rural region in southern Madagascar where TB prevalence, poverty and food insecurity rates are high. We aimed to determine facilitators and barriers to access to and provision of TB care in rural Madagascar during the COVID-19 pandemic. METHODS: We conducted qualitative focus group discussions (FGDs) and in-depth interviews (IDIs) with patients with TB, community health workers, facility-based health workers, public health officials and non-governmental organisation staff. We analysed interviews using thematic analysis. RESULTS: We conducted 11 FGDs and 23 IDIs. We identified three main barriers to access and adherence to TB care: 1) stigma, 2) indirect treatment costs, and 3) food insecurity. The facilitator perceived as most influential was high health worker motivation. The effects of the COVID-19 pandemic on TB care varied between stake-holders; some health workers described delays in TB diagnosis and increased workload. CONCLUSIONS: To improve access and adherence to TB care, both indirect treatment costs and stigma need to be reduced; undernourished patients with TB should receive food support.

CONTEXTE: Les connaissances sur les facteurs influençant l'accès et l'adhésion aux soins antituberculeux, ainsi que sur l'impact de la pandémie de COVID-19 sur les soins antituberculeux dans les milieux à ressources limitées sont rares. Nous avons mené cette étude à Atsimo-Andrefana, une région rurale du sud de Madagascar où la prévalence de la TB et les taux de pauvreté et d'insécurité alimentaire sont élevés. Nous avons cherché à déterminer les facilitateurs et les obstacles à l'accès et à la fourniture de soins antituberculeux dans les zones rurales de Madagascar pendant la pandémie de COVID-19. MÉTHODES: Nous avons mené des discussions qualitatives en groupe (FGD) et des entretiens approfondis (IDI) avec des patients atteints de tuberculose, des agents de santé communautaires, des agents de santé en établissement, des responsables de la santé publique et des membres d'organisations non gouvernementales. Nous avons analysé les entretiens en utilisant l'analyse thématique. RÉSULTATS: Nous avons mené 11 FGD et 23 IDI. Nous avons identifié trois principaux obstacles à l'accès et à l'observance des soins antituberculeux : 1) la stigmatisation, 2) les coûts indirects du traitement et 3) l'insécurité alimentaire. Le facilitateur perçu comme le plus influent était la forte motivation des agents de santé. Les effets de la pandémie de COVID-19 sur les soins antituberculeux varient selon les parties prenantes ; certains agents de santé ont décrit des retards dans le diagnostic de la TB et une augmentation de la charge de travail. CONCLUSIONS: Pour améliorer l'accès et l'adhésion aux soins antituberculeux, il faut réduire à la fois les coûts indirects du traitement et la stigmatisation ; les patients tuberculeux sousalimentés devraient recevoir une aide alimentaire.

Gadolinium deposition in the paediatric brain: T1-weighted hyperintensity within the dentate nucleus following repeated gadolinium-based contrast agent administration.

AIM: To determine whether repeated gadolinium-based contrast agent administration (GBCA) in children is associated with the development of increased T1-weighted signal intensity within the cerebellar dentate nucleus. MATERIALS AND METHODS: With institutional review board approval for this The Health Insurance Portability and Accountability Act-compliant retrospective study, a cohort of 41 patients under the age of 18 years who underwent at least four contrast-enhanced magnetic resonance imaging (MR) examinations of the brain from 2005 to 2015 were identified. For each examination, both dentate nuclei were manually contoured, and the mean dentate nucleus-to-pons signal intensity (DN-P SI) ratio was calculated. The DN-P SI ratios from the last to first MRI examination were compared, and the correlation between DN-P SI ratio and cumulative gadolinium dose was calculated using a linear mixed effect model to control for potentially confounding variables. RESULTS: For the 41 patients in the cohort, there was a significant increase in the mean DN-P SI ratio from the first MRI to the last MRI examination (1.05 versus 1.11, p=0.004). After controlling for patient diagnosis, history of chemotherapy or radiation, sex, and age, there was a significant positive association between DN-P SI ratio and cumulative gadolinium dose (coefficient=0.401, p=0.032). CONCLUSION: Repeated GBCA administration in children is associated with increased T1-weighted signal intensity within the dentate nucleus.

Effects of cytokines and fluconazole on the activity of human monocytes against Candida albicans.

This study evaluates the effects of cytokines, used singly and in combination, on the microbicidal activity of human monocyte-derived macrophages (MDM) against intracellular Candida albicans in the presence and absence of fluconazole. In the absence of fluconazole, the addition of tumor necrosis factor alpha (TNF-alpha), interleukin-1beta (IL-1beta), gamma interferon (IFN-gamma), or IL-4 had no effect on the growth of C. albicans. In contrast, the addition of granulocyte-macrophage colony-stimulating factor (GM-CSF) resulted in decreased growth (P < 0.05), while the addition of IL-10 resulted in increased growth (P < 0.01). In the presence of fluconazole, only the addition of IFN-gamma resulted in an increase in the growth of C. albicans. In the presence or absence of fluconazole, all cytokine combinations except IFN-gamma plus GM-CSF caused significant decreases in growth (P < 0.01). IL-10 and IL-4 did not influence the activity of TNF-alpha or IL-1beta. In the absence or presence of C. albicans the addition of fluconazole, all of the cytokines studied, and combinations of fluconazole and selected cytokines caused increases in nitric oxide (NO) production (P < 0.01). Similar observations were made for superoxide (O(2)(-)) only in the presence of C. albicans. The greatest concentrations of NO and O(2)(-) were produced when C. albicans alone was present in the assays. Our results demonstrate that in the presence of low concentrations of fluconazole (0.1 times the MIC), selected cytokines and their combinations significantly increase the microbicidal activity of MDM against intracellular C. albicans.

Antibacterial effect of telithromycin (HMR 3647) and comparative antibiotics against intracellular Legionella pneumophila.

The activity of the ketolide telithromycin (HMR 3647) against intracellular Legionella pneumophila strain L-1033 was compared with the activities of erythromycin and levofloxacin. To assay intracellular antibacterial activity, human monocytes were allowed to adhere to wells in 24-well tissue culture plates and were then exposed to L. pneumophila cells for 1 h to allow phagocytosis to occur. Antibiotics were added to the wells after removal of unphagocytosed bacteria. Quantitative bacterial cell counts were made from lysed monocytes at 0, 24, 48, 72 and 96 h. The antibacterial effects of antibiotics against intracellular L. pneumophila L-1033 were concentration and time dependent; at 10 x MIC the activity of telithromycin was greater than that of erythromycin and was less than that of levofloxacin (P < 0.01); telithromycin-rifampicin combinations showed no synergy or interference; and removal of telithromycin from assays at 24 h did not affect its intracellular antibacterial activity. In conclusion, the ketolide telithromycin has excellent activity against intracellular L. pneumophila strain L-1033 and should be evaluated for therapy of legionnaires' disease.

Microbicidal activity of MDI-P against Candida albicans, Staphylococcus aureus, Pseudomonas aeruginosa, and Legionella pneumophila.

BACKGROUND: MDI-P (Medical Discoveries, Inc-Pharmaceutical, Layton, Utah) is a clear, colorless liquid generated by electrolysis of preservative-free and endotoxin-free, nonpyrogenic, sterile, injection saline (0.9% NaCl, wt/vol). It contains numerous highly reactive chlorine and oxygen species, including HOCl(-1,) OCl-(1), Cl(-1), Cl(2), O(2-)(1), and O(3). This report presents data on the in vitro microbicidal activity of MDI-P against 4 clinically relevant microbial pathogens that are often difficult to eradicate. METHODS: MDI-P was generated from injection saline by using a patented electrolysis instrument. It was then tested for microbicidal activity at concentrations ranging from 0.01% to 50% against Staphylococcus aureus, Pseudomonas aeruginosa, Legionella pneumophila, and Candida albicans (10(5) to 10(9) colony-forming units/mL). The effect of serum (50% and 90%) and pH on MDI-P activity were also tested. The morphologic effects of MDI-P on microbial cells were studied by light microscopy of cells stained by Gram's method and by transmission electron microscopy. Morbidity, mortality, and the effect of MDI-P on tissues were studied by using a mouse model. RESULTS: The microbicidal activity of MDI-P occurred within the first minute of exposure for all the organisms tested. When 50% MDI-P was tested against cell titers of 10(5) or 10(7) colony-forming units/mL, all test organisms were killed within 1 minute; at lower MDI-P concentrations, C albicans was the most sensitive organism, and L pneumophila was the most resistant. Even with beginning cell titers of 10(9) colony-forming units/mL, killing by 50% MDI-P was >99.9% for all test strains. Furthermore, at the same beginning cell titer, killing of C albicans by MDI-P diluted to 50% with normal human serum rather than injection saline was only slightly reduced. No acute morbidity, mortality, or tissue damage was detected in mice that were intravenously given 17 mL/kg of undiluted MDI-P. CONCLUSIONS: MDI-P is a very fast-acting, broad-spectrum microbicidal material. The lack of evidence for acute morbidity, mortality, or tissue injury, ease of preparation, and low cost suggest that it may be useful for various sterilization and disinfection applications.

Levofloxacin penetrates human monocytes and enhances intracellular killing of Staphylococcus aureus and Pseudomonas aeruginosa.

Intracellular bacteria often cause relapsing and refractory infections. However, these infections can be treated effectively with antibiotics such as ofloxacin which penetrate into the cells containing bacteria. As levofloxacin, the levorotatory isomer of ofloxacin, has enhanced antibacterial activity, we tested the levofloxacin concentration in human monocytes and the effects of intracellular levofloxacin on monocyte killing of Staphylococcus aureus strain ATCC 29213 and Pseudomonas aeruginosa strain PA1348A. Human monocytes were incubated with levofloxacin at various pH values and temperatures. Following incubation, the monocytes were separated from incubation media, and intracellular (C) and extracellular (E) levofloxacin concentrations were determined. Mean C/E ratios after 15 min of incubation with 6 and 12 mg/L levofloxacin at pH 7.4 were 6.4 and 7.1, respectively. C/E ratios were similar at pH 7.4 and 8.0, but decreased at lower pH values. To study the effects of levofloxacin on intracellular killing of S. aureus and P. aeruginosa, opsonized bacteria were added to monolayers of monocytes. Following phagocytosis, monocytes were incubated with various concentrations of levofloxacin, ciprofloxacin and rifampicin, alone or in combination. Levofloxacin (2.5 and 4 mg/L) significantly reduced the survival of cell-associated S. aureus and was more effective than ciprofloxacin at similar concentrations (P < 0.01). Enhanced killing of cell-associated P. aeruginosa by levofloxacin (0.5 and 1.0 mg/L) was also observed. Activities of levofloxacin and ciprofloxacin against cell-associated P. aeruginosa were similar. Addition of rifampicin did not augment the bactericidal activity of levofloxacin. Since levofloxacin is concentrated in human monocytes and increases their bactericidal activity against intracellular bacteria, it should be considered for treatment of infections caused by susceptible intracellular bacteria.

Antibacterial effects of levofloxacin, erythromycin, and rifampin in a human monocyte system against Legionella pneumophila.

The antibacterial activities of levofloxacin, erythromycin, and rifampin against intracellular Legionella pneumophila L-1033, serogroup 1, were studied. In an in vitro system utilizing adherent human monocytes, L. pneumophila L-1033, a phagocytosis time period of 1 h, and antibiotic (levofloxacin, erythromycin, and/or rifampin) at 1 to 10 times the MIC, the CFU/ml values for the monocyte lysate were determined during 0- to 4-day time periods. The decrease in CFU/ml with levofloxacin at pH 7.4 was rapid, occurring within 24 h, and was drug concentration dependent (P < 0.01). The decrease in CFU with rifampin was first observed at 48 h (P < 0.01), while only a minimal decrease in CFU/ml was observed with erythromycin. Combination of levofloxacin and rifampin and of levofloxacin and erythromycin at ten times their MICs significantly decreased the CFU/ml value (P < 0.01), to the value attained by levofloxacin alone, while combination of rifampin and erythromycin did not. Removal of levofloxacin after 24 h of incubation resulted in regrowth of L. pneumophila L-1033, while a continued slow decrease in CFU/ml was seen following rifampin removal; CFU/ml values were unaffected by the removal of erythromycin. At 4 days, and even in assays performed following antibiotic removal, the CFU/ml value continued to be lower in the levofloxacin and rifampin assays than in the assays with erythromycin. Levofloxacin had a significantly higher bactericidal activity against L. pneumophila L-1033 than erythromycin or rifampin. In these assays, the addition of erythromycin or rifampin did not affect the antibacterial activity of levofloxacin.

Effect of pentoxifylline on the course of systemic Candida albicans infection in mice.

Pentoxifylline can decrease the production of tumour necrosis factor alpha (TNF alpha) by endotoxin-stimulated macrophages and may improve survival in animals with overwhelming bacterial sepsis. In this study various doses of pentoxifylline were administered to mice with systemic Candida albicans infection to determine its effect on serum TNF alpha levels, organ fungal burden, and host survival. Intraperitoneal injections of pentoxifylline at 20 mg/kg every 8 h did not affect these endpoints. However, fungal counts were significantly higher in kidneys of animals that received 30 and 60 mg/kg of pentoxifylline every 8 h when compared to controls. Injection of 60 mg/kg of pentoxifylline at 8 h intervals also significantly shortened mean survival from 5.8 to 3.8 days (P = 0.01). Pentoxifylline did not affect peripheral WBC counts, serum TNF alpha and interleukin-6 levels, or the density of neutrophils in tissues. In vitro, pentoxifylline decreased the production of TNF alpha by C. albicans-stimulated macrophages in a dose-dependent manner, but only at concentrations greater than 100 mg/L. In contrast, pentoxifylline suppressed TNF alpha production by endotoxin-stimulated macrophages at concentrations as low as 10 mg/L. Thus, higher doses of pentoxifylline are detrimental in systemic C. albicans infection. However, the detrimental effect is not mediated by alterations in serum TNF alpha or interleukin-6 levels or the aggregation of neutrophils in tissues.

Fluconazole and amphotericin B antifungal therapies do not negate the protective effect of endogenous tumor necrosis factor in a murine model of fatal disseminated candidiasis.

In systemic candidiasis, endogenously produced tumor necrosis factor (TNF)-alpha prolongs survival of the infected host. To determine whether endogenously produced TNF-alpha has a beneficial effect beyond that provided by antifungal therapy, survival was assessed in infected mice that received fluconazole or amphotericin B alone and in combination with anti-TNF-alpha antibody. Neutralization of serum TNF-alpha did not affect survival in fluconazole recipients; however, for amphotericin B recipients, it significantly shortened mean survival. For both fluconazole and amphotericin B recipients, colony counts in organs were significantly higher in animals that also received anti-TNF-alpha antibody. Administration of anti-TNF-alpha antibody with amphotericin B or fluconazole did not affect the morphology of fungi or the inflammatory response in kidneys. This study suggests that exogenous TNF-alpha and drugs that increase the endogenous production of TNF-alpha by the host may be useful adjuncts to fluconazole and amphotericin B for the treatment of systemic candidiasis.

Comparative capacity of four antifungal agents to stimulate murine macrophages to produce tumour necrosis factor alpha: an effect that is attenuated by pentoxifylline, liposomal vesicles, and dexamethasone.

The efficacy and toxicity of certain antifungal agents may be related to their ability to induce the production of cytokines by mononuclear phagocytes. The capacity of incremental concentrations of fluconazole, 5-fluorocytosine (5-FC), amphotericin B (AmB), and liposomal AmB (LAB) to stimulate murine peritoneal and RAW 264.7 macrophages to secrete tumour necrosis factor alpha (TNF alpha) after 3, 6 and 24 h incubation was assessed by L929 cytotoxic bioassay. Fluconazole (2.5-40 mg/L) and 5-FC (25-100 mg/L) did not have a stimulatory effect. However, AmB (0.25-10 mg/L) elicited TNF alpha production by macrophages. This response was concentration-dependent, and peak TNF alpha levels were detected between 3 and 6 h. This effect was attenuated by incorporation of AmB into liposomal vesicles and by pretreating macrophages with pentoxifylline or dexamethasone. AmB I mg/L in combination with 1 x 10(6) cfu of Candida albicans stimulated peritoneal macrophages to produce similar quantities of TNF alpha as AmB alone, and two- to four-fold more TNF alpha than C. albicans alone. Thus, this study suggests that: (1) the immunomodulatory activity and toxicities of AmB, in part, may be attributed to the capacity of this drug to stimulate macrophages to secrete TNF alpha, (2) the TNF alpha that is produced by macrophages in response to AmB may have clinical relevance even in the face of C. albicans infection, and (3) the failure of fluconazole, 5-FC, and LAB to elicit a TNF alpha response may explain their improved side-effect profiles.

Tumor necrosis factor alpha has a protective role in a murine model of systemic candidiasis.

The role of tumor necrosis factor alpha (TNF-alpha) in host defense against systemic Candida albicans infection was evaluated in a murine model of systemic candidiasis in which uniform death occurred between 5 and 6 days after infection. TNF-alpha was first detected at 16 h postinfection and progressively increased thereafter. Peak levels (700 to 900 pg/ml) were measured in mice near death. Administration of 0.5 to 1.0 mg of polyclonal immunoglobulin G (IgG) TNF-alpha antibody (TNF-alpha Ab) to mice 2 h preinfection neutralized serum TNF-alpha for up to 30 h. However, this regimen shortened survival from a mean of 5.5 days for IgG controls to 3.4 days (P = 1.9 x 10(-12)). Semiquantitative cultures of spleen, lung, liver, and kidney conducted at 1, 2, and 3 days postinfection found colony counts of spleen and kidney to be significantly higher for TNF-alpha Ab recipients but only for the first 48 h. Administration of 1.5 and 1.0 mg of TNF-alpha Ab at 2 h before and 48 h after fungal injection, respectively, shortened the mean survival from 4.9 to 2.3 days (P = 5.2 x 10(-8)). This regimen neutralized serum TNF-alpha throughout infection. With this regimen, colony counts of all organs were significantly higher in TNF-alpha Ab recipients at 1, 2, and 3 days postinfection. Histopathologic studies showed an increase in the number and size of C. albicans foci in tissues. Peripheral leukocyte counts and inflammatory response in tissue were similar for TNF-alpha Ab and IgG sham recipients. In vitro, incubation of C. albicans with four to eight times the peak serum levels of TNF-alpha for up to 24 h did not inhibit the rate of germ tube or pseudohypha formation. Thus, TNF-alpha that was produced during infection with C. albicans augmented host resistance against this organism and prolonged survival. The protective effect of TNF-alpha was not mediated by increased leukocytes in blood or tissues nor by a direct anticandidal effect of TNF-alpha. This study suggests that the administration of exogenous TNF-alpha may enhance host resistance against systemic C. albicans infection and may improve host survival.

Isolation and characterization of a transposon-induced cytotoxin-deficient mutant of Pseudomonas aeruginosa.

In order to provide a better system for investigating the role of cytotoxin in pathogenesis, we mutated wild-type Pseudomonas aeruginosa PA158 by introducing a transposon. The resulting pool of mutants was screened for cytotoxin-deficient strains. One mutant strain, PA114F5, was compared with PA158. Except for cytotoxin production and antibiotic resistance (specified by the transposon), the two strains appear isogenic. This mutant strain should be useful in further clarifying the role of cytotoxin in pathogenesis.

Porcine follicular fluid contains both follicle-stimulating hormone agonist and antagonist activities.

Several fractions were prepared from porcine follicular fluid, each having FSH receptor binding inhibitory activity. All were soluble in acidic acetone (pH 3.5) and insoluble in ether (pH 10.5), and could be separated on the basis of charge, using anion exchange HPLC. The effect of these fractions on aromatization of androstenedione to estradiol (basal levels or FSH stimulated) was studied in vitro using Sertoli cells from immature rat testes. Agonist activity, defined as the ability to stimulate secretion of estradiol in the absence of FSH, was present in one fraction weakly retained by the anion exchange column but eluted with a linear gradient between 0.2 and 0.5 M acetate, pH 5.0. In addition to agonist activity, this fraction inhibited binding of [125I]human (h) FSH to hFSH antiserum and to receptor. Another fraction with FSH binding inhibitory activity was more strongly retained by the anion exchange HPLC column and was eluted with 1.0 M acetate, pH 3.0. This fraction demonstrated antagonist activity, as defined by its ability to inhibit FSH-stimulated, but not basal, conversion of androstenedione to estradiol in vitro. Although it inhibited [125I]hFSH binding to receptor, no immunoreactivity could be demonstrated in this fraction. These observations demonstrate that inhibition of [125I]hFSH binding to receptor can reflect either agonist or antagonist activity, and that the latter activities are present in separate and distinct fractions derived from porcine follicular fluid.