Cryptococcal meningitis : epidemiology and therapeutic options

Cryptococcal meningitis causes morbidity and mortality worldwide. The burden of disease is greatest in middle- and low-income countries with a high incidence of human immunodeficiency virus (HIV infection. Patients taking immunosuppressive drugs and some immunocompetent hosts are also at risk. Treatment of cryptococcal meningitis consists of three phases: Induction, consolidation, and maintenance. Effective induction therapy requires potent fungicidal drugs (amphotericin B and flucytosine, which are often unavailable in low-resource, high-endemicity settings. As a consequence, mortality is unacceptably high. Wider access to effective treatment is urgently required to improve outcomes. For human immunodeficiency virus-infected patients, judicious management of asymptomatic cryptococcal antigenemia and appropriately timed introduction of antiretroviral therapy are important.Publisher PDFPeer reviewe

Linezolid for drug-resistant tuberculosis

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess the efficacy of linezolid when used as part of a second-line regimen for treating people with multidrug-resistant (MDR-) and extensively drug-resistant (XDR-) pulmonary tuberculosis (TB), and to assess the prevalence and severity of adverse events associated with linezolid use in this patient grou

Detection and quantification of viable Mycobacterium tuberculosis bacilli in saline-processed stool samples by Tuberculosis Molecular Bacterial Load Assay : a potential alternative for processing stool

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Vitamin D deficiency in Malawian adults with pulmonary tuberculosis : risk factors and treatment outcomes

The study was supported by a Wellcome Trust (London, UK) Clinical PhD Fellowship awarded to DS (086757/Z/08/A) and the Malawi Liverpool Wellcome Trust (MLW) Core grant from the Wellcome Trust.SETTING: Vitamin D deficiency is common in African adults with tuberculosis (TB), and may be exacerbated by the metabolic effects of anti-tuberculosis drugs and antiretroviral therapy (ART). It is unclear whether vitamin D deficiency influences response to antituberculosis treatment. OBJECTIVES : To describe risk factors for baseline vitamin D deficiency in Malawian adults with pulmonary TB, assess the relationship between serum 25-hydroxy vitamin D (25[OH]D) concentration and treatment response, and evaluate whether the administration of anti-tuberculosis drugs and ART is deleterious to vitamin D status during treatment. DESIGN: A prospective longitudinal cohort study. RESULTS : The median baseline 25(OH)D concentration of the 169 patients (58% human immunodeficiency virus [HIV] infected) recruited was 57 nmol/l; 47 (28%) had vitamin D deficiency (<50 nmol/l). Baseline 25(OH)D concentrations were lower during the cold season (P < 0.001), with food insecurity (P = 0.034) or in patients who consumed alcohol (P = 0.019). No relationship between vitamin D status and anti-tuberculosis treatment response was found. 25(OH)D concentrations increased during anti-tuberculosis treatment, irrespective of HIV status or use of ART. CONCLUSIONS : Vitamin D deficiency is common among TB patients in Malawi, but this does not influence treatment response. Adverse metabolic effects of drug treatment may be compensated by the positive impact of clinical recovery preventing exacerbation of vitamin D deficiency during anti-tuberculosis treatment.Publisher PDFPeer reviewe

Perceptions of Research Bronchoscopy in Malawian Adults with Pulmonary Tuberculosis: A Cross-Sectional Study

Bronchoscopy is an established research tool in Malawi, enabling collection of pulmonary samples for immunological, pharmacological, and microbiological studies. It is, however, an invasive clinical procedure that offers no direct benefit to volunteering participants when used in a research capacity alone, and thus informed consent is essential. This study aimed to explore TB patients’ understanding of research bronchoscopy, what would motivate them to participate in research bronchoscopy, and their concerns, in order to inform consenting processes for future clinical studies. We used a qualitative research design. Two focus group discussions were conducted with community members and TB patients to understand their perceptions of bronchoscopy. Transcripts were coded by multiple co-authors and thematic content analysis was used to analyse main findings. We found that Malawian patients with pulmonary TB were willing to participate in a study using research bronchoscopy for health assessment and access to improved healthcare. We identified information of value to potential participants when consenting to that may lessen some of the anxieties expressed by participants. Patient and public involvement is essential to improve informed consent and institutional trust

Risk factors in adolescent suicides

Samoubojstvo je treći vodeći uzrok smrti među adolescentima. Brojni su uzroci koji dovode do povećanja suicidalnog rizika. Dominiraju mentalne bolesti jer je 90 % onih koji su počinili samoubojstvo imalo psihijatrijsku dijagnozu. Odnosi unutar obitelji te odnosi s okolinom također imaju važnu ulogu. Nepripadanje dominantnoj kulturi može povećati suicidalni rizik, pogotovo u onim sredinama koje su zatvorene i netolerantne. Kao najčešći motivi za samoubojstvo mladih spominju se: školski neuspjeh, pad razreda, isključenje iz škole, socijalna nestabilnost, nesigurnost, patološka ljubomora, konflikti s roditeljima i profesorima. Upravo razumijevanje rizičnih čimbenika koji mogu dovesti do samoubojstva ključno je u prevenciji ovakvog ponašanja.Suicide is the third leading cause of death among adolescents. Many causes canincrease suicidal risk. 90 % of those who committed suicide had psychiatric diagnosis. Relationships within the family and with the social surroundings also play an important role. Not being a part of the dominant culture may increase suicidal risk, especially in those societies which are closed and intolerant. The most common motives for youth suicide are school failure, drop in grades, expulsion from school, social instability, insecurity, pathological jealousy, conflict with parents and teachers. Understanding risk factors which can lead to suicide is crucial in preventing this behavior

A tuberculosis molecular bacterial load assay (TB-MBLA)

Funding: European and Developing Countries Clinical Trials Partnership (EDCTP) – Pan African Biomarker Expansion program (PanBIOME) grant SP.2011.41304.008. Support was also obtained the University of St Andrews School of Medicine research grant.Tuberculosis is caused by Mycobacterium tuberculosis (Mtb), a pathogen classified by the United Nations (UN) as a dangerous category B biological substance. For the sake of the workers’ safety, handling of all samples presumed to carry Mtb must be conducted in a containment level (CL) 3 laboratory. The TB molecular bacterial load assay (TB-MBLA) test is a reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) test that quantifies Mtb bacillary load using primers and dual-labelled probes for 16S rRNA. We describe the use of heat inactivation to render TB samples noninfectious while preserving RNA for the TB-MBLA. A 1 mL aliquot of the sputum sample in tightly closed 15 mL centrifuge tubes is boiled for 20 min at either 80 °C, 85 °C, or 95 °C to inactivate Mtb bacilli. Cultivation of the heat inactivated and control (live) samples for 42 days confirmed the death of TB. The inactivated sample is then spiked with 100 µL of the extraction control and RNA is extracted following the standard RNA isolation procedure. No growth was observed in the cultures of heat treated samples. The isolated RNA is subjected to real-time RT-qPCR, which amplifies a specific target in the Mtb 16S rRNA gene, yielding results in the form of quantification cycles (Cq). A standard curve is used to translate Cq into bacterial load, or estimated colony forming units per mL (eCFU/mL). There is an inverse relationship between Cq and the bacterial load of a sample. The limitation is that heat inactivation lyses some cells, exposing the RNA to RNases that cause a loss of <1 log10eCFU/mL (i.e., <10 CFU/mL). Further studies will determine the proportion of very low burden patients that cause false negative results due to heat inactivation.Publisher PDFPeer reviewe

Forgiveness Is the Attribute of the Strong:Nonadherence and Regimen-Shortening in Drug-Sensitive TB

RATIONALE: 'Forgiveness' charts the ability of a drug or regimen to withstand non-adherence without negative clinical consequences. OBJECTIVES: We aimed to determine the influence of regimen length, regimen drugs and dosing, and when during treatment non-adherence occurs on the forgiveness of anti-tuberculosis regimens. METHODS: Using data from three randomised controlled trials comparing experimental four-month regimens for drug-sensitive tuberculosis with the standard six-month regimen, we used generalised linear models to examine how the risk of a negative composite outcome changed as dose-taking decreased. The percentage of doses taken and absolute number of doses missed were calculated, during the intensive and continuation phases of treatment, and overall. A mediation analysis was undertaken to determine how much of the association between intensive phase dose-taking and the negative composite outcome was mediated through continuation phase dose-taking. MEASUREMENTS AND MAIN RESULTS: Forgiveness of the four-month and six-month regimens did not differ for any treatment period. Importantly, four-month regimens were no less forgiving of small numbers of absolute missed doses than the six-month regimen (e.g. for 3-7 missed doses versus no missed doses (baseline), six-month regimen adjusted risk ratio 1.65 (95% confidence interval 0.80-3.41) and four-month regimens 1.80 (1.33-2.45)). No four-month regimen was conclusively more forgiving than another. We found evidence of mediation by continuation phase dose-taking on the intensive phase dose-taking and negative composite outcome relationship. CONCLUSIONS: With the current appetite for, and progress towards, shorter drug-sensitive tuberculosis regimens worldwide, we offer reassurance that shorter regimens are not necessarily less forgiving of non-adherence. Given the importance of continuation phase adherence, patient support during this period should not be neglected

TST positivity in household contacts of tuberculosis patients : a case-contact study in Malawi

This work was supported by a Wellcome Trust Fellowship awarded to DJ Sloan (086757/Z/08/A) a Malawi Liverpool Wellcome Trust (MLW) Core grant awarded by the Wellcome Trust and by a grant from the European Union Action for Diseases of Poverty Program (Sante–2006–105-061).Background:  Screening household contacts of active tuberculosis (TB) patients is recommended for TB control. Due to resource constraints this rarely occurs in lower income countries. Demographic and clinical features of index cases may influence the likelihood of onwards TB transmission. It has also been proposed that accumulation of intracellular lipid bodies within M. tuberculosis cells may also enhance bacterial transmissibility. This study explored whether clinical and bacteriological observations recorded at baseline in TB cases in Malawi could help identify those with the highest risk of onwards transmission, to prioritise contact tracing. Methods:  In this case-contact study, data on clinical presentation, sputum bacterial load and the percentage of lipid body positive acid-fast bacilli (%LB + AFB) on sputum smears were recorded in adults with sputum smear and culture positive pulmonary TB before initiation of therapy. The Tuberculin Skin Test (TST) was used to detect infection with M. tuberculosis amongst household contacts under the age of 15 years. TST positivity of the child contacts was related to characteristics of the index case. Results:  Thirty four index cases brought 56 contacts (median: 1, range: 1–4 contacts each). 37 (66%) of contacts had a positive TST. Cavities or a high percentage of lung affected on index patient CXRs were associated with TST positivity. Multivariate analysis of non-radiological factors showed that male sex, HIV-negative status and raised peripheral blood white blood count (WBC) in index patients were also independent risk factors of TST positivity. Lower %LB + AFB counts were associated with TST positivity on univariate analysis only. Conclusion:  TST positivity is common amongst household contacts of sputum smear positive adult TB patients in Malawi. Contact tracing in this high risk population could be guided by prioritising index cases with CXR cavities and extensive radiological disease or, in the absence of CXRs, those who are HIV-negative with a raised WBC.Publisher PDFPeer reviewe

The occurrence and frequency of genomic mutations that mediate Isoniazid and Rifampicin resistance in Mycobacterium tuberculosis isolates from untreated pulmonary Tuberculosis cases in urban Blantyre, Malawi

This study was funded by the Helse Nord Tuberculosis Initiative (HNTI), a College of Medicine grant supported by the Helse Nord RHF and the University of Tromso.Background The emergence and spread of drug-resistant Tuberculosis (TB) is a major public health threat. TB resistance originates in the course of treatment due to genomic mutations in Mycobacterium tuberculosis (MTB). An increase in new cases with drug-resistant TB could be an indicator of high levels of circulating resistant strains. This study was conducted to determine the occurrence and frequency of genomic mutations that mediate Isoniazid (INH) and Rifampicin (RIF) resistance among isolates from untreated TB cases in urban Blantyre, Malawi. Methods A cross-sectional retrospective study was conducted on a panel of 141(n=141) MTB clinical isolates recovered between June 2010 and January 2012 from ≥2+ Ziehl-Neelsen smear positive new pulmonary-TB patients with no history of treatment. Frozen isolates were revived using the BACTEC MGIT detection system. DNA was extracted using GenoLyse DNA extraction kit and detection of genomic mutations was carried out using the GenoType MTBDRplus Ver 2.0 assay. Results Out of the 141 isolates studied, 3 (2.1%) were found carrying mutations in the katG gene that confer resistance to Isoniazid (INH). No mutations were detected in the inhA promoter region gene that confer weak INH resistance or in the rpoB gene that confer Rifampicin resistance. All katG mutant genes had a S315T1 single point mutation, a genomic alteration that mediates high INH resistance. Conclusion The katG mutant gene conferring resistance to INH was the only genomic mutation observed among the isolates studied and the frequency of occurrence was low. Our findings suggest low levels of circulating drug-resistant MTB strains in urban Blantyre, Malawi.Publisher PDFPeer reviewe