56 research outputs found
Evaluation of giant african pouched rats for detection of pulmonary tuberculosis in patients from a high-endemic setting
No full textThis study established evidence about the diagnostic performance of trained giant African pouched rats for detecting Mycobacterium tuberculosis in sputum of well-characterised patients with presumptive tuberculosis (TB) in a high-burden setting.; The TB detection rats were evaluated using sputum samples of patients with presumptive TB enrolled in two prospective cohort studies in Bagamoyo, Tanzania. The patients were characterised by sputum smear microscopy and culture, including subsequent antigen or molecular confirmation of Mycobacterium tuberculosis, and by clinical data at enrolment and for at least 5-months of follow-up to determine the reference standard. Seven trained giant African pouched rats were used for the detection of TB in the sputum samples after shipment to the APOPO project in Morogoro, Tanzania.; Of 469 eligible patients, 109 (23.2%) were culture-positive for Mycobacterium tuberculosis and 128 (27.3%) were non-TB controls with sustained recovery after 5 months without anti-TB treatment. The HIV prevalence was 46%. The area under the receiver operating characteristic curve of the seven rats for the detection of culture-positive pulmonary tuberculosis was 0.72 (95% CI 0.66-0.78). An optimal threshold could be defined at ≥2 indications by rats in either sample with a corresponding sensitivity of 56.9% (95% CI 47.0-66.3), specificity of 80.5% (95% CI 72.5-86.9), positive and negative predictive value of 71.3% (95% CI 60.6-80.5) and 68.7% (95% CI 60.6-76.0), and an accuracy for TB diagnosis of 69.6%. The diagnostic performance was negatively influenced by low burden of bacilli, and independent of the HIV status.; Giant African pouched rats have potential for detection of tuberculosis in sputum samples. However, the diagnostic performance characteristics of TB detection rats do not currently meet the requirements for high-priority, rapid sputum-based TB diagnostics as defined by the World Health Organization
Updating the global occurrence of Culicoides imicola, a vector for emerging viral diseases
No full textToxoplasmosis and Associated Risk Factors in Antenatal Clinic follow up Pregnant Women in Selected Health Institutes of Jigjiga, East Ethiopia
No full textA Stable Glutamate Biosensor Based on MnO2 Bulk-modified Screen-printed Carbon Electrode and Nafion(R) Film-immobilized Glutamate Oxidase
No full textAn amperometric glutamate biosensor was developed using screen-printed carbon electrodes bulk-modified with MnO2 (5%, m:m) onto which glutamate oxidase was immobilized via Nafion(R) film entrapment. The analytical performance of the biosensor was assessed in a flow injection mode and peak heights of the current response were used to evaluate results. Best responses were recorded at an applied potential of 440 mV (vs Ag/AgCl) a flow rate of 0.2 mL min-1, and a pH of 7.75 of the carrier (0.1 mol L-1 phosphate buffer). The calibration curve exhibited linearity in the concentration range 10-160 mg L-1, with a detection limit (as 3s value) of 1.7mg L-1, and a relative standard deviation 3.3% (c=20 mg L-1, n=10). This biosensor was used for the determination of monosodium glutamate in food seasonings, and the values obtained were similar to those obtained with spectrophotometry. The biosensor exhibited extraordinary stability when left on the FI system at a flow rate of 0.1 mL min-1 at room temperature retaining 50% of the original response towards glutamate even after 65 days. Stored in the working buffer for more than 60 days, the same biosensor showed extended linear range, 20-710 mg L-1. This 'aged' (stored) biosensor was used to determine monosodium glutamate in food seasonings and gave similar result to those obtained with a freshly prepared biosensor.
(South African Journal of Chemistry: 2003 56: 54-59
Comparative Study of Direct Sputum Microscopy with Different Sample Pre-Treatment Procedures for Examination of Acid-Fast Bacilli (AFB)
No full textNo abstract - Available on PD
Simple and Effective Procedure for Immobilization of Oxidases onto MnO2-bulk-modified, Screen-printed Carbon Electrodes
No full textNafion(R) film entrapment of oxidases onto the surface of MnO2-(5%, m:m) bulk-modified, screen-printed carbon electrodes was studied taking the inexpensive glucose oxidase as a model enzyme. The Nafion(R)-enzyme film was formed by drop-coating the suspension onto the surface of the electrode. Comparisons weremadeamong biosensors developed by using as-received, neutralized, and diluted (to 1% in methanol, ethanol or phosphate buffer) Nafion(R) in a flow injection (FI) mode. The amperometric response to injections of standard glucose solution was the highest for biosensors produced using neutralized Nafion(R). The effect of enzyme load per electrode (10-1190 mg) was investigated and 50 mg enzyme in the film per electrode was found to produce very good sensitivity as well as to be economical. Good reproducibility was achieved for three different biosensors (RSD of the means = 5.7%). The operational parameters for the glucose biosensor produced with this immobilization procedure were assessed and figures of merit obtained at the selected parameters. It has been observed that the effect of Nafion(R) to repel interfering ions like ascorbate and urate was lacking in this system. A preliminary investigation incorporating a hydrogen peroxide permselective membrane layer prior to enzyme immobilization gave promising result with polyurethane.
South African Journal of Chemistry Vol.57 2004: 1-
A new amperometric ß-ODAP biosensor
No full textIntroduction The Lathyrus/lathyrism challenge is broad-based by its nature and requires multi-disciplinary efforts of specialists in the field of epidemiology, neurology, biochemistry, chemistry, nutrition, and agronomy. The role of chemists is in systematic determination of minor natural products in L. sativus seeds so that the sole responsibility of ß-ODAP for neurolathyrism is ascertaine
The impact of COVID-19 on the tuberculosis control activities in Addis Ababa
No full textAbstract: The first COVID-19 case was reported in Ethiopia on 13th March 2020 and series of announcements of set of measures, proclamation and directives have been enacted to fight the coronavirus pandemic. These have implications for the regular health services including the TB control program. This brief communication assesses the impact of the COVID-19 response on the TB control activities of Addis Ababa health centers based on research project data. We compared the patient flows in pre-COVID-19 period (quarter 1, Q1) and during COVID-19 (quarter 2, Q2 and quarter 3, Q3) of 2020 at 56 health centers in Addis Ababa from all 10 sub-cities per sub-city. The patient flow declined from 3,473 in Q1 to 1,062 in Q2 and 1,074 in Q3, which is a decrease by 62-76% and 52-80% in Q2 and Q3 respectively as compared to that of Q1. In Q2, Kolfe keranio and Kirkos sub-cities recorded the biggest decline (76 and 75% respectively) whereas Yeka sub-city had the least decline (62%). In Q3, Kirkos sub-city had the biggest decline (80%) and Addis ketema sub-city had the lowest (52%). We conclude that the series of measures, state of emergency proclamation and government directives issued to counter the spread of COVID-19 and the public response to these significantly affected the TB control activities in Addis Ababa city as attested by the decrease in the patient flow at the clinics. Health authorities may inform the public that essential health services are still available and open to everyone in need of these services
Two Strategies for Landmine Detection by Giant Pouched Rats
No full textThis article compares the performance of Giant African Pouched Rats under two different management systems, both appropriate for mine-detection operational use. Employing International Mine Action Standards for accreditation, the researchers outline the process of conditioning and testing these mine-detection animals for field use
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