Sanitary survey of residential areas using Ascaris lumbricoides ova as indicators of environmental hygiene

No Abstract. The Ethiopian Journal of Health Development Vol. 21 (1) 2007: pp. 18-2

Prevalence of intestinal parasitic infections among urban dwellers in southwest Ethiopia

No Abstract. The Ethiopian Journal of Health Development Vol. 21 (1) 2007: pp. 12-1

Human myiasis in an endemic area of Southwestern Ethiopia: Prevalence, knowledge, perceptions and practices

Background: Human subcutaneous myiasis is an endemic, understudied disease in Ethiopia. Objective: The aim of this study was to assess knowledge, perceptions and practices in different urban and rural communities of Jimma Zone, southwestern Ethiopia, related to human myiasis. Method: A cross-sectional, descriptive, comparative study was carried out during March -June 2005 in 5 urban and 3 rural kebeles in Jimma Zone. Kebeles were chosen by random sampling and a total of 1,272 households were selected by systematic random sampling technique for interview. Results: Most subjects (60.0%) mentioned lying on damp soil as the cause of myiasis. More urban than rural communities who wore un-ironed clothes had myiais infestation (p< 0.05). Myiasis was reported to be common in the lower extremities (65.6%), upper extremities (56.7%), abdomen (48.9%) and back (34.9%). A total of 86% dwellers responded that myiasis was more common during the wet season. More than half of the interviewees were knowledgeable about the clinical presentation of the disease. The most common signs and symptoms were itching (94.0%), pus discharge (82.9 %) and papules (79.5%). The majority (87.9%) of the study subjects treated infestations with hot matches. Wearing dry clothes (38.6%) was reported to be effective preventive measure. Nearly 64.8% of the rural and 68.7% of the urban communities knew that human subcutaneous myiasis is preventable. Conclusion: Due to the low levels of knowledge about myiasis, we recommend that community health education programs be developed through the health services to raise the awareness levels about this infestation to the general population.The Ethiopian Journal of Health Development Vol. 21 (2) 2007: pp. 166-17

Evaluation of bleach-sedimentation for sterilising and concentrating Mycobacterium tuberculosis in sputum specimens

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Abstract Background Bleach-sedimentation may improve microscopy for diagnosing tuberculosis by sterilising sputum and concentrating Mycobacterium tuberculosis. We studied gravity bleach-sedimentation effects on safety, sensitivity, speed and reliability of smear-microscopy. Methods This blinded, controlled study used sputum specimens (n = 72) from tuberculosis patients. Bleach concentrations and exposure times required to sterilise sputum (n = 31) were determined. In the light of these results, the performance of 5 gravity bleach-sedimentation techniques that sterilise sputum specimens (n = 16) were compared. The best-performing of these bleach-sedimentation techniques involved adding 1 volume of 5% bleach to 1 volume of sputum, shaking for 10-minutes, diluting in 8 volumes distilled water and sedimenting overnight before microscopy. This technique was further evaluated by comparing numbers of visible acid-fast bacilli, slide-reading speed and reliability for triplicate smears before versus after bleach-sedimentation of sputum specimens (n = 25). Triplicate smears were made to increase precision and were stained using the Ziehl-Neelsen method. Results M. tuberculosis in sputum was successfully sterilised by adding equal volumes of 15% bleach for 1-minute, 6% for 5-minutes or 3% for 20-minutes. Bleach-sedimentation significantly decreased the number of acid-fast bacilli visualised compared with conventional smears (geometric mean of acid-fast bacilli per 100 microscopy fields 166, 95%CI 68-406, versus 346, 95%CI 139-862, respectively; p = 0.02). Bleach-sedimentation diluted paucibacillary specimens less than specimens with higher concentrations of visible acid-fast bacilli (p = 0.02). Smears made from bleach-sedimented sputum were read more rapidly than conventional smears (9.6 versus 11.2 minutes, respectively, p = 0.03). Counting conventional acid-fast bacilli had high reliability (inter-observer agreement, r = 0.991) that was significantly reduced (p = 0.03) by bleach-sedimentation (to r = 0.707) because occasional strongly positive bleach-sedimented smears were misread as negative. Conclusions Gravity bleach-sedimentation improved laboratory safety by sterilising sputum but decreased the concentration of acid-fast bacilli visible on microscopy, especially for sputum specimens containing high concentrations of M. tuberculosis. Bleach-sedimentation allowed examination of more of each specimen in the time available but decreased the inter-observer reliability with which slides were read. Thus bleach-sedimentation effects vary depending upon specimen characteristics and whether microscopy was done for a specified time, or until a specified number of microscopy fields had been read. These findings provide an explanation for the contradictory results of previous studies.Peer Reviewe