Comparison of two concentration techniques in the detection of intestinal parasites

Abstract: The diagnostic performance of two concentration methods, Tween-80 and Formol-Saline, were evaluated using a total of 400 stool samples from patients referred to the Ethiopian Health and Nutrition Research Institute. Both tests showed similar rates of detection; Formol-Saline (50.3%) and Tween-80 (51%), and no significant difference was observed. The sensitivity and specificity of the Tween-80 method relative to the Formol-Saline technique were 97.0% and 95.5%, respectively. However, from the point of view of the relative availability of reagents and simplicity, the Formol-Saline concentration method is recommended for the diagnosis of intestinal parasites in basic service-giving health institutions and peripheral laboratories. [Ethiop. J. Health Dev. 1998;12(2):161-163

Evaluation of parasitological methods for the detection of Strongyloides stercoralis among individuals in selected health institutions in Addis Ababa, Ethiopia

Background: Strongyloides stercoralis causes chronic intestinal infection that may lead to disseminated disease during immunosuppression. Therefore, efficient diagnostic methods are essential to detect silent and latent infections. The present study was aimed to compare the efficacy of parasitological methods for the detection of S. stercoralis infection.Methods: A cross-sectional study was conducted on 351 subjects (226 HIV positive and 125 HIV negative) from October 2005 to May 2006. The study participants were selected by systematic random sampling method. Fresh fecal samples were collected from each participant and processed by different parasitological methods.Results: Among the 351 individuals involved in the study, 43(12.3%) were infected by S. stercoralis. The prevalence of S. stercoralis infection was significantly higher among HIV positive subjects (17.3%) as compared with 3.2% in HIV negative subjects (p=0.001). The odd of being infected by S. stercoralis was significantly higher among AIDS patients (OR=6.31; 95% CI, 2.2-18.1) and HIV patients with diarrhea (OR=9.3; 95% CI 4.6-18.9) as compared with respective controls. Agar plate culture showed superior sensitivity (97.7%) than other methods for detection of S. stercoralis. Similarly, agar plate culture showed strong diagnostic agreement with Baermann’s method (kappa = 0.82; 95% CI 0.72 - 0.92) followed by fecal concentration (kappa= 0.67; 95% CI=0.54-0.80).Conclusion: This study revealed that HIV patients were about 6 folds susceptible for S. stercoralis infection. Similarly, agar plate culture showed superior diagnostic efficiency for detections of S. stercoralis infection.Keywords: S. stercoralis, HIV positive, agar plate cultur

Observation of blood microfilariae during human trypanosomiasis survey in Gambella, south west Ethiopia

Abstract: While conducting a survey on sleeping sickness during 1989-92 in Gambella, South western Ethiopia, microfilariae of Mansonella perstans were detected in the blood of the indigenous population, the Anuaks (1%), and the refugees from Southern Sudan (4.1%). No blood microfilarial infection was detected in resettlers, who arrived in the area from drought affected regions of the country during the 1985/86 resettlement program. Among the diagnostic methods applied, nearly twice more microfilaraemic cases (4.1%) were detected by the Miniature Anion Exchange Centrifugation Technique (M-AECT) while only (1.9%) were detectable by Microhaematocrit Buffy Coat Technique (MHBCT) among the refugees. Using the conventional blood film methods (thin and thick smears) only fewer positive cases (1.0%) were detected compared to the above two techniques. Besides a known standard diagnostic methods for blood filariasis, however, the MHBCT seems preferable as field diagnostic technique. Because it is more rapid, simple to operate and does not necessitate as much advanced preparation and sterile condition as M-AECT, and could be a potential diagnostic tool for blood microfilariae. There is a significant difference (P<0.01) in age groups 15-30 years among Anuaks and refugees. There is no significant difference (P>0.01) in other age groups and sexes among Anuaks and refugees. However, there is a significant difference (P<0.01) in over all positivity among Anuaks and refugees. [Ethiop. J. Health Dev. 1997;11(1):1-5

Paracheck-PF® test Versus Microscopy in the Diagnosis of Falciparum Malaria in Arbaminch

Background: Malaria is a major cause of morbidity and mortality in Ethiopia. Rapid diagnostic tests such as Paracheck Pf are the major tools for falciparum malaria diagnosis as an alternative to microscopy in peripheral health facilities. The objective of this study was to evaluate the sensitivity and specificity of Paracheck Pf against microscopy for diagnosis of P.falciparum infection and observe the persistence of the antigen for an elongated period.Methods: Cross sectional study was undertaken in Arbaminch Zuria at Shele health center from October 2008 to January 2009. Paracheck-Pf versus microscopy comparison was done in conjunction with an artemisinin-based combination therapy efficacy monitoring for a period of 28 days. Standard microscopic procedures were done by experienced laboratory technicians and paracheck-Pf was performed in accordance with the manufacturer’s instruction.Results: out of 1293 examined blood films, 400(31%) were found to be malaria positive. Considering microscopy as the gold standard, paracheck-pf showed sensitivity of 94.1 %( 95%CI: 89.9-98.3%) and specificity of 80.0% (95%CI: 67.6-92.4%). The positive and negative predictive values were 93.3 %( 95%CI: 88.8-97.8%) and 82.1% (95%CI: 70-94.1%), respectively. Comparing microscopy results 98.7 % (79/80), 60% (48/80), 48.1% (37/77), and 44.6 %( 33/74) were also found to be positive by paracheck-pf at days7, 14, 21, and 28, respectively. Conclusion: Paracheck Pf® has a comparable diagnostic performance in detecting P. falciparum infections through the persistence of frequent false positivity is a limitation. Thus, this diagnostic test is not appropriate for monitoring of treatment effect. Keywords: P. falciparum, Paracheck-Pf®, RDT, microscopy.Ethiop J Health Sci. Vol. 22, No. 2 July 201

The human trypanosomiasis situation in Gambella, south western Ethiopia

Abstract: Surveillance of human trypanosomiasis was carried out in Gambella, an endemic region of South Western Ethiopia. The study was conducted in March 1993, October 1993 and April 1994 with the major objective of investigation of the sleeping sickness infection and its vector status in the area. In the present survey no parasitologically confirmed case was detected. The main vectors of the disease, Glossina pallidipes and G. tachinoides in wooded savanna and forest area and G. fuscipes in riverain vegetation, were commonly encountered. Eventhough there were no parasitologically proven cases of sleeping sickness infection due to prolonged combined effect of ecological, climatic and human interference, the presence of potential vectors, Glossina species specially along the major river banks, ecological rehabilitation of the area to its previous conditions and the invasion of the game animals might give way to the reappearance of the parasite, T. b. rhodesiense. Thus, regular active surveillance of the endemic region is of great importance to control the disease at an early stage before the appearance of epidemics which could be more costly financially as well as in human life. Specific ecological requirements and feeding habits of Glossina species, specially of G. morsitans, which was not found in this survey, need further investigation. A comprehensive study on community awareness about sleeping sickness and its vector is also recommended to support future control measures. [Ethiop. J. Health Dev. 1997;11(1):23-28

The prevalence of intestinal parasites in paediatric diarrhoeal and non-diarrhoeal patients in Addis Ababa hospitals, with special emphasis on opportunistic parasitic infections and with insight into the demographic and socio-economic factors

Background: Opportunistic intestinal parasitic infections cause severe diarrhoea specially in infants and in immunocompromised people world wide.Objective: The objective of this study was to assess and determine the prevalence of opportunistic intestinal parasites in paediatric patients with and without diarrhoea in selected hospitals in Addis Ababa. Methods: A cross-sectional study was conducted on 222 children under five years of age who had diarrhoea and on 74 children who had no diarrhoea in selected Hospitals in Addis Ababa. Single stool specimens were collected and screened for intestinal parasitic infections by using direct and concentrated methods. The Modified Ziehl-Neelsen Staining and Modified Water-Ether Sendimentaion methods were used for detecting Coccidial parasites. Results: Of the 222 paediatric diarrhoeal patients, 61(27.5%) were found to be infected with a variety of intestinal parasites and out of 74 children without diarrhoea 11(14.9%) were found to be infected. Among the emerging opportunistic parasites detected in diarrhoeal children were Cryptosporidium parvum (8.1%), Isospora belli (2.3%) and Enterocytozoon bieneusi/ Encephalitozoon intestinalis (0.5%). Other common intestinal parasites detected were Ascaris lumbricoides (0.5%), Trichuris trichiura (0.9%), Giardia lamblia (6.3%), Entamoeba histolytica/ E. dispar (1.4%), Blastocystis hominis (5.9%) and Hymnolepis nana (0.5%). Opportunistic parasites were found to be significantly associated with diarrhoeal and non-breastfed children (

Intestinal parasitic infections in Western Abaya with special reference to Schistosomiasis mansoni

Abstract: A cross sectional investigation on the distribution and prevalence of intestinal parasitic infections was undertaken in Western Abaya, North Omo, in January 1995. As the area is potentially irrigable for modern agriculture, emphasis was placed to explore on the endemicity of schistosomiasis, including malacological assessments. Five percent of the whole population on 1473 people, in 16 villages of the area, were parasitologically examined for intestinal parasites. Among the intestinal parasitic infections, hookworm was demonstrated in all of the villages with prevalences ranging from 4.1% (Algie) to 75% (Wajifo). The majority of the villages (10/16=62.5%) had hookworm prevalences of over 50%. Schistosoma mansoni infections were found in 11 villages with prevalences of up to 53% with more males than females being affected (P<0.001). Infected Biomphalaria sudanica snails with infection rates of up to 2.1% at two sites of Lake Abaya were also found. The importance of the dominant, S. mansoni and hookworm infections in the potentially irrigable area of Western Abaya and feasible measures of their control are discussed. [Ethiop. J. Health Dev. 1999;13(1):21-26

Integrating an NTD with One of “The Big Three”: Combined Malaria and Trachoma Survey in Amhara Region of Ethiopia

The “big three” killer diseases are malaria, HIV/AIDS, and tuberculosis; control programs for these diseases are usually well developed and financed. The neglected tropical diseases (NTDs) are a group of ancient afflictions that are frequently sidelined by planners and are under-resourced. Opportunities of integrating the big three with NTDs have been talked about but not widely acted upon. There is potential synergy for an integrated trachoma and malaria control program since control of both diseases is community-based. The first step in accessing these synergies has been an integrated malaria prevalence and indicator and trachoma prevalence and risk factor survey. This has been achieved at the incremental cost of one additional staff member per field team. The results give unprecedented precision for the calculation of intervention targets for the integrated program and demonstrate that it is possible to integrate NTDs with the “big three.

Performance of Local Light Microscopy and the ParaScreen Pan/Pf Rapid Diagnostic Test to Detect Malaria in Health Centers in Northwest Ethiopia

Background: Diagnostic tests are recommended for suspected malaria cases before treatment, but comparative performance of microscopy and rapid diagnostic tests (RDTs) at rural health centers has rarely been studied compared to independent expert microscopy. Methods: Participants (N = 1997) with presumptive malaria were recruited from ten health centers with a range of transmission intensities in Amhara Regional State, Northwest Ethiopia during October to December 2007. Microscopy and ParaScreen Pan/PfH RDT were done immediately by health center technicians. Blood slides were re-examined later at a central laboratory by independent expert microscopists. Results: Of 1,997 febrile patients, 475 (23.8%) were positive by expert microscopists, with 57.7 % P.falciparum, 24.6 % P.vivax and 17.7 % mixed infections. Sensitivity of health center microscopists for any malaria species was.90 % in five health centers (four of which had the highest prevalence),.70 % in nine centers and 44 % in one site with lowest prevalence. Specificity for health center microscopy was very good (.95%) in all centers. For ParaScreen RDT, sensitivity was $90$70 % in six and,60 % in four centers. Specificity was $90 % in all centers except one where it was 85%. Conclusions: Health center microscopists performed well in nine of the ten health centers; while for ParaScreen RDT they performed well in only six centers. Overall the accuracy of local microscopy exceeded that of RDT for all outcomes. Thi

Malaria prevalence and mosquito net coverage in Oromia and SNNPR regions of Ethiopia.

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.BACKGROUND: Malaria transmission in Ethiopia is unstable and seasonal, with the majority of the country's population living in malaria-prone areas. Results from DHS 2005 indicate that the coverage of key malaria interventions was low. The government of Ethiopia has set the national goal of full population coverage with a mean of 2 long-lasting insecticidal nets (LLINs) per household through distribution of about 20 million LLIN by the end of 2007. The aim of this study was to generate baseline information on malaria parasite prevalence and coverage of key malaria control interventions in Oromia and SNNPR and to relate the prevalence survey findings to routine surveillance data just before further mass distribution of LLINs. METHODS: A 64 cluster malaria survey was conducted in January 2007 using a multi-stage cluster random sampling design. Using Malaria Indicator Survey Household Questionnaire modified for the local conditions as well as peripheral blood microscopy and rapid diagnostic tests, the survey assessed net ownership and use and malaria parasite prevalence in Oromia and SNNPR regions of Ethiopia. Routine surveillance data on malaria for the survey time period was obtained for comparison with prevalence survey results. RESULTS: Overall, 47.5% (95% confidence interval (CI) 33.5-61.9%) of households had at least one net, and 35.1% (95% CI 23.1-49.4%) had at least one LLIN. There was no difference in net ownership or net utilization between the regions. Malaria parasite prevalence was 2.4% (95% CI 1.6-3.5%) overall, but differed markedly between the two regions: Oromia, 0.9% (95% CI 0.5-1.6); SNNPR, 5.4% (95% CI 3.4-8.5), p < 0.001. This difference between the two regions was also reflected in the routine surveillance data. CONCLUSION: Household net ownership exhibited nearly ten-fold increase compared to the results of Demographic and Health Survey 2005 when fewer than 5% of households in these two regions owned any nets. The results of the survey as well as the routine surveillance data demonstrated that malaria continues to be a significant public health challenge in these regions-and more prevalent in SNNPR than in Oromia