Parasitological Contamination of Wastewater Irrigated and Raw Manure Fertilized Vegetables in Mekelle City and Its Suburb, Tigray, Ethiopia

Watering of vegetables in developing countries including Ethiopia is done using untreated wastewater and raw manure of domestic animal origin is used as fertilizer. Thus, vegetables are considered to be the principal  sources of human infection with bacterial, protozoan and helminth parasites. Therefore, the objective of this study was to evaluate the rate of parasitological contamination of pre-harvest vegetables in Mekelle city and its suburban village, ‘Mariam Dahan’. Pre-harvest vegetables were collected from the field during the dry season, washed using physiological saline solution, allowed to sediment overnight, centrifuged and examined microscopically for infective stages of intestinal parasites. Out of the  vegetable samples examined, 32.41% in Mekelle city and 30.49% in  ‘Mariam Dahan’, contained at least one parasitic contaminant. Strongyloides stercoralis was most encountered parasitic contaminant in the study areas, followed by, Taenia and Entamoeba spp. Highest rate of parasitic contamination was detected on Swiss chard, that was 45.5 and 41.67% in Mekelle city and ‘Mariam Dahan’, respectively. Occurrence of infective stages of intestinal parasites on wastewater-irrigated vegetables may pose public health hazards to farming communities in the study  areas. Therefore, evaluation and surveillance of parasitological quality of vegetables is crucial in an attempt to control vegetable-transmitted  parasitic infections.Keywords: Untreated wastewater, Raw manure, Pre-harvest Vegetables, Parasitological contamination, Tigray, Ethiopi

Knowledge, Attitude and Practice (KAP) about Insecticide Treated Net (ITN) usage against Malaria in Kolla Tembien district, Tigray, Ethiopia

Optimal use of insecticide treated nets (ITNs) to prevent malaria in a community depends on vector behavior, mass distribution, knowledge and willingness of people to use the nets. This study was aimed at evaluating knowledge, attitude and practice (KAP) about ITNs at household level in rural sub-distracts of Kolla Tembien. For this purpose, interview questionnaire containing KAP variables were administered to the randomly selected household heads. A total of 368 households were surveyed, and 70.10 % of the respondents were females. The X number of occupants in the households surveyed was found to be 5.50. However, the X number of ITNs owned by the households was found to be 1.07. Most of the respondents (82.34%) indicated ITNs prevent malaria through protection from mosquito bites. Seventy six percent of the respondents claimed children 0.05). Out of the 260 nets inspected for usage and physical condition during the survey period, more than 50% were kept in a box or other container in the households. Nets that were graded as clean and very dirty accounted for 25% and 25.77%, respectively. Physical inspection of the randomly sampled nets also revealed holes ranging from those that didn’t allow a thumb to pass through ( X number = 3.47) to those that were wider than a closed fist ( X number = 1.64). The over all knowledge, attitude and practice of ITN usage was found to be satisfactory in the study district. However, the occupant net ratio must be narrowed and attention needs to be given to malaria vulnerable groups in the household. Continuous monitoring and evaluation of net usage after distribution should be instituted to avoid misuses and associated net damages in the study areas

Infection prevalence of Schistosoma mansoni and associated risk factors among schoolchildren in suburbs of Mekelle city, Tigray, Northern Ethiopia

Schistosomiasis due to infection with Schistosoma mansoniis a public health problem in both tropical and sub tropical countries. Thus, effective control of the disease requires determining its prevalence rate, identifying risk factors of infection and high-risk groups. Therefore, the objective of this study was to establish the prevalence of S. mansoni infection and associated risk factors among schoolchildren in suburbs of Mekelle city, Tigray, Northern Ethiopia. For this purpose, a cross-sectional parasitological examination wasconducted on457 schoolchildren from November, 2010 to March, 2011. Stool samples were collected and examined by the Kato-Katz technique. Semi-structurered interview questionnaire were administered to the study subjectsto identify possible risk factors of infection with S. mansoni. Furthermore, malacological survey was conducted to check the presence of snail intermediate hosts of S. mansoni in the study area. The overall prevalence of S. mansoni in the schoolchildren was 23.9 %. Higher prevalence was detected in male children (30.71%) than in females (14.12 %) (÷ 2 = 16.642, P = 0.000). On the other hand, the highest (31.2%) prevalence was recorded in children with ages ranging from 10 - 14 years followed by thoseaged 5 - 9 (11.4 %) and 15 - 19 (9.8 %) years (÷ 2 = 23.865, P = 0.000), respectively. This study revealed the association of S. mansoni infection with older age groups, 10 -14 years (OR = 0.114, P = 0.001), time of residence in the study area (OR = 0.462, P = 0.011), water source (OR = 0.371, P = 0.020), previous history of schistosomiasis treatment (OR = 0.246, P = 0.000), frequency of water contact (OR = 26.958, P = 0.004), crossing water bodies (OR = 3.049, P = 0.001), working in an irrigated agricultural field (OR = 7.363, P = 0.000) and distance of home from water bodies (OR = 5.163, P = 0.000). Moreover, this study determined the presence of snail intermediate hosts of S. mansoni in the study areas . Hence, the study areas are considered important epidemiological foci for the transmission of S. mansoni. Therefore, it is necessary to undergo wide scalesurveillance and institute proper control and prevention strategies against infection with Schistosoma mansoni.Key words: S.mansoni, Schistosomiasis, Risk factors, Risk groups, Prevalence, Mekelle city, Tigray

Larvicidal effects of Jatropha curcas L. against Anopheles arabiensis (Diptera: Culicidea)

Crude and column chromatographic fractions of methanol leaf extract of Jatropha curcas were tested for their larvicidal activities against laboratory reared late third instar larvae of Anopheles arabiensis. Crude methanol leaf extract of J .curcas had similar larvicidal activity to 0.5 ppm Temephos (positive control) at test concentrations ranging from 125 -1000 ppm while column chromatographic fractions (F1 and F2 ) of the crude methanol leaf extract of J.curcas showed similar larvicidal activities to 0.5 ppm Temephos at 62.5 and 125 ppm test concentrations. Column chromatographic fraction three (F3) showed similar larvicidal activity to 0.5 ppm Temephos at 125 ppm test concentration. The LC50 and LC90 values of crude methanol leaf extract of J.curcas were found to be 92.09 and 241.09 ppm, respectively. Toxic activities of column chromatographic fraction one (F1) (LC50=28.65 ppm; LC90 = 49.20 ppm) were nearly equal to that of column chromatographic fraction two [F2] (LC50= 30.40 ppm; LC90 = 49.80 ppm). Least toxicity on the test larvae was observed by column chromatographic fraction three [F3] (LC50 = 80.70 ppm; LC90 = 123.70 ppm). Thus, the larvicidal activity of crude methanol leaf extract was not due to the synergistic effects of its fractions. Further studies are recommended to identify larvicidal active ingredients from the active column chromatographic fractions of crude methanol leaf extract of J. curcas. Key words: Malaria vector control, Anopheles arabiensis, Botanical larvicides J. curca