Status of Schistosoma mansoni prevalence and intensity of infection in geographically apart endemic localities of Ethiopia: A comparison

BACKGROUND: Schistosomiasis is one of the chronic and neglected tropical diseases affecting rural communities. Heavy infections contribute to anemia and can retard children's growth, physical activity and cognitive function. This study was conducted in order to determine the prevalence, intensity and variation of Schistosoma mansoni infection among human subjects in geographically apart localities. The prevalence and intensity of Schistosoma mansoni infection was assessed in three geographically apart endemic areas of Ethiopia from May to August 2010 through cross-sectional approach.METHODS: A total of 1073 individuals (528 males and 545 females) were found eligible for the study. Their age ranged from 5-60 years with mean age of 11 years in Wondo Genet, 22 years in Kemissie and 24 years in Sille-Elgo. Small plastic sheets were distributed to the study participants and sizable stool specimens were collected and examined using Kato-Katz method (41.7mg template).RESULT: The prevalence of Schistosoma mansoni infection among the study participants in Kemissie, Wondo Genet and Sille-Elgo was 89.6%, 59.9%, and 31.6%, respectively. The highest geometric mean of egg per gram of stool for Kemissie, Wondo Genet and Sille-Elgo was, 5208 and 346, 8472 and 252, 3960 and 91, respectively.CONCLUSION: It was observed that there was comparable variation in the prevalence and intensity of infection among the study localities. Moreover, it is indicated that S. mansoni is still an ongoing public health problem which requires integrated intervention activities in the country.KEYWORDS: Schistosoma mansoni; intensity of infection; geographic variation; Ethiopi

Status of onchocerciasis in Teppi area, Southwestern Ethiopia, after four years of annual community-directed treatment with ivermectin

Background: Information on the impact of annual community-directed treatment with ivermectin (CDTI) on the prevalence and intensity of onchocerciasis as well as its transmission following years of repeated ivermectin distribution is vital to monitor the impact of the control efforts.Objective: To determine the status of the prevalence and intensity of onchocerciasis after four years of ivermectin distribution in Teppi area.Methods: Skin snips were obtained from 390 study participants and kept in physiological saline at room temperature for 24 hours. The emerged microfilariae were counted under 10x microscope objective. The skin snips were weighed and the microfilarial load was expressed as the arithmetic mean of two skin snips per mg of skin snip.Results: Out of the total 390 examined subjects, 87 (22.3%) were found to be positive for microfilaridermia. Significant differences in the prevalence and microfilarial load of the disease were not found among untreated and treated subjects (p > 0.05). Significant reductions of the prevalence (25.5%) and intensity of infection (0.08 – 8mf, mean 1.3) were found compared to prevalence (81%) and intensity of infection ( 0-855, mean 33 ± 5.6) reported before the initiation of the CDTI programme in the study area.Conclusion: The overall results of the study showed a high reduction both in the prevalence and intensity of infection compared to prevalence and intensity of the disease before the initiation of the CDTI programme in the study area. Nevertheless, continued assessment of the long-term impact of repeated annual CDTI programme on onchocerciasis and identification of factors that could affect the sustainability of the programme in various CDTI areas of Ethiopia, could contribute towards the effective control of the programme. [Ethiop. J. Health Dev. 2010;24(1):51-56

Comparative efficacy of albendazole and three brands of mebendazole in the treatment of ascariasis and trichuriasis

Objective: To evaluate the comparative efficacy of 400 mg albendazole (Smith Kline Beecham) as a single dose and three brands of mebendazole (Janssen, Unibios and East African Pharmaceuticals) at doses of 100 mg twice a day for three consecutive days in the treatment of single or mixed infections with Ascaris lumbricoides and or Trichuris trichiura in four treatment groups of school children. Design: Randomized trial. Setting: Wondo-Genet, southern Ethiopia. Subjects: School children, aged six to nineteen years. Results: The percentage cure rate and egg reduction rate obtained with albendazole and mebendazole from the three brands were not significantly different in the treatment of ascariasis. However, significant differences were found among the percentage cure rates and egg reduction rates of the four treatment groups in the treatment of trichuriasis. Comparatively, high cure rate (89.8%) and egg reduction rate (99.1%) were observed in vermox (Janssen) treated group followed by Unibios (India) treated group (53.3% and 96.53% cure and egg reduction rates, respectively), whereas low cure rate (17.1%) and egg reduction rate (69.8%) were seen in the albendazole treated group. Conclusion: The results of this study suggest that in areas of single or mixed infections with Trichuris trichiura and/or Ascaris lumbricoides are common public health problems and where laboratory facilities are not available to make parasite identification, mebendazole (particularly vermox, a product of Janssen laboratory) would be the drug of choice to treat trichuriasis and ascariasis. However, either mebendazole from the different brands or albendazole is effective in the treatment of ascariasis in areas where trichuriasis is not prevalent. East African Medical Journal Vol. 81 No. 3 March 2004: 134-13

Current status of intestinal Schistosomiasis and soiltransmitted helminthiasis among primary school children in Adwa Town, Northern Ethiopia

Background: Epidemiological baseline information on the prevalence and intensity of parasitic infections in a given locality is a prerequisite for development and evaluation of sound control strategies.Objective: To determine the current status of schistosomiasis and soil-transmitted helminthiasis among primary school children in Adwa Town, northern Ethiopia.Methods: A cross-sectional epidemiological study was carried out in eight primary schools in Adwa Town between October and November 2007. Fecal samples of 386 school children in the age group 7-18 were collected andmicroscopically examined using the Kato-Katz and formol-ether concentration methods. A questionnaire was used to identify determinants for Schistosoma mansoni and soil-transmitted helminth infections.Results: The most prevalent intestinal parasitic infection among primary school children in Adwa Town as determined by Kato-Katz (58.7%) and formol ether concentration (60.6%) methods was intestinal schistosomiasis, with an overall intensity of 95.8 eggs per gram of stool. The prevalence of S. mansoni infection was higher in males (70.7%) than in females (57%), as determined by both methods. Less common parasites observed included Ascaris lumbricoides, hookworm species, Hymenolepis nana, Strongyloides stercoralis, and Entamoeba histolytica/dispar.Conclusion: The residents of Adwa Town represent a high-risk community with respect to intestinal schistosomiasis. Hence, mass praziquantel administration to school-age children and all adults considered to be at risk is required once a year until the level of infection falls below the level of public health importance. There is also a need to supplement chemotherapy with other measures such as environmental sanitation and health education to make the impact of chemotherapy sustainable

Transmission of Schistosoma mansoni in Tikur Wuha area, Southern Ethiopia

Background: Although the epidemiology of schistosomiasis is well established and the disease distribution has also been mapped in Ethiopia, discovery of new foci has continuously been reported.Objectives: The objective of this study was to assess the establishment of transmission of schistosomiasis mansoni in Tikur Wuha area, southern Ethiopia.Methods: A cross-sectional epidemiological study involving 375 school children in Tikur Wuha Elementary School was conducted in December 2007 and January 2008. Stool specimens were collected and microscopically examined using Kato-Katz method. Snail survey was also conducted using scoop in Tikur Wuha River and littoral zone of Lake Awassa on the side of Tikur Wuha Kebele (administrative unit). The snails collected were checked for trematode infection by shedding. Laboratory-bred mice were exposed to schistosome cercariae and definite identification of the schistosome was made using eggs and adult worm morphology.Results: The prevalence and intensity of schistosomiasis mansoni was 12% and 69 eggs per gram (epg) of stool, respectively. Biomphalaria sudanica collected in Tikur Wuha River shed schistosome cercariae. Adult S. mansoni worms were harvested from laboratory-bred mice after 6 weeks of laboratory maintenance.Conclusion: The prevalence and intensity of schistosomiasis mansoni among school children was low and the area represents low-risk community. The finding of S. mansoni infected young children, the collection of B. sudanica infected with schistosome cercariae, and the establishment of infection in lab-bred mice all confirmed the transmissionof schistosomiasis mansoni in Tikur Wuha area. Appropriate intervention measures need to be in place to reduce morbidity and transmission of intestinal schistosomiasis in the area

Performance of CareStart™ Malaria Pf/Pv Combo test for the diagnosis of Plasmodium falciparum and Plasmodium vivax infections in the Afar Region, North East Ethiopia

Background: CareStart™ Malaria Pf/Pv Combo test has shown encouraging results for the diagnosis of P. falciparum and P. vivax infections in Ethiopia. Nevertheless, the performance of the test could be affected by different factors like gene polymorphisms, excess heat and humidity. Hence, evaluation of the performance of the test in different settings in Ethiopia is vital for the routine diagnosis of malaria.Objective: To evaluate the diagnostic performance of CareStartTM Malaria Pf/Pv Combo test for the diagnosis of P. falciparum and P. vivax infections in the Afar Region, Northeast Ethiopia.Methods: Finger prick blood samples were collected from a total of 1092 patients who had malaria symptoms and visited three different health facilities in the Afar Region. Giemsa-stained thin and thick blood smears were prepared and microscopically examined under 100 × magnifications for Plasmodium species identification and determination of parasitaemia. CareStart Malaria Pf/Pv Combo test was also performed as per the manufacturer's instructions. The sensitivity and the specificity of the test was determined using microscopy as gold standard.Results: The sensitivity and specificity of the test were 98.5% and 98.0% respectively, with a positive predictive value (PPV) of 91.7% and a negative predictive value (NPV) of 99.7% for the diagnosis of P. falciparum infection. The corresponding sensitivity and specificity for the diagnosis of P. vivax infection were 100% and 99.6% respectively, with PPV and NPV of 86.2% and 100%, respectively.Conclusion: The results of this study revealed high sensitivity and specificity of CareStartTM Malaria Pf/Pv Combo test for the diagnosis of both P. falciparum and P. vivax infections in the study area, though additional study may be needed in the most peripheral hottest areas of the region. [Ethiop. J. Health Dev. 2011;25(3):206-211

Schistosoma mansoni Infection in Finchaa Sugar Estate: Public health Problem Assessment based on Clinical Records and Parasitological Surveys, Western Ethiopia

The survey of Schistosoma mansoni (S. mansoni) in Finchaa Sugar Estate, Western Ethiopia, was conducted to investigate the prevalence and health problems of schistosomiasis with some of the risk factors. The examination was undertaken based on the analysis of retrospective clinical data from the health center and a cross-sectional parasitological examinations using Kato-thick smear slides in April-June 2012/2013. Over the period 2008 to 2013 average prevalence among suspected patients at the health centre was 30.9%. Examination of double kato-thick smear slides from a random sample of 602 individuals from most schistosomiasis affected camp 7 revealed the prevalence of 37.5%. S. mansoni infection is become a year-round public health problem in Finchaa, Sugar Estate possibly due to permanent streams, water bodies and water contact behaviors and also reduced effectiveness of current control measures. Among the 7th camps, village A (camp 7) is the most schistosomiasis affected area (37.5%) followed by Kuyisa (25%). This is attributed to the presence of permanent stream (Fekerie stream) near camp 7. The present finding shows that the prevalence and intensity of schistosomiasis in the more affected camp 7 of Finchaa Sugar Estate was significantly higher among males than in females and its prevalence and intensity was found to be higher among study population within the age group of 11-20 years old. This study indicates that schistosomiasis is a major health problem in Finchaa Sugar Estate with moderate prevalence. The study results will provide an additional clinical and parasitological data on the current status of S. mansoni in Finchaa Sugar Estate and could serve as a guide in designing, developing and implementing intervention strategies to mitigate morbidity due to S. mansoni especially in highly risk groups under the Ethiopian health service system.Keywords: Egg per gram; Finchaa Sugar Estate; Kato-katz; Schistosomiasis; S. mansoni; Public healt

Structural motifs of pre-nucleation clusters

Structural motifs of pre-nucleation clusters prepared in single, optically levitated supersaturated aqueous aerosol microparticles containing CaBr2 as a model system are reported. Cluster formation is identified by means of X-ray absorption in the Br K-edge regime. The salt concentration beyond the saturation point is varied by controlling the humidity in the ambient atmosphere surrounding the 15–30 μm microdroplets. This leads to the formation of metastable supersaturated liquid particles. Distinct spectral shifts in near-edge spectra as a function of salt concentration are observed, in which the energy position of the Br K-edge is red-shifted by up to 7.1 ± 0.4 eV if the dilute solution is compared to the solid. The K-edge positions of supersaturated solutions are found between these limits. The changes in electronic structure are rationalized in terms of the formation of pre- nucleation clusters. This assumption is verified by spectral simulations using first-principle density functional theory and molecular dynamics calculations, in which structural motifs are considered, explaining the experimental results. These consist of solvated CaBr2 moieties, rather than building blocks forming calcium bromide hexahydrates, the crystal system that is formed by drying aqueous CaBr2 solutions

Schistosomiasis mansoni and soil-transmitted helminthiasis in Bushulo village, southern Ethiopia

Background: Schistosomiasis mansoni and soil-transmitted helminthiasis (STHs) are considerable medical and public health problems in Ethiopia. However, information is limited on the epidemiology of these infections in different localities even though it is needed to plan effective prevention and control measures. Objective: This study was designed to determine the prevalence of Schistosoma mansoni and soil-transmitted helminth infections in school children and residents in Bushulo village near Lake Awassa (Hawassa), southern Ethiopia. Methods: Cross-sectional epidemiological and parasitological studies were conducted on schistosomiasis mansoni and STHs in Bushulo village in May and June 2007. A total of 419 participants (353 school children and 66 other residents) were included in the study. The principal investigator interviewed the study subjects about demographic status using structured questionnaires. Moreover, experienced nurse took history and conducted physical examination to assess symptoms and signs related to chronic S. mansoni infection. A single stool sample was collected from each participant and processed using the Kato-Katz technique. Experienced laboratory technician read all slides at Bushulo Health Center. Results: The overall infection rates of schistosomiasis mansoni, trichuriasis, ascariasis and hookworm infection were 73.7%, 41.5%, 37.2% and 28.4%, respectively. Other parasitic infections observed were caused by Hymenolepis nana (1.7%), Taenia species (1.4%), and Enterobius vermicularis (1.4%). Children in the age range 10-14 years and those attending at St. Paul’s School had higher rates of T. trichiura and S. mansoni, respectively. Intensity of infection was higher for A. lumbricoides in the age range 5-9 years. The overall prevalence of any STHs was 67.3%. The rates of single, dual, triple and quadruple infections were 29.6%, 32%, 20.3% and 7.4%, respectively. Conclusion: The high prevalence and intensity of schistosomiasis mansoni and soil-transmitted helminthiasis makes periodic deworming programme urgent to reduce morbidity and transmission of helminthiasis in the area. Provisions of sanitary facilities and clean water supply as well as health education are also critically needed to sustain the impact of chemotherapy

Intestinal parasitic infections among under-five children and maternal awareness about the infections in Shesha Kekele, Wondo Genet, Southern Ethiopia

Background: Few studies have reported the magnitude of intestinal parasitic infections among under-five children in tropical countries. Moreover, there is little information on maternal awareness about intestinal parasitosis.Objective: To determine the prevalence of intestinal parasitosis among under-five children, and assess maternal awareness about it in Shesha Kebkele, Wondo Genet, Southern Ethiopia.Methods: A cross-sectional study involving 288 under-five children was conducted and stool samples were collected and examined for intestinal parasites using Kato-Katz and formol-ether concentration methods. In addition, a total of 130 mothers of under-five children were interviewed regarding their awareness about intestinal parasitic infections.Results: Of the 288 children, 245 (85.1%) were found infected with one or more intestinal parasites. The prevalence of Trichuris trichiura, Schistosoma mansoni and Ascaris lumbricoides, hookworm, and Hymenolepis nana infections as determined by Kato-Katz were 74.7%, 37.2%, 25.7%, 5.9%, and 4.5%, respectively. On the other hand, theprevalence of Strongyloides stercoralis, Giardia lamblia, Entamoeba histolytica/dispar, and Entamoeba coli infections as determined by formol-ether concentration method were 0.69%, 13.2%, 0.35%, and 2.1%, respectively. Most mothers were reasonably aware of the mode of transmission of ascariasis, amoebiasis and giardiasis while they hadvery limited knowledge of bilharzia and hookworm transmission. Almost all of the respondents reported that infections with intestinal parasites could cause retardation of growth and death in children unless treated.Conclusion: Intestinal parasitic infections were prevalent in varying magnitude among under-five children in Wondo Genet area, Southern Ethiopia. Mothers in the study area had a fairly good knowledge of the impact of infections but limited knowledge of the mode of transmission of intestinal parasitic infections. Improvement of sanitation and healtheducation are required besides preventive chemotherapy to control worms (except for schistosomiasis in under-five which need treatment on an individual basis) and other intestinal parasitic infections in the area