Evaluation of copromicroscopy and serology to measure the exposure to Ascaris infections across age groups and to assess the impact of 3 years of biannual mass drug administration in Jimma Town, Ethiopia

Background: The scientific community has recently summarized the desired characteristics for diagnostic tools across the different phases of a soil-transmitted helminth (STH) mass drug administration (MDA) program. Although serology meets some of the desired criteria, there is a scarcity of data on baseline serological profiles in human populations, both prior to and during MDA programs. Methods: In this study, we compared the copromicroscopic and the serological infection profiles in 600 school-aged children (SAC) and 600 adults at the advent of the MDA program in Jimma Town, Ethiopia. The serological profiles were examined by two ELISAs that measure IgG4 responses to the Ascaris suum haemoglobin antigen (AsHb) and a somatic extract of lung stage larvae (AsLungL3). Three years into the MDA program, we sampled another group of 600 SAC from the same schools to assess the reduction in prevalence and intensity of Ascaris infections measured by copromicroscopy and serology. Principal findings: Prior to the start of MDA, copromicroscopy revealed an Ascaris prevalence of 31.0% and a mean fecal egg count of 2,919 eggs per gram (EPG) in SAC. Following three years of biannual treatment, the prevalence reduced to 13.2% (57.8% reduction) and the mean fecal egg count to 1,513 EPG (48.1% reduction). This reduction was also reflected in the serological results. The seroprevalence reduced with 40.9% and 27.4% and the mean optical density ratio reduced with 44.2% and 38.2% as measured by the AsHb or AsLungL3 ELISA respectively. We also showed that, despite a decreasing coproprevalence, seroprevalence to Ascaris increased with age. Conclusions: This study is the first to provide IgG4 response profiles of an endemic population to two different A. suum antigens. The results suggest that exposure to the infectious stages of Ascaris reaches beyond SAC alone. Furthermore, it highlights the possible use of serological assays to monitor changes in STH exposure during MDA programs

The distribution of soil-transmitted helminthiasis by socio-demography and other factors among school children in southern Ethiopia, 2015.

<p>The distribution of soil-transmitted helminthiasis by socio-demography and other factors among school children in southern Ethiopia, 2015.</p

Distribution of single and multiple helminthic infections among school children in southern Ethiopia, 2015.

<p>Distribution of single and multiple helminthic infections among school children in southern Ethiopia, 2015.</p

The distribution of schistosomiasis mansoni by socio-demography and other factors among school children in southern Ethiopia, 2015.

<p>The distribution of schistosomiasis mansoni by socio-demography and other factors among school children in southern Ethiopia, 2015.</p

Infections with <i>Schistosoma mansoni</i> and geohelminths among school children dwelling along the shore of the Lake Hawassa, southern Ethiopia

<div><p>Background</p><p>Infections with <i>Schistosoma mansoni</i> and soil-transmitted helminthes (STHs) are major public health problems in Ethiopia. However, information was scarce on the current status of these infections to guide an intervention in the study area. Therefore, this study was conducted to assess the prevalence of infections with <i>S</i>. <i>mansoni</i> and STHs and associated factors among school children in southern Ethiopia.</p><p>Methods</p><p>This cross-sectional study investigated children who were attending the Finchawa and Tullo junior elementary schools and were residing along the shore of the lake Hawassa in January and February, 2015. A total of 374 students were selected using systematic random sampling technique. Data on socio-demography and related factors was collected using structured questionnaires. A single stool sample was collected from each child and processed using formol-ether concentration technique and examined microscopically for parasites’ ova/larva.</p><p>Results</p><p>The prevalence of parasitic infection with one or more than one helminthiasis was found to be 67.9%. Seven different types of helminths were identified and the most prevalent parasites were <i>Ascaris lumbricoides</i> (44.4%), followed by <i>S</i>. <i>mansoni</i> (31%), <i>Trichuris trichiura</i> (11%), and hookworms (7.7%). The rate of infection with STHs was 52.4%. Single, double, triple and quadruple infections were 42.2, 22.5, 2.4, and 0.8%, respectively. Children who practiced open-field defecation (AOR, 3.6; 95% CI 1.6–8.0; p = 0.001) and had not always washed their hands before eating a meal (AOR, 5.0; 95%CI 2.15–11.7; p <0.001) were more infected with STHs. Moreover, the rate of <i>S</i>. <i>mansoni</i> infection was significantly higher among children who were attending the Finchawa school (AOR, 2.13; 95% CI 1.31–3.46; p = 0.002), aged 11–15 years (AOR, 1.97; 95% CI 1.22–3.19; p = 0.006), had swum in the lake Hawassa (AOR, 2.73; 95%CI 1.20–6.17; p = 0.016), and had involved in irrigation-related activities (AOR, 1.68; 95%CI 1.04–2.71; p = 0.034).</p><p>Conclusion</p><p>The study showed high prevalence of STHs and moderate rate of schisotosomiasis. Mass deworming twice a year for STHs and once every two years for <i>S</i>. <i>mansoni</i>, further to strengthening other prevention measures, is critically needed to reduce these infections to inconsequential level.</p></div

Assessment of the nail contamination with soil-transmitted helminths in schoolchildren in Jimma Town, Ethiopia

Background Large-scale deworming programs have been successful in reducing the burden of disease due to soil-transmitted helminth (STH; Ascaris lumbricloides , Trichuris trichiura and hookworm) infections, but re-infection in absence of other measures is unavoidable. We assessed the role of nail contamination as a source of infection with the goal to evaluate the potential of nail clipping as a simple measure to further reduce STH-attributable morbidity. Methods A cross-sectional study was conducted in Jimma Town (Ethiopia). Both stool samples and clipped nails were collected from 600 schoolchildren and microscopically screened for the presence of STHs. We also interviewed the children to gain insights into their hygiene practices. Subsequently, we explored any associations between infection, nail contamination and personal hygiene. Results Any STH infections were observed in 24.3% of the children ( A . lumbricoides : 18.5%; T . trichiura : 9.8%; hookworm: 0.5%). The intensity of the infections was mainly low, only in a few cases a moderate-to-heavy intensity infection was observed ( A . lumbricoides : 4.3%; T . trichiura : 0.2%). Other helminth species observed were Schistosoma mansoni (5.0%), Hymenolepis nana (2.7%), Taenia spp. and Enterobius vermicularis (&lt;1.0%). The analysis of the nail material revealed the presence of A . lumbricoides (1.7%), Taenia spp. (1.0%), T . trichiura (0.5%), E . vermicularis (0.5%) and H . nana (0.2%). The odds of infection with any STH increased as the frequency of trimming decreased. The odds of nail contamination with any STH and A . lumbricoides were higher for younger children. Conclusions The presence of helminth e

Assessment of the nail contamination with soil-transmitted helminths in schoolchildren in Jimma Town, Ethiopia

Background Large-scale deworming programs have been successful in reducing the burden of disease due to soil-transmitted helminth (STH; Ascaris lumbricloides, Trichuris trichiura and hookworm) infections, but re-infection in absence of other measures is unavoidable. We assessed the role of nail contamination as a source of infection with the goal to evaluate the potential of nail clipping as a simple measure to further reduce STH-attributable morbidity. Methods A cross-sectional study was conducted in Jimma Town (Ethiopia). Both stool samples and clipped nails were collected from 600 schoolchildren and microscopically screened for the presence of STHs. We also interviewed the children to gain insights into their hygiene practices. Subsequently, we explored any associations between infection, nail contamination and personal hygiene. Results Any STH infections were observed in 24.3% of the children (A. lumbricoides: 18.5%; T. trichiura: 9.8%; hookworm: 0.5%). The intensity of the infections was mainly low, only in a few cases a moderate-to-heavy intensity infection was observed (A. lumbricoides: 4.3%; T. trichiura: 0.2%). Other helminth species observed were Schistosoma mansoni (5.0%), Hymenolepis nana (2.7%), Taenia spp. and Enterobius vermicularis (<1.0%). The analysis of the nail material revealed the presence of A. lumbricoides (1.7%), Taenia spp. (1.0%), T. trichiura (0.5%), E. vermicularis (0.5%) and H. nana (0.2%). The odds of infection with any STH increased as the frequency of trimming decreased. The odds of nail contamination with any STH and A. lumbricoides were higher for younger children. Conclusions The presence of helminth eggs under the nails of children highlights a poor personal hygiene. The association between any STH infection and frequency of nail trimming needs to be explored in an intervention study. The recent prevalence of any STH infections indicated that scaling down of the frequency of deworming is justified but that STH is still a public health problem.publishedVersio

Assessment of environmental contamination with soil-transmitted helminths life stages at school compounds, households and open markets in Jimma Town, Ethiopia

Background It remains largely unknown where and how infections with soil-transmitted helminths (STHs; Ascaris , Trichuris , Necator and Ancylostoma ) occur. We therefore aimed to identify possible sources of infection by assessing the environmental contamination in an STH-endemic area. Methods We first performed a series of laboratory experiments designed to optimize a soil straining-flotation method to detect and quantify Ascaris and Trichuris eggs in soil, and to validate the diagnostic performance of the optimized method when followed by microscopy and qPCR. In a second phase, we applied this method to assess the level of STH contamination in 399 environmental samples collected from 10 school compounds, 50 households and 9 open markets in Jimma Town (Ethiopia). Subsequently, we explored associations between the environmental contamination and both the corresponding STH epidemiology at the level of the schools and the household characteristics. Finally, we assessed the knowledge, attitude and practice (KAP) towards STHs in school children. Principal findings Our soil straining-flotation method has an analytical sensitivity of 50 eggs per 100 grams of soil and egg recovery rate of 36.0% ( Ascaris ) and 8.0% ( Trichuris ). The analysis of field samples with both microscopy and qPCR revealed the presence of 8 different helminth species of medical importance, including but not limited to the human STHs. There was a significant association between the environmental contamination and prevalence of any STH infections at the school level only. The KAP indicated a lack of knowledge and awareness of STHs. Conclusions/Significance Our optimized straining-flotation method has a moderate diagnostic performance and revealed that life stages of helminths are ubiquitous in the environment, which might be due to the poor sanitary facilities at both the schools and th

Assessment of environmental contamination with soil-transmitted helminths life stages at school compounds, households and open markets in Jimma Town, Ethiopia

Background It remains largely unknown where and how infections with soil-transmitted helminths (STHs; Ascaris, Trichuris, Necator and Ancylostoma) occur. We therefore aimed to identify possible sources of infection by assessing the environmental contamination in an STH-endemic area. Methods We first performed a series of laboratory experiments designed to optimize a soil straining-flotation method to detect and quantify Ascaris and Trichuris eggs in soil, and to validate the diagnostic performance of the optimized method when followed by microscopy and qPCR. In a second phase, we applied this method to assess the level of STH contamination in 399 environmental samples collected from 10 school compounds, 50 households and 9 open markets in Jimma Town (Ethiopia). Subsequently, we explored associations between the environmental contamination and both the corresponding STH epidemiology at the level of the schools and the household characteristics. Finally, we assessed the knowledge, attitude and practice (KAP) towards STHs in school children. Principal findings Our soil straining-flotation method has an analytical sensitivity of 50 eggs per 100 grams of soil and egg recovery rate of 36.0% (Ascaris) and 8.0% (Trichuris). The analysis of field samples with both microscopy and qPCR revealed the presence of 8 different helminth species of medical importance, including but not limited to the human STHs. There was a significant association between the environmental contamination and prevalence of any STH infections at the school level only. The KAP indicated a lack of knowledge and awareness of STHs. Conclusions/Significance Our optimized straining-flotation method has a moderate diagnostic performance and revealed that life stages of helminths are ubiquitous in the environment, which might be due to the poor sanitary facilities at both the schools and the households, and a poor level of KAP towards STHs. Further research is required to gain more insights into the contribution of these life stages to transmission.publishedVersio