Survey on Intestinal Helminthic Infection Status of Students in Two Counties, Hadong-gun and Goseong-gun, Korea.

This study was conducted to investigate the prevalence of intestinal parasites among students from Goseonggun, Gangwon-do and Hadong-gun, Gyeongsangnam-do as typical low and high endemic counties. From May to July 2017, a total of 2,033 fecal samples were collected at 27 elementary, 10 junior high, and 8 high schools from 2 counties and examined by the Kato-Katz technique for egg-positive surveys (Collection rate: 37.02% [2,033/5,492]). Of the participants examined, 13 (0.64%) were found to harbor eggs of 3 parasitic species, Trichuris trichiura, Clonorchis sinensis and Metagonimus yokogawai. Based on the regional distribution, the egg-positive rate in Goseong-gun was 0% (0/550) and that in Hadong-gun was 0.88% (13/1,483). The positive rates for C. sinensis, M. yokogawai, and T. trichiura in Hadonggun were 0.20% (3/1,483), 0.61% (9/1,483), and 0.07% (1/1,483), respectively. The present survey showed that the prevalence of parasitic infection among students is currently very low even in remote, previously endemic areas, and the present status of parasitic diseases can be summarized as some transmission of fish/food-borne trematodes. Thus, it is necessary to carefully, continuously monitor the trematode infection status, particularly of C. sinensis and M. yokogawai.

Epidemiology and effect of gastrointestinal nematodes on beef cattle from tropical Argentina.

The aim of this work was to study the epidemiology and the harmful effect of gastrointestinal nematodes (GINs) on beef cattle in the piedmont forest and grassland region of northwestern Argentina, between March 2015 and March 2016. Sixty weaned female calves were divided into three groups: STG-calves treated systematically with 200 mcg/kg moxidectin every 40-50 days; LTG-calves treated as usually locally implemented, with 200 mcg/kg ivermectin on May 4 and August 5; and UTG-calves not receiving treatment. Moreover, a group of 20 untreated first-calving cows was monitored. Eggs per gram of faeces (epg) and faeces cultures were performed. Live weight gain (LWG) was recorded. Differences among groups were compared using analysis of variance and Tukey test. At the start of the experiment, mean epg was from moderate to high (595 ± 480); therefore, this group was treated in May. Mean UTG epg peaked (907 ± 754) in mid-winter, decreasing toward spring. LTG epg only decreased partially after treatment, showing 54.2% of ivermectin efficacy. Epg values of STG were always negligible values (95.8% of moxidectin efficacy). The dominant nematode genus was Cooperia (81.9%), followed by Haemonchus (15.5%). The effect of treatments was evident from middle autumn, with STG showing a significantly (p < 0.002) higher LWG than the other groups. Toward the end of the trial, LWG of STG and LTG increased by 27.2 and 8.2%, respectively, to those of UTG. This preliminary study showed a winter epg peak and a negative effect of GINs on LWG, even in moderately infected calves.

Reducing Unnecessary and Duplicate Ordering for Ovum and Parasite Examinations and Clostridium difficile PCR in Immunocompromised Patients by Using an Alert at the Time of Request in the Order Management System.

We implemented hospital information system (HIS) alerts to deter unnecessary test orders for ovum and parasite (O&P) exams and Clostridium difficile PCR. The HIS alerts decreased noncompliant O&P orders (orders after >72 h of hospitalization) from 49.8% to 30.9%, an overall decrease of 19%, and reduced noncompliant C. difficile PCR orders (orders <7 days after a previous positive result) from 30.6% to 19.2%, an overall decrease of 31.9%.

Physician use of parasite tests in the United States from 1997 to 2006 and in a Utah Cryptosporidium outbreak in 2007.

Parasitic infection is uncommon in the United States, but surveys suggest that physicians test when the presence of parasites is unlikely and fail to order appropriate testing when suspicion is high. Numerous studies confirm that immunoassays are more sensitive for Giardia and Cryptosporidium detection, but our experience was that physicians preferentially used ovum and parasite examination (O&P). We conducted a retrospective study of fecal parasite testing at a referral laboratory nationally (1997 to 2006) and during a Cryptosporidium outbreak (Utah, 2007) to correlate physician use of O&P and enzyme immunoassays (EIAs) with the yield of parasites detected. Nationally, of 170,671 episodes, 76.0% (n = 129,732) included O&P, 27.9% (n = 47,666) included Giardia EIA, and 5.7% (n = 9,754) included Cryptosporidium EIA. Most pathogens were Giardia or Cryptosporidium. More episodes were positive when EIA was performed (n = 1,860/54,483 [3.4%]) than when O&P only was performed (n = 1,667/116,188 [1.4%]; P < 0.001), and EIA was more sensitive than O&P. However, more O&P results were positive among patients with both O&P and EIA performed (2.5%) than among those with O&P only performed (1.4%; P < 0.001), suggesting that patients tested by O&P only may have been at lower risk. During the first 10 weeks of the outbreak, physicians also preferentially used O&P over EIA, but no Cryptosporidium cases were detected by O&P. We conclude that clinicians frequently use O&P testing when test performance and epidemiology support the use of immunoassays or no testing. We recommend that stool O&P be limited to patients with negative immunoassay results and persistent symptoms or individuals at increased risk for non-Giardia, non-Cryptosporidium infection. An evidence-based algorithm for the evaluation of patients with suspected intestinal parasitic infection is proposed.

In vitro effects of artesunate on the survival of worm pairs and egg production of Schistosoma mansoni.

The effect of artesunate (ART) on the survival time of adult worm pairs of Schistosoma mansoni and on their egg output during in vitro culture was assessed. ART significantly decreased the survival time of both paired male and female worms at concentrations of 5, 10, 20 and 40 mg l- 1 during in vitro cultivation. An inhibitory effect of ART on the daily egg output of paired female worms during in vitro cultivation was also observed.

Gastrointestinal nematode infection and feeding behaviour of goats in a heterogeneous vegetation: No evidence of therapeutic self-medication.

The aim of this study was to identify modifications in the feeding behaviour of goats browsing a tropical deciduous forest (TDF) when natural gastrointestinal nematode (GIN) infection was suppressed. Continuous bite monitoring through direct observation was implemented in 12 Criollo goats (adults, non-pregnant) foraging for 4 h per day during the rainy season. In the first Period (P1, one observation point) all goats were maintained with natural GIN infection. In the second Period (P2, three observation points), goats were equally distributed into 2 groups: i) moxidectin treated group (TG) used in a suppressive scheme; and ii) naturally infected group (IG). For each observation point, goats were monitored at three timepoints per day (80 min each), for three consecutive days, to estimate their intake of dry matter (DM), condensed tannins (CT), crude protein, metabolizable energy and digestible DM. Live weight (LW), faecal samples and blood samples were obtained every 28 days to determine LW change, faecal egg counts (FEC) and packed cell volume (PCV). During P1 and P2, the TG and IG had similar LW change and PCV. During both periods, the intake of DM, CT and all macronutrients were similar for TG and IG. The suppression of GIN infection did not modify the feeding behaviour of goats. Therefore, a therapeutic self-medicative behaviour was not identified in Criollo goats browsing a TDF.

Schistosoma mansoni infection among preschool age children attending Erer Health Center, Ethiopia and the response rate to praziquantel.

OBJECTIVE: Preschool age children (PSAC) are excluded from community based praziquantel treatment programs mainly due to paucity of evidence on the magnitude of schistosomiasis, efficacy and safety of this treatment in PSAC. The aim of this study is to assess Schistosoma mansoni infection rate and evaluate response to praziquantel in PSAC. A facility based longitudinal study was employed from April to June 2016 at Erer Health Center, Eastern Ethiopia. Stool sample was examined for schistosomiasis in 236 PSAC and repeated after 4 weeks post-treatment in positive individuals. Treatment outcomes were recorded and interpreted. RESULTS: Out of the 236 study participants, 59 (25%) were infected with S. mansoni. Praziquantel treatment (40 mg/kg) resulted in 96.4% cure rate and 99.4% egg reduction rate. Children of 3-5 year old were significantly affected with S. mansoni infection. Nausea and fatigue were common mild adverse events within 4 h of treatment however moderate and severe adverse events and allergic reactions were not observed. In conclusion, praziquantel at 40 mg/kg, the dose utilized in standard care for school age children, is tolerable and efficacious in the treatment of S. mansoni infection in PSAC, which calls for the healthcare system to provide appropriate service for this population.

Modelling anthelmintic resistance by extending eggCounts package to allow individual efficacy.

The same anthelmintic treatment can have variable efficacy on individual animals even if the parasite population is homogenously susceptible. An extension of the R package eggCounts is proposed to take individual efficacy into account using a Bayesian hierarchical model. A simulation study is conducted to compare the performance of five different methods on estimating faecal egg count reduction and its uncertainty interval. Simulation results showed the individual efficacy model offered robust inference to two different data simulation procedures with low root mean squared error on the reduction estimate and appropriate uncertainty estimates. Different methods were used to evaluate the anthelmintic resistance in a dataset from USA with sheep and cattle faecal egg counts, where a strong anthelmintic resistance was detected. Open-source statistical tools were updated to include the proposed model.

Sensitivity of the Point-of-Care Circulating Cathodic Antigen Urine Cassette Test for Diagnosis of Schistosoma mansoni in Low-Endemicity Settings in Côte d'Ivoire.

The sensitivity of a point-of-care circulating cathodic antigen (POC-CCA) urine cassette test for diagnosis of Schistosoma mansoni in low-endemicity settings is poorly understood. We conducted a cross-sectional survey in 14 villages in western Côte d'Ivoire and diagnosed children aged 9-12 years for schistosomiasis. Two stool samples were subjected to triplicate Kato-Katz thick smears each for diagnosis of S. mansoni, whereas a single urine sample was examined by POC-CCA for S. mansoni, filtration for Schistosoma haematobium, and reagent strip for microhematuria. According to the Kato-Katz technique, we found 45 out of 681 children positive for S. mansoni (6.6%) with a mean intensity among infected children of 72.2 eggs per gram of stool. Point-of-care circulating cathodic antigen revealed a prevalence of S. mansoni of 33.0% when trace results were considered positive and 12.5% when trace results were considered negative. Eggs of S. haematobium were found in eight participants (1.2%), whereas the prevalence of microhematuria was 13.5%. A single POC-CCA urine cassette test revealed a several-fold higher prevalence of S. mansoni than multiple Kato-Katz thick smears in this low-endemicity area. Our findings have important ramifications for choosing an appropriate diagnostic tool in low-endemic areas that might be targeted for elimination.

Anthelmintic efficacy against equine strongyles in the United States.

Equine strongyle parasites are ubiquitous in grazing equids across the world. Anthelmintic resistance is widely developed in cyathostomin populations, but very few surveys have evaluated anthelmintic efficacy in equine populations in the United States, and most of these are over 15 years old. The present study was carried out as part of the National Animal Health Monitoring Systems (NAHMS) Equine 2015-2016 study. The aims were to investigate anthelmintic treatment efficacy by means of the fecal egg count reduction test (FECRT) and identify parameters associated with decreased efficacy. Data were collected from equine operations in 28 states via questionnaires and fecal samples submitted for fecal egg count analysis. Participants were instructed to collect samples from six equids at the day of anthelmintic treatments and 14 days later, and they were asked to include an empty syringe with a legible label of the anthelmintic product used in the shipment. Overall, dewormer treatment was effective for 76.3% of operations (84.6% of animals). Macrocyclic lactone use was effective for 88.7% of operations (95.0% of animals) while pyrimidine/benzimidazole use was effective for 21.4% of operations (43.5% of animals). Univariate analysis revealed that overall, macrocyclic lactones exhibited significantly higher efficacy than the pyrimidine and benzimidazole drug classes (p < 0.0001). There were no statistically significant differences observed between geographic regions (West, South Central, North East, and Southeast). Body weight (p = 0.0355), amount of anthelmintic administered (p = 0.0119), and operation size (p = 0.0162) were statistically associated with anthelmintic efficacy, while anthelmintic treatment frequency in the previous 12 months was not (p = 0.7081). Multiple, mixed-effect logistic regression revealed that anthelmintic drug class (p < 0.0001) was the most impactful factor in predicting anthelmintic efficacy, after accounting for operation size, region and clustering of equids at the operation level. Pasture rotation (p = 0.0129) also demonstrated a significant effect using this model. These data document widespread occurrence of reduced anthelmintic efficacy of benzimidazole and pyrimidine products against strongyle infections in equids in the United States. Anthelmintic efficacy patterns were relatively uniform between the four studied regions, and some epidemiological factors were identified to be associated with anthelmintic efficacy against strongyle infections. This information can be useful in devising sustainable parasite control strategies in the future.

The influence of pregnancy on intestinal parasite infection in Thai women.

The relationship between pregnancy and both the susceptibility and pathogenicity of parasite infections is disputed. This study compares the prevalence and intensity (as measured by density of eggs in stool samples) of intestinal helminth infections in pregnant and control groups of women from Khon Kaen Province in the northeast of Thailand. Stool samples were taken at the end of the first, second and third trimesters of pregnancy as well as 2 months after parturition and compared for the two groups. There were no significant changes in the prevalence of any of the common helminth species during the course of pregnancy or between the pregnant and control groups. Nor was there any evidence that the density of helminth eggs in the stool samples differed between sample times or between the pregnant and control groups. Our study therefore supports the hypothesis that pregnancy does not influence the course of human infection with helminths.

Survey of 11 western states for heartworm (Dirofilaria immitis) infection, heartworm diagnostic and prevention protocols, and fecal examination protocols for gastrointestinal parasites.

Heartworm infection in dogs and cats in the western United States is a fairly new phenomenon, and for this reason it is often considered to be of minimal significance. The purpose of this survey was to collect data from 11 western states (Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming) in an effort to assess awareness of heartworm disease and identify areas in which improvement in understanding is needed. To accomplish this goal, veterinary clinics and hospitals in these states were sent a one-page survey in early 2006. The results of the survey demonstrate that cases of heartworm disease have been reported in all 11 states, illustrating the importance of annual testing and the routine use of preventives.

Predictive Value of School-Aged Children's Schistosomiasis Prevalence and Egg Intensity for Other Age Groups in Western Kenya.

World Health Organization recommendations for the timing and target population for mass drug administration (MDA) for schistosomiasis are based on the prevalence of infection in school children within a given community. In a large study comparing MDA approaches for Schistosoma mansoni control, we evaluated whether prevalence of infection and egg burdens in 9- to 12-year-old students reflected infection levels in young children and adults in the same community. Cross-sectional surveys of preadolescents (9-12 years old) were compared with those of first year students (5-8 years old) in 225 villages and adults (20-55 years old) in 150 villages along the Kenyan shores of Lake Victoria. Village schistosomiasis prevalence and intensity levels in preadolescents strongly correlated (P < 0.0001) with prevalence and infection intensity for other age groups in the community. Our findings suggest that S. mansoni prevalence and intensity among 9- to 12-year-olds are valid for community sampling purposes in mapping for MDAs.

Detection and quantification of soluble egg antigen in urine of Schistosoma haematobium-infected children from Kenya.

While research on alternative diagnostic and morbidity markers for infection with Schistosoma haematobium has been going on for a long time, egg counts continue to be used as the gold standard, and infection intensity is thought to reflect the severity of the disease. However, this relationship is not always clear and fluctuation in egg output makes it difficult to classify prevalence correctly. The use of circulating adult worm antigen detection as an alternative diagnostic technique has been applied with varying success. However, this is a measure of worm burden and does not reflect the tissue egg load(s). In the present study we have used an assay that detects soluble egg antigen (SEA) in urine of S. haematobium-infected children, and we have evaluated the applicability of the assay as a diagnostic and morbidity indicator. To evaluate this assay, we have studied a group of 470 children from two schools (Tsunguni and Kibaokiche) in the Coast province of Kenya; 84.8% and 77% were egg-positive while the percentage positive as determined by the SEA-ELISA were 78.8% and 76.2% in Tsunguni and Kibaokiche, respectively. In both schools, SEA levels in urine of S. haematobium-infected children significantly correlated with egg counts (Pearson's r=0.73, P < 0.0001) and with hematuria (Spearman's r=0.65, P < 0.0001). In addition, urinary tract pathology as determined by ultrasound significantly correlated with the SEA levels in urine (Spearman's r=0.3, P < 0.001). The SEA-ELISA compared well with microhematuria within egg count classes and with egg counts within hematuria classes.

Treatment of human pulmonary paragonimiasis with triclabendazole: clinical tolerance and drug efficacy.

An open clinical trial to determine the efficacy and tolerability of postprandial doses of triclabendazole against Paragonimus mexicanus in 62 patients with pulmonary paragonimiasis from the Ecuadorian Amazon region was performed. Praziquantel was used as therapeutic control. Patients were allocated at random to the following 4 therapeutic regimens: triclabendazole, 5 mg/kg once daily for 3 d (16 patients), 10 mg/kg twice on one day (15 patients), and 10 mg/kg in a single dose (16 patients), and praziquantel, 25 mg/kg thrice daily for 3 d (15 patients). Clinical tolerance, based on the frequency and severity of adverse reactions, was superior in all 3 triclabendazole regimens to that of praziquantel. No alteration was observed in hepato-renal functions or haematological values. The clinical symptoms resolved at a comparable rate in all 4 treatment groups. A more rapid parasitological response to treatment, as determined by the reduction in the average number of parasite eggs found in sputum, was seen in patients treated with triclabendazole than with praziquantel. By day 90, 60 patients had no egg detected in their sputum; 2 patients, treated with a single dose of 10 mg/kg, had a few and were re-treated with triclabendazole (5 mg daily for 3 d). On day 365, none of the patients had eggs in their sputum. Triclabendazole can be recommended as an alternative drug of choice for the treatment of pulmonary paragonimiasis; it is as effective as praziquantel in clearing infections and better tolerated.

Factors associated with Schistosoma mansoni infection 5 years after selective treatment in a low endemic area in Brazil.

Five years after a single dose treatment, prevalence, intensity and morbidity of schistosomiasis mansoni were evaluated in Agua Branca, a low endemic community in the South East Brazil (cure rate 94%). At community level, prevalence showed a decrease from 38.9 to 24.5% and the intensity of infection dropped from 119.5 to 38.9 eggs per g of faeces (epg). However, after the exclusion of immigrants, newborn children and individuals that had left the area after the first evaluation, the prevalence among the treated and followed population was not significantly affected. Multivariate analysis showed that the 10-29 age group and water contact for agricultural purposes were independently associated with the presence of infection on post treatment evaluation [OR 3.9 and 5.09, respectively]. A previous treatment among subjects older than 15 years was inversely associated [OR 0.58]. The authors wish to draw attention to the fact that mobility may lead to a serious bias in evaluating the impact of the control programme.

Improvement of counting helminth eggs with internal standard.

The sanitary regulations introduce a requirement for parasitological control of sewage water used for irrigation and fertilisation of crops. The existing methods of estimation of helminth eggs, based on the coproscopic method using sedimentation, desorption, centrifugation and flotation of the material, allow for only 30-75% efficiency. The aim of this paper is to present an improved quantitative estimation method. The proposed method is based on an internal standard. A predetermined number of eggs of Ascaris lumbricoides suis L is coloured with crystalline violet. These marked eggs are added to sample being examined. Counting the marked eggs in the sample and comparing them with their introduced number allows to estimate the efficiency of the procedure. This results in an increase in the efficiency of the method to 100%. It is possible to calculate the real number of helminth eggs in the sample on the basis of the estimated efficiency of the procedure. The sensitivity of the proposed method is at the level of about 0.4 ppm. The necessary number of replications in the method is about 10 times lower than that in the existing methods. The number of natural (not coloured) eggs does not influence the efficiency of the method with an internal standard.

The prevalence and intensity of soil-transmitted helminths in some rural villages in northern peninsular Malaysia.

The prevalence and intensity of soil-transmitted helminths in five rural villages in northern peninsular were investigated. Generally the prevalence and intensity of infection were low in the 0-10- and above 50-year-old age groups when compared with other age groups. The prevalence and intensity of infection in the five villages were quite similar, because of similar socio-economic status. The highest intensity was observed for Ascaris lumbricoides, followed by hookworms and Trichuris trichiura.

[Contamination, by Toxocara spp eggs, in public parks and squares in Botucatu, São Paulo, Brazil]. / Contaminação, por ovos de Toxocara spp, de parques e praças públicas de botucatu, São Paulo, Brasil.

The frequency of Toxocara spp eggs in public parks was determined from March 1995 to February 1996. One hundred and twelve samples were collected from 10 public parks in Botucatu, São Paulo State, Brazil. Samples were processed by the decinormal sodium hydroxide concentration method. Out of the 120 soil samples analyzed, 21 were contaminated with Toxocara spp eggs, corresponding to a 17.5% rate of infestation. Of the ten squares submitted to analysis during the year, six presented contamination. Most of the ova found presented characteristics of inviability, with a consequent low chance of human infection, although the population is not free from the risk of contracting this zoonosis.

[The effectiveness of the Program of Communication and Education in Health on the control of S. mansoni infection in some areas of the state of Bahia]. / Efetividade do Programa de Comunicação e Educação em Saúde no controle da infecção por S. mansoni em algumas areas do Estado da Bahia.

The Program for S. mansoni Control (PCE) has been developed in some areas of the State of Bahia by the Fundação Nacional de Saúde (FNS). In 1989, activities on Information, Education, Communication and Community Mobilization (IEC/MC) were initiated. This study evaluates the epidemiological impact of the IEC/MC, using a quasi-experimental study design strategy, comparing the prevalences of infection for S. mansoni in areas of IEC/MC and estimates of other areas. The data used were routinely collected by the local staff of the FNS. A decrease on the prevalence of S. mansoni infection was found in all study areas, specially in those of IEC/MC activities. Findings indicate that PCE activities are more effective among school-age individuals and male adults, although IEC/MC allows for higher epidemiological impact among women, reflecting the differences among the strategies. These findings point out the need for qualitative evaluation research, as well as cost benefit and cost effectiveness analyses, that are more appropriate for decision making processes.