Validation of the natural sedimentation technique in the diagnosis of chronic fasciolosis.

There are various diagnostic techniques available for chronic fasciolosis in ruminants. However, many of them exhibit low specificity and sensitivity, making them impractical for field use and in low-resource laboratories. The present study evaluates the usefulness of the Natural Sedimentation technique in diagnosing chronic fasciolosis in three domestic species conducted at the Laboratorio de Parasitología y Enfermedades Parasitarias, Facultad de Ciencias Veterinas, Universidad Nacional de Cajamarca. Fecal samples were collected from n = 323 cattle, n = 362 sheep, and n = 231 swine for Fasciola hepatica fecal egg counts. The visualization of adult parasites in animal livers post-mortem was considered the gold standard. Additionally, the sensitivity of the technique was evaluated using five different amounts of feces. In cattle, a sensitivity of 0.93 ± 0.03, specificity of 0.91 ± 0.06, positive predictive value of 0.96 ± 0.03, and negative predictive value of 0.86 ± 0.07 were obtained. In sheep, a sensitivity of 0.79 ± 0.05, specificity of 0.83 ± 0.07, positive predictive value of 0.90 ± 0.04, and negative predictive value of 0.66 ± 0.08 were observed. In swine, a sensitivity of 0.92 ± 0.06, specificity of 1.00 ± 0.00, positive predictive value of 1.00 ± 0.00, and negative predictive value of 0.96 ± 0.03 were found. There was no statistical difference in egg counts when using 1, 2, 3, 4, and 5 g of feces (p = 0.907). Furthermore, 1 to 688 fecal eggs of F. hepatica were counted in 1 g of feces. The Natural Sedimentation technique has both qualitative and quantitative applications with satisfactory results when using 1 g of feces in the diagnosis of chronic fasciolosis in domestic animals. Due to its simplicity, it can be implemented in field conditions and low-resource laboratories.

Prevalence, Risk Factors and Diagnosis of Helminths in Thoroughbred Horses Kept at Training Centers in Rio de Janeiro, Brazil.

The aims of this study were to determine the prevalence of helminths in Thoroughbred horses in Rio de Janeiro; make correlations with risk factors for these infections; and compare the efficiency of three floatation solutions applied in the quantitative Mini-FLOTAC technique. Fecal samples from 520 horses were collected from six training centers between 2019 and 2021. These were subjected to the Mini-FLOTAC technique using three solutions: NaCl (density = 1.200 g/mL), ZnSO4 (1.350 g/mL) and ZnSO4 (1.200 g/mL); and also to qualitative techniques. Information on the horses' sex and age of horses was retrieved from the studbook; data on management from a questionnaire. The overall prevalence of intestinal parasites was 71.9%, with significant differences between training centers (P ≤ .05). On farm C, 87.7% of the samples presented strongylids and 38.7% had Parascaris spp., with the highest egg counts per gram of feces (EPG), of 358.33 and 40.41 respectively. Horses less than 3 years of age were about eight times more likely to be parasitized by strongylids and eleven times more likely to have EPG ≥500. The NaCl solution used in Mini-FLOTAC enabled recovery of the greatest number of samples with high EPG and reached the highest sensitivity values in the diagnosis when compared to the other solutions. Moreover, in the diagnoses, the levels of agreement between the results from the solutions used in Mini-FLOTAC were substantial. However, in estimating the EPG, full agreement between the results from the solutions used in Mini-FLOTAC was not obtained.

Effects of hypertonic solutions on two species of human intestinal parasites during fecal examination.

Aim: Ova and parasite examination by flotation requires hypertonic solutions, which can damage the egg and cyst membranes, leading to false negatives. The authors investigated the harmful effects of ZnSO4 and C12H22O11 solutions on the ova and parasite examination. Materials & methods: The authors processed samples using the Three Fecal Test technique. Aliquots were floated in different pH levels, temperatures and solution densities. Results: Densities above 1.12 g/ml led structures to collapse after 6-10 min. pH neutralization of the ZnSO4 solution did not prevent the parasites from changing. Conclusion: All structures were altered when standard methods were performed. To delay collapse, the parasite floating under 5 °C is highly desirable.

Fecal exams require solutions that can damage the intestinal parasite's shape. This is bad for diagnosis. The authors investigated the harmful effects of these solutions on fecal exams. The authors processed samples using a technique called the Three Fecal Test. Fecal samples were floated in different conditions, including neutral and acidic solutions, high and low temperatures and varying densities of chemical solutions. Densities above 1.12 g/ml altered the structures of parasites. Neutral solutions did not prevent the structures from changing. The structures of all parasites were altered when the usual techniques were performed. Thus, the techniques for diagnosing intestinal parasites in feces must be improved. Temperatures under 5 °C are the best for preventing the destruction of parasite membranes.

The application of the FLOTAC technique for detection of helminth eggs of medical and veterinary importance in soil samples.

The FLOTAC technique was initially developed to detected infective stages of parasites in animal and human feces. Recently, its applicability has been extended by the use in pastures and vegetables for human consumption. However, its use for the detection of parasites in the soil has never been investigated. In this study, we assessed the performance of the FLOTAC and compared with centrifugal flotation (CFT) and spontaneous sedimentation (SST) techniques. A total of 50 soil samples were collected from the Metropolitan region of Recife, Northeastern Brazil. Initially, samples were standardized, and then assessed in duplicate by the FLOTAC, CFT and SST. Cohen's kappa coefficient, sensitivity, specificity, positive and negative predictive values, and accuracy of the FLOTAC, CFT and SST were assessed using the results of the combination of all three techniques as gold standard. Out of all analyses performed, in 96% (48/50), helminth eggs of parasites were detected. In particular, 96% (48/50) of samples analysed through the FLOTAC technique, 76% (38/50) for CFT and 28% (14/50) for SST were positive. Nematode eggs of the Ancylostomatidae and Ascarididae families were those mostly detected in this study. Overall, the FLOTAC presented high values of sensitivity, demonstrating that this method may also be employed for detection of parasites in soil samples. This study opens new possibilities for the use of the FLOTAC technique, highlighting its role as a potential tool for detecting environmental contamination by parasites of medical and veterinary importance.

Use of the FLOTAC technique as a new coproparasitological diagnostic method in aquatic mammals and comparison with traditional methods.

The inadequate choice of a diagnostic method or the option for techniques that have low sensitivity and specificity may limit the diagnosis of parasitic agents that affect aquatic mammals. The aim of this study was to evaluate the performance of the FLOTAC technique and compare it with three traditional methods (Willis, sedimentation and centrifugation- flotation) used in the diagnosis of gastrointestinal parasites in aquatic mammals. For this, 129 fecal samples from 12 species were collected. Each sample was submitted to laboratory processing using the Willis, Hoffman techniques, Faust method and FLOTAC. Sensitivity, specificity, real prevalence, estimated prevalence, positive predictive value, negative predictive value, correct classification (accuracy) and incorrect classification were evaluated to compare the different diagnostic methods. The highest frequency of positive samples occurred using FLOTAC (46.51%), compared to Hoffman (23.25%), Faust (10.07%) and Willis techniques (6.97%). In the samples analyzed, the occurrence of Strongylidae eggs and Eimeriidae oocysts was frequently observed. The FLOTAC technique proved to be the most appropriate technique and due to its efficacy, is strongly recommended for coproparasitological evaluations in aquatic mammals.

A simple method for purification of Strongyloides venezuelensis eggs from rat faeces.

The aim of this study was to develop a simple method to purify Strongyloides eggs from rat faeces using a sucrose gradient centrifugal-flotation technique. This procedure is simple, rapid and possesses a high efficiency in recovering Strongyloides eggs without faecal detritus in less than one hour, thus eliminating the use of complex apparatus and different chemical substances. The possibility of working with pure and live Strongyloides eggs opens up a wide range of future studies on the biology of this parasite. This study constitutes the first report in the scientific literature on purifying Strongyloides eggs using a sucrose density gradient.

Nutraceutical properties of Leucaena leucocephala, Manihot esculenta, Cajanus cajan and a foliage blend in goat kids infected with Haemonchus contortus.

Protein and condensed tannin-rich foliage (TRF) are potentially useful as nutraceuticals. The main objective of this study was to evaluate the diet and anthelmintic properties of three TRF types both individually and in combination. We hypothesized that synergistic or antagonistic effects on feed and anthelmintic values related to associations between TRF types may occur. Nutritional and anthelmintic characteristics of Leucaena leucocephala, Manihot esculenta, Cajanus cajan and a mixture of the compounds were evaluated using alfalfa pellets as a control. TRF ingredients were combined with Dichantium hay (48 and 52% of dry matter intake respectively) in mixed diets were consumed by Creole goat kids. Measurements were carried out in animals without parasites and in animals artificially infected with Haemonchus contortus. Individual feed intake and the digestibility of each diet was measured along with kid growth. There were no significant differences between the growth rates of pre-infected animals and animals fed mixed diets that included alfalfa. A strong anthelmintic activity is observed with Leucaena leucocephala contrary to other TRFs. This work confirms variable dietary and anthelmintic properties of TRF. The combination of TRF did not have synergistic or antagonistic effects on feed value or the anthelmintic potential of TRF.

Comparison of Four Parasitological Techniques for Laboratory Diagnosis of Eggs from Spirometra spp. in Wild Mammal Fecal Samples.

PURPOSE: This study aimed to compare the performance of four different microscopic coproparasitological techniques in relation to egg recovering and the frequency of alterations in the eggs observed through each technique. METHODS: A total of 213 fecal samples from free-living carnivorous mammals were collected between 2017 and 2018 in Itatiaia National Park, RJ, Brazil. Faust and modified Sheather floatation techniques as well as Lutz and modified Ritchie sedimentation techniques were applied. RESULTS: The total positivity rate for Spirometra spp. eggs was 24.4%, and these were detected mainly through Lutz and modified Ritchie sedimentation techniques, with substantial agreement (kappa = 0.73; p = 0.00 < 0.05; McNemar p value = 1.0; Fisher's exact test p = 0.616). Faust and modified Sheather flotation techniques did not present good egg recovery, with frequencies of 6.6% and 7.5%, respectively. Eggs with morphological alterations were mostly observed through Faust (17.3%) and modified Sheather (13.5%). Both flotation techniques presented statistically significant frequencies of deformed eggs, in comparison with the sedimentation techniques (p = 0.00). Low frequencies of deformed eggs were observed when the samples were analyzed through modified Ritchie and Lutz sedimentation techniques. CONCLUSIONS: From these results, sedimentation techniques such as modified Ritchie and Lutz methods were more efficient for diagnosing the eggs of this helminth in fecal material from free-living carnivores and should always be used when analyzing fecal samples from hosts of different species.

Diagnostic performance of a single and duplicate Kato-Katz, Mini-FLOTAC, FECPAKG2 and qPCR for the detection and quantification of soil-transmitted helminths in three endemic countries.

BACKGROUND: Because the success of deworming programs targeting soil-transmitted helminths (STHs) is evaluated through the periodically assessment of prevalence and infection intensities, the use of the correct diagnostic method is of utmost importance. The STH community has recently published for each phase of a deworming program the minimal criteria that a potential diagnostic method needs to meet, the so-called target product profiles (TPPs). METHODOLOGY: We compared the diagnostic performance of a single Kato-Katz (reference method) with that of other microscopy-based methods (duplicate Kato-Katz, Mini-FLOTAC and FECPAKG2) and one DNA-based method (qPCR) for the detection and quantification of STH infections in three drug efficacy trials in Ethiopia, Lao PDR, and Tanzania. Furthermore, we evaluated a selection of minimal diagnostic criteria of the TPPs. PRINCIPAL FINDINGS: All diagnostic methods showed a clinical sensitivity of ≥90% for all STH infections of moderate-to-heavy intensities. For infections of very low intensity, only qPCR resulted in a sensitivity that was superior to a single Kato-Katz for all STHs. Compared to the reference method, both Mini-FLOTAC and FECPAKG2 resulted in significantly lower fecal egg counts for some STHs, leading to a substantial underestimation of the infection intensity. For qPCR, there was a positive significant correlation between the egg counts of a single Kato-Katz and the DNA concentration. CONCLUSIONS/SIGNIFICANCE: Our results indicate that the diagnostic performance of a single Kato-Katz is underestimated by the community and that diagnostic specific thresholds to classify intensity of infection are warranted for Mini-FLOTAC, FECPAKG2 and qPCR. When we strictly apply the TPPs, Kato-Katz is the only microscopy-based method that meets the minimal diagnostic criteria for application in the planning, monitoring and evaluation phase of an STH program. qPCR is the only method that could be considered in the phase that aims to seek confirmation for cessation of program. TRIAL REGISTRATION: ClinicalTrials.gov NCT03465488.

Therapeutic efficacy of albendazole against soil-transmitted helminthiasis in children measured by five diagnostic methods.

BACKGROUND: Preventive chemotherapy (PC) with benzimidazole drugs is the backbone of soil-transmitted helminth (STH) control programs. Over the past decade, drug coverage has increased and with it, the possibility of developing anthelmintic resistance. It is therefore of utmost importance to monitor drug efficacy. Currently, a variety of novel diagnostic methods are available, but it remains unclear whether they can be used to monitor drug efficacy. In this study, we compared the efficacy of albendazole (ALB) measured by different diagnostic methods in a head-to-head comparison to the recommended single Kato-Katz. METHODS: An ALB efficacy trial was performed in 3 different STH-endemic countries (Ethiopia, Lao PDR and Tanzania), each with a different PC-history. During these trials, stool samples were evaluated with Kato-Katz (single and duplicate), Mini-FLOTAC, FECPAKG2, and qPCR. The reduction rate in mean eggs per gram of stool (ERR) and mean genome equivalents / ml of DNA extract (GERR) were calculated to estimate drug efficacy. PRINCIPAL FINDINGS AND CONCLUSIONS: The results of the efficacy trials showed that none of the evaluated diagnostic methods could provide reduction rates that were equivalent to a single Kato-Katz for all STH. However, despite differences in clinical sensitivity and egg counts, they agreed in classifying efficacy according to World Health Organization (WHO) guidelines. This demonstrates that diagnostic methods for assessing drug efficacy should be validated with their intended-use in mind and that other factors like user-friendliness and costs will likely be important factors in driving the choice of diagnostics. In addition, ALB efficacy against STH infections was lower in sites with a longer history of PC. Yet, further research is needed to identify factors that contribute to this finding and to verify whether reduced efficacy can be associated with mutations in the ß-tubulin gene that have previously been linked to anthelmintic resistance. TRIAL REGISTRATION: ClinicalTrials.gov NCT03465488.

Criteria for identification of Schistosoma mansoni eggs in faecal sediments prepared with the Helmintex method and stained by ninhydrin.

Helmintex is a sensitive method used for detecting Schistosoma mansoni eggs. Here, we describe the observed frequency of six proposed criteria associated with the identification of S. mansoni eggs prepared with the Helmintex method and stained with ninhydrin. The efficacy of these criteria in classifying S. mansoni eggs when applied in various combinations was also examined. Nine observers registered the presence or absence of 6 different criteria in 100 eggs using a microscope at 100x magnification. Ninhydrin purple, which was frequently observed, was the criterion associated with the lowest inter-observer variability. At least three criteria were associated with a significantly better performance in egg identification. In conclusion, ninhydrin staining and a combination of criteria are recommended for microscope examination of faecal sediments.

Comparison of Kato-Katz Thick Smear, Mini-FLOTAC, and Flukefinder for the Detection and Quantification of Fasciola hepatica Eggs in Artificially Spiked Human Stool.

We compared the diagnostic performance of the standard method (Kato-Katz) with two recently developed methods (Mini-FLOTAC and Flukefinder) for the detection and quantification of Fasciola hepatica eggs in human stool. Uninfected human stool samples were artificially spiked with F. hepatica eggs to reach final concentrations of 14, 28, 41, or 96 eggs per gram of stool (epg). Only Flukefinder showed 100% sensitivity in all but the samples with the lowest concentration of eggs (14 epg), in which it had a sensitivity of 60%. Each of the methods underestimated the true fecal egg counts (FECs), Flukefinder resulting in the most biased egg counts (egg counts 0.18 times lower than the expected FECs). Only the Flukefinder resulted in more precise results (coefficient of variance < 30%) from FECs of 96 epg onward. The outcome of this study indicates that the Flukefinder is a useful alternative diagnostic method for human fascioliasis in stool.

Comparison of two methods for the quantification of gastrointestinal nematode infective larvae from pasture / Comparação de dois métodos para quantificação de larvas infectantes de nematódeos gastrintestinais da pastagem

The economic losses caused by gastrointestinal nematodes are one of the biggest obstacles in the small ruminants production. Understanding the population dynamics of the infective larvae (L3) in the pasture is the key point to develop control programs, and reliable results depend on the used methodology to quantify L3 numbers. The use of the sampling directly from the pasture appears as a viable option, since it is not required the use of animals with an esophageal fistula or tracer animals, decreasing the costs involved in the study. Therefore, the present project, which had as objective evaluate the efficiency of two collection methods for quantification of L3 in the pasture, utilized 64 lambs (n = 16) allocated to four integrated crop-livestock systems (treatments) with 12 paddocks each. Pasture samples were collected every nine days. The W method consists in traversing the area in the form of a W and again an inverted W, forage samples being collected every 10 steps, and the Square method, in tossing a 0.16 m2 square to four random points within the area, the forage within the square being collected after each toss. After the forage samples had been processed, the L3 were recovered and identified. Cohens Kappa coefficient (k) was determined. The W-transect and Random-plot methods did not differ (p ? 0.05) with respect to the number of L3 recovered from the pasture, and...(AU)

As perdas econômicas causadas por nematódeos gastrintestinais são um dos maiores entraves na produção de pequenos ruminantes. Entender a dinâmica populacional das larvas infectantes (L3) no capim é o ponto chave para que se desenvolva programas de controle, e resultados confiáveis dependem das metodologias utilizadas para quantificar o número dessas L3. O uso da amostragem diretamente da pastagem aparece como uma opção viável, já que não requer o uso de animais fistulados ou traçadores, reduzindo os custos envolvidos no estudo. Assim, no presente estudo, que teve como objetivo avaliar a eficácia de dois métodos de coleta para quantificação de L3 na pastagem, foram utilizados 64 cordeiros (n = 16) alocados em quatro sistemas integrados de produção agropecuária (tratamentos) com 12 piquetes cada. As amostras de pasto foram coletadas a cada nove dias. O método W consiste em percorrer a área sob a forma de um W e novamente um W invertido, sendo as amostras de forragem coletadas a cada 10 passos, e o método Quadrado, em lançar um quadrado de 0,16 m² em quatro pontos aleatórios dentro da área, sendo coletada a forragem contida dentro do quadrado após cada lance. Após o processamento das amostras de forragem, as L3 foram recuperadas e identificadas. O coeficiente Kappa de Cohen (k) foi determinado. Os métodos W e Quadrado não diferiram (P >= 0,05), quanto ao número de L3 recuperadas do...(AU)

Criteria for identification of Schistosoma mansoni eggs in faecal sediments prepared with the Helmintex method and stained by ninhydrin

Helmintex is a sensitive method used for detecting Schistosoma mansoni eggs. Here, we describe the observed frequency of six proposed criteria associated with the identification of S. mansoni eggs prepared with the Helmintex method and stained with ninhydrin. The efficacy of these criteria in classifying S. mansoni eggs when applied in various combinations was also examined. Nine observers registered the presence or absence of 6 different criteria in 100 eggs using a microscope at 100x magnification. Ninhydrin purple, which was frequently observed, was the criterion associated with the lowest inter-observer variability. At least three criteria were associated with a significantly better performance in egg identification. In conclusion, ninhydrin staining and a combination of criteria are recommended for microscope examination of faecal sediments.

Implication of the fecal egg count reduction test (FECRT) in sheep for better use of available drugs / Implicação do teste de redução da contagem de ovos nas fezes (TRCOF) em ovinos para melhor uso dos anti-helmínticos disponíveis

The aim here is to present data on the efficacy of anthelmintics in sheep flocks in Rio de Janeiro, Brazil, and to discuss the interpretation of the fecal egg count reduction test (FECRT) for each nematode genus. Fecal eggs counts and pre- and post-treatment coprocultures were performed, the former to evaluate the efficacy of and the latter to determine the overall parasite prevalence. An additional efficacy test was performed at Farm / 1 a year after the initial test. Severe anthelmintic resistance was found for the flocks, with no FECRT sensitivity at any of the 22 farms evaluated. However, an analysis of the infective larvae showed that some drugs were effective against certain parasitic genera; i.e., levamisole was more effective against Haemonchus spp. and moxidectin against Trichostrongylus spp. In the additional FECRT performed at Farm / 1, moxidectin and nitroxynil were ineffective separately, but when applied in combination they were highly effective due to their efficacy against Haemonchus (nitroxynil) and Trichostrongylus (moxidectin), respectively. The use of the FECRT targeting the parasitic nematode species prevalent on farms may make it possible to choose more effective anthelmintics.(AU)

O objetivo deste trabalho foi apresentar dados sobre a eficácia de anti-helmínticos em rebanhos ovinos no Rio de Janeiro, Brasil, e discutir a interpretação do teste de redução da contagem de ovos nas fezes (TRCOF) para cada gênero de nematoide. A contagem de ovos fecais (OPG) e coprocultura pré e pós-tratamento foram realizadas para avaliar a eficácia e a prevalência geral do parasito, respectivamente. Um teste de eficácia adicional foi realizado na Fazenda / 1 após um ano do teste inicial. Resistência anti-helmíntica grave foi encontrada, não havendo sensibilidade no TRCOF em nenhuma das 22 fazendas avaliadas. No entanto, na análise das larvas infectantes observou-se que algumas drogas foram eficazes contra certos gêneros parasitários; por exemplo, o levamisol foi mais eficaz contra Haemonchus spp. e a moxidectina contra Trichostrongylus spp. No TRCOF adicional realizado na Fazenda 1, a moxidectina e o nitroxinil foram ineficazes separadamente, mas quando aplicados em combinação, foram altamente eficazes devido à sua eficácia contra Haemonchus spp. (nitroxinil) e Trichostrongylus spp. (moxidectina), respectivamente. O TRCOF visando às espécies de nematoides parasitas prevalentes nas fazendas pode possibilitar a escolha de anti-helmínticos mais eficazes.(AU)

Comparison of two methods for the quantification of gastrointestinal nematode infective larvae from pasture / Comparação de dois métodos para quantificação de larvas infectantes de nematódeos gastrintestinais da pastagem

The economic losses caused by gastrointestinal nematodes are one of the biggest obstacles in the small ruminants production. Understanding the population dynamics of the infective larvae (L3) in the pasture is the key point to develop control programs, and reliable results depend on the used methodology to quantify L3 numbers. The use of the sampling directly from the pasture appears as a viable option, since it is not required the use of animals with an esophageal fistula or tracer animals, decreasing the costs involved in the study. Therefore, the present project, which had as objective evaluate the efficiency of two collection methods for quantification of L3 in the pasture, utilized 64 lambs (n = 16) allocated to four integrated crop-livestock systems (treatments) with 12 paddocks each. Pasture samples were collected every nine days. The W method consists in traversing the area in the form of a W and again an inverted W, forage samples being collected every 10 steps, and the Square method, in tossing a 0.16 m2 square to four random points within the area, the forage within the square being collected after each toss. After the forage samples had been processed, the L3 were recovered and identified. Cohens Kappa coefficient (k) was determined. The W-transect and Random-plot methods did not differ (p ? 0.05) with respect to the number of L3 recovered from the pasture, and...

As perdas econômicas causadas por nematódeos gastrintestinais são um dos maiores entraves na produção de pequenos ruminantes. Entender a dinâmica populacional das larvas infectantes (L3) no capim é o ponto chave para que se desenvolva programas de controle, e resultados confiáveis dependem das metodologias utilizadas para quantificar o número dessas L3. O uso da amostragem diretamente da pastagem aparece como uma opção viável, já que não requer o uso de animais fistulados ou traçadores, reduzindo os custos envolvidos no estudo. Assim, no presente estudo, que teve como objetivo avaliar a eficácia de dois métodos de coleta para quantificação de L3 na pastagem, foram utilizados 64 cordeiros (n = 16) alocados em quatro sistemas integrados de produção agropecuária (tratamentos) com 12 piquetes cada. As amostras de pasto foram coletadas a cada nove dias. O método W consiste em percorrer a área sob a forma de um W e novamente um W invertido, sendo as amostras de forragem coletadas a cada 10 passos, e o método Quadrado, em lançar um quadrado de 0,16 m² em quatro pontos aleatórios dentro da área, sendo coletada a forragem contida dentro do quadrado após cada lance. Após o processamento das amostras de forragem, as L3 foram recuperadas e identificadas. O coeficiente Kappa de Cohen (k) foi determinado. Os métodos W e Quadrado não diferiram (P >= 0,05), quanto ao número de L3 recuperadas do...

Ocorrência de parasitos gastrintestinais diagnosticados em bovinos pelo laboratório de doenças parasitárias da Universidade Federal de Pelotas (Brasil), nos anos de 2015 a 2017 / Occurrence of gastrointestinal parasites diagnosed in cattle by the laboratory of parasitic diseases of the Federal University of Pelotas (Brazil), from 2015 to 2017

Entre os anos de 2015 a 2017, foram recebidas e examinadas pelo Laboratório de Doenças Parasitárias (LADOPAR) da Universidade Federal de Pelotas 3.058 amostras de fezes de bovinos advindas de animais da região sul do Estado do Rio Grande do Sul, Brasil. A técnica coproparasitológica de Gordon & Whitlock (1939) foi utilizada para o diagnóstico. Do total de amostras, 82,4% apresentaram-se positivas para algum parasito gastrintestinal. Ovos da superfamília Strongyloidea foram os mais frequentes, sendo observados em 59,18% das amostras (1810/3058). Foram observados, ainda, ovos dos gêneros Trichuris, Strongyloides, Nematodirus, Moniezia e Superfamilia Ascaroidea, e também oocistos de coccídeos. A partir dos resultados obtidos, conclui-se que parasitos gastrintestinais estão presentes nas criações de bovinos da região sul do Estado e, através de exames coproparasitológicos, é possível implementar medidas sanitárias e preventivas nos rebanhos.

Between the years 2015 and 2017, 3,058 samples of cattle faeces from the southern region of Rio Grande do Sul State, Brazil, were received and examined by the Laboratory of Parasitic Diseases (LADOPAR) of the Federal University of Pelotas. Gordon & Whitlock’s (1939) coproparasitological technique was used for the diagnosis. Of the total samples, 82.4% were positive for some gastrointestinal parasite. Eggs of the Strongyloidea superfamily were the most frequent, observed in 59.18% of the samples (1810/3058). Eggs of the genus Trichuris, Strongyloides, Nematodirus, Moniezia and Ascaroidea Superfamily, as well as coccidian oocysts were also observed. From the results obtained, it is concluded that gastrointestinal parasites are present in bovine from the southern region of the state and, through coproparasitological examinations, it is possible to implement sanitary and preventive measures in the herds.

Ocorrência de parasitos gastrintestinais diagnosticados em bovinos pelo laboratório de doenças parasitárias da Universidade Federal de Pelotas (Brasil), nos anos de 2015 a 2017 / Occurrence of gastrointestinal parasites diagnosed in cattle by the laboratory of parasitic diseases of the Federal University of Pelotas (Brazil), from 2015 to 2017

Entre os anos de 2015 a 2017, foram recebidas e examinadas pelo Laboratório de Doenças Parasitárias (LADOPAR) da Universidade Federal de Pelotas 3.058 amostras de fezes de bovinos advindas de animais da região sul do Estado do Rio Grande do Sul, Brasil. A técnica coproparasitológica de Gordon & Whitlock (1939) foi utilizada para o diagnóstico. Do total de amostras, 82,4% apresentaram-se positivas para algum parasito gastrintestinal. Ovos da superfamília Strongyloidea foram os mais frequentes, sendo observados em 59,18% das amostras (1810/3058). Foram observados, ainda, ovos dos gêneros Trichuris, Strongyloides, Nematodirus, Moniezia e Superfamilia Ascaroidea, e também oocistos de coccídeos. A partir dos resultados obtidos, conclui-se que parasitos gastrintestinais estão presentes nas criações de bovinos da região sul do Estado e, através de exames coproparasitológicos, é possível implementar medidas sanitárias e preventivas nos rebanhos.(AU)

Between the years 2015 and 2017, 3,058 samples of cattle faeces from the southern region of Rio Grande do Sul State, Brazil, were received and examined by the Laboratory of Parasitic Diseases (LADOPAR) of the Federal University of Pelotas. Gordon & Whitlocks (1939) coproparasitological technique was used for the diagnosis. Of the total samples, 82.4% were positive for some gastrointestinal parasite. Eggs of the Strongyloidea superfamily were the most frequent, observed in 59.18% of the samples (1810/3058). Eggs of the genus Trichuris, Strongyloides, Nematodirus, Moniezia and Ascaroidea Superfamily, as well as coccidian oocysts were also observed. From the results obtained, it is concluded that gastrointestinal parasites are present in bovine from the southern region of the state and, through coproparasitological examinations, it is possible to implement sanitary and preventive measures in the herds.(AU)

Kato-Katz thick smears as a DNA source of soil-transmitted helminths.

Despite the reduction in the prevalence of soil-transmitted helminthiases in many regions of the world, morbidity rates remain high in some rural regions. The Kato-Katz technique is a simple, inexpensive and field-applicable tool commonly used for the diagnosis and worm-burden characterization of these infections. Molecular studies have revolutionized our understanding of the epidemiology and evolutionary genetics of parasites. In this study we recovered helminthic DNA from Kato-Katz slides (n = 93) prepared in 2011 in the Brazilian Amazon. We achieved DNA recovery by polymerase chain reaction (PCR) in 84% of cases for Ascaris sp. and 75% of cases for hookworms. The sequencing confirmed the specific species of the amplicons. The slides stored for a few years could be analysed using this methodology, allowing access to DNA from a large collection of samples. We must consider the Kato-Katz thick smears as a source of helminth DNA. This can significantly reduce logistical difficulties in the field in terms of obtaining, preserving, transporting and initial processing of samples.

Modification and optimization of the FECPAKG2 protocol for the detection and quantification of soil-transmitted helminth eggs in human stool.

BACKGROUND: Standard diagnosis of human soil-transmitted helminth (STH) infections is based on the microscopic detection of helminth eggs in stool and supports programmatic decision making in control programs. However, the current standard diagnostic techniques still show a number of limitations. Recently, the FECPAKG2 method was developed to detect helminth infections and asses drug efficacy in sheep or cattle. It includes a device that takes digital images of helminth eggs that have been concentrated into one microscopic field of view and stores these images online for future evaluation. The goal of this study was to introduce a standard operating procedure (SOP) for the detection and quantification of human STH eggs using the FECPAKG2 and to optimize 2 crucial steps of the protocol, namely the sedimentation step (aimed at separating sinking eggs from floating debris) and the accumulation step (aimed at concentrating the eggs by flotation). METHODOLOGY/PRINCIPAL FINDINGS: A total of 55 stool samples from naturally infected children were used from 4 different geographical areas (Ethiopia, Laos, Tanzania and Brazil). The results showed that Trichuris eggs generally moved slower than eggs of the other two STH species during both sedimentation in water in the FECPAKG2 sedimenter as during accumulation in flotation solution in the FECPAKG2 cassettes. The highest number of eggs were present in the slurry of the sedimenter after overnight sedimentation (Ascaris: 95.7%, Trichuris: 89.8% and hookworm: 94.2% of the eggs). A minimum of 24 minutes were needed to ensure the accumulation of at least 80% of the eggs from all three STH species in the FECPAKG2 cassette (Ascaris: 96.1%; Trichuris: 88.2% and hookworm: 87.6%). CONCLUSIONS/SIGNIFICANCE: This study introduces for the first time a SOP for the FECPAKG2 method. Different aspects of the method for diagnosing human STH infections were optimized. Our study forms the basis for a thorough and objective evaluation of the system as a diagnostic tool that could be implemented in STH control programs.