Academic literature on the topic 'Baermann technique'

To gain insight into the different extraction processes used in laboratories in various European countries and the effect these methods might have on the number of Meloidogyne second-stage juveniles (J2) extracted from soil samples, a ring test with 2 elements was conducted. The first element used the Baermann funnel as a method performance test. The second element was a proficiency test, in which the laboratory’s standard technique was compared with the Baermann method. Chilled samples of 100 cm3 (10 per extraction method) were sent to participants in insulated containers. In the nematode counts distinction was made between Meloidogyne J2, other plant-parasitic nematodes and/or saprophytes. A total number of 18 participants took part in the method performance test and 13 institutes took part in the proficiency test using 11 different extraction techniques. The initial population density in the soil was 2025 J2 (100 cm3 soil)−1, determined by Oostenbrink elutriator and 4 weeks incubation. In the method performance test the institutes found Meloidogyne J2 numbers varied between 0 and 705 J2 (100 cm3)−1. Using the Baermann extraction method the median number per institute ranged from 0 to 377 J2 (100 cm3)−1. In the proficiency test comparison amongst the different methods showed an increase of more than 100-fold, with the highest median of 3733 J2 (100 cm3)−1 and the lowest of 34 J2 (100 cm3)−1; the difference was caused mainly by the incubation effect. For the other plant-parasitic nematodes and the saprophytes, the differences between the most and least efficient extraction methods were much smaller. The variance of the Meloidogyne counts was the highest for the standard Baermann extraction technique; other similar techniques also had high variances. The automated zonal centrifuge had the lowest variance. The Baermann method is not advisable for survey purposes.

Background Soil-transmitted helminths (STH) are common in low and middle income countries where there is lack of access to clean water and sanitation. Effective diagnosis and treatment are essential for the control of STH infections. However, among STH parasites, Strongyloides stercoralis is the most neglected species, both in diagnostics and control strategies. Diagnostic methods cover different approaches, each with different sensitivities and specificities, such as serology, molecular techniques and microscopy based techniques. Of the later, the Baermann technique is the most commonly used procedure. In the literature, several ways have been described to perform the Baermann method, which illustrates the overall lack of a ‘(gold) reference standard’ method for the diagnosis of S. stercoralis infection. In this study we have evaluated the performance of three Baermann techniques in order to improve the reference standard for the microscopic diagnosis of S. stercoralis infection thereby facilitating individual case detection, mapping of the disease and proper evaluation of treatment responses. Methods/Principal findings A community based cross sectional study was conducted at Zenzelima, Bahir Dar Zuria Ethiopia. A total of 437 stool samples were collected and analyzed by the following procedures: conventional Baermann (CB), modified Baermann (MB), and modified Baermann with charcoal pre-incubation (MBCI). The diagnostic sensitivity and Negative Predictive Value (NPV) of each technique was calculated using the combination of all the three techniques as a composite reference standard. Our result indicated that larvae of S. stercoralis were detected in 151 (34.6%) stool samples. The prevalence of S. stercoralis infection based on the three diagnostic methods was 9.6%, 8.0%, and 31.3% by CB, MB, and MBCI respectively. The sensitivity and NPV for CB, MB, and MBCI were 26.7% and 70.8%, 22.1% and 69.6%, and 87.0% and 93.2%, respectively. The MBCI showed significant difference (P- value = <0.001) in the sensitivity and NPV values when compared with CB and MB values. The agreement between CB, MB, and MBCI with the composite reference standard was 31.8%, 26.7%, 89.6%, respectively. Conclusion/Significance Our results suggest the superior performance of MBCI. It is relatively easy to implement, simple to perform and comparatively cheaper. The CB is by far the commonly used method in routine diagnostic although this technique significantly underestimates the true burden of the disease and thereby contributing to the exclusion of S. stercoralis from the control strategies. Therefore, MBCI is recommended as a routine microscopy-based diagnostic test for S. stercoralis infection, particularly in settings where molecular procedures are not available.

Abstract Parasitic diseases reflect the health and balance of ecosystems, affecting not only individuals but also entire populations or communities. The aim of this study was to report on the diversity of parasitic helminths detected in the feces of a wild feline in southern Brazil. Parasites were obtained from fecal samples, and four techniques were used for parasitological examination: direct examination, centrifugal flotation with zinc sulfate (Faust technique), simple sedimentation (Hoffman technique) and Baermann-Moraes. The parasites were identified through micrometry and morphology, as follows: Ancylostoma sp., Toxocara sp., Trichuridae, Aelurostrongylus abstrusus, Alaria sp., and Spirometra sp. We recorded the genus Ancylostoma parasitizing L. colocolo for the first time.

Strongyloidiasis is a soil-transmitted helminthiasis with a high global prevalence. Objectives: We aimed to evaluate the prevalence of Strongyloides stercoralis infection and assess strongyloidiasis serology as a screening technique in the Peruvian Amazon. Material and Methods: We performed a cross-sectional study of strongyloidiasis in 300 pregnant women in Iquitos (Peru) from 1 May 2019 to 15 June 2019. Women were tested using serology (Strongyloides IgG IVD-ELISA kit) as an index test and the modified Baermann technique and/or charcoal fecal culture as the parasitological reference standard. Results: The reference tests showed S. stercoralis in the stool of 30 women (prevalence: 10%; 95% confidence interval [CI] 7.1% to 13.9%), while 101 women tested positive on the blood test (prevalence: 33.7%; 95% CI 28.6% to 39.4%). Fourteen of the 15 women (93.3%) with positive results according to the modified Baermann technique, and 14 of the 23 women (56.5%) with positive charcoal cultures also had positive serological results. Serology showed a sensitivity of 63.3% and a negative predictive value of 94.4%. Conclusion: In Iquitos, pregnant women have a high prevalence of S stercoralis. S. stercoralis ELISA could be an excellent tool for population-based screening, as it has a high negative predictive value that can help to rule out the presence of active infection.

Although Aelurostrongylus abstrusus infections in domestic cats (Felis silvestris catus) have sporadically been reported in Colombia, there is still no data available on epidemiology nor on the biology of this neglected lungworm parasite. Thus, this epidemiological study aimed to evaluate the occurrence of patent A. abstrusus infections in domestic cats from the Colombian Federal State of Antioquia. In total, 473 fecal samples of indoor/outdoor domestic cats were collected and analyzed thereafter by the Baermann funnel migration technique for the presence of A. abstrusus first stage larvae 1 (L1). The occurrence of A. abstrusus was confirmed in 0.4% (2/473) of investigated cats. Due to the presence of patent A. abstrusus infections in investigated cats, it is unfailing to include this lungworm within differential diagnoses of feline pulmonary disorders. Despite the fact that the Baermann funnel technique is currently the cheapest and the gold standard diagnostic tool for feline aelurostrongylosis, this technique is still unknown by Colombian veterinary surgeons and rarely utilized in small animal veterinary clinics. The current survey intends to generate awareness on this neglected parasitosis and to be considered as a baseline study for future surveys monitoring feline aelurostrongylosis not only in domestic/stray cats but also in endemic wild felid species of Colombia.

ABSTRACTFaecal cultures were established using bovine faeces containing known numbers of eggs from either Oesophagostomum radiatum, Haemonchus placei, Cooperia pectinata or a mixture of all three. A substantially greater percentage of larvae was recovered from cultures of O. radiatum and C. pectinata than was recovered from cultures of H. placei. The same pattern was observed in mixed cultures although yields of larvae from all species in mixed cultures were significantly reduced (p<0·001). The lower recovery of H. placei was not associated with a lower viability of H. placei eggs. Of the three different methods of harvesting larvae, the jar and mesh recovery technique was the least effective and significantly fewer larvae were recovered with this technique than with the Baermann and inversion techniques (p<0·05). The results are discussed with reference to the use of faecal culture and larval differentiation in the diagnosis of mixed species nematode infections of cattle.

SummaryThe presented clinical observation shows an atypical case of Angiostrongylus vasorum intraocular infection in an 18-month-old male beagle from north-eastern Slovakia. The dog presented with a motile worm in the anterior chamber of the right eye. No ocular signs or symptoms of a systemic disease were observed. The faecal examination using Baermann´s technique and fl otation was negative. Diagnosis was established following surgical removal of the worm. The specimen was determined as an A. vasorum female based on morphological features and confirmed by means of PCR technique and sequencing. To the best of our knowledge, the presented manifestation is the first ocular case of angiostrongylosis with absence of typical symptoms or signs of the disease.

Dissertação de Mestrado Integrado em Medicina Veterinária
O número de casos de parasitoses respiratórias nos nossos animais de companhia, causadas por nemátodes pulmonares, tem aumentado nos últimos anos em várias áreas geográficas, incluindo a Europa. Aelurostrongylus abstrusus e Angiostrongylus vasorum têm assumido especial importância nos gatos e cães, respectivamente. Ambos podem provocar pneumonia verminosa no animal, de gravidade variável, mas a infecção por A. vasorum pode resultar ainda em alterações neurológicas e da coagulação. Diversos estudos têm sido realizados de modo a averiguar a prevalência destas parasitoses, as quais aparentam estar subestimadas em vários países. Este trabalho foi elaborado com o intuito de avaliar a situação epidemiológica de A. abstrusus em gatos e A. vasorum em cães no distrito de Lisboa. Para isso foi realizada uma pesquisa em 100 amostras (50 de gatos e 50 de cães), maioritariamente fecais, mas também pulmonares de animais necropsiados. As amostras foram analisadas através da técnica de Baermann, actualmente considerado o método de eleição no diagnóstico destas parasitoses. A sua detecção e identificação foram baseadas na morfologia das larvas L1. Os resultados obtidos foram 12% (6/50) para A. abstrusus em gatos e 2% (1/50) para A. vasorum em cães. Estes dados realçam a presença de A. abstrusus e A. vasorum em gatos e cães, respectivamente, no distrito de Lisboa, em Portugal. Assim, este facto deve ser tido em consideração pelo médico veterinário na prática clínica, assim como a utilização rotineira da técnica de Baermann para o diagnóstico destes parasitas.
ABSTRACT - Aelurostrongylus abstrusus and Angiostrongylus vasorum (Nematoda: Angiostrongylidae) infection in cats and dogs from Lisbon, Portugal - The number of cat and dog lungworm reported cases has increased in various geographic areas, including Europe. Aelurostrongylus abstrusus and Angiostrongylus vasorum assume special importance in cats and dogs, respectively. Both cause verminous pneumonia, with different levels of severity, but the infection by A. vasorum may also result in neurological and coagulation problems. Several studies have been conducted in order to determine their prevalence, which seems to be underestimated in many countries. This study aimed to assess the epidemiological situation of A. abstrusus and A. vasorum in cats and dogs in the Lisbon area. A research was performed in 100 samples (50 cats and 50 dogs), mostly fecal, but also from lungs of necropsied animals. All samples were screened with Baermann technique, currently considered the gold standard in their diagnosis. L1’s detection and identification was based on their morphology. The results showed a prevalence of 12% (6/50) for A. abstrusus in cats and 2% (1/50) for A. vasorum in dogs. These data emphasize the presence of A. abstrusus and A. vasorum, respectively in cats and dogs in the Lisbon area, Portugal. Therefore, it should be taken into consideration for veterinarians in clinical practice, as the routine use of Baermann’s technique for the diagnosis of these parasites.

Dissertação de Mestrado Integrado em Medicina Veterinária
Os metastrongilídeos pulmonares são nemátodes com um ciclo de vida indireto dada a existência de hospedeiros intermediários e hospedeiros paraténicos. As formas adultas habitam no aparelho respiratório dos hospedeiros definitivos, os felídeos domésticos e selvagens. A aparente dispersão geográfica em território europeu associada ao aumento crescente do número de casos publicados tem despertado o interesse dos parasitologistas e médicos veterinários. O metastrongilídeo pulmonar da espécie Aelurostrongylus abstrusus é o de maior importância clínica nos gatos domésticos (Felis silvestris catus), no entanto, as espécies Troglostrongylus brevior, Troglostrongylus subcrenatus, Oslerus rostratus e Angiostrongylus chabaudi também podem afetar estes felídeos. O presente rastreio parasitológico teve como objetivo primordial avaliar a prevalência de infeção por metastrongilídeos pulmonares através da técnica de Baermann, numa amostra de 103 gatos domésticos residentes na Área Metropolitana de Lisboa e acompanhados no Hospital Escolar Veterinário da Faculdade de Medicina Veterinária da Universidade de Lisboa. A única espécie de metastrongilídeo pulmonar detetada foi A. abstrusus com uma prevalência aparente de 4,9% (IC 95% [2,1 – 10,9%]). Os gatos diagnosticados com infeções por A. abstrusus não manifestavam sinais clínicos compatíveis com a infeção parasitária, o que demonstra a dificuldade em estabelecer um diagnóstico clínico e a importância de incluir a técnica de Baermann nos testes coprológicos de rotina. O tratamento destes gatos é importante para quebrar o ciclo biológico do parasita, evitando que se tornem fontes de contaminação ambiental e, consequentemente, fontes de infeção para os hospedeiros intermediários. Durante o rastreio também foram detetadas formas de parasitas gastrointestinais através de uma técnica de flutuação com solução saturada de sacarose, nomeadamente Ancylostoma sp. (5,8%; IC 95% [2,7 – 12,1%]), Toxocara cati (3,9%; IC 95% [1,5 – 9,6%]), Cystoisospora felis (2,9%; IC 95% [1,0 – 8,2%]) e Cystoisospora rivolta (1,9%; IC 95% [0,5 – 6,8%]). Os responsáveis pelos gatos incluídos no rastreio foram sujeitos a um questionário que, entre outras informações, permitiu avaliar os hábitos de desparasitação interna. Apesar de 74,8% (77/103) dos gatos da amostra terem sido desparasitados internamente, a maioria não fazia profilaxia com anti-helmínticos que atuassem nos metastrongilídeos pulmonares. Apesar da prevalência de A. abstrusus verificada neste rastreio ser considerada relativamente baixa, este parasita não deverá ser subestimado na prática clínica devido ao seu caráter emergente na região mediterrânica e ao seu potencial patogénico nos gatos domésticos.
ABSTRACT - Survey of metastrongyloid lungworms in domestic cats (Felis silvestris catus) from the metropolitan area of Lisbon, Portugal - Metastrongyloid lungworms are nematodes with an indirect life cycle given the existence of intermediate hosts and paratenic hosts. The adult worms live in the respiratory system of definitive hosts, the domestic and wild felids. The apparent geographic spread in the european territory associated with an increased growth of published cases has aroused interest in parasitologists and veterinarians. The metastrongyloid lungworm Aelurostrongylus abstrusus is the specie with the most clinical importance in domestic cats (Felis silvestris catus), however, the species Troglostrongylus brevior, Troglostrongylus subcrenatus, Oslerus rostratus and Angiostrongylus chabaudi can also affect these felids. This parasitological survey aimed to evaluate the prevalence rate of infection by metastrongyloid lungworms, using the Baermann technique, in a sample of 103 domestic cats residents in the metropolitan area of Lisbon and attended in the Small Animal Hospital of the Faculty of Veterinary Medicine, University of Lisbon. The only species of metastrongyloid lungworms detected was A. abstrusus with an apparent prevalence rate of 4.9% (IC 95% [2.1 – 10.9%]). Cats diagnosed with A. abstrusus infection were subclinical parasite carriers which demonstrates the difficulty on stablishing a clinical diagnosis and the importance of regular faecal examinations, including the Baermann technique. The treatment of these cats is important to interrupt the parasite’s life cycle, avoiding them to become sources of environmental contamination and, consequently, sources of infection to intermediate hosts. During the survey were also detected forms of gastrointestinal parasites through a faecal flotation technique with saturated sugar solution, such as Ancylostoma sp. (5.8%; IC 95% [2.7 – 12.1%]), Toxocara cati (3.9%; IC 95% [1.5 – 9.6%]), Cystoisospora felis (2.9%; IC 95% [1.0 – 8.2%]) and Cystoisospora rivolta (1.9%; IC 95% [0.5 – 6.8%]). The cat’s owners included in this survey also answered a questionnaire which, among other questions, allowed the evaluation of their parasitic control measures. Although 74.8% of the cats were dewormed, the majority didn’t do prophylaxis using anthelmintics with efficacy on metastrongyloid lungworms. Although the prevalence rate of A. abstrusus detected in this survey can be considered relatively low, this parasitic disease should not be underestimated at clinical practice level due to its emergent scenario on Mediterranean region and pathogenic potential in domestic cats.

Quantitative methods for taking sediment, soil, and litter samples, together with the different approaches and apparatus to extract the animals, are described. Mechanical methods discussed include wet and dry sieving, flotation, and elutriation. Behavioural or dynamic methods such as Berlese and Baermann funnels are described. Chemical and electrical methods to drive animals from cover are described, and the efficiency of the different extraction techniques is reviewed.