McMaster Egg Counting Technique Research Articles

Satureja hortensis L. and Calendula officinalis L., Two Romanian Plants, with In Vivo Antiparasitic Potential against Digestive Parasites of Swine.

Internal parasitic diseases of swine constitute a major welfare and health concern in low-input livestock farming. Due to an increase in chemical resistance, phytotherapeutic remedies have become an alternative for the prophylaxis and therapy of digestive parasitosis, albeit few remedies have been subjected to scientific validation. Low-input swine farming in Romania has adopted the traditional use of phytotherapy for controlling pathogens in livestock. The current study aimed to assess the antiparasitic potential of Calendula officinalis and Satureja hortensis against digestive parasites of swine in two low-input farms. The fecal samples were collected from sows, fatteners, and weaners, and were tested using the following coproparasitological methods: centrifugal sedimentation, flotation (Willis, McMaster egg counting technique), Ziehl-Neelsen stain modified by Henricksen, modified Blagg method, and in vitro nematode larvae/protozoan oocyst cultures. Six species of digestive parasites were diagnosed, namely Ascaris suum, Trichuris suis, Oesophagostomum spp., Balantioides coli, Eimeria spp., and Cryptosporidium spp., in various combinations, dependent on the swine category. A dose of 140 mg/kg bw/day of C. officinalis and 100 mg/kg bw/day of S. hortensis powders administered for 10 consecutive days revealed a strong antiprotozoal and anthelmintic activity on the aforementioned parasites. The curative efficacy can be attributed to the presence of polyphenols, sterols, tocopherols, and methoxylated flavones. In conclusion, our results indicate that S. hortensis and C. officinalis are promising alternatives to the commercially available antiparasitics, enabling their use as natural antiparasitic products against gastrointestinal parasites in pigs.

Anticoccidial efficacy of Garcinia kola (Heckel H.) against experimental Eimeria tenella infection in chicks.

There is a need to advance commercial poultry production to cater to the essential protein needs of an ever-increasing population, however, the rampant occurrence of coccidiosis infection poses a threat to this achievement. This study evaluated the in vivo anticoccidial activities of the extracts and fractions of Garcinia kola against experimental Eimeria tenella infection using broiler chickens as experimental subjects. A total of 40 broiler chicks were experimentally infected with E. tenella and assigned randomly into five groups consisting of eight chicks each. Three days post experimental infection groups I and II were administered orally with tween 80 (0.8%) and Amprolium (30mg/kg) and served as untreated and treated control groups, respectively whereas Groups III, IV, and V were administered orally with crude methanol extract (CME) at doses of 200, 400 and 600mg/kg, respectively, for five consecutive days. Daily weight gains were recorded and faecal oocysts per gram (OPG) counts were made by the McMaster Egg counting technique. Blood samples from each experimental group were collected on days 0, 3, 6, and 8 for haematological examination. In the acute toxicity studies, the CME of G. kola did not produce any toxic effect or mortality at doses between 10 and 5000mg/kg. The CME G. kola was then considered safe and the LD50 was assumed to be > 5000mg/kg. Graded doses of CME of G. kola considerably (P < 0.05) improved body weight gain and decreased OPG in a dose-depended manner. There was also significant improvement in the Packed Cell Volume (PCV), Red Blood Cell (RBC) and White Blood Cell (WBC) counts upon treatment with the graded doses of CME of G. kola. Besides, G. kola significantly decreased histopathological lesions in the caecum. The results of this study indicates that G. kola may provide beneficial effects against E. tenella-induced coccidiosis in broiler chickens.

A brief study on butterfly diversity in Kaptanganj block, Basti, Uttar Pradesh, India

Objective: The present study has been designed to determine the prevalence, species composition and associated risk factors with Eimeria sp. infections of cattle and buffaloes in semi-arid eastern plains of Rajasthan to establish epidemiological data which will help to formulate effective control strategies in near future.Methods: A total of 649 faecal samples were collected randomly from dairy animals of different four districts of semi-arid eastern plains of Rajasthan during summer, rainy and winter season from March 2016 to January 2017 and examined qualitatively by faecal floatation to visualize Eimeria sp. oocyst and quantitatively by modified McMaster egg counting technique. Identification of morphotypes was done using established identification keys following sporulation and micrometry.Results: An overall prevalence of 27.73% (180/649) was recorded for coccidiosis in dairy animals with a significant difference (p

Effectiveness of neem oil versus Praziquantel/Oxfendazole for treatment of endoparasites in Eared Doves (Zenaida auriculata): A randomized controlled trial

It is often difficult to control parasite loads in captive animals in zoological institutions and there is the concern of rising drug resistance. Therefore, alternatives to parasite control should be investigated. Neem fruit (Azadirachta indica) is a herb native to India and has long been used in ancient Ayurvedic medicine. It has also been noted to have anti-parasitic properties and has been used as an alternative method of combatting endoparasitism in various animals successfully. In this randomized controlled trial, the effectiveness of neem oil as a dewormer was compared to the chemical dewormer wormout gel (Vetafarm, 20 g/L Praziquantel, 20 g/L Oxfendazole) and was tested in a group of 18 eared doves (Geopelia striata). These 18 doves were randomized equally into 3 groups where one group was given neem oil daily, the second group was given wormout gel (Vetafarm, 20 g/L Praziquantel, 20 g/L Oxfendazole) once and the last group was the control group and given water daily. Faecal tests (wet mount and McMaster egg counting technique) were done by a veterinary lab technician that was blinded to the group assignment. The faecal tests were done and the weight of each bird was recorded on admission, daily during the treatment period and 1 day after the treatment was finished. The daily weights and faecal test results were recorded down and the mean parasite ova per gram of feces and mean number of days where the parasite ova count was negative were calculated for each dove. The means were analyzed and the results showed that there were no significant benefits of using neem oil as a dewormer as compared to the wormout gel. Even though there was no significant benefits of using neem oil as a dewormer as compared to wormout gel in this study, further studies should be performed on neem as a natural antiparasitic alternative as not much knowledge about neem use in birds is available.

Prevalence of gastrointestinal worms in Wonosobo and thin-tailed sheep on the slope of Mount Sumbing, Central Java, Indonesia.

Aim:This study was conducted to determine the prevalence of gastrointestinal (GI) worms in Wonosobo and thin-tailed sheep from the slope of Mount Sumbing.Materials and Methods:Fecal samples (n=305) were collected directly from the rectum of Wonosobo and thin-tailed sheep during the dry and rainy seasons in Wonosobo Regency, Central Java Province, Indonesia. The presence of GI helminth eggs in the fecal samples was assessed using the modified McMaster egg counting technique. The identification of the eggs or oocysts was done on the basis of their morphology and size.Results:The highest prevalence of GI worms was observed in male thin-tailed sheep (76.47%) during the rainy season, whereas the lowest prevalence was observed in female Wonosobo sheep (47.36%) during the dry season. The types of GI nematodes observed in these two types of sheep were Haemonchus contortus, Ostertagia spp., Trichostrongylus spp., Bunostomumspp., Trichuris spp., and Moniezia spp. The GI worms with the highest prevalence were of Haemonchus spp. and were observed in male thin-tailed sheep. The prevalences of the two types of sheep assessed at an altitude of 1150 m above sea level were higher than those observed at the altitude of 1586 m. The prevalence of clinical and sub-clinical parasites infestation in Wonosobo and thin-tailed sheep in Kwadungan village was significantly different (p<0.05).Conclusion:This study showed that two types of local sheep on the slope of Mount Sumbing are infected with various GI worms during the dry and rainy seasons. The highest prevalence of GI worms was found in thin-tailed sheep at an altitude of 1150 m above sea level during the rainy season, with H. contortus being the most prevalent GI parasites.

In vivo Efficacy of Murraya paniculata Leaf in Controlling Natural Helminthiasis in Goat

This study investigated the in vivo effect of Murraya paniculata leaf on gastrointestinal nematodes reduction, growth rates and haematological changes of goats. Four experimental groups (n = 6) of goats naturally acquired gastrointestinal nematodes were control (GI) (untreated), positive control (GII) (treated with albendazole, 6 mg/Kg BW) and GIII and GIV treated with 5 and 10 g/Kg BW of M. paniculata leaves. Fecal samples collections were performed weekly for assessment of fecal egg count. Number of nematode eggs in goat feces (egg per gram; EPG) was determined from week 0 (pre-treatment) to week 8 (post-treatment) by modified McMaster egg counting technique. EPG values of GIV goats were significantly lower than that of the controls and those receiving the albendazole (p<0.05) at week 3. GII goats showed highly effective at EPG reduction in 1-2 weeks after giving albendazole and then the efficiency decreased until the end of the experiment. The effect of M. paniculata leaves on growth rate was studied by examining goat weight on days 0, 30, 60 and 90. GIV group revealed significantly higher weight change than other groups (p<0.05). The feeding of M. paniculata leaves at different levels did not affect on haematological parameters, glucose, total protein, urea, albumin and globulin of goats. It was found that values of the haematological parameters were within the range of the standard values. Compound analysis of M. paniculata leaves revealed that M. paniculata leaves contained higher protein content than grass and the protein content was closed to the meal concentrate. This corresponds to the best growth rates of GIV goats. The results demonstrated that M. paniculata leaves reduce the gastrointestinal nematode eggs of goats efficiently, safely and environment-friendly.

Gastrointestinal Parasites in Giraffes Kept in Zoological Gardens of the Czech Republic

Abstract Parasite prevalence was investigated in giraffes (Giraffa camelopardalis) housed in six major Czech zoological gardens: Zoo Ostrava, Zoo Dvůr Králové nad Labem, Zoo Liberec, Zoo Olomouc, Zoo Praha, and Zoo Plzeň. In autumn 2012 and in spring 2013, 120 faecal samples from 21 animals were examined using the McMaster egg counting technique. Propagative stages of three parasite groups were discovered, namely eggs of the nematodes of the order Strongylida (prevalence 25.8%), whipworms Trichuris spp. (prevalence 25%), and oocysts of the unicellular coccidia of the genus Eimeria (prevalence 1.7%). The results indicate that captive giraffes in the Czech zoos are not substantially affected by parasitic infection.

English

Donkeys (Ass-Equus-assinus) and camels (Camelus dromedarius) in Uganda are mainly owned by low income earners and peasant farmers, mainly in the semi-arid North-eastern Uganda in Karamoja and Sebei sub-regions. The animals however, seem to receive little or relatively no veterinary care. This study was carried out in Moroto and Amudat districts, Karamoja sub-region, Uganda in March 2016. Faecal samples of 110 randomly selected camels and donkeys of all age and sex were collected directly from their rectum. The faecal samples were examined by flotation method, sedimentation technique, McMaster egg counting technique and faecal culture to identify and determine the burden of parasites in different age groups. Lungworms ovaculture revealed Dictyocaulus cameli (29.3%) of camels and Dictyocaulus arnfieldi (15.4%) of donkeys. Cestode eggs detection revealed family Anoplocephalidae which includes seven species of cestodes identifiable as eggs in faeces or as adults in the gastro-intestinal tract of camels (18.3%) and donkeys (15.4%). Coccidia species included Eimeria cameli (11%) and Eimeria Leuckarti (3.85%) in camels and donkeys, respectively. Trematodes were detected in 5 camels as Fasciola gigantica. Overall, EPG count was observed for strongyles at 58.5% in camels and 42.3% in donkeys.&nbsp;The results of this study will provide insights into the health of donkeys and camels in Uganda and provide a way forward to their veterinary care and management for improved production and productivity. Key words: Gastrointestinal parasites, donkey, camels, Karamoja, Uganda. &nbsp

Genetic differences in the body weight and haematological traits of Nigerian indigenous chickens infected with Eimeria tenella.

In an effort to shed more light on the tolerance of indigenous chickens to coccidiosis, we compared the body weight, faecal oocyst load and haematological parameters based on sex and genotypes of Eimeria tenella-infected chickens. Three hundred chicks from three genotypes (normal-feathered, frizzle-feathered and naked-neck) of Nigerian indigenous chickens which comprised 100 birds per genotype were raised for 6weeks. At 3weeks old, each chick was weighed and faecal, and blood samples were collected before inoculation. Subsequently, the birds were weighed and faecal samples collected at days 1, 3, 6, 9, 12 and 15 post-inoculation. Blood samples were collected from 50 chicks per genotype at 3 and 5weeks post-inoculation. Blood parameters were determined and faecal samples subjected to McMaster egg counting technique. Results showed genotype, and sex had significant effects on body weight from day 1 to 15 post-inoculation. Normal-feathered chicks had the highest body weight while frizzle-feathered chicks showed lowest body weight at post-inoculation. E. tenella was identified in caecal and lower intestinal mucosa of the genotypes, but genotype had no significant effect (p > 0.05) on the lesion score. There were no significant differences in haematological values among genotypes (p > 0.05) except for lymphocytes where naked-neck chicks had the highest lymphocytes' count (1.83 ± 0.02%), followed by normal-feathered (1.79 ± 0.02%) and the frizzle-feathered (1.68 ± 0.02%). The present values of body weight, faecal oocyst and haematological parameters obtained seemed not to be convincing enough to suggest that the genotypes were different in terms of tolerance to coccidiosis.

Prevalence of intestinal parasitism of swine in a North Central State of Nigeria

Objective: Swine production is one of the most popular and promising livestock production industries in many parts of Nigeria. It prides itself in contributing to the supplementation of the overall national protein intake, gainfully engaging the citizenry in the industry and generating foreign exchange to the nation through export of produce and products. However, the swine production industry in Nigeria faced with religious and cultural constraints as well as several infectious diseases. The objective of this study was to investigate the prevalence of intestinal parasites in swine in the North Central State of Nigeria. Materials and methods: A total of 920 pigs comprising of 874 (95%) and 46 (5%) foreign and indigenous breed of pigs respectively were investigated in this study. Quantitative Mcmaster egg-counting technique was used for counting eggs of parasites. Semi-structured questionnaires was used to generate demographic data during October 2014 to March 2015. Results: Fifty five percent pigs were found to be positive for Hyostrogylus rubidus, while Ascaris suum, Trichuris suis and other unidentified eggs were present in 23, 17 and 5% pigs, respectively. ‘Red Stomach Worm’ infection in swine was the highest parasitic burden observed as compared to other parasites. Spreading of infection within sexes had a P value of >0.5. Conclusion: The prevalence of parasites in pigs obtained in this work is a consequence of improper husbandry measures and irregular veterinary medical intervention.

Identification of human intestinal parasites affecting an asymptomatic peri-urban Argentinian population using multi-parallel quantitative real-time polymerase chain reaction.

BackgroundIn resource-limited countries, stool microscopy is the diagnostic test of choice for intestinal parasites (soil-transmitted helminths and/or intestinal protozoa). However, sensitivity and specificity is low. Improved diagnosis of intestinal parasites is especially important for accurate measurements of prevalence and intensity of infections in endemic areas.MethodsThe study was carried out in Orán, Argentina. A total of 99 stool samples from a local surveillance campaign were analyzed by concentration microscopy and McMaster egg counting technique compared to the analysis by multi-parallel quantitative real-time polymerase chain reaction (qPCR). This study compared the performance of qPCR assay and stool microscopy for 8 common intestinal parasites that infect humans including the helminths Ascaris lumbricoides, Ancylostoma duodenale, Necator americanus, Strongyloides stercoralis, Trichuris trichiura, and the protozoa Giardia lamblia, Cryptosporidium parvum/hominis, and Entamoeba histolytica, and investigated the prevalence of polyparasitism in an endemic area.ResultsqPCR showed higher detection rates for all parasites as compared to stool microscopy except T. trichiura. Species-specific primers and probes were able to distinguish between A. duodenale (19.1 %) and N. americanus (36.4 %) infections. There were 48.6 % of subjects co-infected with both hookworms, and a significant increase in hookworm DNA for A. duodenale versus N. americanus (119.6 fg/μL: 0.63 fg/μL, P < 0.001) respectively. qPCR outperformed microscopy by the largest margin in G. lamblia infections (63.6 % versus 8.1 %, P < 0.05). Polyparasitism was detected more often by qPCR compared to microscopy (64.7 % versus 24.2 %, P < 0.05).ConclusionsMulti-parallel qPCR is a quantitative molecular diagnostic method for common intestinal parasites in an endemic area that has improved diagnostic accuracy compared to stool microscopy. This first time use of multi-parallel qPCR in Argentina has demonstrated the high prevalence of intestinal parasites in a peri-urban area. These results will contribute to more accurate epidemiological survey, refined treatment strategies on a public scale, and better health outcomes in endemic settings.

A standardised faecal collection protocol for intestinal helminth egg counts in Asian elephants, Elephas maximus.

The quantitative assessment of parasite infection is necessary to measure, manage and reduce infection risk in both wild and captive animal populations. Traditional faecal flotation methods which aim to quantify parasite burden, such as the McMaster egg counting technique, are widely used in veterinary medicine, agricultural management and wildlife parasitology. Although many modifications to the McMaster method exist, few account for systematic variation in parasite egg output which may lead to inaccurate estimations of infection intensity through faecal egg counts (FEC). To adapt the McMaster method for use in sampling Asian elephants (Elephas maximus), we tested a number of possible sources of error regarding faecal sampling, focussing on helminth eggs and using a population of over 120 semi-captive elephants distributed across northern Myanmar. These included time of day of defecation, effects of storage in 10% formalin and 10% formol saline and variation in egg distribution between and within faecal boluses. We found no significant difference in the distribution of helminth eggs within faecal matter or for different defecation times, however, storage in formol saline and formalin significantly decreased egg recovery. This is the first study to analyse several collection and storage aspects of a widely-used traditional parasitology method for helminth parasites of E. maximus using known host individuals. We suggest that for the modified McMaster technique, a minimum of one fresh sample per elephant collected from any freshly produced bolus in the total faecal matter and at any point within a 7.5 h time period (7.30am–2.55 pm) will consistently represent parasite load. This study defines a protocol which may be used to test pre-analytic factors and effectively determine infection load in species which produce large quantities of vegetative faeces, such as non-ruminant megaherbivores.

Gastro-intestinal nematodes of goats reared under communal small scale farming conditions in Botswana

The study was carried out in goats reared under communal small scale farming conditions near Gaborone, Botswana, to evaluate two sample preparation methods for McMaster egg counting technique, determine worm egg counts (WEC), identify nematode genera by larval culture, and determine abomasal and intestinal worm counts. Goat faecal samples (n = 30) were collected, split, and paired for preparation by either the simple method or the standard method and WEC was performed using the McMaster technique. The simple method resulted in significantly higher WEC than the standard method (p =0.04). The WEC of a cohort of goats from Modipane communal small scale farmers (n = 30) was found to be 995±229 eggs per gram (EPG). Larval culture of Modipane herds identified Trichostrongylus spp at 86 percent and Haemonchus spp, Ostertagia spp, Oesophagostomum spp, and Chabertia spp all occurring at less than 5 % each. Abomasal worm counts of two separate groups of goats at slaughter were found to be 110 ± 28 Haemonchus spp (n = 21) and 277 ± 129 Haemonchus spp (n = 30) in goats with WEC of 836 ± 236 EPG and 642 ± 120 EPG respectively. Intestinal worms were not found in the group (n = 30) that was tested for them. It was concluded that there is a significant worm burden among goats reared under communal small scale farming conditions in Botswana. Keywords: Nematodes, McMaster technique, goats, abomasal worm count, worm burden

A Toxocara cati eggs concentration method from cats’ faeces, for experimental and diagnostic purposes

Toxocariosis is a zoonotic parasite infection worldwide distributed, now considered a neglected disease associated to poverty. For experimental infection in animals and to develop the diagnosis in humans it is necessary to obtain large number of Toxocara spp. larval eggs. Toxocara cati eggs recovered percentage from faeces of infected cats was determined employing a novel egg concentration method. The McMaster egg counting technique and the concentration method were applied on 20 positive cats’ sample faeces obtained from naturally infected cats. The mean percentage of eggs recovered by the concentration method was 24.37% higher than the count obtained by McMaster egg counting technique. The main advantage of this method is that it can be obtained a small final volume with a high number of recovered eggs and a good quality inoculum for experimental and diagnostic purposes.

Prevalence and intensity of intestinal helminths in carnivores and primates at Vakilabad Zoo in Mashhad, Iran

This study was carried out to identify intestinal parasitic helminth infection in carnivores and primates at Vakilabad Zoo in Mashhad. In a cross-sectional study from June 2012 to September 2012, a total of 47 fresh faecal samples were collected and examined using sedimentation and flotation tests and the McMaster egg counting technique. Amongst the infected animals, both carnivores and primates demonstrated multiple infections with more than one helminth parasite. The genera detected in carnivores were Toxocara (75 %), Toxascaris (90.6), Ancylostoma (81.25 %), Strongyloides (68.75 %) and Taenia (56.25 %). In carnivores, African lions had the highest mean intensity of parasitic infection (eggs per gram of faeces (EPG) = 134.25), and brown bears had the lowest (EPG = 0.5). All primates were infected with Hymenolepis and then Ancylostoma (66.66 %) and Strongyloides (4 %). Asian monkeys had the highest mean intensity of parasitic infection (EPG = 2.5) and the spider monkey the lowest (EPG = 0.71). In conclusion, regular monitoring of parasitic disease in zoos is necessary. Infections can be controlled by using suitable anti-helminthic therapy and management procedures.

Bovine trypanosomosis and gastrointestinal helminthosis in settlement villages of Bedele district, South-western Ethiopia

This cross-sectional study was carried out from October 2011 to March 2012 to assess the concurrent infections of bovine trypanosomosis with gastrointestinal (GI) helminthes in Peasant Associations of Bedele district settlement areas located in Illubabor Zone, Southwestern part of Ethiopia. A total of 500 randomly selected cattle were examined using Buffy Coat Technique and coprological examinations. Faecal examination was done by sedimentation and flotation techniques following the standard procedures to identify eggs of parasitic helminthes. Those faecal samples that were positive for flotation technique were subjected to eggs per gram (EPG) count using Mc Master egg counting technique and the degree of infestation was categorized as light, moderate and severe. Out of total cattle examined, 21(4.2%) were positive for Trypanosoma congolense and 321(64.2%) were found to harbor one or more gastrointestinal helminthes infection. Helminthes identified were Fasciola species (51.4%), paramphistomum species (18.7%), the protozoan Eimeria species (6.2%), Trichuris species (6.85%), Trichostrongyles (11 %) and mixed infections (6%). The overall mean PCV value recorded was 26.7±3.9 and it was 26.8±3.9 in trypanosome negative animals and 22.9±3.3 in trypanosome positive animals. The overall mean EPG recorded was 172±99.6. Among 21 cattle found positive for T. congolense, 18 (85.7%) were concurrently infected with (GI) helminthes particularly Fasciolosis (38.1%) and statistically there was significant association (P &lt; 0.05) between trypanososmosis and GI helminthes infection. Age and sex of sampled cattle were not found to influence GI helminthes prevalence (p&gt;0.05). Infection with T. congolense and Fasciola species is the most prevalent form of co-infection in cattle within study areas. In conclusion, any attempts to control or prevent trypanosomosis or GI helminthes infection through different management approaches, need to address the possibility of concurrent infections especially in trypanosomosis endemic areas to save the losses in advance.Key words: Bedele, Cattle, Concurrent, Ethiopia, GI helminthes, Trypanosomosis

Common gastrointestinal parasites of indigenous camels (Camelus dromedarius) with traditional husbandry management (free-ranging system) in central deserts of Iran

Gastrointestinal parasites of domesticated animals, especially in animals with traditional husbandry management cause reduction in production and performance of them. Aim of our study was to determine prevalence of gastrointestinal parasites in indigenous camels, with traditional husbandry management that have no direct contact with other livestock. This study was carried out between Kerman and Yazd provinces of Iran, midsummer 2011. Fecal samples of 100 randomly selected camels of all age and sex, collected directly from their rectum. The fecal samples were examined by direct smear, simple flotation technique, centrifugal sedimentation technique, and McMaster egg counting technique and fecal culture to identification and determine the burden of parasites in different age groups. Nematode eggs and Eimeria oocysts were found (64%) and (24%) in fecal samples respectively. Parasite eggs that observed in camel feces were belong to Nematodirus spp. (52%), Trichostrongyle type eggs (49%), Haemonchus spp. (38%), Trichuris spp. (14%) Marshallagia spp. (10%) and Eimeria cameli (24%), the age of infected camels with helminthic infections was significantly higher than non-infected camels (p<0.05), there was also a significant correlation between age and severity of coccidiosis (p<0.05). Camel calves and camels below 5years old were more infected with the Eimeria sp. than older ones. This study revealed gastrointestinal parasites is a major problem of indigenous camels with traditional husbandry, so parasite control programs must be established for increasing the productivity of this useful animal and industrial system for breeding camels recommended to increase productivity of them, especially where harsh climatic condition affected other livestock.

Comparison of the Kato-Katz thick smear and McMaster egg counting techniques for monitoring drug efficacy against soil-transmitted helminths in schoolchildren on Pemba Island, Tanzania

The Kato-Katz thick smear technique is widely used to assess prevalence and intensity in soil-transmitted helminth (STH) control programmes, but its usefulness in monitoring anthelminthic drug efficacy needs to be validated and compared with other methods. A promising alternative is the McMaster egg counting technique. In the present study, the efficacy of single-dose albendazole against STH infections in 430 schoolchildren on Pemba Island was assessed using both the Kato-Katz and McMaster techniques. The study revealed comparable drug efficacy results for both methods and confirmed the potency of the McMaster technique as an alternative method for monitoring large-scale deworming programmes.

Which McMaster egg counting technique is the most reliable?

This study focuses on the comparison of three selected modifications of the McMaster counting technique, namely the McMaster method modified by Wetzel (W) and Zajíček (Z), as well as the concentration McMaster technique according to Roepstorff and Nansen (R&N). These modifications differ in the weights of faeces examined (W, 2 g/Z, 1 g/R&N, 4 g), flotation solutions (W, NaCl/Z, MgSO(4) + Na(2)S(2)O(3)/R&N, NaCl + glucose), centrifugation (W, none/Z, 2,000 RPM for 2 min and 2,000 RPM for 1 min/R&N, 1,200 RPM for 5 min), number of McMaster chambers investigated (W, 3/Z, 2/R&N, 2), and multiplication factors used (W, 67/Z, 33/R&N, 20). To investigate the sensitivity and reliability of these methods, nematode eggs (Teladorsagia circumcincta) were used. Parasite elements are distributed through negative binomial distribution in naturally infected host faeces, and the number of parasite elements in a given amount of faeces sample is unknown to man. Therefore, we decided to prepare the exact number of eggs which were added to the parasite negative faeces; the faecal sample was then investigated. From this perspective, this is the first time a comparison of the McMaster methods has been so accurately investigated. This approach allows us to evaluate the real sensitivity and reliability of the tested method. As the findings of this study indicate, the highest sensitivity and reliability were obtained using the Roepstorff and Nansen modification. This McMaster modification is able to detect 20 eggs per sample (in 70% of samples). Concentrations of 200 and 500 eggs can be found in almost 100% of samples. Moreover, this method is simple, cheap and fast. For these reasons, we can recommend this method for routine veterinary practice.

Assessment of the Anthelmintic Efficacy of Albendazole in School Children in Seven Countries Where Soil-Transmitted Helminths Are Endemic

BackgroundThe three major soil-transmitted helminths (STH) Ascaris lumbricoides, Trichuris trichiura and Necator americanus/Ancylostoma duodenale are among the most widespread parasites worldwide. Despite the global expansion of preventive anthelmintic treatment, standard operating procedures to monitor anthelmintic drug efficacy are lacking. The objective of this study, therefore, was to define the efficacy of a single 400 milligram dose of albendazole (ALB) against these three STH using a standardized protocol.Methodology/Principal FindingsSeven trials were undertaken among school children in Brazil, Cameroon, Cambodia, Ethiopia, India, Tanzania and Vietnam. Efficacy was assessed by the Cure Rate (CR) and the Fecal Egg Count Reduction (FECR) using the McMaster egg counting technique to determine fecal egg counts (FEC). Overall, the highest CRs were observed for A. lumbricoides (98.2%) followed by hookworms (87.8%) and T. trichiura (46.6%). There was considerable variation in the CR for the three parasites across trials (country), by age or the pre-intervention FEC (pre-treatment). The latter is probably the most important as it had a considerable effect on the CR of all three STH. Therapeutic efficacies, as reflected by the FECRs, were very high for A. lumbricoides (99.5%) and hookworms (94.8%) but significantly lower for T. trichiura (50.8%), and were affected to different extents among the 3 species by the pre-intervention FEC counts and trial (country), but not by sex or age.Conclusions/SignificanceOur findings suggest that a FECR (based on arithmetic means) of >95% for A. lumbricoides and >90% for hookworms should be the expected minimum in all future surveys, and that therapeutic efficacy below this level following a single dose of ALB should be viewed with concern in light of potential drug resistance. A standard threshold for efficacy against T. trichiura has yet to be established, as a single-dose of ALB is unlikely to be satisfactory for this parasite.Trial RegistrationClinicalTrials.gov NCT01087099