Gastrointestinal nematodes and mineral deficiencies in yearling cattle in Santiago del Estero, northern Argentina.

The aims were to study the epidemiology and the effect of gastrointestinal nematodes (GINs) on yearling cattle in a semiarid region in Argentina and to evaluate the mineral serum levels. Ten- to twelve-month-old calves were monitored between November and April 2019. Animals were divided into three groups: untreated control (CONG; n = 20); group treated with moxidectin (MXD, 200 µg/kg) every 30-40 days (MXDG; n = 20); group equally MXD treated and mineral supplementation administered in November and January (MMG; n = 20). Individual GIN egg counts (epg) and fecal cultures were made every 30-40 days. Animal live weight gain was determined. On 7-11-18, 25-1-19, and 3-4-19, serum levels of Se, Cu, Zn, Mg, and Ca were determined by atom absorption spectrophotometry. At the start of the trial, epg values were low (x̄ = 5.5), which increased only in CONG towards the end of the assay (x̄ = 229). In both GMXD and MMG, epg remained very low (x̄ = 4.1). Cooperia spp. (81%) prevailed over Haemonchus spp. (9%) and Oesophagostomum spp. (9%). Deficiency of Se ranged between marginal and important, except for MMG, although mean values were always below normal. Cu was marginally deficient in CONG and MXDG on the first two sampling dates, whereas MMG had normal values after treatment. Mg had low values in the three groups (x̄ = 1.5 mg/dl), whereas Ca and Zn exhibited normal values. Live weight gain (LWG) was higher in MMG than in MXDG, with significant differences (p < 0.05) by mid-January and then, when epg increased, dewormed groups showed higher LWG (p < 0.034) than CONG. A negative effect of GINs on LWG was observed, as well as low to marginal levels of Se, Cu, and Mg.

Gastro-intestinal parasitism and control practices in dairy cattle in North-west Cameroon (Central Africa).

PURPOSE: The main objective of this study was to assess the gastrointestinal parasitism in relation with the worm control practices (WCP) in dairy cattle in areas of major importance for dairy/milk production of Cameroon. METHODS: Fresh fecal samples were randomly collected from 402 cattle from August to October 2016 in North West Cameroon, and analyze using the McMaster technique. Data on WCP were collected using a questionnaire. RESULTS: A total of 11 parasites species were identified: Trichostrongylus sp. (5.97%); Oesophagostomum sp. (5.47%); Haemonchus sp. (2.48%); Bonostomum sp. (1.74); Cooperia sp. (1.49%). Toxocara sp (0.24%); Ostertagia sp. (0.50%); Nematodirus sp. (0.74%); Trichuris sp. (0.50%); Moniezia sp. (0.50%); Eimeria sp. (0.50%). The mean individual parasite load for helminthes and protozoa ranged from 100 to 400 eggs per gram of feces (epg) and 333-400 oocysts per gram of feces (opg), respectively. Most farmers (95.12%) used conventional drugs (Albendazole, Doramectin, Fenbendazole, Ivermectin.) to deworm animals as compared with traditional phytotherapy (e.g., Carica papaya leaves) (4.88%). The mean epg/opg in animals treated with conventional drugs was significantly higher (p < 0.05) than in those receiving traditional treatment. Animals treated less than four times a year with conventional drugs had the highest (p < 0.05) mean epg/opg compared with animals treated four to six times a year. CONCLUSION: This study suggests that treating at least four times a year with conventional drugs, and at least two times a year with traditional approaches could help reducing GIP burden in dairy cattle in North West Cameroon. Since the majority of farmers use conventional drugs, it is imperative for them to appropriately use these conventional drugs for a better control of GIP on their farms.

Comparison of the efficacy of crude methanolic extracts of Cassia occidentalis and Euphorbia hirta with levamisole-HCL against gastrointestinal nematodes of economic importance to goat production in Uganda.

Natural compounds from medicinal plants provide safe and sustainable alternatives to synthetic anthelmintics. In this study, we assessed in vitro and in vivo anthelmintic activity of Cassia occidentalis (NH-A) and Euphorbia hirta (NH-B) and compared it with levamisole-HCl. The shoots of NH-A and whole plant of NH-B were used to prepare extracts using 70% methanol which were used in the in vitro and in vivo assays. In vitro assays of crude methanolic extracts (CMEs) of NH-A and NH-B on larvae of mixed gastrointestinal nematodes (GINs) of goats revealed mortalities of 95.7% (at 100 mg ml-1) and 98.1% (at 50 mgml-1) 24 h postexposure. In vivo assays of NH-A administered orally at doses of 100, 300, 900, and 2700 mg kg-1 bwt revealed dose- and time-dependent anthelmintic effects in goats experimentally infected with mixed species of GINs. NH-B exhibited similar properties when administered at doses of 50, 100, 200, and 400 mg kg-1 bwt. Both NH-A (900 mg kg-1 bwt) and levamisole (7.5 mg kg-1 bwt) achieved a 100% reduction in fecal egg count per gram (EPG) on day 21 and day 14 respectively posttreatment. NH-B (400 mg kg-1 bwt) achieved 93.1% and 86.1% reduction in fecal EPG 7 and 14 days postexposure respectively compared with 88.2% and 82.3% reduction with levamisole-HCl 7 and 14 days postexposure. Our results show that extracts of both plants can disrupt helminth lifecycles by suppressing the egg-laying capacity in adult worms but also kill their infective larvae. Future studies should aim at establishing synergies or antagonisms between the two plant extracts and further development for control of helminths in goats.

Effects of anthelmintic treatment and feed supplementation on parasite infections and morbidity parameters in Cambodian cattle.

Helminth infections are the cause of morbidity in Cambodian cattle but other factors such as nutritional deficiencies and concurrent diseases may enhance the effects of parasites. The present study aimed to investigate the impact of anthelmintic treatment, feed supplementation, or both on gastrointestinal strongyle (GIS) and trematode infections as well as on morbidity parameters in Cambodian village cattle. At the beginning of the dry season, cattle populations in six villages were randomly assigned to a group: (A) receiving anthelmintic treatment (ivermectin+clorsulon) at week 0; (P) feed pellet supplementation during week 0-13 or both (AP). On five visits (week 0-29), faecal and blood samples were obtained for parasitological examination and haematocrit determination, respectively. Body condition (BCS), hind quarter fouling (HQFS), diarrhoea (DS), and conjunctiva colour (FAMACHA©) were scored and heart girth circumference was determined. To investigate the impact of treatment over time (week 0-29), a mixed model was used with treatment, time, and their interaction as fixed effects, and animal and village as random factors. At baseline, the proportion of GIS positive animals was high (67.9%), whereas trematode infections were low (Paramphistomum: 8.8%; Fasciola: 2.6%). Very thin to emaciated cattle (BCS 1-2) were more prevalent (11.4%) and FAMACHA© scores of ≤3 or below (65.8%) less prevalent than in an earlier study in the region. A Time ⨯ Treatment interaction was present for faecal egg counts (FEC) of GIS, GIS prevalence (both p<0.0001), PCV (p=0.0034), DS (p=0.0086) and HQFS (p=0.0241). For GIS FEC, treatment groups differed at a specific time point, with levels of treatment group P being higher than in A at week 6 (p=0.0054). For Paramphistomum prevalence as well as FAMACHA© scoring, heart girth and BCS, the interaction between treatment and time was not significant, yet, time in itself had a significant impact on all (p<0.0001). The beneficial effects of protein supplementation were unclear from the current study.

The potential of Nigerian bioactive plants for controlling gastrointestinal nematode infection in livestock.

Bioactive compounds from marine and terrestrial organisms have been used extensively in the treatment of many diseases in both their natural form and as templates for synthetic modifications. This review summarizes present knowledge about anthelmintic effects of the extracts of bioactive plants in Nigeria against helminth parasites of ruminants. Plants traditionally used in livestock production are discussed. The main focus is hinged on in vitro and in vivo activities of secondary plant metabolites against nematodes of livestock. This review provides insight into preliminary studies of medicinal plants, which can be investigated further to discover promising molecules in the search for novel anthelmintic drugs and nutraceuticals.

Cluster-randomised trial of the impact of school-based deworming and iron supplementation on the cognitive abilities of schoolchildren in Sri Lanka's plantation sector.

OBJECTIVE: To assess the impact of deworming and iron supplementation on the cognitive abilities and educational achievement of school-age children in Sri Lanka. METHODS: Prospective, placebo-controlled randomised study. The treatment group received deworming and weekly iron supplementation for 6 months; the control group received placebo for both the anthelmintic and iron. A mixed effects regression model was used to answer the main research question. To increase the precision of this study's estimates, various background variables were controlled for that were not related to treatment but could have some impact on the outcome. RESULTS: The prevalence of soil-transmitted helminth (STH) infection was reduced in the treatment group (n = 615), with significant differences between treatment and control groups (n = 575) in the levels of Ascaris and Trichuris. No impact was found on haemoglobin (Hb) levels, nor any significant impact on concentration levels or on educational test scores. CONCLUSION: Decline in STH prevalence alone, in the absence of improved Hb status, produced no evidence of impact on concentration levels or educational test scores.

Gastrointestinal nematodes of moose (Alces alces) in relation to supplementary feeding.

Winter supplementary feeding of wildlife is controversial because it may promote parasite and disease transmission by host aggregation. We investigated the effect of winter supplemental feeding of Scandinavian moose (Alces alces) on gastrointestinal (GI) parasite infection in two counties of southern Norway by comparing fecal egg counts of moose using, and not using, feeding stations between January 2007 and March 2010. We identified three different GI nematodes based on egg morphology. All three were found in Hedmark county while in Telemark county we found only Trichuris sp. (prevalence 33%). Prevalence of Trichostrongylidae (65%) and Nematodirus sp. (26%) in Hedmark was not affected by feeding station use. However, the probability of infection varied significantly between years sampled (Trichostrongylidae) and age class (Nematodirus sp.). Fecal egg counts (FEC), a proxy for intensity of infection, of Trichostrongylidae were higher in the year when winter weather conditions were more challenging and prevalence was higher, and decreased with increasing body mass. Adult moose had higher FECs than did juvenile moose, and female juveniles had lower abundances than did male juveniles. Use of feeding stations did not affect probability of infection with any of the nematodes or intensity of infection with Trichostrongylidae. We discuss our findings in terms of parasite life histories and recommend that parasitologic surveillance be included in the monitoring of feeding programs.

[Effect of mass chemotherapy in late stage of soil-borne nematodiasis control].

OBJECTIVE: To evaluate the effects and influencing factors of mass chemotherapy in the late stage of soil-borne nematodiasis control so as to provide the evidence for the development of control programs. METHODS: Six villages were divided into three groups: the target chemotherapy, the selective chemotherapy and the control. By observation in three consecutive years, the indexes, mass infection rates, infection degrees and re-infections of soil-borne nematodes, were compared among the 3 groups. The influencing factors were also analyzed. RESULTS: The population infection rates of soil- borne nematodes decreased by 85.94%, 43.10% and 20.87%, respectively, in the three groups after chemotherapy compared with those before the intervention. A higher hookworm infection rate appeared and the chemotherapy effect was impacted in the target chemotherapy group, as some key population applied fresh human waste in vegetable plots. The re-infection rate was 16.65 times of the new infection rate. CONCLUSIONS: Chemotherapy is still useful in the late stage of soil-borne nematode control. It is more important to enhance management of using manure and health education on focus population.

Association between nematode larvae and "low worm egg count diarrhoea" in sheep in Western Australia.

Nine flocks of sheep with a high prevalence (>30%) of diarrhoea and severe breech faecal soiling were investigated over a three-year period to examine the causes of diarrhoea in sheep with low mean faecal worm egg counts (WEC). All nine flocks were located in the southwest of Western Australia in areas with a winter rainfall pattern (Mediterranean climate). There was no difference (p=0.304) in WEC of diarrhoeic sheep (loose faeces and severe breech faecal soiling) and "normal sheep" (pelleted faeces and mild or no breech faecal soiling). Teladorsagia (Ostertagia) circumcincta and Trichostrongylus spp. were the nematodes most commonly identified by total worm counts and differentiation of larvae recovered from faeces and pasture. Larval stages of strongyle worms accounted for the largest proportion of total worm counts in both diarrhoeic and normal sheep. Adult worm burdens were small in most sheep. Diarrhoeic sheep had higher numbers of fourth stage larvae than normal sheep (p=0.046). There was no histopathological evidence of bacterial or viral causes of diarrhoea in any of the flocks or bacteriological evidence of bacterial infections associated with diarrhoea. Two flocks had marginal selenium glutathione peroxidase (selenium) levels. One flock was diagnosed with helminthosis based on rising WEC and high total worm counts. Larval hypersensitivity diarrhoea, nutritional factors or a combination of these two factors were the most likely causes of diarrhoea in the other eight flocks based on exclusion of other known causes of diarrhoea. Treatment with moxidectin and an ivermectin controlled-release capsule did not change faecal moisture content of treated sheep compared to untreated sheep three to five weeks after treatment. The findings suggest that the immune response to strongyle larvae may explain some cases of low WEC diarrhoea observed during winter-spring in immunocompetent mature sheep grazing in Mediterranean environments.

The effect of long-term feeding of fresh and ensiled cassava (Manihot esculenta) foliage on gastrointestinal nematode infections in goats.

The benefit of long-term feeding of fresh or ensiled cassava foliage on gastrointestinal parasite in goats was evaluated. Eighteen male goats (15.15 +/- 2.83 kg and between 4-6 months) were randomly allocated into three treatments supplemented with 200 g of wheat bran head(-1) day(-1). All groups were fed ad-libitum on either grass (CO), fresh cassava (CaF) or ensiled cassava foliage (CaS). At the beginning of the trial, each goat was inoculated with 3000 L3 containing approximately 50% Haemonchus contortus. Individual LWt, FEC and PCV were measured at weekly intervals for 10 weeks. At the termination of the experiment all goats were slaughtered for worm recovery and enumeration. The goats in CaF and CaS had similar weight gains while those in CO lost weight (p < 0.05) through the trial. FEC in CaF and CaS were lower (p < 0.05) than CO during the patency of parasite infections, but there was no difference between CaF and CaS goats. PCV of all groups decreased from above 30% to around 25% at the end of the trial. The compositions of established worm burdens were mainly H. contortus (19-40%) and Trichostrongylus colubriformis (55-76%). TWB did not differ among the groups, however, CaS significantly reduced H. contortus burdens, as compared to CaF and CO (p < or = 0.005). Thus, ensiled cassava foliage reduced the H. contortus population while the fresh foliage only reduced worm fecundity.

Livestock disease threats associated with intensification of pastoral dairy farming.

This paper provides an overview of the changes in the pasture-based dairy systems of New Zealand and Australia that may influence the health of cattle. There are relatively few available data that can be used to quantify the effects of increased intensification of milk production on the health of cattle. There is evidence that increased production increases the risk of mastitis and culling for udder health. Increased risks of mastitis with treatment with somatotropin support these findings; however, the risk of mastitis may decrease with increased milking frequency. Larger herds with greater stocking density should increase the risk for infectious disease, but evidence to support this contention is sparse. Very intensive grazing patterns associated with higher grass yields achieved using better cultivars and greater use of fertilisers favour nematode parasites. There is some evidence of anthelmintic resistance in both nematodes and liver fluke. Veterinarians will need to be aware of the potential for these to reduce the productivity of cattle. There have been benefits of improved nutrition on the efficiency of energy use for dairy production. Diseases such as bloat and ketosis appear to be of lower prevalence. It also appears that mineral nutrition of pasture-fed cattle is being better addressed, with gains in the control of milk fever, hypomagnesaemia and trace-element deficiencies. However, acidosis is a condition with a high point prevalence in pasture-based dairy systems where cows are fed supplements; one study in Australia found a point prevalence of approximately 11% of cows with acidosis. There is evidence from this study that the neutral detergent fibre (NDF) in pasture-based diets may need to be higher than 30% of the diet to maintain rumen stability. Laminitis and acidosis are different conditions with a similar pathogenesis, specifically highly fermentable diets. The prevalence of lameness was 28% in herds in Australia, suggesting that this condition must be a focus for preventive medical approaches, including the design of laneways, feed pads and dairies.

Anthelmintic efficacy and dose determination of Albizia anthelmintica against gastrointestinal nematodes in naturally infected Ugandan sheep.

Weight loss, stunted growth, and death caused by gastrointestinal parasites are major constraints to livestock productivity, especially in tropical and developing countries where regular use, and misuse, of anthelmintics has led to nematode resistance. Albizia anthelmintica Brong. (Fabaceae) is traditionally employed throughout East Africa to treat helminth parasitosis in livestock. Reported efficacy has varied from 90% against mixed nematodes to just 19% against Haemonchus contortus alone. The objective of this study was to assess the anthelmintic effect of A. anthelmintica against naturally occurring infections of mixed gastrointestinal parasites, and to establish an effective treatment dose, in sheep under pastoral field conditions of northern Uganda. A. anthelmintica bark was collected and prepared according to local custom and packed into gel capsules. Fifty-five young female local mixed-breed lambs were randomly assigned to six groups, including a positive control group that received levamisole (synthetic anthelmintic) and a negative control group that received no treatment. Following the World Association for the Advancement of Veterinary Parasitology (WAAVP) dose determination guidelines, the other four groups were treated with varying doses of A. anthelmintica. Statistical analyses (using generalized linear models) were performed to assess treatment effect. There was a significant treatment (group) effect on parasite egg/oocyte counts per gram (EPG) for nematodes, but not for coccidia. The most effective dose against nematodes (0.8g, 58.7mg/kg) closely approximates what is usually given by traditional healers, 0.9g/adult sheep. It provided major and significant reduction in EPG as compared to the negative control. Anthelmintic efficacy was estimated using percent faecal egg count reduction (FECR). Other than the positive control, animals in the standard dose group showed the greatest decline in shedding of nematode eggs, with an FECR of 78%. This study indicates that A. anthelmintica holds potential as part of an integrated management plan for the control of helminths in developing countries.

The effects of short-term feeding of fresh cassava (Manihot esculenta) foliage on gastrointestinal nematode parasite infections in goats in Cambodia.

The antiparasitic effect of cassava (Manihot esculenta Crantz) was tested in goats artificially infected with gastrointestinal parasitic nematodes. Each experimental group consisted of 6 pen-fed goats kept on a slatted floor. The treatments compared were: 1) controls fed grass only, 2) cassava replaced grass for 3 weeks from the commencement of larval dosing period, and 3) cassava replaced grass for 3 weeks after the worm infection was patent. A total of 2000 mixed-species infective nematode larvae (L3) were administered to each goat in four doses of 500 L3/day, commencing 5 weeks after removal of previously acquired infections with ivermectin. The faecal egg counts (FEC) reduced in both cassava fed groups during the time of feeding, compared to the controls. Although, FEC increased differently with time (P < 0.05), total adult worm burdens at slaughter (week 15) were not different between the treatment groups. No differences in live weight gain, or packed cell volume, between treatments were found. Whilst these results show limited evidence of an anthelmintic effect of cassava in the diet, they do suggest that feeding, or supplementation, of cassava over an extended period may prove beneficial.

The effect of iron fortification and de-worming on anaemia and iron status of Vietnamese schoolchildren.

Previous data from Vietnam show that anaemia is highly prevalent among schoolchildren, who are considered not to be iron deficient. Trichuris infection doubled the risk of anaemia. The present study aimed to evaluate the hypothesis that de-worming is more effective than iron fortification in an anaemic, infection-prone population. In a trial with a 2 x 2 factorial design, 425 anaemic children aged 6-8 years were randomly assigned to receive either iron-fortified noodles or placebo, and mebendazole or placebo. Outcomes considered were change in haematological indicators of iron status (Hb, serum ferritin (SF), serum transferrin receptor (TfR) and haemoglobinopathies analysis); inflammations (C-reactive protein (CRP)); parasite infection status (hookworm, Trichuris and Ascaris infection); and IgE. ANOVA and logistic regression were used to assess the effects of iron fortification and de-worming on Hb, SF, TfR, body iron and anaemia. Hb improved in all groups after 6 months of intervention. Iron fortification significantly improved Hb, SF and body iron (2.6 g/l, 16.3 microg/l and 1 mg/kg, respectively). Prevalence of elevated IgE was very high at baseline (99%) and significantly reduced to about 75% in all groups after intervention. De-worming unexpectedly showed no effect on Hb, iron status and IgE level. It is concluded that iron fortification slightly improved anaemia and iron status in anaemic schoolchildren in rural Vietnam that were not considered iron deficient. Chronic infection or other unidentified factors may play an important role in the seasonal reduction of anaemia seen in all treatment groups.

Microorganisms and parasites in chronic infective diarrhea.

AIM: To reveal the pattern of microorganisms in chronic infective diarrhea cases. METHODS: We examined all patients suffering from chronic infective diarrhea over a six year period The patients were examined physically and at the same time laboratory tests,colon enema X-ray and colonoscopy, ileoscopy, upper GI endoscopy and small bowel X-ray were performed. RESULTS: We found 138 (66. 7%) chronic infective diarrhea from 207 chronic diarrhea patients. Parasitic causes were Candida albicans (48.55%), Blastocystis hominis (6.52%), Entamoeba histolytica (3.62%), and Giardia lamblia (3.62%) etc. Bacterial causes were Pathogenic E. coli(34.78%), Aerobacter aerogenes (3.62%), Mycobacterium tuberculosis (3.62%), Geotrichum (1.45%), Shigella sonnei(0. 72%), Salmonella paratyphi (2.89%)etc. CONCLUSION: The most frequent microorganisms and parasites found in chronic infective diarrhea were pathogenic E.coli and Candida albicans.

Effect of urea-molasses block supplementation on grazing weaner goats naturally infected with gastrointestinal nematodes.

The influence of feeding urea-molasses blocks (UMB) on growth and gastrointestinal (GI) nematode parasitism of weaner goats grazing the same pasture was investigated on a farm in Nyandarua District, Kenya. Thirty female Small East African goat kids at an average age of 5 months were initially treated with albendazole orally (5 mg kg(-1) body mass) and randomly assigned into one of two groups: group I were fed UMB prepared using a cold process and group II kids (controls) received no block supplementation (NBS). The UMB were given in the evening when the animals returned from grazing and were consumed during the night at a rate of 95.0 g head(-1) day(-1). Supplementation was undertaken for 3 consecutive months from July to September 2001 and January to March 2002. Body mass of the kids and faecal egg counts were measured monthly and larval cultures were performed on positive faecal samples of kids of each group. Five goats from each group were randomly selected for slaughter and total counts and identification of worms at the end of June 2002. Significant differences (P < 0.05) were found in cumulative mass gains of kids in group I from September compared with those in group II. On termination of the study kids in group I had gained an average of (+/- SD) 20.4 +/- 1.4 kg while those in group II had gained 11.8 +/- 1.1 kg. From January 2002, faecal egg counts of the kids in the UMB group differed significantly (P < 0.05) from those of the NBS group and at slaughter, the mean (+/- SD) worm counts for the UMB group was 482 +/- 299 while that of the NBS group was 1 302 +/- 410. In all the goats, Haemonchus contortus was the predominant nematode recovered. These results indicate that UMB had significant effects in the control of GI nematode parasitism and enhanced growth of the young goats.

Impact of mass chemotherapy on the morbidity due to soil-transmitted nematodes.

This review summarises current knowledge of the ill-effects of soil-transmitted helminthiasis and takes a detailed look at studies that have been published over the past decade describing the effect of mass anthelminthic use on the health of endemic communities. Mass chemotherapy appears to give maximal returns in terms of improved health in areas where hookworm is a major problem and albendazole is used regularly, along with iron supplements; in children it improves physical growth and iron stores, and in pregnant women it reduces the prevalence of iron-deficiency anaemia. In areas where ascariasis is common, the directly attributable benefits of chemotherapy may be minimal, but it can facilitate the entry of other health care programmes in children, because deworming for ascariasis is often much desired and appreciated by the community. In areas with Vitamin A deficiency and endemic ascariasis, Vitamin A supplementation can be combined with deworming: anthelminthics do not impair Vitamin A absorption but the worms may interfere with Vitamin A uptake by reducing fat absorption. Where trichuriasis is a major problem, single dose chemotherapy may take some time to reduce prevalence, but reduction of heavy infections will reduce the incidence of Trichuris Dysentery Syndrome, probably benefit the learning abilities of affected schoolchildren, and may reduce anaemia and stunting. In general, children should be treated as early as possible, and in areas of very high prevalence, thrice-yearly mass chemotherapy probably improves health better than twice-yearly treatment.

Soil-transmitted nematode infections and mebendazole treatment in Mafia Island schoolchildren.

In August 2000, a cross-sectional study was performed to assess the prevalence and intensity of soil-transmitted nematode infections in schoolchildren on Mafia Island. Hookworm infection was widespread (72.5% prevalence) whereas Trichuris trichiura was less prevalent (39.7%) and Ascaris lumbricoides was present at a low prevalence (4.2%), mainly in urban areas. In a subsample of the study population, both Necator americanus and Ancylostoma duodenale were found, although N. americanus was more prevalent. This survey was followed by a parasitological evaluation of mebendazole treatment using a single, 500-mg dose. The data on outcome were used for comparison with those from recent studies of similar treatment regimens in the neighbouring island of Pemba, Zanzibar, where periodic chemotherapy with mebendazole to schoolchildren has been implemented as part of a helminth-control programme since 1994. A higher efficacy of mebendazole against hookworm infection was found in Mafia Island (where a cure 'rate' of 31.3% and an egg-reduction 'rate' of 78.1% were recorded) when compared with that observed in Pemba Island, possibly indicating that hookworms may be developing mebendazole resistance on Pemba Island as a result of intense exposure to the drug there.

Effects of anthelmintic treatment and feed supplementation on grazing Tuli weaner steers naturally infected with gastrointestinal nematodes.

A study was carried out to determine the epidemiology of gastrointestinal nematodes in indigenous Tuli cattle and the effect of dietary protein supplementation and anthelmintic treatment on productivity in young growing cattle. Forty steers with an average age of 18 months were divided into 4 groups; 1) fenbendazole (slow release bolus) and cottonseed meal (FCSM group), 2) fenbendazole (FBZ group), 3) cottonseed meal (CSM group) and 4) control (no cottonseed meal and no fenbendazole) (control group). Performance parameters measured included worm eggs per gram of faeces (EPG), packed cell volume (PCV), albumin and live-weight gain. Results showed that faecal worm egg counts were lower and PCV was higher in the FCSM and FBZ groups than in the CSM and control groups (P < 0.01). Weight gains were higher in the CSM and FCSM groups than in the FBZ and control groups (P < 0.05). The cost benefits of anthelmintic treatment and dietary supplementation were apparent in this study. The improved growth performance of the FCSM, FBZ and CSM groups reflected a financial gain over the controls on termination of the study. The dominant genera of gastrointestinal nematodes on faecal culture, pasture larval counts and necropsy were Cooperia and Haemonchus. The incidences of Trichostrongylus, Oesophagostomum and Bunostomum were low.