PARASITOLOGIE

• Ascaris suum: cDNA microarray analysis of 4th stage larvae (L4) during self-cure from the intestine.
• Attempts to separate female Ascaris suum antigen and to investigate its partial characterization.
• Clinical coccidiosis in a boar stud.
• A comparison of the susceptibility of growing Mukota and Large White pigs to infection with Ascaris suum.
• Efficacy of ivermectin against Sarcoptes scabiei var suis in pigs.
• Efficacy of ivermectin in swine food. [Eficacia de una formulacion de ivermectina para uso en alimentos de cerdos].
• Endoparasites in organic pig herds. [Endoparasitter i okologiske svinebesaetninger.]
• Helminth control practices and infections in growing pigs in France.
• Injectable 1% ivermectin anthelmintic activity in swine naturally parasitized. [Atividade anti-helmintica da Ivermectina 1% injetavel em suinos naturalmente parasitados.]
• Parasitoses in pastures in Salamanca: uncultivated areas. [Parasitosis en las dehesas salmantinas: reservorios silvestres.]
• Risk factors associated with mange occurrence and prevalence in pigs during the growing and finishing phases, in the south region of Brazil. [Fatores de risco associados a ocorrencia de sarna sarcoptica e prevalencia em suinos nas fases de crescimento e terminacao, na regiao Sul do Brasil.]
• Skin trim losses at slaughter – Merial/Elanco/National Pork Board’s [NPB] Initiatives with the Packing Industry.
• Toward a better diagnosis of swine scabieswith a new antibody ELISA kit.
• Application techniques of the “Productivity Calculator” against the resurgence of Sarcoptes scabiei var. suis.

Ascaris suum: cDNA microarray analysis of 4th stage larvae (L4) during self-cure from the intestine.
MORIMOTO M, ZARLENGA D, BEARD H, ALKHAROUF N, MATTHEWS BF, URBAN J F, JR.
Experimental Parasitology. 2003 , 104 ( 3/4 ): p.113-121
There is spontaneous cure of a large portion of Ascaris suum 4th-stage larvae (L4) from the jejunum of infected pigs between 14 and 21 days after inoculation (DAI). Those L4 that remain in the jejunum continue to develop while those that have moved to the ileum are eventually expelled from the intestines. Although increases in intestinal mucosal mast cells and changes in local host immunity are coincidental with spontaneous cure, the population of L4 that continue to develop in the jejunum may counteract host protective mechanisms by the differential production of factors related to parasitism. To this end, a cDNA library was constructed from L4 isolated from pig jejunum at 21 DAI, and 93% of 1920 original clones containing a single amplicon in the range 400-1500 bp were verified by gel electrophoresis and printed onto glass slides for microarray analysis. Fluorescent probes were prepared from total RNA isolated from: (1) 3rd stage-larvae from lung at 7 DAI, (L3); (2) L4 from jejunum at 14 DAI (L4-14-J); (3) L4 from jejunum at 21 DAI (L4-21-J); (4) L4 from ileum at 21 DAI (L4-21-I), and; (5) adults (L5). Cy3-labeled L3, L4-14-J, L4-21-I and L5 cDNA, and Cy5-labeled L4-21-J cDNA were simultaneously used to screen the printed arrays containing the L4-21-J-derived cDNA library. Several clones showed consistent differential gene expression over two separate experiments and were grouped into 3 distinct transcription patterns. The data showed that sequences from muscle actin and myosin, ribosomal protein L11, glyceraldehyde-3-phosphate dehydrogenase and the flavoprotein subunit of succinate dehydrogenase were highly expressed in L4-21-J, but not in L4-21-I; as were a collection of un-annotated genes derived from a worm body wall-hypodermis library, and a testes germinal zone tissue library. These results suggest that only actively developing A. suum L4 are destined to parasitize the host and successfully neutralize host protective responses. 31 ref.

Attempts to separate female Ascaris suum antigen and to investigate its partial characterization.
TAKASHIMA M, OHMI H, WATANABE T, OKAMOTO K, KANOE M, NAGAI S.
Veterinary Journal vol. 165 ( 2 ): p.164-168 (2003)
The location and separation of Ascaris suum antigen for serological testing was investigated. The antigenic constituent was rich in the ovary of the adult worm and was obtained by dialysis with 50% ammonium sulfate saturated solution. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and immunoblotting analysis demonstrated that the heat labile antigenic preparation showed one major and seven faint bands. The major band seemed also to be a glycoprotein. The sera from pigs with/without hepatic milk spot showed relatively high precipitation titres, while, those from the specific pathogen free pigs manifested low titres. 13 ref.

Clinical coccidiosis in a boar stud.
YAEGER MJ, HOLTCAMP A, JARVINEN JA
Journal of Veterinary Diagnostic Investigation. 2003 , v15 , N4 (Jul) , p 387-389
This report describes an outbreak of coccidiosis in a boar stud. A live, untreated, adult boar with a history of diarrhea was submitted to the Iowa State University Veterinary Diagnostic Laboratory, Ames, IA. For a 3-month period, approximately 40% of the boars in this stud had developed gray to brown diarrhea that lasted 1-3 days. Affected boars did not lose condition, and antibiotic therapy did not appear to affect the clinical course of the disease. At necropsy, the distal ileum was palpably thickened and covered by a thick, yellow-green, fibrinous exudate. Microscopic changes in the ileum consisted of an erosive enteritis associated with the presence of numerous coccidia within mid to superficial villus enterocytes. The mucosa was covered by a fibrinous exudate admixed with numerous nonsporulated coccidian oocysts. A light growth of Salmonella enterica serovar Derby was isolated from the small intestine of this animal, but laboratory tests were negative for Lawsonia and Brachyspira spp. Individual or paired fecal samples were obtained from 6 additional boars experiencing similar clinical signs. Numerous Eimeria spinosa oocysts were identified in these samples. Neither Salmonella nor Brachyspira spp. were cultured from submitted fecal samples. Necropsy of a live boar and examination of feces from 6 additional animals confirmed that the mild, sporadic, transient diarrhea in this boar stud was due to coccidiosis.

A comparison of the susceptibility of growing Mukota and Large White pigs to infection with Ascaris suum.
ZANGA J, CHIMONYO M, KANENGONI A, DZAMA K, MUKARATIRWA S.
Veterinary Research Communications. 2003 , 27 (8): p.653-660
The influence of A. suum infection on the haematology, liver-related serum enzymes, blood urea and live weight gain in Mukota and Large White (LW) weaner pigs was compared. Six pigs of each genotype were infected with a single dose of 4000 A. suum eggs per pig and another six were not. The pigs were kept for 100 days. Blood was collected daily for the first 7 days and also after 100 days. In the infected pigs, there was an increase (p< 0.05) in alanine aminotransferase (ALT) activity in the LW but not in the Mukota pigs. Although the alkaline phosphatase (ALP) activity rose (p< 0.05) in both infected and non-infected LW pigs from day 1 to day 3, the activity in the non-infected LW pigs then decreased, while that of the infected LW pigs remained elevated. The infected LW pigs had higher (p< 0.05) levels of ALT, ALP and aspartate aminotransferase than their non-infected counterparts. Non-infected LW pigs tended to have higher (p<0.05) haematological parameters, daily weight gain and urea concentrations than infected LW pigs, but these differences were not significant. These preliminary findings suggest that more A. suum larvae reached the livers in the LW than in the Mukota pigs and that the latter may be more resistant to A. suum infection. 14 ref.

Efficacy of ivermectin against Sarcoptes scabiei var suis in pigs.
GEURDEN T, VERELST A, SOMERS R, DIERICKX N, VERCRUYSSE J.
Veterinary Record. 2003, 153 ( 9 ): p.272-273
The objective of the study is to demonstrate that ivermectin injected intramuscularly in pigs is as efficient against S. scabiei as when it is injected subcutaneously, and to assess injection site reaction. Also, the alternative dosage levels and duration of administration for ivermectin in feed was determined. A total of 159 pigs were studied. Results showed that intramuscular administration is as effective as subcutaneous administration, and does not result in injection site reactions. Besides oral treatment at 100 micro g/kg for 7 consecutive days, alternative dose schemes are also 100% efficient. 9 ref.

Efficacy of ivermectin in swine food. [Eficacia de una formulacion de ivermectina para uso en alimentos de cerdos].
PERALTA JL, BONO MF, RUIZ MF, ORCELLET VM.
Revista de Medicina Veterinaria (Buenos Aires). 2003 , 84 ( 1 ): p.12-13
Evaluation of an ivermectin formulation to be mixed with feed for swine naturally infested with gastrointestinal and pulmonar nematodes was carried out. 12 hogs were allocated into 2 groups, treated and untreated control. Treatment consisted of feed dosed with 333 g of Ivervet Premix per 1000 kg of feed. An efficacy percentage (PE) of 100% was determined for Ascaris suum, Oesophagostomum dentatum, Trichuris suis, Metastrongylus apri, and M. pudendotectus and of 99.7% for Hyostrongylus rubidus. 6 ref.

Endoparasites in organic pig herds. [Endoparasitter i okologiske svinebesaetninger.]
CARSTENSEN L, ROEPSTORFF A, VAARST M.
DJF Rapport, Husdyrbrug. 2003 , ( No.49 ): 40 pp.
From March to October 1999 a study was made of parasites present in faeces and soil samples collected from 9 privately owned pig farms in Denmark which had been run on organic lines for a few months to 8 years; the size of the herds varied from 12 to 258 sows. the The endoparasites found were Ascaris suum in 28% of 12-week-old piglets, 33% of slaughter pigs and 4% of the sows; Trichuris suis in 4%, 13% and <1%, and Oesophagostomum spp. in 5%, 14% and 20%, respectively; no strongylid parasites were found. Very few Trichuris eggs were found in the soil, but they were present in 14% of the samples from areas used by the sows and 35% from areas used by the slaughter pigs. The first infective eggs were identified in July and the last in August. The numbers of Oesophagostomum larvae increased in pasture samples from May to October. 20 ref.

Helminth control practices and infections in growing pigs in France.
BELOEIL P A, CHAUVIN C, FABLET C, JOLLY J P, EVENO E, MADEC F, REPERANT J M
Livestock Production Science 81 ( 1 ): p 99-104 May 2003
Internal parasite control practices and helminth infestations were investigated in 78 pig farms in France. Pooled faecal samples were taken from pens housing 16-week-old pigs. Samples were examined by coproscopy. Farm practices were checked for the risk factors of infestation previously described in literature. Information was obtained during a visit of the facilities and an interview with the farm owner/manager. Anthelmintics were used in most herds (97%). Treatments were routinely prescribed, such as flubendazole in the diet of the piglets and ivermectin for sows. Finisher pig infestation may occur despite these treatments: five samples in our study contained helminth eggs, four samples contained strongylid eggs (Hyostrongylus rubidus or Oesophagostomum spp.), and one sample contained Trichuris suis eggs. We can conclude that helminths are controlled, but that parasites can still be present in indoor intensive pig operations. Hygiene efforts must be continued.

Injectable 1% ivermectin anthelmintic activity in swine naturally parasitized. [Atividade anti-helmintica da Ivermectina 1% injetavel em suinos naturalmente parasitados.]
TOMA SB, MOREIRA RJC, CANAVACI FHT.
A Hora Veterinaria. 2003 , ( No.135 ): p.31-33.
The objective of this work was to evaluate the anthelmintic action of one formulation of ivermectin 1% injectable in pigs. 18 male crossbred pigs (LW x 1/2 Piau/Duroc) received a dosage of one ml/33 kg of body weight (300 mg/kg). The maximum efficacy (100%) was observed against Ascaris suum, Metastrongylus apri, and Globocephalus urosubulatus. Efficacy values of 98.9, 99.9, and 99.6% were observed against Trichuris spp., Oesophagostomum dentatum, and Strongyloides ransomi, respectively.

Parasitoses in pastures in Salamanca: uncultivated areas. [Parasitosis en las dehesas salmantinas: reservorios silvestres.]
OLEAGA PEREZ A, PEREZ SANCHEZ R, RAMAJO MARTIN V.
Albeitar. 2003 ( No.66 ): p.8-10
Between January 2000 and December 2001, 833 faecal samples from 632 domestic cattle, sheep, goats and pigs, 201 samples from wild animals (mountain goats, hares, rabbits, partridges and pigeons) and 49 samples from horses, dogs, hens and pheasants in the Salamanca area of Spain were analysed. Parasites were detected in the faeces of 78.4% of cattle, 74.5% of sheep and goats, 36% of pigs, 33.35% of horses, 53.6% of dogs, 84.6% of hens, 100% of pheasants, 58% of mountain goats, 65.5% of hares and rabbits and 100% of partridges and pigeons. Data are tabulated for the incidence of 27 different types of parasite (coccidia, nematodes, trematodes and cestodes) in the various species. 8 ref.

Risk factors associated with mange occurrence and prevalence in pigs during the growing and finishing phases, in the south region of Brazil. [Fatores de risco associados a ocorrencia de sarna sarcoptica e prevalencia em suinos nas fases de crescimento e terminacao, na regiao Sul do Brasil.]
PEDROSO-DE-PAIVA D, MORES N, BARIONI JUNIOR W, COSTA OAD, SOBESTIANSKI J, AMARAL AL DO
Ciencia Rural. 2003, 33 ( 4 ): p.731-736.
An epidemiological research was carried out in 64 swine herds in the South region of Brazil. The objective of this study was to determine the prevalence of mange and to identify the set of risk factors that best explain the occurrence of mange during the growing and finishing phases in swine operations. A protocol was applied enclosing the variables of the ecosystem in intensive swine operation. The data were analysed by multiple correspondence analyses, identifying 10 variables associated with the occurrence of mange. These variables were area less than 0.85 m2/pig, air volume less than 3.0 m3/pig, handling of building in the continuous system, air humidity less than 60% or greater than 70%, use of mashed meal offered ad libitum with ration having a composition different from the recommendation techniques, excess of flies in building, and occurrence of other illness presented in the group of pigs. These variables were shown in a map, which allowed the visualization of the factors associated with groups of pigs having low, average, and high prevalence of mange. Of the 3948 pigs examined in the slaughter plant, 16.64% had erythematous papules dermatitis in the skin which was indicative of mange. 20 ref.

Skin trim losses at slaughter – Merial/Elanco/National Pork Board’s [NPB] Initiatives with the Packing Industry.
MEISINGER D
Proceedings of the 35th Annual Meeting of the American Association of Swine Veterinarians, March 6-9, 2004, Des Moines, Iowa, Abstract No. 103
Not much is known about the costs or losses associated with parasites at the packing plant level. In order to investigate the perceptions that hog slaughterers have about mange and its associated losses in their plants, a survey was undertaken with the largest packers in the US. Seven packers, representing 27 large slaughter plants, responded to the survey of the ten that were solicited. The costs of skinning either totally or partially on a rail out line were estimated to be fairly significant by all the packers. The costs to the packer include downtime, extra labor, loss of product or loss of product value if it goes to rendering, and the hassle associated with something out of the routine flow in these high volume lines. It is estimated that, on average, the total cost of Ascaris infection is 3-5 euros per slaughtered pig [3.52 US$ - 5.87 US$].

Toward a better diagnosis of swine scabieswith a new antibody ELISA kit.
VERCRUYSSE J, PEELAERS I.
Proceedings of the 35th Annual Meeting of the American Association of Swine Veterinarians, March 6-9, 2004, Des Moines, Iowa, Abstract No. 107
Reliable and sensitive diagnosis of sarcoptic mange appears to be the main problem for adequate control and eradication programmes. Conclusive diagnosis of swine scabies is not always easy to obtain because of the minute size of the parasite and its intracutaneous localisation, in combination with non-specific clinical symptoms including pruritus. Recently, a new antibody ELISA kit designed to allow herd based testing for the presence of the mange mite in finisher pigs, was developed at the Faculty of Veterinary Medicine, Ghent, Belgium, based on free living mite as antigen source. The Ghent test outperforms two commercial tests in sensitivity and matches or betters the other performances in specificity. Meat extract samples offer the opportunity to reduce procurement costs compared to serum samples and increase sample availability as meat extract samples can be readily obtained during the harvest process. The ELISA kit on meat juice seems also to be a reliable source of antibodies to mange mites, which may also offer a reliable diagnostic tool to packing plants to determine if skin lesions seen on carcasses are due to S. scabiei. In addition, this test now allows veterinarians, packers and producers to identify early low levels or subclinical stages of mange infestation, often ignored and/or underestimated on a herd level.

Application techniques of the “Productivity Calculator” against the resurgence of Sarcoptes scabiei var. suis.
WEISS DL, HOLTKAMP D, GARCIA R, MELANCON JJ.
Proceedings of the 35th Annual Meeting of the American Association of Swine Veterinarians, March 6-9, 2004, Des Moines, Iowa, Abstract No. 111
Merial Ltd. has developed a Herd Mange/Lice Elimination (HM/LE) spreadsheet on Excel that helps veterinarians and producers compare the financial results of mange elimination for several different production scenarios. The “Productivity Calculator” estimates a return on investment (ROI) and other financial measures given the cost of the HM/LE program and expected improvements in key breeding herd and grow-finish productivity measures once the mange mites, Sarcoptes scabiei var. suis, are eliminated. Several different protocols are available to be demonstrated with different types of production systems using both injectable and in-feed premix IVOMEC products. The Productivity Calculator allows for the input of real world expectations that veterinarians can use to plan herd management practices for mange elimination. The ability to compare worst case and best-case scenarios, when mange is known to be in the swine population, helps veterinarians support their recommendations.