肺虫、ィクチオカウルス属、Dictyocaulus属

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/12/17 08:15:21」(JST)

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Dictyocaulus is a genus of nematode parasites of the bronchial tree of horses, sheep, goats, deer, and cattle. Dictyocaulus arnfieldi is the lungworm of horses, and Dictyocaulus viviparus is the lungworm affecting ruminants.

Dictyocaulus viviparus: lungworm of cattle, deer

D. viviparus is the most common lungworm of cattle; the infection is also known as husk or parasitic bronchitis. Although classified as the same parasite, some people believe that the D. viviparus of deer and elk should be reclassified as a different species, including D. eckertii in New Zealand. However, both species have been shown capable of cross-infecting cattle and cervids (at least in New Zealand) .^[1]

The parasite has a simple but interesting life cycle, with dipersal facilitated by a fungus.

Adult D. viviparus worms reside in the bronchial tree of the animal's lungs. They lay eggs into the airways (bronchi). These eggs are coughed up and subsequently swallowed by the host. The eggs hatch into Stage 1 larvae (L1) in the gastrointestinal tract of the ruminant host. These L1 larvae are shed in the feces or manure. In the feces, larvae mature through two stages and become infective as L3 stage larvae. Cattle feces supports the growth of Pilobolus sp. fungi. The L3 larvae of D. viviparus invade the inside of these fungi, and wait in the fungal sporangium. When the fungus sporulates, the larvae are dispersed as much as 10 feet in a pasture.

Cattle grazing then ingest the L3 larvae. These larvae go through the intestinal system and penetrate the intestinal wall. They use the lymphatic system to reach the mesenteric lymph nodes, where they mature once again into L4 stage larvae. The L4 larvae use the blood supply and the lymphatic system to reach the lungs, where they become adults. The life cycle is completed.

Diagnosis of D. viviparus infection

Microscope detection of L1 larvae in feces
Microscope detection of eggs or larvae in the coughed up sputum or bronchoalveolar lavage fluid from affected animal
Blood serology test for worm antigens (available in some countries / states)

Treatment of lungworm infections

Lungworms can be treated with ivermectin, albendazole, fenbendazole, febantel and other anthelmintics. Pasture management should take into consideration the infectiveness of these organisms.

D. arnfieldi in horses and donkeys

D. arnfieldi is similar to D. viviparus in cattle, but only affects equids. Donkeys usually show no disease and can be silent carriers (and shedders) of this parasite, which causes clinical signs in horses. Routine deworming of horses and donkeys may help prevent cross infection when kept together. Pastures that housed donkeys may be infected with lungworm larvae. As a result, horses and donkeys should not be grazed together. These drugs are given with three weeks intervals between treatments.

References

^ Johnson; MacKintosh, CG; Labes, RE; Taylor, MJ; Wharton, DA; et al. (2003). "Dictyocaulus species: cross infection between cattle and red deer". New Zealand Veterinary Journal 51 (2): 93–98. doi:10.1080/00480169.2003.36346.

English Journal

Comparison of two serum and bulk-tank milk ELISAs for diagnosing natural (sub)clinical Dictyocaulus viviparus infection in dairy cows.

Ploeger HW, Holzhauer M, Uiterwijk M, Van Engelen E.Author information Department of Infectious Diseases and Immunology, Veterinary Faculty Utrecht, P.O. Box 80165, 3508 TD Utrecht, The Netherlands. Electronic address: h.w.ploeger@uu.nl.AbstractLungworm antibody ELISAs developed in Germany (DE) and The Netherlands (NL) were compared using four sets of serum (S) and bulk-tank milk (BTM) samples from adult dairy cows. The samples originated from 37 farms with or without a suspected clinical lungworm infection during August-October 2010 (Dataset 1), from cows excreting lungworm larvae or not during August-October 2010 (n=59) or May-June 2011 (n=164) (Dataset 2), from 305 farms in a national survey during October 2010 (Dataset 3), and 14 zero-grazing farms during February-April 2011 (Dataset 4). During August-October 2010, covering the second half of the grazing season, the NL-S and NL-BTM ELISA outperformed the DE-S and DE-BTM ELISAs in terms of sensitivity. For at least the NL-S and DE-S ELISA the opposite was found during May-June 2011, covering the end of the winter housing period and the early grazing season. Of the 305 farms in the survey 62.6% were found positive with the NL-BTM ELISA, whereas 2.6% was found positive with the DE-BTM ELISA. ODR values for the zero-grazing farms indicated that a cut-off value of 30% for the DE-BTM ELISA might be more appropriate than the currently used 41%. Results suggest that the NL ELISAs also respond to lungworm antigens other than Major Sperm Protein as used in the DE ELISAs. It is concluded that the generally higher sensitivity of the NL-BTM ELISA makes it better suited for large-scale prevalence studies and herd health monitoring programmes than the DE-BTM ELISA, positivity of which is more associated with the presence of clinical lungworm infection. Reducing the cut-off value of the DE-BTM ELISA from the original 49.3% to the current 41% or the possibly more appropriate 30% increased its sensitivity for detecting lungworm infections, but did not lead to similar sensitivity estimates as found for the NL-BTM ELISA.
Veterinary parasitology.Vet Parasitol.2014 Jan 17;199(1-2):50-8. doi: 10.1016/j.vetpar.2013.10.002. Epub 2013 Oct 14.
Lungworm antibody ELISAs developed in Germany (DE) and The Netherlands (NL) were compared using four sets of serum (S) and bulk-tank milk (BTM) samples from adult dairy cows. The samples originated from 37 farms with or without a suspected clinical lungworm infection during August-October 2010 (Data
PMID 24188965

Reduced efficacy of moxidectin and abamectin in young red deer (Cervus elaphus) after 20 years of moxidectin pour-on use on a New Zealand deer farm.

Mackintosh CG, Cowie C, Fraser K, Johnstone P, Mason PC.Author information AgResearch Invermay, PO Box 50034, Mosgiel 9053, New Zealand. Electronic address: colin.mackintosh@agresearch.co.nz.AbstractA study was undertaken on weaned 4-5 month old farmed red deer to test the efficacy of moxidectin and abamectin anthelmintics, given by three different routes of administration, compared with an untreated control. Faecal samples were collected on days 0, 7 and 14 for a faecal egg count reduction test (FECRT), blood samples were collected on days 0, 0.5, 1, 2, 3, 5, 7, 10 and 14 for pharmacokinetics, and the deer were killed on days 14 or 15 for total nematode count. The control group averaged 1264 adult Ostertagia-type nematode parasite species and treatment efficacy was 77.4% for moxidectin injection, 26% for oral moxidectin and 27.6% for pour-on moxidectin, while the treatment efficacy was 72.4% for abamectin injection, 70.1% for oral abamectin (Hi-Mineral) and 34.1% for pour-on abamectin. Both moxidectin and abamectin injections were significantly more efficacious than their equivalent pour-ons. There was a significant difference in efficacy between oral abamectin (Hi-Mineral) and oral moxidectin (P<0.01). The control group averaged 2956 adult lungworm (Dictyocaulus eckerti) and 50 Oesophagostomum venulosum in the large intestine and treatment efficacy against these nematodes was 100% for all treatments. There were negligible numbers of other gastro-intestinal nematodes. At slaughter, there was a significant correlation (P=0.02) between FEC and Ostertagia-type nematodes in the untreated controls. Relatively few eggs were found in faeces from treated animals at 7 and 14 days post-treatment despite significant worm burdens in all six treatment groups, suggesting egg-laying suppression in resistant nematodes, and all three different FECRT calculations tended to overestimate the efficacy of the treatments compared with actual nematode counts. Peak plasma concentrations (Cmax) for both actives were measured 12h after treatment for injection and oral and at 5 days for pour-on. Cmax (ng/ml) for moxidectin injection, oral and pour-on were 71.8, 8.3 and 0.4, respectively, and for abamectin injection, oral and pour-on were 62.1, 30.3 and 10.0, respectively. Area under the curve (AUC) estimates for moxidectin injection, oral and pour-on were 106.6, 12.9 and 6.1, respectively, and for abamectin injection, oral and pour-on were 162.7, 57.5 and 74.3, respectively. The results demonstrate that significant anthelmintic resistance to moxidectin and abamectin is present on this deer farm. However, the injection was the most effective route of administration in young deer for both anthelmintics, although <80% efficacious. We conclude that the FECRT is unreliable in deer when anthelmintic resistance is present.
Veterinary parasitology.Vet Parasitol.2014 Jan 17;199(1-2):81-92. doi: 10.1016/j.vetpar.2013.09.028. Epub 2013 Sep 28.
A study was undertaken on weaned 4-5 month old farmed red deer to test the efficacy of moxidectin and abamectin anthelmintics, given by three different routes of administration, compared with an untreated control. Faecal samples were collected on days 0, 7 and 14 for a faecal egg count reduction tes
PMID 24144515

Cytokine mRNA expression in bronchoalveolar lavage cells during Dictyocaulus viviparus infection in calves.

Holmgren S, Hagberg Gustavsson M, Lundén A, Wattrang E.Author information Section of Parasitology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden.AbstractThe purpose of this study was to monitor local cytokine responses to Dictyocaulus viviparus in calves during primary infection and re-infection. Bronchoalveolar lavage fluid (BALF) was collected weekly from experimentally infected calves and interleukin-2 (IL-2), IL-4, IL-5, IL-10 and IFN-γ mRNA expression was quantified in BALF cells. The major finding was a prominent transient increase in IL-4 mRNA expression, compared to that of uninfected calves, observed in BALF cells collected 2-3 weeks post primary D. viviparus infection. At 2 weeks post infection macroscopic worms were also first observed in BALF. Calves re-infected after 10 weeks were partially immune which was evident at slaughter 5 weeks post infection as a lower worm burden than in previously naïve calves infected at the same time. IL-4 mRNA expression in BALF cells 2 weeks post re-infection was increased compared to that of uninfected animals but not as high as that of primarily infected calves. BALF cell expression of the other cytokines tested for was not as clearly effected by the D. viviparus infection. It seems likely that the strong IL-4 response observed during primary infection reflects an innate response to the worms that may initiate an ensuing Th2 response, which confers protective immunity. This article is protected by copyright. All rights reserved.
Parasite immunology.Parasite Immunol.2013 Oct 22. doi: 10.1111/pim.12083. [Epub ahead of print]
The purpose of this study was to monitor local cytokine responses to Dictyocaulus viviparus in calves during primary infection and re-infection. Bronchoalveolar lavage fluid (BALF) was collected weekly from experimentally infected calves and interleukin-2 (IL-2), IL-4, IL-5, IL-10 and IFN-γ mRNA ex
PMID 24147800