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(recip. undisclosed). WormMail.20110121.
In this issue:
Trichostrongylus in humans. WormFaxNSW. Abamectin toxicity-lambs. Elimination of flukes, Plant poisonings. Blackberries.
Trichostrongylus infection in travellers visiting a New Zealand sheep farm
Wall CW and others (2010). An unusual case of hypereosinophilia and abdominal pain: an outbreak of Trichostrongylus imported from New Zealand. J Travel Med 2011; 18: 59-60.
A colleague from NZ (D Leathwick) pointed me to this interesting paper.
A 62 year old British woman spent a week on a sheep farm in NZ. Shortly afterwards she felt dizzy and nauseated, followed by abdominal pain, bloating, diarrhoea and weight loss.
Haematology ordered by her GP (Cornwall, UK) showed eosinophilia. Clinical and other investigations (at Royal Cornwall Hospital) revealed nothing of note, apart from increasing eosinophilia.
Later the woman got an email from two friends who had been on the same trip, developed similar symptoms, and had them investigated (in New Zealand). (That’s one for the Kiwis :-).
They were found to have eosinophilia, and Trichostrongylus
sp eggs in faecal samples.
The email exchange resulted in further investigations, at the Hospital for Tropical Diseases, on the woman back in the UK. Trichostrongylus
sp eggs were found in her faeces also. Albendazole 400 mg twice daily for 3 days led to full recovery in 6 weeks and almost complete resolution of her peripheral eosinophilia.
(I wonder if our medical colleagues considered the resistance status of the isolate? But, I guess this sort of treatment regimen with albendazole could be efficacious even against benzimidazole-resistant Trichostrongylus
The source of the infection was traced by veterinarian Dr Chris Morley (Ministry of Agriculture, NZ) to the use of sheep manure as an organic fertiliser on a salad garden.
(Which prompts a side note: there have been humans cases in Australia of fasciolosis – e.g. one case I know of just east of Walcha, in NSW, associated with eating water cress (in salad presumably), the source presumed to be wild water cress growing alongside a waterway on a liver fluke-infected property. It pays to be circumspect in such cases, unless you habitually use salad dressing based on triclabendazole 😉 . My recollection is that Dr Joe Boray
was involved in this and/or similar (human) cases and prevailed upon the health authorities to treat the patients with triclabendazole, instead of a somewhat less suitable anthelmintic. It helps that Joe was involved in the development of this drug in his Ciba-Geigy days).
spp of course are common in herbivores including sheep in Australia, New Zealand and elsewhere. Humans usually are infected through exposure to animal faeces, via contaminated food or water, and most commonly in Asia and the Middle East. As well as this NZ case, several cases of human infection have been reported in Australia. One report from Sydney involved manure from a pet goat being used to fertilise an organic garden. Wall and colleagues also state that five human cases have been reported from rural Australia with a similar transmission method proposed.
was listed in an early draft of the DII Zoonoses Primefact
, but later deleted. Perhaps it should be reinstated. http://www.dpi.nsw.gov.au/agriculture/livestock/health/humans/zoonoses
While we are speaking of zoonoses, I see Therese Wright has written a Primefact (No. 1069) on Bats and Health Risks
WormFaxNSW – December 2010
The latest issue should be up on website soon. http://www.dpi.nsw.gov.au/aboutus/resources/periodicals/newsletters/wormfax
Abamectin toxicity in lambs – South Australia
Another colleague (GD Gray) drew my attention to this (It’s nice to have such helpful colleagues 🙂 . See Animal Health Surveillance Vol 15: 3 p12
On a property in the mid north of South Australia, 19 out of 32 marked lambs were found dead. Necropsies were unremarkable. The report implies the lamb were less than 6 weeks old and had been drenched with a combination drench containing abamectin.
Clinical signs in a live affected lamb were considered to be consistent with abamectin toxicity. The drench gun had been set to a dose for 40 kg animals.
How long do liver fluke remain after effective treatment?
The following is from a recent (20100812) note from Dr JC Boray:
Treatment with triclabendazole (TCBZ) causes irreversible, drastic changes in the integument of TCBZ-susceptible Fasciola hepatica
. The flukes are paralysed but it takes more than 2 weeks for them to be eliminated from the bile ducts (Fairweather and Boray, 1999; Walker,S.M.and others (2004).
Flukes killed by closantel will be eliminated within 2 weeks.
Fairweather and Boray (1999). Fasciolicides:Efficacy, Actions, Resistance and its Management, The Veterinary Journal,158:81-112.
Walker,S.M., McKinstry, B., Boray, J.C.., Brennan,G.P.,Trudgett, A., Hoey, E.M., Fletcher, H. and Fairweather, I. (2004). Response of two isolates of Fasciola hepatica to treatment with triclabendazole in vivo and in vitro, Parasitology Research, 94: 427-438. "
Plant poisonings – southern NSW (Tony Morton and others)
(This is not quite worm-related, but is interesting nonetheless and perhaps reflects my continuing interest in pathology, plant poisoning, and animal health in general.-SL).
Loosestrife Kills Cattle
Heavy cattle losses on a farm near Wagga Wagga have been caused by eating the poisonous plant loosestrife District Veterinarian Tony Morton said today.
Initial thoughts that the losses in stubble paddock were from grain poisoning quickly changed when evidence of massive kidney damage was seen and there was no evidence of grain poisoning in the rumen.
Eliz Braddon, Senior District Veterinarian (SDV) at Young, is seeing similar problems in sheep.
Loosestrife loves wet conditions and chemical farming, this year has been ideal for its reappearance as a problem weed so it’s important to check lower lying areas of paddocks for its presence and keep stock off it if found.
Little of it has been seen over the run of drought years.
Prior to that it had caused repeated heavy losses of sheep especially in the wetter areas of the old Wagga Board e.g. The Rock-Mangoplah, Tarcutta but had also been seen sporadically elsewhere e.g. Ganmain in localised wet areas.
Similarly Steve Whittaker SDV at Albury has also seen substantial losses in wet years.
Sorrel is another weed often found in similar areas and it too is a potent cause of kidney damage and death.
Witchgrass Killing Sheep
Witchgrass (hairy panic) has caused widespread problems in sheep with photosensitisation and deaths across a huge area Wagga Wagga based District Veterinarian Tony Morton reports.
Witchgrass loves bare areas and summer rain so this year’s stubbles suit it perfectly.
Witchgrass appears to be most toxic when young and growing rapidly, there are generally less problems after it has been killed with herbicide but occasionally even then problems occur.
Weaner sheep are most susceptible, adult sheep more resistant and cattle are rarely affected.
Sheep usually cope with small amounts of witchgrass in the diet, once it’s is more than 50% of the available paddock feed sheep problems are likely. Unfortunately it’s close to 100% of the green feed in many paddocks
If mobs are carefully monitored for the signs of photosensitisation (swollen droopy ears, damage to the nose and about the eyes) and quickly moved off the witchgrass as soon as symptoms are seen losses can be minimal.
Any photosensitised sheep should be shedded, they soon learn to seek the shade and walk out of the shed after dark to feed and water.
There are plenty of other causes of photosensitisation so seek veterinary advice if there is any doubt.
The biggest smash up we have seen this season with sheep photosensitisation was on a massive infestation of Small St John’s Wort in a stubble paddock. This small plant appears quite innocuous and its presence in stubble was surprising.
Lupin Stubbles Likely To Kill
The very wet summer means phomopsis fungus is already present on lupin stubbles checked by local plant pathologists District Veterinarian Tony Morton said today.
The phomopsis fungus thrives on dead plants after harvest when conditions are moist and is the cause of stock deaths.
Lupinosis poisoning is one of the worst, most gut wrenching poisonings a farmer is likely to see.
Typically when the first few dead animals are seen there are a handful of sick animals as well. Even if the mob is the promptly removed from the lupin stubble as the weeks go by the deaths continue and it’s quite common for another 10% of the mob to die.
In “normal” years with the modern lupin varieties we usually don’t see lupinosis deaths until March after repeated rainfall. This summer we had a lot more rain and humidity than normal and it logically follows that the lupin stubbles will be a lot more toxic than normal.
The risks of grazing lupin stubbles now with either sheep or cattle appear to out weight the likely benefits Tony concluded.
A G Morton
District Vet @ Wagga Wagga
For further information, contact your local District Veterinarian:
Albury: Steve Whittaker and Brigit Pitman (02) 6040 4210;
Gundagai: Ian Masters (02) 6944 1588;
Wagga Wagga: Tony Morton and Helen McGregor (02) 6923 0900;
Young: Eliz Braddon (02) 63821255
For those with Blackberries