Drench Resistance and Sheep Worm Control – Primefact 478 – revised

To: WormMail list (recip. undisclosed).    WormMail 201102241030

Drench Resistance and Sheep Worm Control – Primefact 478 – revised

Copy attached.

It should also be on our website soon (Currently the first edition (2007) is still there).

Regards

SL

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WormMail. 20110204. Meet The Boss Man

To: WormMail list (recip. undisclosed).  WormMail. 20110204. Meet The Boss Man

 

Meet the Boss Man.

 

I first met Arthur Le Feuvre at his Queensland DPI office in Warwick. I
am not sure why I dropped in. It was just before WormBoss got rolling.
Perhaps I had just heard of this 'sheepo' (as 'sheep and wool officers'
are known in NSW), and wanted to say g'day.

 

Le Feuvre is large, larger than life. I'm a tad over 6 foot (183 cm)
tall: Arthur is several tads taller again. I think he used to play
football (rugby). I imagine the scrums were a bit lopsided and he
wouldn't need lifting in the line-outs. When not playing football he
could easily have served as a temporary strainer post in an outback
Queensland fence-line.

 

His office was large too, and full of interesting books, old and new,
and assorted paraphernalia. His mind might be like that as well: large
and full of interesting and unexpected things.

 

I first heard of the idea that was to become WormBoss when Brown Besier
rang me early in the days of the Sheep CRC. Brown, a vet parasitologist
with the WA Dept of Agriculture, was program manager for things wormy in
the CRC. No doubt Brown asked lots of other people as well, but Le
Feuvre had worked his magic.

 

There was an earlier attempt to create a national project providing
information and resources supporting best practice in sheep worm
control, the number one endemic disease, from an economic viewpoint, of
sheep in Australia. This ancestor of WormBoss was known as SCIPS -
Sustainable Control of Internal Parasites in Sheep - and was supported
by Australian Wool Innovation, or whatever it was called then. The
project was lead by Nick Sangster, then an Associate Professor
(parasitology) at the Sydney Uni vet school, and now a Prof, at CSU
Wagga Wagga. Others in the team were the usual suspects - vets,
parasitologists and others - from the various states.

 

Before SCIPS a standard reference for vets, parasitologists and others
was a book CSIRO published on the epidemiology and control of helminths
of sheep. The information in this needed updating, expanding and
re-publishing. It was thought that publishing another (paper) book would
be too expensive and harder to expand, revise and distribute, so SCIPS
took advantage of the burgeoning world wide web instead.

 

SCIPS blossomed for a while, but then withered a little on the vine. The
website still exists however ('last time I looked) and some of its
material was used by the WormBoss Team (some of whom were also
SCIP-ees), although re-written to a fair degree, a broader audience
being in view.

 

And so one of Arthur's ideas was born, although he would be quick to add
that the idea that became WormBoss was kicked around by Arthur along
with a few others, including Maxine Lyndal-Murphy (parasitologist at Qld
DPI, now DEEDI) and veterinarian Deb Maxwell, who was then with Qld DPI.

 

In this respect Arthur is a bit like Keith Dash, the father of WormKill
(with Hugh Gordon perhaps being a grandfather, and Ian Barger an
uncle or cousin?). Like Keith Dash, although the leader and champion, Arthur was
inclusive, fostering a good, cooperative spirit among the initial core
team, as well as engaging a wide range of other players and
stakeholders.

 

Again, like Dash, Arthur came up with the name for the new program.
Keith Dash's epiphany happened in the shower after his morning run. He
turned up at a WormKill planning meeting (Armidale, winter 1984) and
said he had a name: 'WormKill!'.  I am not sure how Arthur came up with
WormBoss. It may not have been in the shower, but quite possibly
involved quantities of fluid nonetheless.

 

After 2-3 years of frantic work, Arthur and team had WormBoss -
www.wormboss.com.au - launched in 2005.

 

Before WormBoss was launched, Arthur was saying that, if successful,
this could serve as a model for projects on lice and flies. Arthur
already had FlyBoss and LiceBoss in view and indeed, for most of its
development, Arthur took the lead of FlyBoss as well.

 

The effort was well-focussed because, after worms, flies and lice are
the next most important disease agents for sheep in Australia.

 

Arthur retired from Qld DPI a few years ago, which freed him up for
other projects, for example 'VetsPets' and recording songs and yarns
about outback Queensland.  But he is still actively involved in the
on-going development and promotion of WormBoss, which for several years
has been under the leadership of Rob Woodgate, from Western Australia.

 

Although approaching his 69th this year, the irrepressible Le Feuvre is
still going strong, much like his father who is 97. Clearly he comes
from a line of long if slightly damaged livers.

 

By way of disclaimer, I have no conflicts of interest in writing this,
it was entirely unsolicited, and Arthur probably would be slightly
embarrassed if he had seen this beforehand.I don't even expect a beer
from Arthur, not least because I can't drink it.

 

So, why write all this?  Because people forget, or never knew, and some
people - and things they have done - shouldn't be forgotten.

 

SL

 

5 AM  4th Feb 2011    e&oe.

 

WormMail.20110201 Trichostrongylosis in humans – redux

WormMail.20110201  Trichostrongylosis in humans – reduxTrichostrongylosis in humans – Australia

You might recall the WormMail several days ago about the people, one a woman from the UK, who got diarrhoea, abdominal pain and eosinophilia subsequent to a week’s stay on a New Zealand sheep farm. (Wall and others, 2010).  (Article reproduced at the bottom of this email; also in the new edition of Turning the Worm (#28, January 2011).

The long and short of that story was that the people picked up Trichostrongylus sp infective larvae from the salads they were eating. The salads were home-grown (and perhaps not washed overly well?) in a garden that used fresh sheep manure.

The subjects were treated with albendazole and recovered. I commented/wondered at the time if the drug resistance status of the Trichostrongylus isolate was considered.

Following that article, Nick Sangster (CSU Wagga Wagga) drew my attention to an article, authored by him and others, that reported on similar cases in Australia. (Ralph and others, 2006).

These authors note that isolated cases of trichostrongylosis in humans have long been recognised in Australia. Sixty cases were reported from Queensland by the Hookworm Campaign between 1923 and 1928, and five cases were detected out of 46 000 stool examinations at a Queensland laboratory between 1992 and 1995.

However, Trichostrongylus eggs are commonly mistaken for hookworm eggs, the adult worms may also be misclassified (as Enterobius, for example), symptoms may be mild or absent, and the pre-patent period may be long, with reported delays of 4 months to 2 years between onset of symptoms and detection of eggs in faeces. (Still quaintly referred to as ‘stools’ in human medical literature).

The two cases described by Ralph and others (2006) were suburban goat keepers, who had eaten vegetables from gardens fertilised with goat faeces. Both had abdominal pain, diarrhoea and eosinophilia.  It took a little while for the correct diagnosis of trichostrongylosis to be made, not helped by the fact that no eggs were seen in patient 2’s faeces, presumably due to a long pre-patent period (c.f. the PPP of around 3 weeks in small ruminants such as goats and sheep).

The authors note that the tendency to use stool immunoassays for Giardia and Cryptosporidium in many cases in medical labs rather than the more laborious traditional microscopic examinations for parasites, may miss a number of locally acquired parasite infections such as hookworm, Trichuris trichiura, Strongyloides stercoralis, Isospora belli, Fasciola hepatica and Brachylaima cribbi as well as Trichostrongylus sp.

Once a diagnosis of trichostrongylosis was made, these two patients were treated with benzimidazoles (BZs), mebendazole in one case and albendazole in the other, with zero or partial effect. As there was collaboration between medical and veterinary parasitologists in this case, it was understood that the parasites were very likely BZ-resistant, and treatment with the macrocyclic lactone (ML), ivermectin (200 ug/kg), was undertaken with good results, although, as the authors note, ML-resistant T. colubriformis isolates in Australia have been reported (Le Jambre and others, 2005).   (I think I might be asking for treatment with the novel anthelmintic, monepantel).

Ralph and others (2006) suggest the following lessons can be learnt from these two cases:

·        Trichostrongylosis may be an under-recognised cause of eosinophilia and/or gastrointestinal symptoms in Australia.

·        Stool microscopy for parasite eggs is the only means of diagnosing trichostrongylosis, but is no longer routinely performed by many laboratories.

·        The eggs of Trichostrongylus sp. and hookworm are very similar and can easily be confused, even by experienced laboratory staff.

·        People fertilising their vegetable gardens with manure from herbivores, especially goats, should be advised to thoroughly wash or cook their garden produce before consumption; efficient composting is also effective in killing larvae.

·        The drug of choice is ivermectin, because of high rates of resistance to benzimidazoles.

Personally, I think this last point regarding the drug of choice now needs re-visiting.

Additionally I suggest that the risk of using fresh sheep manure could be just as high as for goat manure (and perhaps alpaca manure as well, given that alpaca can carry sheep and cattle worms).

Sangster also notes that laboratory-acquired infections are possible through mouth-pipetting techniques.  (One or two readers of WormMail may be acquainted with some cases).

I would re-iterate that good hygiene and food safety can markedly reduce the risk of many if not most zoonoses.  See Primefact 814. (The revised edition will have Trichostrongylus reinserted).

SL

References

Le Jambre LF, Geoghegan J, Lyndal-Murphy M (2005). Characterization of moxidectin resistant Trichostrongylus colubriformis and Haemonchus contortus. Veterinary Parasitology 128: 83-90.

Ralph, A, O’Sullivan, MVN, Sangster, NC, Walker JC (2006) Abdominal pain and eosinophilia in suburban goat keepers. Medical Journal of Australia 184, 467-469

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.

Footnotes

‘Eosinophilia’ means that there are more eosinophils than normal (usually referring to a blood smear/blood count). Eosinophils are a type of white blood cell that may be elevated in parasitic infections. They are called eosinophils (‘lovers of eosin’) because they contain granules that stain red (from eosin) in H&E (haematoxylin and eosin) stained histology sections. (They look very pretty 😉

Trichuris sp – ‘whipworms’; Trichostrongylus sp (intestinal species (e.g. T. colubriformis, T. vitrinus): ‘black scour worm’; abomasal: ‘stomach hair worm’ (T. axei); Strongyloide – ‘threadworm’; Isospora sp – coccidia, less common than Toxoplasma or Cryptosporidium;  Fasciola hepatica – liver fluke;  Brachylaima –  a recently discovered trematode (‘fluke’); human cases from South Australia (via ingestion of white-shelled snails); first documented case in 1996.

(From WormMail.20110201)

Trichostrongylus infection in travellers visiting a New Zealand sheep farm

Reference: 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 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).

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.

[Sidenote – fasciolosis in humans

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).]

Trichostrongylus 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.

(This article was first published in the Wormmail e-newsletter. WormMail.20110121. Both these articles appear in TTW # 28, Jan 2011).

Regards

SL