In this issue
- Gems from Dash
- District worm control programs – KM Dash
- Oesophagostomum (nodule worm and large bowel worm) – KM Dash
- WormFaxNSW-June 2015
- RamSelect launched
- Delusional parasitosis
- Wild Dog Alert
- Viruses that spread from animals to humans are on the rise?
- Hackers ‘kill’ car as it drives
- World vision
Gems from Dash
Dr Keith Dash, veterinarian, parasitologist and former CSIRO research scientist, and the ‘father’ of WormKill, recently sent me a couple of necessarily short pieces he wrote for another purpose, and gave me permission to share them with readers of WormMail.
Being the consummate team player, Keith might eschew the title of ‘father’ of WormKill, the first of the ‘modern’ Australian sheep worm control programs, but because of his involvement in the development and marketing (aka ‘extension’) of WormKill , which led onto WormBuster, DrenchPlan and others, he knows a lot about how these ‘district’ programs worked. Regarding Oesophagostomum, Keith’s PhD was on this, so I think he knows a thing or two about that as well.
District worm control programs – KM Dash
“The increasing problem of anthelmintic resistance in the 1980s prompted collaboration between CSIRO, the NSW Department of Agriculture and Rural Land Protection Boards (RLPBs) to design new worm control programs for the main climatic zones in the state. The first of these, ‘Wormkill’, was introduced in northern NSW in 1984 with the dual aim of suppressing H.contortus and slowing the rate of development of anthelmintic resistance in T.colubriformis. The program involved concurrent treatment at 2-3 specified times each year with closantel, a long-acting anthelmintic highly effective against H.contortus, and a short-acting broad-spectrum anthelmintic effective against T.colubriformis. The original program was highly successful and was adopted by 85% of producers but gradually lost effectiveness as resistance to closantel developed. More sophisticated programs, still using the ‘Wormkill’ name, have since been developed and introduced to deal with the constant challenge of anthelmintic resistance”.
(Editorial note: The RLPBs have ‘morphed’ over the years. They were Pastures Protections Boards for a century or so, including during the 1980s, and had their genesis in (successful) NSW sheep scab eradication campaigns in the 19th century. In recent decades PP Boards became RLPBs, then Livestock Health and Pest Authorities (LHPAs), then, in the last few years, Local Lands Services (LLS) by way of marriage with Catchment Management Authorities. More here and here. As to sheep worm control programs, Your Program in WormBoss is, these days, the place to go. You won’t find better. SL).
Oesophagostomum (nodule worm and large bowel worm) – KM Dash
“Oesophagostomum species are members of the superfamily Strongyloidea. Adult worms are found in the caecum and colon of sheep. Oe. columbianum (nodule worm) was once a major parasite in the summer rainfall area of Australia but it is now rare after the widespread use of broad-spectrum anthelmintics. Oe. venulosum (large bowel worm) is widely distributed in New Zealand and all temperate areas of Australia but rarely causes problems. In both species, third-stage larvae encyst in the wall of the small intestine, develop to early fourth-stage larvae, migrate back to the intestinal lumen, and pass down to the caecum and colon. In Oe. venulosum 4th stage larvae continue development to the adult stage in the large intestine. In Oe columbianum some 4th stage larvae are retained in the wall of the lower small intestine or enter a second tissue phase in wall of the large intestine and are captured in thick-walled caseous nodules. This excessive tissue response may be because sheep are ‘unnatural’ hosts of Oe. columbianum, the ‘natural’ hosts being African antelopes”.
More on Oesophagostomum:
The June edition has been published at:
RamSelect – new tool for ram buyers launched
” NSW DPI’s contribution included the following (in no particular order):
- Luke Stephen’s (Technical Specialist-Sheep Breeding) involvement included an intensive 4 week period working with software developers in San Francisco, as well as follow up work after returning from the U.S.
- Matias Suarez (Technical Specialist-Beef Breeding) did foundational work in the form of “Bull Rank” which was licensed to the Sheep CRC for use in sheep.
- Kevin Atkins (former NSW DPI scientist/geneticist) also contributed and additionally RamSelect drew on background work Dr Atkins and Jess Richards (Research Officer) did over a number of years.”
People within the NSW DPI (and LLS?) firewall can see the blog post on RamSelect here: https://dpiactive.dpi.nsw.gov.au/ramselect-com-au-is-online-and-operational/ Make sure you ‘like’ the blog post. (Luke may even by you a beer).
In my first three veterinary ‘careers’ – private practice, semi-government field vet, and lab-bound veterinary pathologist – the common thread was that I mainly did diagnostic work and often this involved internal parasites.
Despite this I seldom used pepsinogen as a diagnostic aid, so I resorted to the texts to get a better feel of how to interpret the test and how useful the test is.
This is my summary of the section on pepsinogen in the textbook, Veterinary Medicine (ed: Radostits et al., 10th Ed.):
* an aid to diagnosis in ostertagiosis
* may be elevated also with haemonchosis
*difficult to standardize. Results between labs may not be entirely comparable
* levels decline after effective drench but do not return to pre-infection values
* older immune cattle may show elevated levels when grazing contaminated pasture, even though few worms have established.
Of course there can be oft-overlooked but good information in your own backyard. Here is the blurb from the NSW DPI Vet Lab pages
“Pepsinogen estimations from serum or plasma
“In adult cattle, estimations of serum or plasma pepsinogen concentrations are considered a useful indicator of abomasal damage and of value in the diagnosis of type II ostertagiasis.
“Pepsinogen is produced in the gastric mucosa as the inactive precursor of pepsin. Abomasal damage results in increased blood pepsinogen concentration. The assay measures the presence of pepsinogen through the ability of the test serum or plasma to breakdown a protein substrate to peptide fragments. Results are compared with a tyrosine standard, and expressed in terms of U/L of tyrosine.
“Specimens required: serum, heparinised or EDTA plasma.
“Activity is stable for several days at 4°C for several days and several months at -20°C. Haemolysis has little effect on activity.
“Interpretation of results: pepsinogen values should be interpreted on a herd rather than an individual basis. False negatives may occur.
“Level (U/L) Interpretation
< 5 No significant abomasal damage
5-10 Minor damage*
10-15 Moderate damage
> 15 Major abomasal damage
* Levels of 5 or greater are considered indicative of damage sufficient to cause production loss.
“Increased serum pepsinogen levels due to abomasal mucosa damage may be associated with larval stages of Ostertagia ostertagi in cattle, especially in adults, but are insufficiently specific and so should be used with caution and at best only as a herd test.”
Hutchinson GW, 2009. Nematode Parasites of Small Ruminants, Camelids and Cattle Diagnosis with Emphasis on Anthelmintic Efficacy and Resistance Testing. Australia-New Zealand Diagnostic Standard Procedures (ANZDSPs). Accessed July 2015: http://www.scahls.org.au/Procedures/Pages/ANZSDPs.aspx
by James G. H. Dinulos, MD
“In delusional parasitosis, patients mistakenly believe that they are infested with parasites.
“Patients have an unshakable belief that they are infested with insects, worms, mites, lice, or other organisms. They often provide vivid descriptions of how the organisms enter their skin and move around their bodies, and bring samples of hair, skin, and debris such as dried scabs, dust, and lint on slides or in containers (the matchbox sign) to prove that the infestation is real. The condition is considered a somatoform type of delusional disorder. Patients may have other psychiatric or physical disorders (e.g., structural brain disorders, toxic psychosis)”
See! Parasites are important and they are everywhere – even in your imagination.
Wild Dog Alert
Viruses that spread from animals to humans are on the rise?
A story from the ABC by Marty McCarthy:
‘Viruses that spread from animals to humans are on the rise, so what are they and how can scientists stop them?’
In the meantime, attention to the basics like hand hygiene, other aspects of hygiene, and managing risk, can make a big difference.
For more information, see here: http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0011/334001/Zoonoses-animal-diseases-transmissible-to-humans.pdf
Hackers ‘kill’ car as it drives
Another ABC story:
“I dream of a world where a chicken can cross the road, and not have its motives constantly questioned.”