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Posted: Mon Sep 25, 2006 10:42 pm
by Pauline
My friend's daughter has contracted Q fever.Since it is said that the germ can stay active for one year in dust, it seems impossible to trace it back to the source,as she has been in contact with sheep hay,cattle e.t.c. However,is there a test to show that contacted cattle or sheep are carriers,and what should be done,or who should be informed if such a test were to be positive?
Posted: Tue Sep 26, 2006 1:37 pm
by ann
For those of us not in the know what is Q fever?
Posted: Tue Sep 26, 2006 8:00 pm
by Ryan
Q fever is a bacterial infection (although it's correct classification is under review) associated mainly with pregnant ruminants, but which can also affect humans, (although domestic animals and a variety of wild animals have also been associated with human infections).
In ruminants, it can cause abortions but symptoms are not specific, and it's virtiually impossible without tests to tell whether or not the abortion is due to Q fever. Blood tests can be used to detect recent infection; however, shedding of the organism can occur in even if the blood samples are negative (i.e. the test is not foolproof).
Once a cow or sheep is infected, the organism can remain in the udder, lymph nodes, placenta, and uterus, from which it can be shed in subsequent calvings/lambings and lactations.
The greatest risk of transmission occurs at birth by inhalation, ingestion, or direct contact with birth fluids or tha placenta. The organism is also shed in milk, urine, and faeces. High-temperature pasteurisation does kill it though.
The majority of outbreaks in people have been associated with wind dispersion of contaminated dried birth products. Farmers and vets are at risk while helping at calvings/lambings etc. Slaughterhouse workers are at risk from contact with infected carcasses, hair, and wool. Transmission can also happen by drinking unpasteurised milk.
For treatment of cattle & sheep, tetracycline can be effective, but treatment needs to be continued for up to a month(!) In known infected herds, seperating pregnant animals, and burning reproductive products can reduce spread of the organism.
However, to the best of my knowledge, it is not particularly common as a cause of abortion (in livestock) or in humans.
I know that there are members of this site from NZ; again, I may be wrong, but I think NZ is one of the very few places where Q fever is not found.
Posted: Sat Sep 30, 2006 4:23 pm
by Kathy Millar
Thanks for the info, Ryan. I have never heard of Q virus here in Canada. I was chatting with a dairy farmer the other day and he said that Canada is considered free of livestock TB and brucilosis and that the Gov't was thinking of trying to eradicate Jhonne's disease (pardon my spelling!) I don't always like the implications of that as it means more regulations. We also have BSE.
Kathy
Posted: Sun Oct 01, 2006 1:53 am
by Inger
No, never heard of it in NZ either. We still have a few cases of Tb here though, in certain areas. We've never had the desease in the area we live in, so the tri-annual testing is just a formality for us. Brucellosis in cows is pretty much a desease of the past, but the sheep version is still being dealt with.
There is a new desease called Bovine Viral Diahorrea which has become the 'thing' to get on top of now. I don't think its going to take to long to cull the affected animals out of NZ's cattle herds as there isn't a pest animal as a vector, which is what's holding us up with the Tb. Possums carry Tb here and they are still in plague proportions in our native forest (thanks to whoever decided to start up a fur industry here). 
Fortunately, not all the possums throughout the country carry it (as in our area), so many farmers have one less thing to worry about. We do have to be very careful about any stock that we buy into our herd from a Tb affected area though and that includes animals that are moved about for grazing. So vigilance is still essential.
Leptosporosis is very high on the list of deseases to be aware of here, because rats and mice carry it. So most dairy farmers innoculate their herds against it yearly.