I'm a little confused by this discussion. In my mind a carrier is an animal that is infected but its immune system stops it from causing detrimental effects (symptoms). Sometimes virus can still shed to other animals, as this can be a separate process to causing disease in its host.

 

I think the problem is in the definition of immunity and infection. Immunity simply means stopping an invading agent before it can cause significant disease. So immunity can mean that an animal will not show symptoms when it is infected (because of a defense launched by special cells in the body), and also that it can't be infected in the first place (eg defences at the point of entry) – both of these are forms of immunity. Melb is referring to the first point, Liv to the latter. But I think you are both arguing the same point – a bird carries the disease, but doesn’t show symptoms, because it has immunity (cells within the body stop the disease process), but it can still have the virus/bacteria inside it. It just doesn’t show symptoms – that is the key point when infected.

 

HIV is a virus of the immune system - the symptom is lack of immunity. That's why it's impossible to vaccinate against it - vaccination only helps it because it stimulates the immune cells to take up the virus.

 

I think the idea of latency is mixed up in here too - like a herpesvirus. A third of those exposed carry herpesvirus in our nerves and it sits there dormant until something else like stress/damage precipitates it- and voila, you get coldsores. But it is always there, and it can still be spread occasionally if the conditions are right. We can’t fight it with the immune system because it is hidden away in the nerve.

 

Phew. Virology/microbiology is not a simple subject, as I can clearly remember!

 

Anyhow. I'm with Sailor on this (just did JETACAR stuff too). Antibiotics are thrown around far too freely these days - both for humans and animals- and is the reason there are resistant superbugs now.

 

The idea behind the yearly or whatever antibiotics is that some bacteria are obligate parasites, so they simply cannot survive without a host. So if you kill them all in one go, within the birds, there should be none left in the environment after a certain time. However that isn't to say a wild bird couldn't re-infect your flock and they would have zero immunity to it. You also run the risk of not killing them all if you haven't done a full course (power and duration) so the bugs that repopulate are even more resistant to antibiotics.

 

On a side note, one of my vet friends just told me - she was mucking out one of the uni bird aviaries a couple months ago. Later that day one of the lecturers was... ":hap: But those birds have psittacosis!" She'd been aeroslising the faeces and breathing in, and was totally fine - guess she was lucky!

 

Hope I haven't confused things even more.. My head hurts… O.O

I think I'm going to look more closely at Chlamydophila to see how it does its work.. Liv where did you read about that lack of immunity stuff?

Edited April 25, 200817 yr by Chrysocome

I have read in quite a few places where people are feeding their birds an annual feed of antibiotics to clear their birds of psittacosis, whether they have symptoms or not, from my understanding this seems a very dangerous thing to do, in regards to résistance to antibiotics.

 

It’s a bit like us as Budgie breeders each year choosing which birds we breed together to produce the best birds or show winners.

 

Bacteria don’t breed sexually like our birds, but breed by division [cell division] so you don’t get variability like you do in sexual breeding, but still simple life forms mutate & are not exactly alike. So when you feed antibiotics the antibiotic is like the stud breeder, it selects who lives or dies & the thing with simple cell life forms is that whereas with sexual breeding if only one survived the species will die out, but with bacteria even if only one cell survived it will continue it’s division unchecked till there could be millions like itself. The more times you feed antibiotics the more chances you have of selecting bacteria immune to it.

 

The bacteria causing Psittacosis must be a pretty resilient strain, as when using the correct does which is Doxycline Hydrochloride 40mg/g they recommend using it for 7 to 10 days for most bacterial infections, but for psittacosis they recommend 45 days, a few years ago it was for 30 days, which suggests to me that either the bacteria is already getting immune to the disease & takes longer to knock or that they have found out it takes longer than they thought. Also in my opinion this antibiotic is quite expensive & feeding it annually seems an expensive exercise when you are not even sure that Psittacosis is present & especially if not fed for the full term as this will certainly aid in the bacterium becoming immune to the antibiotic & making it useless in treating it later. Also some are feeding a cheaper type of antibotic similar or a weaker strength, which also seem dangerous as if weaker or different in some way it's effects will be less, but will still start the selection process with bacteria to becoming immune.

Liv where did you read about that lack of immunity stuff?

 

Here is were I read it ---- > HERE

 

I agree with the over use of antibiotics... Which is why I had my initial idea.

If many show breeders use antibiotics as preventative measures, could also explain the reason why (in general) the show type budgie is not as hardy as the pet type.

 

There have been some great points raised!

It seems that it is a big topic with lots of different views.

Wow that's an extremely scary disease. I feel bad for not quarantining my second budgie, so I'll try to keep a good eye on them to make sure nothing's wrong with them.

 

As for the HIV thing, they have found people immune to it in Africa. The virus connects to a certain receptor of the cells, and in those people it's missing (making the virus unable to connect and reproduce).