OPMV discussion

Posted: Sat Nov 11, 2006 4:55 am Post subject: OPMV discussion

I hope the following isn't too wordy - sorry about that!

Viral disease infections in snakes is undoubtedly the biggest threat faced by the hobby in 2006. The worst thing about it is that we know so little about it – a condition that isn’t changing very quickly. Despite the increasing number of preliminary diagnoses of OPMV amongst hobbyist collections, very little in the way of solid conclusions can be drawn with regards to how the infections are transmitted and how they can be controlled. The Australian Reptile Park was the first collection to report an outbreak of OPMV – on the same day that it received a preliminary diagnosis in 2002. As we were to later learn, we were far being the first collection to receive that diagnosis from the same pathology lab (IDEXX) – we were merely the first to report it. A detailed account of the experience will appear in an article in the next issue of Reptiles Australia. What I’d like to report here are some of the conclusions we’ve drawn, along with some of our theories concerning the these viruses (there are at least two strains of OPMV present in Australia – plus Reovirus and IBD). Also, probably of most interest, I’ve summarized some of the measures we took in controlling the disease. Most of these recommendations have been posted in earlier discussion forums, including back in 2003.

After declaring a complete state of panic after our preliminary diagnosis four years ago (almost to the day), we began a long and detailed plan to contain and eradicate the infection. Meetings involving all relevant staff members were held at least daily. We researched the subject thoroughly – which was not difficult, since practically nothing was known at the time (an unfortunate reality that has not changed much in the four years since our outbreak). We spoke to relevant people in five US zoos and several venom laboratories that had battled outbreaks during the previous five to ten years. Below are some of the ideas and procedures that we developed, some of which may be helpful. Most of these hygiene procedures continue to be part of our day-to-day ‘standard operating procedures’ (SOPs) at the Reptile Park.

1) Quarantine Establish an effective quarantine process to isolate incoming snakes for an appropriate period with the view of observing the advancement of any disease syndromes prior to exposure to the principal collection. Beyond maintaining a separate quarantine facility, it is a good idea, where possible, to compartmentalize the collection. In conjunction with good hygiene practices, confinement of the infection to a discrete area/room/building can limit the infection to a manageable ‘block’ of the collection.
2) Foot-baths and liberal use of disinfectants Use of foot-baths with disinfectant leading into and out of every snake room. Although I’m not certain of the value of this practice, at the least it certainly helps maintain a mind-set of cleanliness and good hygiene.
3) Latex gloves use of disposable latex gloves. As a preventative measure, I’d argue that disposable surgical-type latex gloves are a must. And you can clean them between cages/snakes/whatever with corrosive disinfectants such as Virkon S without wiping out your skin. When extracting venom, in the interest of minimizing any cross contamination between snakes, I not only change my latex gloves between each cage bank, but I spray and wipe Virkon S from the gloves between snakes. To get through say 50 snakes, I’ll use upwards of ten pairs of latex gloves – really a negligible expense in the big picture.
4) Water bowl hygiene Dave Barker once wrote that the keeper’s thumb posed the greatest threat to any zoo’s reptile collection – and I’d argue that this threat is even greater for hobbyists. In almost every water bowl handling scenario that I’ve observed in large hobbyist collections, I have instinctively cringed, and volunteered my unsolicited opinion. If traditional water bowls are to be used, then considerable thought should be given to the cleaning and handling strategies adopted. As water bowls are removed from enclosures they should be immediately and fully submerged in an appropriate disinfection solution (e.g. hypo or quaternary ammonia) and soaked for an appropriate period before being washed with due hygienic care. However – there is a MUCH better way to go! One of the first strategies we adopted at the Reptile Park was the deployment of disposable ‘Chinese food’ type containers. We use the rectangular type. These can be purchased by the carton-load from suppliers of packaging materials – accessible through the yellow pages.
5) Hygienic feeding techniques Obviously, common sense has to prevail in every aspect of the snake-keeping process. With respect to feeding snakes, you wouldn’t want to use forceps/tongs to offer food to the snakes without disinfecting the business end of these every time a snake over-shoots the food item and makes contact or nearly makes contact with the forceps. A simple trick is to grab thawed rodents by tail tip with the forceps – or thawed day-old-chicken by the toe, and do what you can to avoid any contact by snake to feeding device.
6) Mite prevention Because of the possible role of snake mite in spreading blood-borne diseases such as OPMV, it is imperative that they do not become established in collection. To do this at the Reptile Park, we provided an overkill strategy that allowed us to be 100% confident in preventing the possibility of mites either spreading diseases within the collection, or ‘hitch-hiking’ on keepers or visitors to other snake collections. The following might be regarded as extreme overkill for the hobbyist, but it demonstrates the extreme nature of the measures we undertook during the first two years after the outbreak.
a. We maintained a practice of heavy internal treatments (Ivermectin), regular spraying of caging and animals with ‘Orange Medic’ during all cage cleans, and weekly fogging of all reptile holding rooms. Reptiles in pits were regularly dunked in Orange Medic solutions, and as per all other Reptiles, ‘topped up’ with high doses of Ivermectin, either delivered with food or via injection. In this manner we could maintain total confidence that mites were not a factor – an important accomplishment considering the nature of the visitor experience to the Reptile Park, which includes hands-on experience.

7) The use of the ‘Fogmaster Tri-Jet 6208’ is a fantastic strategy that allows you to ‘fumigate’ entire rooms with compounds such as F-10 (non-corrosive disinfectant) or Orange Medic (in my opinion, still the best anti-mite preparation available). If you do a web-search you’ll find that fogging with F-10 is a common practice employed in the control and avoidance of the avian equivalent to OPMV – Newcastle Disease, which is another form of paramyxovirus. When we were initially treating the room where our outbreak occurred, we ‘fogged’ on a weekly basis with F-10, and occasionally with Orange Medic just for good measure. We also fogged all other indoor areas with both compounds – because ‘why not?’. I highly recommend use of the fogmaster for extensive penetration of whatever sensible compound you wish to coat all surfaces of a room (including cage interiors) with. Its easy to find via Google. Always wear protective breathing apparatus – i.e. canister type gas mask when fogging. Not sure what long term effect the fogging has on snakes that breathe the stuff, but I’ve seen no ill effects as yet.

This is a pivotal time for the hobby, and a time when all snake keepers need to review their activities and husbandry processes – particularly with regards to hygiene and disease management and avoidance practices. An excellent publication has been produced by the NSW National Parks & Wildlife Service, and is available on-line at http://www.nationalparks.nsw.gov.au/PDFs/hygiene_protocol_snakes.pdf . This pamphlet should be regarded as ‘the bible’ of snake keeping hygiene – at least until something better comes along.

Hopefully the above info will help get some keepers thinking. What may be a feasible idea at this stage is the development of some sort of one-day seminar where anyone and everyone, from reptile hobbyists, zoo keepers, relevant experts and authorities get together for guest talks and open-forum discussions. Although I am very very busy at this time, I would be happy to participate in the planning and organizing of such an event, if (for example) ARK was to take a leadership in developing such a concept.

There are several very high profile veterinary pathologists who could probably be talked into giving talks – but it may be necessary to charge attendance fees in order to meet their travel costs. I’m sure Tim Hyndman – a PhD candidate who is working on developing a better diagnosis technique for Australia would attend.

John Weigel

Posted: Sat Nov 11, 2006 6:21 am Post subject:

Holding a seminar for interested parties is a very good idea, i'm sure there would be a lot of support from the herp community. I'm 100% for it and hopefully somehting will come of it.

Thankyou for your input John, there are some very good points in your post, I just made a banner to rotate on the site to draw some attention to the hygiene protocol document from NSW NPWS. It's a very good starting point that everybody should pirint out for reference

Hopefully Reptiles Australia will hit the newsagents real soon

Shane

Posted: Sat Nov 11, 2006 6:50 am Post subject:

Great post Smile

,

One question though; does feeding birds (chickens) to your snake collection in any way increase the chance of introducing OPMV, given that this virus is similar to "Newcastle Disease, which is another form of paramyxovirus".

Cheers,

Varanus.

Posted: Sat Nov 11, 2006 7:13 am Post subject:

John,
Thanks for getting involved in this issue and offering advice on it.

I honestly think that mites could be a vector in enabling OPMV,IBD into peoples collections,what is your gut feeling about this and do you still fog snakerooms etc on an ongoing basis?

Also what steps are taken at the ARP re volleys and other workers who have hands on roles within the park so as to break any link between the park and private collections and visa versa?

Posted: Sun Nov 12, 2006 12:58 am Post subject:

Shane - re an OPMV seminar.

I think there would be great value in it - for a number of reasons. Firstly, whilst some of the 'big' questions about the virus and its nature are still unanswered - experts like Dr Tony Ross and others are able to provide updates on where we are at, and for laymen like myself, give a much better understanding of what is known, and what likely features the disease will prove to have.

But equally, if we do get some momentum going, and I know that is something Shane is devoted to, the hobby will benefit in two ways. Firstly we can facilitate getting good advice about general disease control and disease avoidance to 'the masses' through not only the attendance at such an event, but through followup publications and discussions. But secondly, don't underestimate 'people power' and the ability that the hobby has to get proper focus from government bodies onto the need for funded research projects such as Tim Hydnman's. E.G. can you imagine a day when we have a vaccine?

From a practical perspective, I know that both Shane and myself are already stretched very thin in terms of taking on something as big as organising a seminar. May I suggest that a three to four hour 'workshop', with two or three half-hour talks from whatever experts can be rustled up, could be hitched onto some other amateur herp event - say a reptile expo? Or alternatively, can we get one of the herp societies to organise a herp conference with attendant workshop on OPMV being a central part of the package?

Varanus, Australian chicken growers are pretty confident that there are no current Newcastle disease issues in the country, so I don't worry about the appropriateness of chickens as a feed source. BTW there has been some experimentation with use of Newcastle Disease vaccine in snakes. Not sure how successful that has been.

Mark, yes we (I) continue to do an occassional fogging of our snake rooms with both F10 and Orange medic. It is a safe procedure if gas mask is used, and in our case, if it is done after hours.

Regarding our use of 'herp mad' one-day-a-week volunteers, and employees who keep snakes at home. The reality is that yes, we do worry about the possibility of getting a disease from unhygienic practices of private keepers. We do have very stringent hygienic processes, and we monitor the situation as closely as is practicable (achievable), and there is undoubtedly some trade off when you have to balance factors such as wishing to continue our important educational work while encouraging development of zoo professionals. I believe we do a very good job in this regard, and I'm personally proud of the fact that a great number of zoo professionals in Australian zoos got their start in our volunteer program. I think it will be a sad day if and when we disallow reptile keepers from the program - but it is something we have debated here, I can assure you.

John

Posted: Sun Nov 12, 2006 3:10 am Post subject:

This is something I feel we should all work towards, I can understand how busy you are John but it's great to have your knowledge and suggestions to draw from, we need you here.

All we need are some knowledgeable/passionate people with some organizational skills to make this happen, I'm keen to be involved.

A seminar with leading edge speakers would have so much to offer and would be a good basis to create information sheets etc, transcripts from such an event would be like gold and there is no reason voice and/or video of such an event wouldn't be in demand by all who missed out.

I feel the costs could be easily taken care of considering the interest and how it effects all of us.

There is a lot that can be done to benefit all, i'd be happy to setup a website dedicated to OPMV if there was enough information made available.

Comments?
Shane

Posted: Sun Nov 12, 2006 9:29 am Post subject:

There are alot of good ideas there which will benefit all in the hobbie. The sooner we can start to learn more about this disease, the sooner we can all start to protect our collections better

Posted: Sun Nov 12, 2006 9:51 am Post subject:

Thanks John for the insight on how you controlled the disease a while ago.

Unfortunately for us, we were obviously too complacent with cage to cage hygeine, and also not observing longer quarantine times than 6 months. We had an outbreak in our collection we found out about about 3 or so weeks ago, showed up in a snake we had owned for 10 months.

We have taken the advice onboard and used diposable bowls since then, latex disposable gloves and extremely minimal contact even during cleaning. So far, we only have had 2 snakes showing signs, one of them was the one we euthanized and got tested, the other appears to have recovered, and her mate who was in and out for breeding during that time are in the hospital room away from the house and main collection. We find it strange that she has almost fully recoverd, despite her being so affected by it.

I'd be interested why you prefer the vikonS over F10? And how long was it before you could say with confidence your park was clean of the disease? Did you worry about seemingly non-affected carriers?

It's been frustrating to say the least to find out information about this disease, especially being on the forefront of it. Most of that is because there is still little known about it I guess. Discussing it more with private keepers is definately needed, most dont' know what it is and most don't care because they think it's a rare thing. There are breeding loans, expos, herp meetings bringing animals, no quarantining etc etc, which is really scary to think what the future holds for the snakes in private collections.

Posted: Sun Nov 12, 2006 9:45 pm Post subject:

Posted: Mon Nov 13, 2006 12:41 am Post subject:

Nome and Venom,

Those are the core questions really, aren't they? The ones that can keep you up at night. When I spoke to a range of collection heads in US institutions that had OPMV outbreaks four years ago (their outbreaks had been in the few years prior to that) I got the impression that the view then - and its a view I took comfort from, was that in an environment of good hygiene, affected collections were treated like a bushfire - sick animals (flames) were euthanased, and any animals showing any signs of illness thereafter made a one-way trip to a separate building with appropriate shift in keeper assignment and preservation of good quarantine mentality.

But the yanks have something we don't have in Australia - titre-level tests of relative abundance of OPMV antibodies in snakes. That test costs about $20-40US, and can give an indication of whether the snake has been subjected to exposure to the virus. It doesn't prove that it is infected, it just gives an indication of exposure previously, and with followup tests you can see if the level is going up (bad) or not.

In our case, in the absence of any diagnostic tests beyond chopping up brain tissue, we took the hard decision of euthanasing any and all animals that may have had exposure to the snakes that defintely were sick. This was made much easier by the fact that the collection was split into several rooms, and the disease appeared to be confined to one room.

But neither ARP, nor anyone else in Australia keeping snakes can be less than vigilant.

Changing the subject slightly, I recently participated in a zoo meeting where an address from Dr Tony Ross - probably Australia's leading expert on animal viruses talked about OPMV. An interesting point he raised was that IF the virus is transmitted via breathing out viral particles, then high humidity would be an important consideration. Just another clue, but that's mostly what we have at this stage.

John

Posted: Mon Nov 13, 2006 2:50 am Post subject:

Thanks for the comments John.

It seems a very difficult situation for some time after the last known sick animal has been removed from a collection.

The only solution to this problem (at this stage) seems to be to maintain adequate quarantine and disinfecting maintenance procedures, as suggested.

Is there any news when this titre level test will be available to us here?

Posted: Mon Nov 13, 2006 5:35 am Post subject:

Being a virus I would have assumed that if tests show antibodies that would indicate an immunity??????????????
If an animal that has had the virus survives it would be immune and not a carrier????????????
Do I know what Im talking about????? No! but Im just floating the idea??????

Posted: Mon Nov 13, 2006 6:09 am Post subject:

Questions we'd all love to have answers to. I don't know.

Shane

Posted: Mon Nov 13, 2006 6:31 am Post subject:

Posted: Mon Nov 13, 2006 8:28 am Post subject: