Alex Lewis, [08 Oct 2022 at 11:30:12]: Can anyone explain the risk of introducing Trypanosoma positive animals into a non tsetse fly areas? Dave Cooper, [08 Oct 2022 at 12:04:35]: Many potentially and confirmed Trypanosoma positive animals have moved from N KZN all over SA obviously without any problems. However the veterinary authorities in Eswatini and SA see it differently. What is the reason why we have to bleed hippo when bringing them to SA? Alex Lewis, [08 Oct 2022 at 12:18:28]: Is there research to show we can inject and sterilize? Roy Bengis, [08 Oct 2022 at 15:45:47]: The problem is that Trypanosoma vivax can be transmitted mechanically by other be biting flies like Tabanids. Most of the other Trypanosomes require biological transmission by tsetse flies Dave Cooper, [08 Oct 2022 at 16:25:29]: Noted Roy. Not sure if something like Samorin would sterilise an infection before movement?? Rob Jackson, [08 Oct 2022 at 16:36:14]: Possibly Triquin, I found cerebral recurrence in horses that recovered when treated with Samorin. I dont think it crosses the blood/brain barrier. Triquin worked on the horses with chronic nervous signs. Samorin did not. Alex Lewis, [08 Oct 2022 at 17:26:21]: Is there any sterilisation research, as I would need something like that to try and avoid bleeding the hippo. If I was to treat and test, what hippo-side tests would be best option? Roy Bengis, [09 Oct 2022 at 09:50:32]: Thanks Rob, that is good to know. Alex, I do not know of an animal side field test for Trypanosomes. Risk mitigation would include treatment plus movement into a tsetse free area . Alex Lewis, [09 Oct 2022 at 12:02:15]: Thanks Roy. If I catch and treat, how long after treatment if kept in tsetse fly free area before test will come up clean? Dave Cooper, [09 Oct 2022 at 16:01:20]: Eswatini I negotiated a buffy coat smear. All that was required was a centrifuge and microscope. For test such as PCR etc you are going to wait a long time. What species from where to where? Roy Bengis, [10 Oct 2022 at 09:19:31]: Thanks Dave, that is a practical possibility, and I have used it, first looking for movement in a wet preparation with a cover slip, followed by a buffy coat smear that is fixed and stained. I am not sure what the sensitivity is in animals that have a low parasitaemia. I have used a small micro-haematocrit battery driven centrifuge, and then one needs to break the micro-haematocrit tube at a level close to the buffy coat. One also needs a good field microscope with solar/mirror or 12 volt car battery illumination. Alex, I have seen no reference as to the duration of sero-positivity or PCR positivity after treatment.🦏🦏🐃 Richard Burroughs; Roy, this is an interesting discussion. I know about T. vivax being transmitted by tabanids. Dave Cooper’s initial comment and query is valid. Surveys of cattle in Zululand have found 5% prevalence of T vivax. The border from S Mozambique into N Kwazulu as we know is a superhighway, and there is definitely T. vivax in S Mozambique. The point is then with the movement of rhino and hippo out of Ezemvelo reserves, some will carry T. vivax. It then questions the value of this import condition, not that it is likely to be changed easily. Rob Jackson, [10 Oct 2022 at 09:58:43]: Book talks about using a hanging drop under the slide which may make it easier to pick up movement. Wet preparation worked, as did DiffQuick thick slides but with lots of searching. I tried to screen horses via anaemia, tried dourine test as a screen as it was all we had Roy Bengis, [10 Oct 2022 at 10:04:06]: Richard, I concur with your facts and sentiments. What we need to ascertain is whether it is possible to chemo-therapeutically sterilise infection with T. vivax infection Dave Cooper, [10 Oct 2022 at 10:40:29]: I agree Richard, but the question remains with all the species moved from NKZN has there ever been a problem? I also only know Samorin as a possibly sterilise but causes severe reactions in Equids and rhino! In spite of 50% dilution and meticulous sterilise injection of only 10ml/site all 30 rhino sent to Rwanda developed abscesses. Alex Lewis, [10 Oct 2022 at 10:46:16]: I have had very bad reactions to samorin in donkeys and mules also trying everything to be clean. If I was to do a practice run of hippo to catch in the Zambezi valley move to vector free bomas on my farm (out of tsetse area but lots of mean tabanids) and did a serial treatment with different products to try and prove sterilisation. What would be adequate proof that sterilisation has occurred? Because obviously from a conservation perspective treatment, even if multiple treatments would be best. For example, treat at capture and move to vector-free areas in RSA to repeat better tests more easily . Alex Lewis, [10 Oct 2022 at 12:17:31]: If one was to do a PM to prove sterilisation of Trypanosoma sp., where would they hide? Richard Burroughs I agree Dave, and that is the point I should have expanded on. As far as I know, T vivax has never been found outside of Zululand, (maybe suspect KNP) and the question needs to be asked if rhino or hippo play any role in its transmission, so what is the value in limiting the movement of these sp. into RSA? Do we know what role these species play, if any? Roy Bengis, [10 Oct 2022 at 15:02:55]: Hi Alex, most preferred wildlife hosts in tsetse endemic areas are premune and may have very low parasitaemias. The major part of their life cycle in vertebrate hosts is intravascular, although some species do enter other tissues (e g brain). I don't think that a PM would be very useful. Alex Lewis, [10 Oct 2022 at 15:11:27]: Thanks. So safe to say if we can not find in blood samples (may be repeated), then we can certify animal non-infective? Roy Bengis, [10 Oct 2022 at 18:58:42]: Alex, I would love to support that statement, but unfortunately we are dealing with biological systems. I would word it :" unlikely to be infective". It's the best we can do, and the official government veterinary structures need to understand that the risk is miniscule, and accept that in their risk assessment / mitigation protocol.
