EPIDEMIOLOGY REPORT WESTERN CAPE DEPARTMENT OF AGRICULTURE VETERINARY SERVICES. What is tested for in the National Residue Program?...

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1 EPIDEMIOLOGY REPORT Volume 2, Issue 1 Jan 2010 WESTERN CAPE DEPARTMENT OF AGRICULTURE VETERINARY SERVICES What is tested for in the National Residue Program?...cont Synthetic Steroids 1. Melengesterol Acetate (MGA) Melengesterol acetate (MGA) is a progestogen and a synthetic anabolic steroid used: to improve efficiency in feed utilization; growth stimulation and oestrus suppression in feedlot heifers 5,3. It is also used as an oestrus synchronization agent for cattle 5,1. Effect on humans In general terms the results of open clinical trials in humans indicate reasonably good tolerance to large daily doses of MGA 3. MGA can block ovulation and the menstrual or oestrous cycle in females of various species 5. The effects of MGA and the significant levels of MGA residue in meat still require much scientific work, but there is no doubt that this hormone has an influence on the endocrine systems of mammals that it is introduced into. 2. Medroxyprogesterone Acetate (MPA) Use in Humans Medroxyprogesterone Acetate (MPA) is a progestin which is a synthetic variant of the human hormone progesterone 2. It is used in female humans as an oral contraceptive and in hormonal replacement therapy. In males the uses are more sinister and is used in the treatment of paedophiles and patients with mental illness that exhibit sexually inappropriate behaviour (References in Light and Holroyd 2006) 4. In these cases it works by lowering testosterone levels and thereby sex drive whilst not causing feminisation. The side effects in humans are varied and numerous. Use in Animals Neutered male and female cats with bilateral alopecia caused by sex hormone imbalances may respond to MPA treatment. There are other uses for MPA in small animal veterinary work but it is generally only used as a last resort as the side effects of treatment can be significant 1. References 1. Anon 2005 The Merck Veterinary Manual (9 edn). Merck & Co., Inc, Whitehouse Station, New Jersey, USA 2. Anon 2010 Medroxyprogesterone. Wikipedia 3. Joint FAO WHO expert Committee on Food Additives 2000 Toxological evaluation of certain veterinary drug residues in food. Report # Light S A, Holroyd S 2006 The use of medroxyprogesterone acetate for the treatment of sexually inappropriate behaviour in patients with dementia. J.Psychiatry Neurosci. 31: Scientific Committee on Veterinary Measures relating to Public Health 1999 Assessment of Potential risks to Human Health from Hormone Residues in Bovine Meat and Meat products. Report # XXIV/B3/SC4

2 Page 2 VOLUME 2, ISSUE 1 Vaccinations SV SV Beaufort West SV Boland SV George SV Malmesbury SV Swellendam SV Vredendal Species Disease Total Vaccinated 56 AFRICAN HORSE SICKNESS AVIAN 515 BOVINE ANTHRAX AFRICAN HORSE SICKNESS AFRICAN HORSE SICKNESS Total Vaccinations within the Province: January BOVINE AFRICAN HORSE SICKNESS ANTHRAX AVIAN Disease and Species 2 502

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5 VOLUME 2, ISSUE 1 Page 5 New/Current Outbreaks and Cases: January 2010 Sum of Total Outbreaks Sum of Total Cases Totals (Log Scale) ANAPLASMOSIS 2 43 BABESIOSIS (REDWATER) 1 25 CYSTICERCOSIS (Cysticercus bovis) LUMPY SKIN DISEASE DISTEMPER SHEEP SCAB BOVINE OVINE Species and Disease Outbreak Investigations The sheep scab outbreak seen in the Malmesbury district has been ongoing with regard to treatment of infected and suspect flocks, with most farms having completed the required treatments. No new cases have been reported from the affected area. There has however been a flare up of the mite near Piketburg, with 3 confirmed properties showing evidence of the affliction. Both the George and Beaufort West offices are reporting on the number of suspected distemper virus cases they see. Most of these cases are based on clinical signs and are not confirmed in the lab but, due to the quite unique and recognizable symptoms of severe canine distemper virus infection, the values can be viewed as being reasonably accurate. The values obviously don't give an indication of what is occurring in the rest of the population that is not seen by the SV. There have been reports in the press of large numbers of dogs in the southern Boland area falling prey to canine parvo virus. Although the disease is highly contagious it is easily controlled by vaccination which should be administered on a yearly basis in adult animals. Parvovirus is not a notifiable disease. The cysticercosis cases which are reported on by the SV Malmesbury office are those cases which are noted by the meat inspectors at the various abattoirs in the area. The points on the accompanying map are not indicative of the source of the disease, but rather where the signs of the disease have been seen. 5

6 THE BACK PAGE (with) ANSWER If 5 healthy chickens take 5 days to die after being simultaneously infected with Newcastle disease virus, how long will it take 10 healthy chickens to die under the same circumstances? It will also take 10 chickens 5 days to die from NCD infection based on the questions criteria. If 5 chickens take 5 days to die from NCD after being simultaneously being infected it follows that 1 chicken will take 5 days to die from the disease. Notifiable Disease Web Database There is no back page question this issue, but what is more exciting to replace it is a screen shot of our newly developed web based system for mapping and submitting notifiable diseases. The system is currently being tested by the Boland offices AHT s and as soon as all the tweaking has been done the system will be implemented throughout the Province. FC Basson from the GIS department deserves all the credit for his hard work in making this a reality. The basic use of the system involves navigating to a point on the map where either a routine vaccination was performed or where an outbreak occurred and then entering the relevant information of that point. The coordinates of the point are automatically loaded into the relevant fields, although coordinates can be manually inputted after which the pointer scrolls automatically to said point. This system will hopefully be a stepping stone on the path to the newly developed CADIS system. Disclaimer: This newsletter is published on a monthly basis for the purpose of providing up-to-date information regarding epidemiology of animal diseases in the Western Cape Province. Much of the information is therefore preliminary and should not be cited/utilised for publication John Grewar: State Vet Epidemiology Phone: JohnG@elsenburg.com Lugen Govender: Data Processor - Epidemiology Phone: LugenG@elsenburg.com 6