Comparatively, we are a pristine country when it comes to many trans-boundary diseases. Also the fact that we have a veterinary cordon fence demarcation, makes us even more pro-active to any “new” developing diseases colonising our neighbouring countries on the continent.
One such disease breathing down our neck is the Peste des petits ruminants (PPR), also known as goat plague. (Don’t worry about the French pronunciation we will use the common abbreviation PPR.)
PPR is primarily a disease of sheep and goats and is caused by a paramyxovirus of the Morbillivirus genus, which is a virus closely related to the one causing cattle rinderpest disease (thank God that disease has been eradicated from the face of world in 2011). In fact, some authors refer to PPR as Ovine (sheep) Rinderpest. The virus is also related to the one causing canine distemper (honde siekte) and human measles. Apart from goats and sheep it can also affect wild ruminants such as gemsbok, oryx and gazelle. Cattle and pigs are also susceptible to infection but don’t get sick and are not able to transmit the disease to other animals.
Fortunately, PPR does not cause infection in humans; therefore, there are no public health issues to be considered. However, the most worrisome feature of this disease is that it spread like wild fire even through inhalation, direct contact with infected materials such as faeces, saliva, water, and feed troughs. And it causes a lot of deaths to infected animals. It is what we refer to as a disease of economic importance especially since people in Namibia rely heavily on sheep and goats for fresh meat and we are also exporting sheep and lamb.
PPR was first described in 1942 in Cote d’Ivoire, West Africa, now it is endemic in most African countries, the Middle East and Indian subcontinents. Following an outbreak in DRC and Tanzania in 2010, SADC has developed a regional PPR Control Strategy in response to the outbreak of this disease in order to contain/ control the spread of the virus. Currently, closer to home, the disease was diagnosed in northern Angola.
If the disease happens to spread to southern Angola, then we will be sitting on a time bomb. We know our animals in the north tend to graze into southern Angola because of the porous border that exists between the two countries, and this poses a major risk to introduce PPR into Namibia.
Coming down to the disease itself, it is the young animals (4 to 8 months) that often have severe disease. Mostly the animal will have the virus for about 4-5 days (incubation period) before it can show clinical signs of being sick. It was also noted that poor nutrition, stress of movement, and animals with parasites, worsen the clinical signs.
What farmers will notice is that affected animals are depressed, don’t eat and show sudden high fever (40-41C) which remains high for 2-8 days. Other noticeable signs are a runny nose (nasal discharge) which later on becomes thick and pussy-like (muco-purulent) and can crust over and block the nostrils. Similarly, the eyes get similar discharge that also crust and cement eyelids together preventing the animal to see properly. The affected animal will also cough heavily with a dry whiney sound (bronchopneumonia), and show difficulty in breathing and sneeze a lot in an attempt to clear the nose. Severe diarrhoea can be seen in most affected animals and when you enter an affected flock you see all these animals stained with sticky faeces. Pregnant animals will abort. If you open the mouth, you will see typical ulcers around the lips and gums and Orf-like lesions can be seen around the mouth in recovering cases. In the final stages, animals will have lost a lot of weight, succumb from severe dehydration and usually die after 5-10 days.
On opening of the dead animal (carcass), the inflammation of several organs is clear especially the mouth, stomach, intestines. Bloody splashes around organs are also noticeable in most cases. “Zebra-striped” lesions on the intestines and rectum are said to be typical in some cases.
There is no proper treatment of PPR, although antibiotics especially oxy-tetracycline (Swamycin, Terramycin or Agramycin) and penicillin in combination with anti-inflammatory, multivitamins and multi-minerals tend to help with recovery from the disease. However, this is not advisable as the disease spread fast and the best “treatment” is to just slaughter all infected animals. Proper disposal of carcasses, decontamination of facilities and equipment as well as quarantining all potential in contact animals, are also guaranteed ways of controlling the disease from spreading. Fortunately, there is also a vaccine available on the market which gives strong immunity against PPR.
The question is “Can we avoid PPR as a country?” Yes and No. why?
Yes, by raising awareness, we can avoid disastrous consequences of carrying PPR into the country through movement of animals. If it is confirmed that the disease has reached our northern neighbours especially southern Angola, then we must be vigilant and not allow sheep and goats coming from that part of the continent into Namibia. In fact, although this has sensitive socio-economic impact on the people living around the northern Namibian border with Angola, animals grazing into Angola must be restricted in total. On the other hand, without a proper fence between the neighbouring Angola, the possibility of preventing the introduction of PPR (among other diseases) into Namibia will remain a vacuum.
The fight to improve our country animal health status and to prevent the introduction of new diseases remains a priority of the veterinary services. And with PPR breathing down our necks, we as stakeholders have to brace ourselves and keep by the imposed rules of veterinary services in order to safeguard our livestock industry.