A U.N. agency warns that more than 50-million sheep and goats in 15 southern Africa countries may be at risk of contracting a deadly viral disease.  The warning follows an outbreak of the disease earlier this year in Tanzania.

The disease is called Peste des Petits Ruminants or PPR.  The Food and Agriculture Organization says the disease is on a par with rinderpest, which has devastated cattle in the past.  But while rinderpest is on the verge is being eradicated, PPR is on the verge of spreading across southern Africa.

A potential plague

The FAO?s Jan Slingenbergh is head of EMPRES, the Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases.

?It is the plague of small ruminants.  It can be a very aggressive killer virus.  But, at times, it also hides itself and does not show much clinical disease.  But usually it brings a lot of damage, a lot of clinical disease and it kills a lot of animals,? he says.

After the damage is done, PPR can lie in wait for another opportunity to strike.

?Once the epidemic has been through an area it may stay away for two, three years.  And then, by that time, there is a new population of small ruminants of sheep and goats, many of which are young animals.  They?ve never, ever been exposed.  And then again a new epidemic starts,? he says.

2010 outbreak

Fear that the PPR virus might spread follows its detection earlier this year in southern Tanzania, near the border with Mozambique.

?Now, incursion from Tanzania into Mozambique may not be a major, immediate threat.  But with the virus circulating in the southern highlands of Tanzania, there is a high probability that the virus finds its way into Zambia and Malawi,? he says.

The FAO official says there?s a chance the PPR virus is still circulating in southern Tanzania, even if there are no active outbreaks.  To stem the possible spread, the U.N. agency recommends widespread vaccination.

?That would be the top priority in order to sanitize, to remove any field strains that might still be present,? says Slingenbergh.

It also recommends much greater surveillance for possible PPR outbreaks in northern Tanzania.  This would allow immediate action to be taken should a problem arise.

Slingenbergh says Morocco faced a PPR epidemic and took decisive action.

?Morocco not too long ago became overrun by the same Peste des Petits Ruminants virus.  And what Morocco did was quite exemplary.  It vaccinated the entire national flock of sheep and goats.  And with it, it has probably eliminated virus circulating in Morocco,? he says.

Slingenbergh says all southern African countries should take the situation in southern Tanzania very seriously.  He says the justification exists to prepare for the worst.