Peste Des Petits Ruminants - A Permanent Burden on the Development of Small Ruminant in Ivory-Coast

Research Article

Austin Virol and Retrovirology. 2015;2(1): 1008.

Peste Des Petits Ruminants - A Permanent Burden on the Development of Small Ruminant in Ivory-Coast

Couacy-Hymann E¹*, Koffi YM¹, Godji P¹, Kouassi LA¹, Kouakou KC¹, Krou AH¹ and Nana P¹

11LANADA - Central Laboratory for Animal Diseases - Virology Laboratory, Ivory-Coast

*Corresponding author: Couacy-Hymann E, LANADA - Central Laboratory for Animal Diseases, Virology Laboratory, BP 206 Bingerville, Ivory-Coast

Received: December 02, 2014; Accepted: March 29, 2015; Published: March 31, 2015


PPR is a major constraint of the development of small ruminants in areas where it is endemic such as Ivory-Coast.

On the period 2009-2012, we conducted a PPR survey in four selected regions (Agboville, Bongouanou, Dabou and Yamoussokro). Based on reports from the field veterinary technicians we investigated fourteen outbreaks of PPR causing estimated mortality cases of 1300 goat’s ad 450 sheep. Appropriate tissue and swabs samples were collected along with 746 randomly collected serum samples. Using the N-cELISA technique, an overall seroprevalence of 35.6% (266/746) was found ranging from 12.9% in Yamoussokro region to 56.7% in Bongouanou region with a yearly seroprevalence varying from 25.2% in 2012 to 40.7% in 2010. All the tissue and swabs samples were positive by RTPCR and the PPR virus was isolated from eight tissue samples on the monkey CV1 cell line expressing sheep-goat SLAM protein. These strains felt into PPRV lineage II.

Keywords: PPR; RT-PCR; ELISA; Disease surveillance; Small ruminant; Ivory-Coast


Peste Des Petits Ruminants (PPR) is a serious and contagious plague of small ruminants, mostly sheep and goats, in many developing countries in Africa, near and Middle-East and southern Asia [1]. Within Africa, PPR has now extended to southwards in Tanzania, Democratic Republic of Congo and Angola [2,3]. Outbreaks of PPR have been also reported across North Africa including Algeria, Morocco, Tunisia [4-6] along with the European part of Turkey [7]. In southwest Asia, China has reported PPR spread all over the country starting during year 2007 in Tibet region [8]. The current spread of PPR over large geographically areas can be due to the eradication of RPV from the world. Animal of all ages are susceptible and the transmission route remains oral and respiratory secretions following close contact between infected and naive population.

The disease is highly contagious and case fatality rates in some outbreaks can approach 90% in susceptible populations and, as a consequence of the effects of epidemics, the local and rural economies of the affected countries can be devastating [9,10]. Since small ruminants are a major resource for the rural populations then they are more seriously affected by epidemics of PPR. Nowadays there are efficient attenuated vaccines to be used to prevent this disease and to control its extension [11-13]. In addition, there are new diagnostic tools available after a quick report of any outbreak of PPR.

Depending on any predisposing factors and the virulence of the infecting virus, clinical manifestation for PPR can be seen in peracute, acute, sub-acute and sub-clinical forms. However, PPR in sheep and goats is generally observed as an acute disease. The peracute form of disease is often seen in kids infected at the age of 4 months and older during the time frame whereupon any pre-existing maternal antibody levels wane. This per-acute form of disease has a short incubation period (2 days) with a rapid development of pyrexia with body temperature rising to 40-42oC. Depression, congestion of mucous membranes, oculo-nasal discharge, dyspnoea and profuse watery diarrhea lead to the death of infected animals within 4-5 days.

In the acute form of disease a 3-4 day incubation period precedes development of pyrexia and the onset of other clinical disease signs, including watery oculo-nasal discharge, congestion of the mucous membranes of the buccal cavity, conjunctiva of the eye and the vulva. A diarrhoeic phase follows, often resulting in the generation of bloody faecal matter leading to dehydration and ultimately death of the animal. As the disease progress, the watery oculo-nasal discharge may become mucopurulent and can occlude the nostrils, predisposing to dyspnoea.

In the sub-acute form of disease, the animals do not develop severe clinical disease and low mortality rates are seen. With this form of infection, the animals may develop temperatures ranging from 39- 40oC, but do not develop the characteristic clinical signs normally associated with PPRV infection. Animals usually recover from the disease within 10-14 days. A sub-clinical form of disease is also seen in large ruminants (buffalo and cattle), where the infected animals are able to clear virus in the complete absence of clinical disease, but seroconvert to PPRV, often generating strong neutralizing antibody responses. Sheep and goat are the main susceptible host of PPRV.

The causative agent, Peste Des Petits Ruminants Virus (PPRV) is a negative-strand RNA virus with a monosegmented genome of length 15,948 and containing 6 genes encoding 6 structural proteins which are the Nucleocapsid protein (N), the Phosphoprotein (P), the Matrix protein (M), the Fusion protein (F), the Haemagglutinin protein (H) and the Polymerase protein (L). In addition, the P gene also encodes the three non-structural proteins V, W, C. It belongs to family Paramyxoviridae and the genus Morbillivirus together with Rinderpest Virus (RPV), Measles Virus (MV), Canine Distemper Virus (CDV) and marine mammalian Morbilliviruses [14]. There are four lineages of PPRV based on the differentiation determined by the sequence comparison of a small region of the F gene [15] or the N gene [16,17]. However, it has been demonstrated recently that the N gene is more divergent therefore more suitable for phylogenetic distinction between closely related PPRV viruses [18]. Historically, African PPRV isolates were lineages I, II, III (with mainly West African countries harbouring lineages I and II and East African countries with lineage III) and the Middle-East and Asian isolates were lineage IV. Within a short time this distribution has deeply changed : in West Africa : lineage II is spreading with the trend to push out lineage I confined to Ivory-Coast, Conakry Guinea and Burkina-Faso with a co-circulation of lineage I. Moreover in 2009, lineage II was identified in Ivory-Coast [19] where probably the two lineages are co-circulating. Lineage IV has been found in Africa with an extension from East Africa (mainly Sudan, lineages III and IV) up to Nigeria where lineage II is still circulating [4,20] and to Southern part : Democratic Republic of Congo (DRC) and Angola (Diallo, personal communication). Northern African countries have Lineage IV too [20].

The present study aimed to investigate PPR outbreaks on time based on the early reports from field staff and early detection and confirmation from the laboratory that will help to trace the lineage strain in circulation within the country. It is also to make a differential diagnosis with other syndromic diseases such as pasteurollosis or internal parasite infestation. This is based on the collection of appropriate specimen on the field.

Materials and Methods

Sampling sites and samples collection

Four regions were selected to perform this survey on PPR: Agboville, Bongouanou, Dabou, in the southern part of the country which is the forest region and Yamoussokro in the centre being the Presavannnah region (Figure 1). They were visited by the Virology- Laboratory’s team in close collaboration with local veterinary field personnel. A total of 28 villages were visited. Each village, being an epidemiology unit, with animals flocks living and grazing together on the same pasture. Both active and passive disease surveillance were used during this study and appropriate outbreak investigation was conducted along with the collection of good quality samples. From the outbreak investigation, tissue samples and oral, ocular and nasal swabs were collected on the period 2009-2012 from the three southern regions (Agboville, Bongouanou and Dabou) and from all sick animals of the concerned flocks (Table 1). In addition, a total of 746 serum samples (319 and 427 samples from goats and sheep respectively) were randomly collected from each epidemiology unit including Yamoussokro region with a minimum of 25 serum samples per unit (Table 2).