Volume 17, Number 7–July 2011
Asian Lineage of Peste des Petits Ruminants Virus, Africa
Olivier Kwiatek, Yahia Hassan Ali, Intisar Kamil Saeed, Abdelmelik Ibrahim Khalafalla, Osama Ishag Mohamed, Ali Abu Obeida, Magdi Badawi Abdelrahman, Halima Mohamed Osman, Khalid Mohamed Taha, Zakia Abbas, Mehdi El Harrak, Youssef Lhor, Adama Diallo, Renaud Lancelot, Emmanuel Albina, and Geneviève Libeau Comments to Author
Author affiliations: Control of Exotic and Emerging Animal Diseases, Montpellier, France (O. Kwiatek, R. Lancelot, E. Albina, G. Libeau); Central Veterinary Research Laboratories, Soba, Sudan (Y.H. Ali, I.K. Saeed, M.B. Abdelrahman, H.M. Osman, Z. Abbas); University of Khartoum, Shambat, Sudan (A.I. Khalafalla, A.A. Obeida); Rabak Veterinary Research Laboratory, White Nile State, Sudan (O.I. Mohamed); Atbara Veterinary Research Laboratory, River Nile State, Sudan (K.M. Taha); Biopharama, Rabat, Morocco (M. El Harrak, Y. Lhor); and International Atomic Energy Agency, Vienna, Austria (A. Diallo)
Suggested citation for this article
Abstract
Interest in peste des petits ruminants virus (PPRV) has been stimulated by recent changes in its host and geographic distribution. For this study, biological specimens were collected from camels, sheep, and goats clinically suspected of having PPRV infection in Sudan during 2000–2009 and from sheep soon after the first reported outbreaks in Morocco in 2008. Reverse transcription PCR analysis confirmed the wide distribution of PPRV throughout Sudan and spread of the virus in Morocco. Molecular typing of 32 samples positive for PPRV provided strong evidence of the introduction and broad spread of Asian lineage IV. This lineage was defined further by 2 subclusters; one consisted of camel and goat isolates and some of the sheep isolates, while the other contained only sheep isolates, a finding with suggests a genetic bias according to the host. This study provides evidence of the recent spread of PPRV lineage IV in Africa.
Peste des petits ruminants virus (PPRV) belongs to the genus Morbillivirus, in the family Paramyxoviridae. Like other members of the same genus, such as rinderpest virus, Canine distemper virus, Measles virus, and marine mammal viruses, PPRV is highly pathogenic for its natural hosts (1). As consistently reported by the World Organisation for Animal Health, PPRV causes high death rates in livestock. It has a major economic effect, particularly in the intertropical regions of Africa, on the Arabian Peninsula and in the Middle East and Asia (2–5). The main signs of the acute form of the disease are high fever, mouth ulceration, diarrhea, and pneumonia.
Although rinderpest virus was eradicated after intensive vaccination campaigns in the last quarter of the 20th century (6), PPRV has continued to spread in Africa and Asia. In East Africa, outbreaks occurred in 2007 in Uganda and Kenya and in 2009 in Tanzania (7); in North Africa, an outbreak occurred in 2008 in Morocco. Genotypic classification of PPRV has identified 4 lineages and appears to be an efficient tool to survey virus spread worldwide. Genetic variability is based on partial sequencing of the fusion (F) protein gene (8,9) and of the 3′ end of the nucleoprotein (N) gene (10). Both are well conserved genes with ≈10% nt mean variability between the most distantly related sequences (11); this variability can exceed 30% on some parts of the sequence. However, because the N gene is the most abundantly transcribed virus gene, sensitivity is better achieved with N mRNAs (12). Viruses of lineage I and II are restricted to western and central Africa; lineage III is common to eastern Africa and the southern part of the Middle East. In Asia, only viruses of lineage IV have been detected.
In Sudan, continuous outbreaks of PPRV have occurred for >30 years, mainly in sheep and goats (2,13). Although PPRV infection is well documented in small ruminants, data are rare for other species, such as cattle, buffalo, and camels. In 1997, a PPRV was isolated from pathologic samples collected during a rinderpest-like disease outbreak among buffalo in India (14). In September 2004, outbreaks of PPRV in Sudan affected both sheep and camels (15,16). In camels, a respiratory syndrome was the prominent disease characteristic observed, resembling a previous case reported in Ethiopia during 1995–1996 (17).
More recently, in summer 2008, Morocco reported outbreaks of PPRV for the first time (18). Because PPRV needs close contact for transmission, this new epizootic was likely the result of introduction of the virus into North Africa through the movement of live infected animals. To characterize PPRV strains identified in Sudan during 2000–2009 and in Morocco during the extensive 2008 outbreaks, a phylogenetic analysis was carried out on wild-type PPRV sequences obtained from biological samples collected from sheep, goats, and camels in these 2 countries.
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Suggested Citation for this Article
Kwiatek O, Ali YH, Saeed IK, Khalafalla AI, Mohamed OI, Obeida AA, et al. Asian lineage of peste des petits ruminants virus, Africa. Emerg Infect Dis [serial on the Internet]. 2011 Jul [date cited]. http://www.cdc.gov/EID/content/17/7/1223.htm
DOI: 10.3201/eid1707.101216
Comments to the Authors
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Geneviève Libeau, Biological Systems Department – CIRAD, Control of Exotic and Emerging Animal Diseases (UPR15) TA A-15/G Campus Int., Baillarguet 34398 Montpellier CEDEX 5, France; email: genevieve.libeau@cirad.fr
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