Asian Lineage of Peste des Petits Ruminants Virus, Africa

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 fi rst reported outbreaks in Morocco in 2008.Reverse transcription PCR analysis confi rmed 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 defi ned 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 fi nding with suggests a genetic bias according to the host.This study provides evidence of the recent spread of PPRV lineage IV in Africa. P este des petits ruminants virus (PPRV) belongs to thegenus 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 classifi cation of PPRV has identifi ed 4 lineages and appears to be an effi cient 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 Asian Lineage of Peste des Petits Ruminants Virus, Africa