Samples collected from wild and domestic suids in Nigeria, over a three year period Despite simultaneous field presence, individual co-infection was not observed. This study has reaffirmed the epidemiological utility of the CVR genome region for distinguishing between geographically and temporally constrained genotype I viruses, and has revealed the presence of multiple ASFV variants in Nigeria.

The aims of this study were to compare three commercial porcine reproductive and respiratory syndrome virus (PRRSV) realtime reverse transcription-PCR (RT-PCR) assays for detection of genetically diverse PRRSV isolates in serum, semen, blood swabs, and oral fluids collected from experimentally infected boars and to evaluate the effects of sample pooling. Six groups of three boars negative for PRRSV were each inoculated with one of six PRRSV isolates (sharing 55 to 99% nucleotide sequence identity in ORF5). Samples were collected on days ؊2, P orcine reproductive and respiratory syndrome virus (PRRSV) continues to be the most important pathogen affecting pigs in North America (1). PRRSV is a small, enveloped, single-stranded positive-sense RNA virus of the family Arteriviridae and can be divided into two genotypes: type 1 (European type [EU]) and type 2 (North American type [NA]) (2). Although a variety of commercial vaccines are available on the global market, the virus remains difficult to control, and the demand for PRRSV-naïve replacement genetics and, with it, the need for highly sensitive and specific assays that can detect genetically diverse strains and provide information on the most appropriate samples for testing continue to grow.Presently, many boar studs in the United States are PRRSV negative and are routinely tested for PRRSV to ensure that PRRSV-free semen is used in breeding herds for artificial insemination (1). If previously negative boar studs become infected with PRRSV, it is critical to detect the virus as soon as possible so that any shipments of possible PRRSV-contaminated semen can be stopped.The reverse transcription-PCR (RT-PCR) method in the realtime format is one of the most commonly used techniques for detection of PRRSV RNA because of its sensitivity and specificity and relatively short test turnaround time. However, the high mutation rate, rapid evolution, and genetic variability of PRRSV strains complicate the development of long-term reliable diagnostic assays, and consequently cases of false-negative results with commercially available assays have been reported (3-5).Active PRRSV surveillance in boar studs relies mainly on collection and testing of serum, semen, blood swabs, and, more recently, oral fluids (6, 7). The choice of sample type should take into consideration the availability and ease of collection in addition to the sensitivity and specificity of the RT-PCR assay. Studies have shown that PRRSV RNA can be detected in boar serum, oral fluids, and blood swabs as early as 24 to 48 h postinfection and in semen samples as early as 48 to 120 h postinfection (6-9). Isolatespecific differences in the levels of PRRSV replication and shedding in the host have been reported (10), and as veterinarians and diagnosticians consider using alternative sampling methods, it is important to conduct an unbiased comparison of the ability of different commercial real-time RT-PCR tests to detect genetically diverse isolates of PRRSV in new and conventional sample types.The sample collection ...

African swine fever (ASF) was first introduced into Nigeria through Lagos state in 1997. The disease rapidly spread to Ogun state in 1998 and extended to the Niger Delta (Delta, Rivers and Akwa Ibom states) in the same year. In 1998, Kaduna, Plateau and Benue states all north of the country experienced ASF for the first time. Poor farm biosecurity, bad abattoir practices and extensive/free range pig farming systems led to extensive spread of the diseases to about 16 Nigerian states excluding the far northwest and north east. A total of 1036 field samples collected over a 6-year period covering 19 Nigerian states were analysed during the period under review; 805 samples were PCR positive and 231 negative. Positive samples were detected in all three surveillance phases and from all agroecological zones across the country. For the first time since its incursion, ASF was identified in some states; Bauchi, Adamawa Taraba and Gombe with chances of control very slim and further spread of the virus northward envisaged. Outbreaks of the disease are now a perennial problem with an increasing disease burden in areas where high numbers of pigs are produced in the country. The National Veterinary Research Institute (NVRI), Vom, since 2002 investigated ASF based on tissue submissions and reports made by individuals, private & commercial farms and agricultural bodies. We present an analysis of geographical and temporal distribution of ASF in the country from 2002 to 2007 and a review of historic outbreaks since the first incursion. Risk factors and prospects for control are discussed.

FIG 1: PCR analysis of DNA extracted from tissue samples from a red river hog (Potamochoerus porcus), showing a single, specific band for all five tissue types (lanes 1 to 5) when measured against a 50 base pair molecular weight marker (lane M).