Sequence and phylogenetic analysis of canine parvovirus-2 isolates in dogs revealed circulation of three subtypes in Nigeria.

Canine parvovirus-2 (CPV-2) is the most common viral cause of gastroenteritis in puppies in Nigeria and worldwide. After its emergence in 1978, the wild-type CPV-2 was rapidly replaced by three antigenic subtypes CPV-2a, CPV-2b and CPV-2c. Subtype CPV-2a has been reported in Nigeria based on limited number of samples. As such, this study was carried out with 56 faecal samples and four CPV-2 vaccines using polymerase chain reaction and sequencing to have a better idea of CPV-2 subtypes circulating in dogs in Nigeria. 54 (96.4%) out of the 56 samples were positive for CPV-2 subtypes. CPV-2a is the predominant subtype followed by CPV-2b and CPV-2c. Also, co-existence of subtypes CPV-2a and CPV-2b; and CPV-2a and CPV-2c were found in some dogs. Sequence analysis revealed the occurrence of three mutations D413 N, N426D/E, and T440A. To our knowledge, this is the first report of the three subtypes of CPV-2 in Nigeria.

Detection of DNA Fragmentation in Liver of Goats Exposed to Lead Poisoning in Bagega District of Zamfara State, Nigeria.

The ubiquitous presence of lead (Pb) and its release by anthropogenic activities has remained a majorenvironmental pollution risk to both humans and animals. Lead toxicity has been associated with different systemic toxicitiesand biochemical impacts (such as oxidative stress and DNA damaging effects) with dire health consequences. In Nigeria,the health problem associated with lead toxicity has been overwhelming in the Bagega District of Zamfara State whereartisanal gold mining has resulted in widespread environmental lead contamination. For this study, 24 goats were selectedfrom two communities, 12 goats (exposed groups) selected from Bagega District, Zamfara (a community with widespreadmining and lead contamination), while 12 goats (control) were selected from Apete, Ibadan with no previous mining history.The liver lead levels in the two groups were evaluated using the using Atomic Absorption Spectrophotometry and the leadlevel in the exposed group was categorized into 3 exposure categories (viz mild, moderate and severe). Representative liversamples from the 3 tissue lead exposure categories were analyzed using agarose gel electrophoresis for the detection ofapoptotic oligonucleosomal DNA fragmentation. The tissue lead level in the goats from the exposed group (32.42±13.85mg/kg) was significantly higher than the control group (0.36±0.12 mg/kg). DNA ladder was detected in the 3 exposure categories with a dose-related degree of DNA fragmentation. This study highlights the role of oligonucleosomal DNAfragmentation and apoptosis in the pathogenicity of lead in lead exposed goats and the associated the dose-gradient impactof tissue lead level on the degree of DNA fragmentation.

Isolation and preliminary characterization of chicken anemia virus from chickens in Nigeria.

Chicken anemia virus (CAV) was isolated for the first time from the Nigerian chicken population. The virus was recovered from necropsied birds from broiler and pullet flocks that suffered disease outbreaks tentatively diagnosed as infectious bursal disease. A sensitive polymerase chain reaction (PCR) assay detected CAV DNA in tissues of necropsied birds. Restriction endonuclease analysis performed with the 733-bp PCR product and the Cfo I enzyme indicated at least two different CAVs were circulating among the Nigerian chicken population. Four isolates were obtained from pooled liver and thymus tissues using the MDCC-MSB1 cell line. These isolates were found to be antigenically closely related to the Cuxhaven-1 (Cux-1) reference strain of CAV when reacted with four monoclonal antibodies prepared against the Cux-1 virus. One of the isolates (isolate A) induced thymus atrophy, bone marrow aplasia, and low hematocrit values when inoculated into 1-day-old specific-pathogen-free chickens. These findings not only demonstrate that CAV is present in Nigeria, but they also likely represent the first cell culture isolation of the virus in Africa.

Serologic evidence of chicken infectious anemia in commercial chicken flocks in southwest Nigeria.

Sera samples from seven poultry farms in southwest Nigeria consisting of 7 broiler, 10 pullet, 1 layer, 1 cockerel, and 1 broiler breeder flocks were tested for the presence of chicken infectious anemia virus (CIAV) antibodies using a commercial enzyme-linked immunosorbent assay kit. Eleven of the 20 flocks (55%) and six out of seven (86%) farms were positive for CIAV antibodies. The seroprevalence largely depended on the age of the flocks. Seroprevalence was higher within the older pullet and layer flocks (83%-100%) than in the younger broiler flocks (0%-83%). In essence, all flocks older than 6 to 8 wk became infected. This is the first report of serologic evidence of CIAV in Subsaharan Africa. Since Southwest Nigeria is the main port of entry of imported chicken and the hub of major poultry breeders, the disease can probably be found throughout the country and beyond. Further studies are necessary to assess economic losses due to CIAV and the cost benefit of countermeasures.