Potentially toxic metals in dust, blood, and hairs from exposed security dogs in an oil and gas industry

Environmental pollutants pose a health risk to animals and humans. We evaluated levels of some potentially toxic metals in environmental dust, blood, and hair samples of apparently healthy security dogs from a crude oil well drilling site (A) and liquefied natural gas production site (B) industrial environments in Nigeria. These samples were routinely digested and analyzed for lead, cadmium, nickel, chromium, and zinc using atomic absorption spectrophotometry assay. Mann‑Whitney U test was used to compare concentrations of the metals in different samples. Dust samples contained a high amount of the metals considered. There was no significant difference between levels of heavy metals in blood and hair samples from dogs guarding both sites, except for blood (p = 0.034) and hair (p = 0.015) chromium which were higher in those securing site A compared with site B. Higher nickel (p = 0.001) and zinc (p = 0.001) with lower chromium (p = 0.004) levels occurred in the hair samples than in the blood. Lead was not detected in blood and hair samples suggesting safety. There was no correlation between the same metal in blood and hair. Hair chromium and nickel levels were above the reference suggesting toxic exposure. There is a need for regular monitoring and decontamination of air pollutants within similar facilities for environmental safety.

Genetic diversity of canine parvovirus variants circulating in Nigeria

Canine parvovirus (CPV) is a fast-evolving single-stranded DNA virus that causes severe and fatal gastrointestinal disease in dogs. Lately, several mutations affecting viral protein (VP) capsid resulting in highly pathogenic variants with distinctive immunological and clinicopathological characteristics abound. This study involved screening stools of 44 randomly selected clinical cases of canine gastroenteritis from 4 cities (Ibadan, Jos, Makurdi, and Zaria) in Nigeria for CPV antigen using an on-the-spot immunoassay test kit, as well as, molecular detection of viral nucleic acid by polymerase chain reaction. Subsequently, nucleic acid sequencing of 1195-bp amplicons encompassing the VP2 encoding region was done. The resultant 40 high-quality amino acid sequences obtained were analysed for the identification and grouping of the viruses into their discrete variants - CPV-2a, CPV-2b, or CPV-2c, using key amino acids substitutions - Asn, Asp, or Glu respectively at position 426 of the VP2 gene. One-third (11/40; 27.5%) of the analysed sequences were identified as CPV-2a and two-third (29/40; 72.5%) as CPV-2c. The original CPV and CPV-2b were not detected. Also, the "new CPV-2a variant" with mutation S297A identified had two additional mutations (Y324I and T440A) associated with selective pressure and vaccination failure in their sequences. Similarly, unique CPV-2c mutants carrying genetic markers (S297A, Y324I, and Q370R) that are highly related to CPVs of Asian origin were observed. These findings revealed a high level of divergence of existing CPVs in circulation; suggesting that CPV is rapidly evolving in Nigeria lately.

Molecular characterisation of canine parvoviruses from clinical samples and vaccines in Nigeria

Canine parvovirus (CPV) the causative agent of canine parvovirus enteritis is an intractable pathogen of dogs characterised by mutations, evolutionary changes and eventual vaccine failure. The disease is a serious problem in dogs with limited studies conducted in Nigeria. Therefore, this study was designed to characterise the subtypes of CPV isolates in six commonly used vaccines and 157 clinical samples collected from seven states in Nigeria from June 2016 to March 2018. Faecal samples collected from the clinical cases were subjected to in-clinic immunoassay to detect viral antigens. Polymerase chain reaction (PCR) was used to amplify viral VP2 gene in the samples and commonly used vaccines in Nigeria. Thereafter, PCR products were sequenced and analysed. The result showed that 93.0% of the dogs tested positive for CPV in both assays; 72.8% were puppies less than six months old, with 58.3% of them vaccinated. Partial VP2 gene sequence and phylogenetic analysis of 11 random clinical samples showed that CPV-2c 7(63.6%) and CPV-2a 4(36.4%) were the predominant subtypes in Nigeria; with genetic signatures that are 98.7% to 99.9% closely related to Asian and European strains, respectively. No CPV-2b was detected. Amino acid mutation analysis divulged some imperative transmutation sites: D305Y, Y324I, Q370R, N375D, T440A, Y444S, I447M and Y451C in the isolates. The viruses in the vaccines were characterised as the wild-type CPV. The genetic variability, viral population heterogeneity and phylogenetic linkage with isolates from other countries probably suggest transboundary migrations and local differentiations are contributing to continuous CPV evolution and vaccine failure in Nigeria.

Seroprevalence and risk factors of brucellosis in goats in selected states in Nigeria and the public health implications

Available reports on brucellosis in Nigeria are largely confined to cattle while it is believed that other ruminants like sheep and goats are equally exposed to the disease. To have an insight into the role of goats in the epidemiology of brucellosis in Nigeria, we conducted a cross-sectional study between June 2011 and May 2013 to determine the seroprevalence of brucellosis in goats in some selected states in Nigeria. Serum samples were collected from goats at different locations and tested for antibodies to Brucella spp using the Rose Bengal Test (RBT), samples positive by RBT were further subjected to Competitive Enzyme Linked Immunosorbent Assay (cELISA). Data collected to determine risk factors were also analysed using chi-square and logistics regression statistics. Out of a total of 2827 samples tested from the different states (Benue = 331; Borno =195; Oyo = 2155; Sokoto = 146), we recorded an overall seroprevalence of 2.83% (Benue = 17.30%; Borno = 2.05%; Oyo = 0.60% and Sokoto = 0.00%) by RBT. The cELISA further supported 9.45% (7/74) of the total RBT positive samples. Logistic regression analysis showed that the location (p = 0.004) and source (p < 0.0001); are probable risk factors to be considered in the epidemiology of brucellosis with sex (p = 0.179); age (p = 0.791) and breed (p = 0.369) not playing any major role. Our findings reveal a relatively low seroprevalence of brucellosis among goats screened except for Benue State. Since most of the goats sampled in the present study were from the abattoirs, further farm level investigations are required to determine the role of goats in the epidemiology of brucellosis in Nigeria since they share common environment with sheep and cattle that are natural hosts of Brucella species which are of major public health threat.