Serological and molecular epidemiology of foot-and-mouth disease viruses in agro-pastoralist livestock herds in the kachia grazing reserve, Nigeria.

The Kachia Grazing Reserve (KGR) is located in Kaduna state in north-western Nigeria and consists of 6 contiguous blocks housing 744 defined households (HH), all engaged in livestock keeping. It is considered as a homogenous epidemiological unit and a defined study area. In 2012, all cattle and sheep of 40 selected HH were sampled to determine sero-prevalence of antibodies to foot-and-mouth disease virus (FMDV) and of FMDV. The overall sero-prevalence of antibodies to the non-structural 3ABC protein (NSP-3ABC ELISA) was 28.9% (380/1,315) (30.6% cattle; 16.3% sheep), and in 4.5% (62/1,380) (5% cattle; 0.6% sheep) of the examined sera FMD viral RNA could be detected by real-time RT-PCR (rRT-PCR). Additionally, in 2012 and 2014 serum, epithelium and probang samples were collected from cattle in reported FMD outbreaks and the causative FMDVs were molecularly characterized. Approximately half (28/59) of the outbreak sera reacted positive in NSP-3ABC ELISA, and 88% (52/59) of the outbreak sera contained detectable viral RNA. Overall, antibodies against five FMDV serotypes (O, A, SAT1, SAT2 and SAT3) were detected by solid phase competitive ELISA with combinations of two or more serotypes being common. Of the 21 FMDVs that could be isolated 19 were sequenced and 18 were confirmed as SAT2 (lineage VII) while one was characterized as serotype O (EA-3 topotype). Phylogenetic analysis revealed a close relationship between Nigerian FMDV strains and strains in this region and even with strains in North-Africa. Our findings indicate that FMD constitutes an endemic health problem to cattle rearing in the agro-pastoralist community in the KGR and that the KGR is not a closed epidemiological unit. Insight into the local FMDV epidemiology and in the circulating FMDV serotypes/strains is of support to the relevant authorities in Nigeria when considering the need for an FMD control policy to improve animal production in grazing reserves.

Heat induced epitope retrieval for rabies virus detection by direct fluorescent antibody test in formalin-fixed dog brain tissues.

There is a great need for a chemical method of tissue preservation that would allow sample storage for extended periods at room temperature. This study aimed at retrieving and detecting rabies virus antigen by direct fluorescent antibody test (DFAT) in formalin-fixed dog brain tissues. Forty fresh dog brain specimens were collected as paired samples from rabies suspected cases that were received for postmortem detection of rabies in the Central Diagnostic Laboratory, National Veterinary Research Institute, Vom. One portion of each paired sample was prepared for fresh fluorescent antibody testing and the other portion was prepared for epitope retrieval and florescent antibody testing following fixation in 10% neutral buffered formalin. DFAT on formalin-fixed tissue exhibited a sensitivity of 100% in comparison to DFAT on fresh-tissue. No false positive result was obtained in formalin-fixed DFAT procedure, demonstrating 100% specificity. There was no apparent difference in the intensity of fluorescence in DFAT on fresh sample and formalin-fixed DFAT following heat induced epitope retrieval (concordance = 98%; 95% C.I. 0.9660 to 0.9903). The strength of agreement between DFAT on formalin-fixed and DFAT on fresh tissue was very good (Cohen's kappa coefficient value= 1.000; 95% C.I. 1.000-1.000). This study provides new information on the retrieval of rabies antigen by heat induced epitope retrieval for DFAT on formalinized tissues. Formalin could therefore, be used henceforth to fix tissues of rabies suspected cases for routine diagnosis, transportation or archival purposes. The heat induced epitope retrieval can be routinely used to retrieve rabies virus antigen for DFAT in cases where only formalin-fixed tissues are available or when preservation by freezing is difficult.

Molecular characterization of dermatophytes isolated from cattle in Plateau State, Nigeria.

Dermatophytes from cattle were successfully characterized to species and strain levels for the first time in Nigeria. This study was undertaken to isolate and characterize dermatophytes from cattle in Plateau State, Nigeria. Two molecular techniques were utilized. The first was the use of polymerase chain reaction (PCR) to amplify the internal transcribed spacer regions of the ribosomal DNA using ITS-1 and ITS-4 as primers. This was followed by restriction fragment length polymorphism analysis of the amplified ITS regions using the enzyme MvaI to identify dermatophyte species. The second technique was a PCR using the short oligonucleotide 5'-GACAGACAGACAGACA-3' as primer for the RAPD typing of the isolates for identification of dermatophytes based on species specific profiles. Profiles of dermatophytes and their correlation with location, site of infection and severity of disease were also investigated. Both PCR-RFLP and RAPD analysis identified 26 Trichophyton verrucosum and 22 Trichophyton mentagrophytes. The PCR-RFLP analysis of the ITS regions produced two distinct profiles for both T. mentagrophytes and T. verrucosum. The first Profile for T. mentagrophytes consisted of two fragments of approximately 320 bp and 280 bp in length while the second was approximately 350 bp and 250 bp in length. The first profile for T. verrucosum consisted of two fragments having bands of approximately 380 bp and 220 bp. The second profile had a single band of undigested fragment of approximately 600 bp in length. Both T. mentagrophytes and T. verrucosum yielded identifiable fragments by RAPD analysis. Six profiles were produced for T. mentagrophytes and the PCR finger prints ranged from 1 to 9 bands with sizes ranging from approximately 350 to 5000 base pairs in size. Amplification of T. verrucosum isolates produced four Profiles. The PCR fingerprints ranged from 5 to 7 bands with sizes ranging from 500 bp-5000 bp. The results indicate that differences in location could contribute to variations in PCR amplicons of dermatophytes and strain differences in dermatophytes may be responsible for variation in clinical dermatophytosis but no significant association was observed between profiles of dermatophytes and the site of infection. The PCR-RFLP analysis of the internal transcribed spacer regions using the primer set ITS1/ITS4 and RAPD analysis using (GACA)4 as primer were successfully used to accurately identify dermatophytes from cattle to species and strain levels. Few molecular studies targeting dermatophytes of cattle are available in the literature. As far as we know, this may be the first report of molecular characterization of cattle dermatophytes from Africa.

Equine Dermatophytosis: A Survey of Its Occurrence and Species Distribution among Horses in Kaduna State, Nigeria.

This study was designed to determine the occurrence and species distribution of dermatophyte from cutaneous skin lesions of horses in Kaduna State, Nigeria. A total of 102 skin scrapings were collected from 102 horses with skin lesions. Mycological studies were carried out using conventional techniques. Dermatophytes were isolated from 18 (17.6%) of the 102 samples collected. The 18 dermatophytes were distributed into 10 different species belonging to Microsporum (n = 5) and Trichophyton (n = 5) genera. T. verrucosum (n = 4) was the most predominant species isolated followed by M. equinum (n = 3), T. vanbreuseghemii (n = 2), M. gypseum (n = 2), and M. canis (n = 2). Others include M. fulvum (n = 2), T. mentagrophytes (n = 1), T. equinum (n = 1), T. soudanense (n = 1), and M. gallinae (n = 1). The present study reveals the occurrence of dermatophytes in cutaneous skin lesions of horses in Kaduna State, Nigeria. In addition for the first time in this environment the anthropophilic dermatophyte T. soudanense was isolated from horses. These findings have great economic, veterinary, and public health significance as they relate to the cost of treatment and dissemination of zoonotic dermatophytes.

Serosurvey of peste des petits ruminants virus in small ruminants from different agro-ecological zones of Nigeria.

Peste des petits ruminants, caused by the peste des petits ruminants virus (PPRV), is a highly contagious and economically important transboundary viral disease of domestic and wild small ruminants and a major hindrance to small-ruminant production in Nigeria. The seroprevalence and distribution of PPRV antibodies in small ruminants in rural households, farms, live animal markets and slaughter slabs across the six different agro-ecological zones of Nigeria were determined. A total of 4548 serum samples from 3489 goats and 1059 sheep were collected in 12 states. A PPRV competitive enzyme-linked immunosorbent assay was used to test the samples and the data analysed with R statistical software version 3.0.1. The study animals included all ages and both sexes. The overall prevalence estimate of sera positive for PPRV antibodies was 23.16% (n = 1018 positive samples per 4548 total samples, 95% confidence interval: 21.79% - 24.57%). There were significant differences in the seroprevalence between the states (p = 0.001). Taraba State had the highest seroprevalence of 29.51%, whilst the lowest seroprevalence of 14.52% was observed in Cross River State. There were no significant differences in the PPRV seroprevalence between male and female animals (p = 0.571), age (p = 0.323) and between species (p = 0.639). These data indicate the current seroprevalence to PPRV in the small-ruminant population in Nigeria.

Molecular detection of Nigerian field isolates of Mycoplasma mycoides subsp. mycoides as causative agents of contagious bovine pleuropneumonia.

Contagious bovine pleuropneumonia (CBPP) is a highly contagious respiratory disease affecting cattle and is widely distributed in the sub-Saharan Africa. The objective of this study was to detect Mycoplasma mycoides subspecies mycoides (Mmm) the causative agent of CBPP from 90 cattle at slaughter using polymerase chain reaction-Restriction fragment length polymorphism. In this study, 450 samples suggestive of CBPP in Maiduguri, Yola and Gombe township abattoirs were processed according to standard protocols. The isolation rate was found to be 3.33% and percentage of identification with PCR-RFLP yielded 1.56%. Subsequently, QIAxcel revealed molecular size of 574 bp for Mycoplasma mycoides subcluster. Further analysis of PCR amplicons with restriction digestion, confirmed the presence of Mmm 16 S rRNA of CAP 21 genomic region with molecular sizes of 180 bp and 380 bp. Thus, the 380 bp fragments delineated Mmm from Mycoplasma mycoides subsp. capri. Three isolates (BL5, BL6 and AL1) were from lungs and four from pleural fluids (APF2, APF8A, APF8B and APF9) were isolated and identified, while a vaccine strain T1/44 was re-detected along with the field isolates. No sample from Gombe had Mmm. In conclusion, the findings of this study have detected the presence of Mmm as causative agent of CBPP. Measures such as surveillance, quarantine and vaccination are hereby recommended for the control of CBPP in Nigeria.

Dog ecology and population studies in Lagos State, Nigeria.

Dog population dynamics have a major impact upon the effectiveness of rabies control strategies. As such, understanding domestic dog ecology has been recognized as central to the design of effective rabies control programmes. This study was conducted to determine the dog ecology in Lagos State using compound dog count and street dog count in the three senatorial districts (Lagos West, East and Central) of Lagos State from February, 2011 to January, 2012. A total of 546 questionnaires were distributed for the compound dog count and all were completed and returned. Various aspects of dog ecology were determined, including size, sex, breed of the dog population, management of dogs and rabies awareness among the respondents. Out of the 546 compounds surveyed, 518 (94.87%) owned at least one dog. A total of 1,427 dogs were counted from the street counts while a total of 1,447 dogs (2.8 dogs/compound) were counted from the compound count. The dogs comprised of 583 males and 864 females, out of which 64.10% are confined. The dog vaccination coverage in the dog population surveyed was 64.10% and administered majorly (91.30%) by veterinarians. Security (60%) and pets (26%) were the major reasons for keeping dogs. Majority (88.80%) of the respondents were aware of rabies and its mode of transmission, but still believed in the use of concoctions (40.40%), herbs (19.90%) and consumption of the organ of the offending dog (11.50%) for the treatment of rabies. The findings of this study showed a male: female ratio of dog to be 1:1.5 and a dog: human ratio of 1:5.6. There was also a responsible dog ownership as majority of the respondents do confine, vaccinate and provide food for their dogs. Vaccination coverage of the total dog population was however below the 70-80% target recommended by the World Health Organization to achieve herd immunity.

Rabies and dog bites cases in lagos state Nigeria: a prevalence and retrospective studies (2006-2011).

This study was carried out to determine the prevalence of rabies antigen in brain of dogs slaughtered for consumption and those that died in veterinary clinics as well as to obtain a 6-year retrospective data on dog bites/suspected dog rabies cases in Lagos State. Dog brain samples were collected from dog slaughter slabs and veterinary clinics (for dogs that died in clinics) across the Lagos state while data for retrospective studies (2006-2011) of dog bite/suspected rabies cases were collected from public (government owned) and private veterinary clinics across the state. Out of the 444 brain samples collected and tested for presence of rabies antigen using the direct fluorescent antibody technique (DFAT) only 7 (1.58%) were positive for the rabies antigen. A total of 196 dog bites/suspected rabies cases were encountered between January 2006 and December, 2011 in the veterinary clinics with adults been the major (55.61%) victims. Majority (96.43%) of the offending dogs were not quarantined at the time of bite and only one out of the quarantined dogs died and was confirmed positive for rabies antigen. The result of this study indicates that rabies antigen is present among dogs slaughtered in Lagos State and may pose a threat to public health. Though, available records showed that provocation of dogs was the major cause of dog bites and both children and adults fell victim of dog bites, there was a poor record keeping practice in the veterinary clinics across the state.

Complete genome sequence of a street rabies virus isolated from a dog in Nigeria.

A canine rabies virus (RABV) was isolated from a trade dog in Nigeria. Its entire genome was sequenced and found to be closely related to canine RABVs circulating in Africa. Sequence comparison indicates that the virus is closely related to the Africa 2 RABV lineage. The virus is now termed DRV-NG11.

Dermatophytes from skin lesions of domestic animals in Nsukka, Enugu State, Nigeria.

BACKGROUND: Dermatophytes are well-recognized cutaneous fungi with public health implications. In Nigeria, several studies have been carried out on dermatophytosis in humans; however, data on dermatophytes in animals are lacking. OBJECTIVES: This study was conducted to determine the occurrence and species of dermatophytes in skin lesions in domestic animals in Nsukka Agricultural Zone of Enugu State, Nigeria. ANIMALS: Forty-six domestic animals (dogs, goats, sheep and pigs) presented for sale in the local markets in the study area and with suspected lesions of dermatophytosis were used for the study. METHODS: Plucked hairs and epidermal scales from the skin lesions of affected animals were inoculated on Sabouraud dextrose agar slants containing 0.05 mg/mL of chloramphenicol and 0.5 mg/mL of cycloheximide. Inoculated slants were incubated at room temperature (27°C) for up to 4 weeks and examined at 2-3 day intervals for fungal growth. Laboratory identification of the fungal isolates was based on their colonial, microscopic and biochemical characteristics. RESULTS: Of the 46 animals with suspected lesions of dermatophytosis, six (13.0%) were positive for a dermatophyte, and the following dermatophytes were identified: Microsporum gypseum, two of 12 sheep; Microsporum audouinii, one of 16 dogs; Trichophyton mentagrophytes, one of 16 dogs and one of 12 sheep; and Trichophyton schoenleinii, one of 13 goats. CONCLUSIONS AND CLINICAL IMPORTANCE: Anthropophilic dermatophytes are among the fungal agents associated with dermatophytosis in animals in Nsukka Agricultural Zone. These dermatophytes could constitute health risks to humans in contact with the animals.