We analysed the sequence diversity in the reverse transcriptase (RT)/ribonuclease H (RNaseH) coding region of 19 badnavirus isolates infecting yam (Dioscorea spp.) in Ghana, Togo, Benin, and Nigeria. Phylogenetic analysis of the deduced amino acid sequences revealed that the isolates are broadly divided into two distinct species, each clustering with Dioscorea alata bacilliform virus (DaBV) and Dioscorea sansibarensis bacilliform virus (DsBV). Fourteen isolates had 90-96% amino acid identity with DaBV, while four isolates had 83-84% amino acid identity with DsBV. One isolate from Benin, BN4Dr, was distinct and had 77 and 75% amino acid identity with DaBV and DsBV, respectively, and may be a member of a new badnavirus species infecting yam in West Africa. Viruses of the two main species were present in Ghana, Togo and Benin and were observed to infect both D. alata and D. rotundata indiscriminately. This is the first confirmed report of DsBV infection in yam in Ghana and Togo. The results of this study demonstrate that members of two distinct species of badnaviruses infect yam in the West African yam zone and suggest a putative new species, BN4Dr. We also conclude that these species are not confined to limited geographic regions or specific for yam host species. However, the three badnavirus species are serologically related. The sequence information obtained from this study can be used to develop PCR-based diagnostics to detect members of the various species and/or strains of badnaviruses infecting yam in West Africa.

Surveys were conducted in 2004 and 2005 to determine the incidence and distribution of viruses infecting yams in four major yam-producing agro-ecological zones in Benin. Yam leaves collected from 69 fields and one experimental screen house were indexed for Cucumber mosaic virus (CMV), Dioscorea mottle virus (DMoV), Yam mild mosaic virus (YMMV), Yam mosaic virus (YMV) and yam-infecting badnaviruses [Dioscorea alata bacilliform virus (DaBV) and Dioscorea sansibarensis bacilliform virus (DsBV)] by enzymelinked immunosorbent assay and immunocapture polymerase chain reaction. Eighty-two per cent and 66% of leaf samples tested in 2004 and 2005, respectively, were infected with CMV, YMMV, YMV and/or badnaviruses.DMoV was not detected. Yam-infecting badnaviruses were the most prevalent virus infection, detected in 45% of the total leaves sampled followed by YMV (31%), YMMV (27%) and CMV (2%). Although the occurrence of CMV was low, this is the first record of CMV in yams in Benin. Mixed virus infections were detected in 48% (2004) and 39% (2005) of the infected leaves. A mixture of YMMV and badnaviruses (DaBV or DsBV) was the most common mixed infection detected. Dioscorea alata, with a higher incidence of badnavirus infection (81%), YMMV (51%) and CMV (8%) was more heavily infected than Dioscorea rotundata.

Yam leaves were collected during surveys of major yam producing agro‐ecological zones (AEZs) in Ghana (n = 628) and Togo (n = 218) respectively, in 2005. Leaf tissues were tested for Cucumber mosaic virus (CMV), Dioscorea mottle virus (DMoV), Yam mild mosaic virus (YMMV), Yam mosaic virus (YMV) and badnaviruses by enzyme‐linked immunosorbent assay (ELISA), immunocapture‐polymerase chain reaction (IC‐PCR) and/or IC‐reverse transcription‐PCR (IC‐RT‐PCR). Eighty‐one percent (370/459) and 78.9% (127/161) of symptomatic leaf samples from Ghana and Togo, respectively and 56.2% (95/169) and 57.9% (33/57) of non‐symptomatic leaf samples, reacted positive to CMV, YMMV, YMV and/or badnaviruses, but DMoV was not detected. The highest incidence of YMV and badnaviruses was observed in the forest–savannah transition and Guinea savannah AEZ respectively in Ghana. In Togo, incidence of badnaviruses across the four AEZ ranged from 50 to 57.9%; however, Savane Derivée Seche AEZ had the highest incidence of badnaviruses (57.9%), YMV (34.2%) and CMV (7.9%). Mixed infection of badnaviruses and YMMV was the most frequent (105 of 276 mixed infections) in the two countries and Dioscorea alata was more heavily infected than D. rotundata in both countries.

Vegetable crops are highly susceptible to a wide range of pests and diseases among which are the root-knot nematodes (Meloidogyne species). Traditionally, identification of Meloidogyne species had been based on use of morphological characters such as the perennial pattern. In recent times, accuracy of nematode identification using only morphological tools has been challenged due to similarities in morphological characters of some nematode species. The aim of this study was to identify the root-knot nematodes associated with some vegetable crops cultivated on Covenant University farm, Ota, South-west, Nigeria using molecular tools and to determine the population densities of Meloidogyne spp. on the selected vegetable crops. Plant-parasitic nematodes were extracted from soil and roots of Abelmoschus esculentus, Celosia argentea and Corchorus olitorius cultivated on Covenant University farm. The nematode species were identified and counted under a compound microscope. The molecular characterization of the Meloidogyne species was done using single adult female nematodes and eggs which were picked out for DNA extraction and amplified with specie-specific primers through Polymerase Chain Reaction (PCR) and separated on 0.5% agarose gel. High population of plant-parasitic nematodes was recorded on the vegetable crops cultivated on covenant university farm. Also significantly higher population (p<0.005) o f Meloidogyne spp. were found in association with C. argentea and Corchorus olitorius than those recorded on Abelmoschus esculentus from the vegetable farm. The molecular characterization of the Meloidogyne species from the farm indicates Meloidogyne incognita as the nematode species associated with the vegetable crops.

The aim of this study was to assess the levels of human papilloma virus (HPV) infection and vaccination awareness among members of the general population across three Nigerian States. A descriptive cross-sectional study among 758 persons selected by convenience sampling was conducted from March to July 2016. Structured questionnaires were administered to consenting participants and analysed using descriptive and inferential statistical methods in SPSS V20. Awareness to HPV infection and vaccination was very low at 1.40 ± 1.803 out of 6 points. Only 31.97% of respondents had heard about HPV while 17.5% were aware of the existence of a vaccine. The most prevalent sources of information amongst respondents who had heard about HPV were Doctors (13.08%) and the Media (9.91%). Bivariate analysis showed that respondents who consulted with gynaecologists, knew someone who had cervical cancer or had received HPV vaccination were more likely to be aware of HPV infection and vaccination. Gynaecologists (p < 0.0001) and previous vaccination (p < 0.0001) were the most important contributors to HPV awareness in a multivariate analysis. This study underpins the need for urgent intervention to raise awareness for HPV.

Background: The World Health Organisation recently launched a campaign to reduce Hepatitis B Viral Infections by 80% globally. Achieving this goal is partly predicated on proper awareness of persons in regions of high transmission. Objective: The aim of this study was to assess the Hepatitis B Virus (HBV) infection knowledge status of persons across three states in Nigeria. Methods: A descriptive cross-sectional study among 758 persons selected by convenience sampling was conducted from March to July 2016. Structured questionnaires were administered to consenting participants and analysed using descriptive and inferential statistical methods in SPSS V20. Findings: Respondents showed average knowledge with a mean knowledge score of 4.85 ± 2.69 out of a max score of 9.00. Respondents belonging to the working class had significantly better knowledge (5.59 ± 2.34 p < 0.001) than respondents in other categories. High-risk behaviour such as having multiple partners was predominant among respondents belonging to a public institution. A total of 242 (31.96%) of study respondents were aware of the existence of a vaccine for HBV, whereas only 161 (21.2%) had received at least one dose of vaccination against HBV. Previous knowledge of HBV infection, previous HBV testing, and knowing someone who had HBV infection were predictors of HBV infection knowledge as well as vaccination. Conclusion: This study has shown the urgent need for intervention targeted at raising awareness about HBV infection and the existence of a vaccine.

Yam (Dioscorea spp., family Dioscoreaceae) is one of the most important food crops cultivated in the West African yam zone comprising the forest and savannah areas of Nigeria, Ghana, Côte d'Ivoire, Republic of Benin, and Togo, which account for more than 90% of the 4.59 million ha of yam cultivation worldwide (1). A survey was conducted in 2005 to document viruses in yams in Ghana, Togo, and the Republic of Benin. Samples (1,405) from five species of yam showing mosaic, chlorosis, and stunting as well as asymptomatic plants were tested for Dioscorea bacilliform virus (DBV, genus Badnavirus), Yam mosaic virus (YMV, genus Potyvirus), and Yam mild mosaic virus (YMMV, genus Potyvirus), the three most common viruses infecting yams. In addition, samples were tested for Cucumber mosaic virus (CMV), since CMV was previously reported to infect yams in Côte d'Ivoire (2) and Nigeria (3). In protein-A sandwich-ELISA with polyclonal antibodies to a cowpea isolate of CMV, 23 of the 1,405 samples (6 of 218 samples from Togo, 13 of 628 samples from Ghana, and 4 of 559 samples from Republic of Benin) tested positive for CMV. The CMV-positive samples were from D. alata (N = 16) and D. rotundata (N = 7), whereas all samples from D. cayenensis, D. dumetorum, and D. bulbifera tested negative. CMV was detected as mixed infections with DBV, YMV, or YMMV in 21 of 23 samples. Some of these samples showed puckering, chlorosis, mottling, and crinkling, whereas some plants infected by two or more viruses were asymptomatic. Only two samples from D. rotundata had a single infection of CMV and they showed mild chlorotic symptoms in young leaves that were inconspicuous in mature leaves. In sap inoculations, the virus induced systemic mosaic in Nicotiana glutinosa. The presence of CMV in ELISA-positive yam samples was further confirmed by immunocapture-reverse transcription (IC-RT)-PCR using CMV antibodies as trapping antibody and oligonucleotide primers specific for a 485 nt corresponding to 3′ end of the coat protein gene and C-terminal noncoding region of RNA-3 (4). To confirm the specificity of IC-RT-PCR, the 485-bp amplicons from an isolate from the Republic of Benin was cloned into pCR2.1 (Invitrogen, Carlsbad, CA) and three independent clones were sequenced from both orientations. Pairwise comparison of a consensus sequence (Accession No. EU274471) with corresponding sequences of other CMV isolates deposited in GenBank showed 99% identity at the nucleotide sequence level (Accession No. U22821) and revealed that the CMV isolate from yam belongs to sub-Group IA. To our knowledge, this is the first report of CMV infection in yams (D. alata and D. rotundata) in Ghana, Togo, and the Republic of Benin. Together with a previous documentation of CMV in D. alata and D. trifida in Côte d'Ivoire and Nigeria (2,3), this report adds to existing knowledge on distribution of CMV in yams with implications for yam production and germplasm distribution in the West Africa Region. References: (1) FAO. Online publication. FAOSTAT, 2007. (2) C. Fauquet and J. C. Thouvenel. Plant Viral Diseases in the Ivory Coast. ORSTROM: Documentation Techniques. Paris, 1987. (3) Jd'A. Hughes et al. Phytopathology 87:S45, 1997. (4) S. Wylie et al. Aus. J. Agric. Res. 44:41, 1993.

Cassava mosaic disease (CMD), caused by cassava mosaic begomoviruses (CMBs), is a major threat to cassava production in Nigeria. The predominant CMBs in Nigeria are African cassava mosaic virus (ACMV), East African cassava mosaic virus (EACMV) and East African cassava mosaic Cameroon virus (EACMCV), which are transmitted through infected stem cuttings and whitefly vectors. This study was conducted in 2015 and 2017 to assess the epidemiology of CMD and the current distribution of CMBs in cassava farms in South West (SW) and North Central (NC) Nigeria. A survey of cassava farms was undertaken, and samples representative of disease symptoms were collected and assessed using molecular techniques. A total of 184 and 328 cas-