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Tick-borne viruses (TBVs) capable of transmitting between ticks and hosts have been increasingly recognized as a global public health concern. In this study, Hyalomma ticks and serum samples from camels were collected using recorded sampling correlations in eastern Kenya. Viromes of pooled ticks were profiled by metagenomic sequencing, revealing a diverse community of viruses related to at least 11 families. Five highly abundant viruses, including three novel viruses (Iftin tick virus, Mbalambala tick virus [MATV], and Bangali torovirus [BanToV]) and new strains of previously identified viruses (Bole tick virus 4 [BLTV4] and Liman tick virus [LMTV]), were characterized in terms of genome sequences, organizations, and phylogeny, and their molecular prevalence was investigated in individual ticks. Moreover, viremia and antibody responses to these viruses have been investigated in camels. MATV, BLTV4, LMTV, and BanToV were identified as viral pathogens that can potentially cause zoonotic diseases. The transmission patterns of these viruses were summarized, suggesting three different types according to the sampling relationships between viral RNA-positive ticks and camels positive for viral RNA and/or antibodies. They also revealed the frequent transmission of BanToV and limited but effective transmission of other viruses between ticks and camels. Furthermore, follow-up surveys on TBVs from tick, animal, and human samples with definite sampling relationships are suggested. The findings revealed substantial threats from the emerging TBVs and may guide the prevention and control of TBV-related zoonotic diseases in Kenya and in other African countries.

Domestication of the helmeted guinea fowl (HGF; Numida meleagris) in Africa remains elusive. Here we report a high-quality de novo genome assembly for domestic HGF generated by long- and short-reads sequencing together with optical and chromatin interaction mapping. Using this assembly as the reference, we performed population genomic analyses for newly sequenced whole-genomes for 129 birds from Africa, Asia, and Europe, including domestic animals (n = 89), wild progenitors (n = 34), and their closely related wild species (n = 6). Our results reveal domestication of HGF in West Africa around 1,300–5,500 years ago. Scanning for selective signals characterized the functional genes in behavior and locomotion changes involved in domestication of HGF. The pleiotropy and linkage in genes affecting plumage color and fertility were revealed in the recent breeding of Italian domestic HGF. In addition to presenting a missing piece to the jigsaw puzzle of domestication in poultry, our study provides valuable genetic resources for researchers and breeders to improve production in this species.

Newcastle disease (ND) causes significant economic losses in the poultry industry in developing countries. In Kenya, despite rampant annual ND outbreaks, implementation of control strategies is hampered by a lack of adequate knowledge on the circulating and outbreak causing-NDV strains. This study reports the first complete genome sequences of NDV from backyard chicken in Kenya. The results showed that all three isolates are virulent, as assessed by the mean death time (MDT) and intracerebral pathogenicity index (ICPI) in specific antibody negative (SAN) embryonated eggs and 10-day-old chickens, respectively. Also, the polybasic amino acid sequence at the fusion-protein cleavage site had the motif 112RRQKRFV118. Histopathological findings in four-week-old SPF chicken challenged with the NDV isolates KE001, KE0811, and KE0698 showed multiple organ involvement at five days after infection with severe effects seen in lymphoid tissues and blood vessels. Analysis of genome sequences obtained from the three isolates showed that they were 15192 base pair (bp) in length and had genomic features consistent with other NDV strains, the functional sites within the coding sequence being highly conserved in the sequence of the three isolates. Amino acid residues and substitutions in the structural proteins of the three isolates were similar to the newly isolated Tanzanian NDV strain (Mbeya/MT15). A similarity matrix showed a high similarity of the isolates to NDV strains of class II genotype V (89–90%) and subgenotype Vd (95–97%). Phylogenetic analysis confirmed that the three isolates are closely related to NDV genotype V strains but form a distinct cluster together with NDV strains from the East African countries of Uganda and Tanzania to form the newly characterized subgenotype Vd. Our study provides the first description of the genomic and pathological characteristics of NDV of subgenotype Vd and lays a baseline in understanding the evolutionary dynamics of NDV and, in particular, Genotype V. This information will be useful in the development of specific markers for detection of viruses of genotype V and generation of genotype matched vaccines.

Background Yellow-feathered chickens (YFCs) have a long history in China. They are well-known for the nutritional and commercial importance attributable to their yellow color phenotype. Currently, there is a huge paucity in knowledge of the genetic determinants responsible for phenotypic and biochemical properties of these iconic chickens. This study aimed to uncover the genetic structure and the molecular underpinnings of the YFCs trademark coloration. Results The whole-genomes of 100 YFCs from 10 major traditional breeds and 10 Huaibei partridge chickens from China were re-sequenced. Comparative population genomics based on autosomal single nucleotide polymorphisms (SNPs) revealed three geographically based clusters among the YFCs. Compared to other Chinese indigenous chicken genomes incorporated from previous studies, a closer genetic proximity within YFC breeds than between YFC breeds and other chicken populations is evident. Through genome-wide scans for selective sweeps, we identified RALY heterogeneous nuclear ribonucleoprotein (RALY), leucine rich repeat containing G protein-coupled receptor 4 (LGR4), solute carrier family 23 member 2 (SLC23A2), and solute carrier family 2 member 14 (SLC2A14), besides the classical beta-carotene dioxygenase 2 (BCDO2), as major candidates pigment determining genes in the YFCs. Conclusion We provide the first comprehensive genomic data of the YFCs. Our analyses show phylogeographical patterns among the YFCs and potential candidate genes giving rise to the yellow color trait of the YFCs. This study lays the foundation for further research on the genome-phenotype cross-talks that define important poultry traits and for formulating genetic breeding and conservation strategies for the YFCs.

We describe the first genome isolation of Middle East respiratory syndrome coronavirus (MERS-CoV) in Kenya. This fatal zoonotic pathogen was first described in the Kingdom of Saudi Arabia in 2012. Epidemiological and molecular evidence revealed zoonotic transmission from camels to humans and between humans. Currently, MERS-CoV is classified by the WHO as having high pandemic potential requiring greater surveillance. Previous studies of MERS-CoV in Kenya mainly focused on site-specific and archived camel and human serum samples for antibodies. We conducted active nationwide cross-sectional surveillance of camels and humans in Kenya, targeting both nasal swabs and plasma samples from 1,163 camels and 486 humans collected from January 2016 to June 2018. A total of 792 camel plasma samples were positive by ELISA. Seroprevalence increased with age, and the highest prevalence was observed in adult camels (82.37%, 95% confidence interval (CI) 79.50–84.91). More female camels were significantly seropositive (74.28%, 95% CI 71.14–77.19) than male camels (P

Newcastle disease (ND) is a serious disease of poultry that causes significant economic losses. Despite rampant ND outbreaks that occur annually in Kenya, the information about the NDV circulating in Kenya is still scarce. We report the first countrywide study of NDV in Kenya. Our study is aimed at evaluating the genetic characteristics of Newcastle disease viruses obtained from backyard poultry in farms and live bird markets in different regions of Kenya. We sequenced and analyzed fusion (F) protein gene, including the cleavage site, of the obtained viruses. We aligned and compared study sequences with representative NDV of different genotypes from GenBank. The fusion protein cleavage site of all the study sequences had the motif 112RRQKRFV118 indicating their velogenic nature. Phylogenetic analysis revealed that the NDV from various sites in Kenya was highly similar genetically and that it clustered together with NDV of genotype V. The study samples were 96% similar to previous Ugandan and Kenyan viruses grouped in subgenotype Vd This study points to possible circulation of NDV of similar genetic characteristics between backyard poultry farms and live bird markets in Kenya. The study also suggests the possible spread of velogenic NDV between Kenya and Uganda possibly through cross-border live bird trade. Our study provides baseline information on the genetic characteristics of NDV circulating in the Kenyan poultry population. This highlights the need for the ND control programmes to place more stringent measures on cross-border trade of live bird markets and poultry products to prevent the introduction of new strains of NDV that would otherwise be more difficult to control.

This is the first country-wide surveillance of bat-borne viruses in Kenya spanning from 2012–2015 covering sites perceived to have medium to high level bat-human interaction. The objective of this surveillance study was to apply a non-invasive approach using fresh feces to detect viruses circulating within the diverse species of Kenyan bats. We screened for both DNA and RNA viruses; specifically, astroviruses (AstVs), adenoviruses (ADVs), caliciviruses (CalVs), coronaviruses (CoVs), flaviviruses, filoviruses, paramyxoviruses (PMVs), polyomaviruses (PYVs) and rotaviruses. We used family-specific primers, amplicon sequencing and further characterization by phylogenetic analysis. Except for filoviruses, eight virus families were detected with varying distributions and positive rates across the five regions (former provinces) studied. AstVs (12.83%), CoVs (3.97%), PMV (2.4%), ADV (2.26%), PYV (1.65%), CalVs (0.29%), rotavirus (0.19%) and flavivirus (0.19%). Novel CalVs were detected in Rousettus aegyptiacus and Mops condylurus while novel Rotavirus-A-related viruses were detected in Taphozous bats and R. aegyptiacus. The two Rotavirus A (RVA) strains detected were highly related to human strains with VP6 genotypes I2 and I16. Genotype I16 has previously been assigned to human RVA-strain B10 from Kenya only, which raises public health concern, particularly considering increased human-bat interaction. Additionally, 229E-like bat CoVs were detected in samples originating from Hipposideros bats roosting in sites with high human activity. Our findings confirm the presence of diverse viruses in Kenyan bats while providing extended knowledge on bat virus distribution. The detection of viruses highly related to human strains and hence of public health concern, underscores the importance of continuous surveillance.

We analyzed variations in 90 mitochondrial DNA (mtDNA) D-loop and heat shock protein 70 (HSP70) gene sequences from four populations of domesticated helmeted Guinea fowls (70 individuals) and 1 population of wild helmeted Guinea fowls (20 individuals) in Kenya in order to get information about their origin, genetic diversity, and traits associated with heat stress. 90 sequences were assigned to 25 distinct mtDNA and 4 HSP70 haplotypes. Most mtDNA haplotypes of the domesticated helmeted Guinea fowls were grouped into two main haplogroups, HgA and HgB. The wild population grouped into distinct mtDNA haplogroups. Two mtDNA haplotypes dominated across all populations of domesticated helmeted Guinea fowls: Hap2 and Hap4, while the dominant HSP70 haplotype found in all populations was CGC. Higher haplotype diversities were generally observed. The HSP70 haplotype diversities were low across all populations. The nucleotide diversity values for both mtDNA and HSP70 were generally low. Most mtDNA genetic variations occurred among populations for the three hierarchical categories considered while most variations in the HSP70 gene occurred among individuals within population. The lack of population structure among the domestic populations could suggest intensive genetic intermixing. The differentiation of the wild population may be due to a clearly distinct demographic history that shaped its genetic profile. Analysis of the Kenyan Guinea fowl population structure and history based on mtDNA D-loop variations and HSP70 gene functional polymorphisms complimented by archaeological and linguistic insight supports the hypothesis that most domesticated helmeted Guinea fowls in Kenya are related to the West African domesticated helmeted Guinea fowls. We recommend more molecular studies on this emerging poultry species with potential for poverty alleviation and food security against a backdrop of climate change in Africa.