BackgroundXenomonitoring is an approach of epidemiological infection risk assessment addressing vector-transmitted infections like malaria in hematophagous arthropods. Standardization and automation can facilitate its use even in remote areas. In this study, the suitability of an automated commercial loop-mediated isothermal amplification (LAMP) assay, originally designed for the detection of malaria parasite DNA in human blood, was assessed for its applicability for xenomonitoring purposes.MethodsAn automated generic LAMP assay for malaria detection in human blood was applied with Anopheles spp. samples. The results were compared with commercial generic as well as species-specific real-time PCR.ResultsLAMP identified 15/43 (34.9%, 95% CI (20.1%; 50.9%)) mosquitoes artificially exposed to Plasmodium berghei, while this was the case for 22/43 (51.2%, 95% CI (35.5%; 66.7%)) samples applying real-time PCR. Considerably less discrepancy was observed with Anopheles spp. imported to Germany from field studies with 12/172 pools (7.0%, 95% CI (3.7%; 11.9%)) for LAMP and 13/172 pools (7.6%, 95% CI (4.1%; 12.6%)) for real-time PCR. Single testing and typing of DNA isolates indicated an overall infection rate of 1.2% (20/1711) with Plasmodium falciparum, P. malariae and P. ovale. Low rates of invalid results during a field exercise proved the general suitability of the LAMP approach for use at tropical settings.ConclusionsImperfect sensitivity in case of artificial exposure of mosquitoes to non-human plasmodial species was detected for both compared molecular approaches with slightly lower sensitivity of the LAMP approach. For Anopheles spp. infected with Plasmodium spp. causing human malaria, comparable diagnostic reliability could be shown for both approaches and the LAMP assay was shown to be suitable for application under tropical field conditions.

Comprehensive risk assessment for vector-borne disease requires effective monitoring of various vector groups. However, this depends on the traps' ability to capture multiple vector families. This study compares 3 commercially available traps, BG-Sentinel 2, BG-Trap Station as a combination of a BG-Pro and Gravid trap, and the Encephalitis Virus Surveillance trap, with the VectorCube, a newly developed prototype. Multiple openings enable multidirectional vector capture, and color cues can be easily attached and changed. All traps were tested under a uniform, carbon dioxide flow rate at 10 sampling sites (6 in Germany and 4 in Gabon) using a 4 × 4 Latin square design. Each site completed at least 1 full Latin square rotation, resulting in 48 trap comparison days. A total of 3,477 blood-seeking insects from 6 families were captured: 2,797 Culicidae, 324 Simuliidae, 268 Ceratopogonidae, 76 Muscidae, 8 Glossinidae, and 4 Psychodidae. Most Culicidae were collected with the BG-Sentinel 2 followed by the VectorCube. The VectorCube captured the majority of Simuliidae, Muscidae, and Glossinidae observed in this study, while Psychodidae were exclusively collected with BG-Sentinel 2 and BG-Trap Station in Gabon. Mean family richness per trapping session was highest in the VectorCube, followed by BG-Sentinel 2, BG-Trap Station, and Encephalitis Virus Surveillance trap. Overall, the VectorCube and BG-Sentinel 2 demonstrated the highest performance in vector abundance and diversity, driven primarily by high Culicidae catches, whereas captures of non-mosquito hematophagous Diptera occured at lower frequencies and were more site-dependent, including sporadic captures of larger-bodied vectors such as Muscidae and Glossinidae.

African indigenous cattle harbor rich genetic diversity shaped by long-term adaptation to tropical climates and endemic diseases, notably trypanosomiasis. To investigate the genetic basis of natural disease resistance, we analyzed 33,147 SNPs in 1,047 individuals from 17 breeds using complementary selection scans (iHS, XP-EHH, and Rsb) in a multi-cohort framework. Fifteen pairwise comparisons across six breed groups enabled robust detection of recent positive selection, capturing both within-breed and breed-specific adaptive signals. We identified 229 selective regions, with 47 outlier SNPs consistently detected by multiple methods. Selection signals were enriched on chromosomes 5, 7, and 29, containing candidate genes such as ATF4, PKNOX2, DNAJB7, TEF, NFE2, and several SPINK and HOXC family members, many associated with immune function and trypanosome challenge response. These genomic regions represent promising targets for the development of breeding strategies aimed at enhancing disease resilience. By identifying genomic regions under selection, this study provides interesting insights for sustainable livestock improvement and conservation efforts in West and Central Africa. Our findings support the integration of indigenous genetic resources into breeding programs designed to optimize productivity while maintaining resilience to environmental and disease pressures.

Accurate identification of mosquito species is essential for effective vector control and mitigation of mosquito-borne disease outbreaks. Traditional morphological identification requires highly specialized personnel and is time-consuming, while molecular techniques can be cost-effective and dependent on comprehensive genetic information. Wing geometric morphometry has emerged as a promising alternative, leveraging detailed geometric measurements of wing shapes and vein patterns to distinguish between species and detect intraspecies variations. This paper presents a curated dataset of 18,104 mosquito wing images, collected from 10,500 mosquito specimens, annotated with extensive meta-information, designed to support research in wing geometric morphometry and the development of machine learning models, ultimately supporting efforts in vector surveillance and research.

Phlebotomine sand flies of the genus Sergentomyia are considered to be of minor importance as vectors of Leishmania parasites pathogenic to humans, but are known to transmit lizard parasites of the subgenus Sau-roleishmania, including L. (S.) adleri. However, knowledge on the geographic distribution of Sauroleishmania spp. and the infection rates in the vectors is very limited. Therefore, our study aimed (1) to further elucidate the distribution and prevalence of Sauroleishmania spp. in their respective vectors and (2) to assess the potential risk for occasional transmission of Leishmania parasites to international military personnel deployed in camps in Mali and Niger. A total of 1,482 wild-caught sand flies (Sergentomyia spp. and closely related Grassomyia spp.) were screened by real-time PCR for the presence of Leishmania DNA. Thirty-two sand fly pools were tested positive, with six from Mali and 26 from Niger. The DNA of four representative isolates was sequenced. The resulting sequences revealed a homology to L. adleri, which leads to the first report of this species from Mali and Niger to the best of our knowledge. The results suggest that Sergentomyia (Sintonius) clydei might be the natural sand fly vector, while Grassomyia spp. appear to be refractory. No Leishmania sp. pathogenic to humans was detected in these sand flies.

In Mauritania, several mosquito-borne viruses have been reported that can cause devastating diseases in animals and humans. However, monitoring data on their occurrence and local distribution are limited. Rift Valley fever virus (RVFV) is an arthropod-borne virus that causes major outbreaks throughout the African continent and the Arabian Peninsula. The first Rift Valley fever (RVF) epidemic in Mauritania occurred in 1987 and since then the country has been affected by recurrent outbreaks of the disease. To gain information on the occurrence of RVFV as well as other mosquito-borne viruses and their vectors in Mauritania, we collected and examined 4,950 mosquitoes, belonging to four genera and 14 species. The mosquitoes were captured during 2018 in the capital Nouakchott and in southern parts of Mauritania. Evidence of RVFV was found in a mosquito pool of female Anopheles pharoensis mosquitoes collected in December on a farm near the Senegal River. At that time, 37.5% of 16 tested Montbéliarde cattle on the farm showed RVFV-specific IgM antibodies. Additionally, we detected IgM antibodies in 10.7% of 28 indigenous cattle that had been sampled on the same farm one month earlier. To obtain information on potential RVFV reservoir hosts, blood meals of captured engorged mosquitoes were analyzed. The mosquitoes mainly fed on humans (urban areas) and cattle (rural areas), but also on small ruminants, donkeys, cats, dogs and straw-colored fruit bats. Results of this study demonstrate the circulation of RVFV in Mauritania and thus the need for further research to investigate the distribution of the virus and its vectors. Furthermore, factors that may contribute to its maintenance should be analyzed more closely. In addition, two mosquito pools containing Aedes aegypti and Culex quinquefasciatus mosquitoes showed evidence of dengue virus (DENV) 2 circulation in the city of Rosso. Further studies are therefore needed to also examine DENV circulation in Mauritania.

Autochthonous taurine and later introduced zebu cattle from Cameroon differ considerably in their resistance to endemic pathogens with little to no reports of the underlying genetic make-up. Breed history and habitat variations are reported to contribute significantly to this diversity worldwide, presumably in Cameroon as well, where locations diverge in climate, pasture, and prevalence of infectious agents. In order to investigate the genetic background, the genotypes of 685 individuals of different Cameroonian breeds were analysed by using the BovineSNP50v3 BeadChip. The variance components including heritability were estimated and genome-wide association studies (GWAS) were performed. Phenotypes were obtained by parasitological screening and categorised in Tick-borne pathogens (TBP), gastrointestinal nematodes (GIN), and onchocercosis (ONC). Estimated heritabilities were low for GIN and TBP (0.079 (se = 0.084) and 0.109 (se = 0.103) respectively) and moderate for ONC (0.216 (se = 0.094)). Further than revealing the quantitative nature of the traits, GWAS identified putative trait-associated genomic regions on five chromosomes, including the chromosomes 11 and 18 for GIN, 20 and 24 for TBP, and 12 for ONC. The results imply that breeding for resistant animals in the cattle population from Northern Cameroon might be possible for the studied pathogens; however, further research in this field using larger datasets will be required to improve the resistance towards pathogen infections, propose candidate genes or to infer biological pathways, as well as the genetic structures of African multi-breed populations.

Background: Crimean-Congo hemorrhagic fever virus (CCHFV) belongs to the Nairovididae family in the Orthonairovirus genus and is an emerging tick-borne virus. It is endemic in most parts of Africa, Asia, as well as southern Europe, and can cause severe hemorrhagic symptoms in humans with high fatality rates (5-30 %). Methods: Hyalomma ticks were collected from four different livestock herds (cattle and camel) from Mauritania in 2018. The tick species was determined morphologically and confirmed on a molecular level by using cytochrome oxidase 1 gene marker (CO1). For the detection of CCHFV, ticks were tested individually with a one-step multiplex real-time RT-qPCR. Subsequently, the S-segment of all positive samples were sequenced to determine the CCHFV genotype. Results: Overall, 39 of 1,523 ticks (2.56 %) collected from 63 cattle and 28 camels were tested positive for CCHFV. Three Hyalomma ( H .) species were identified. The highest prevalence of CCHFV was found in Hyalomma rufipes (5.67 %; 16/282), followed by H. dromedarii (1.89 %; 23/1,214) and H. impeltatum (0 %; 0/21). Positive ticks were found on only 6 out of 91 host animals. Sequence analysis of the positive samples revealed the presence of two different CCHFV lineages (Africa I and Africa III). Conclusions: This study reveals a CCHFV prevalence of 2.56 % in Hyalomma ticks collected from camels and cattle in Mauritania. The true prevalence of unfed ticks may however be lower since a considerable number of ticks may have been passively infected during the ingestion of the blood meal by co-feeding or viremia of the host. The study shows that tick control measures should be implemented, especially in the examined areas.

Ixodid ticks represent vectors and reservoirs for a broad range of zoonotic pathogens. Collected ticks from field studies are therefore usually stored in ethanol, which in higher concentrations effectively inactivates most of the known tick-borne pathogens. Although commonly practiced as gold standard for inactivation, hardly any scientific data demonstrate that ethanol sufficiently penetrates the comparatively thick cuticula of ticks. Therefore, Amblyomma hebraeum tick pools were stored for 21 days in ethanol (96%). Afterwards, the ethanol was removed and the ticks were homogenized. Quantitative 1H-NMR spectroscopic analysis was applied to determine the residual concentration of ethanol inside the ticks. 1H-NMR spectroscopic analysis revealed that ethanol constituted 28.3–42.6 mg of the total weight of three ticks in the pools (89.9–121.5 mg). In addition, the low-pathogenic Hazara orthonairovirus (HAZV) was used as a cell culture model for this study. The virus was exposed to ethanol concentrations between 0 and 60% and incubated under various temperature conditions for four time periods. Afterwards, the residual virus infectivity was determined by titration. Following ethanol exposure, HAZV did not grow in cells after 9 h of exposure to an ethanol concentration of 25%. These results demonstrate an extremely low ethanol resistance of the virus, which was generally in line with previously reported ethanol inactivation data for Crimean-Congo hemorrhagic fever orthonairovirus (CCHFV). After prolonged storage and impregnation, comparable ethanol concentrations are achieved in the ticks, indicating the suitability of this inactivation method also for Bunyaviruses in ticks. At the very least, a massive virus inactivation can be assumed. Definitive proof of virus inactivation would require a bioassay of ethanol-treated infected ticks under appropriate biosafety conditions.

Dugbe orthonairovirus (DUGV), a tick-borne zoonotic arbovirus, was first isolated in 1964 in Nigeria. For over four decades, no active surveillance was conducted to monitor the spread and genetic variation of DUGV. This study detected and genetically characterized DUGV circulating in cattle and their infesting ticks (Amblyomma and Rhipicephalus (Boophilus)) in Kwara State, North-Central Nigeria. Blood and or ticks were collected from 1051 cattle at 31 sampling sites (abattoirs and farms) across 10 local government areas of the State. DUGV detection was carried out by RT-qPCR, and positive samples sequenced and phylogenetically analysed. A total of 11824 ticks, mostly A. variegatum (36.0%) and R. (B.) microplus (63.9%), were obtained with mean tick burden of 12 ticks/cattle. Thirty-four (32 A. variegatum and two R. (B.) microplus) of 4644 examined ticks were DUGV-positive, whereas all of the cattle sera tested negative for DUGV genome. Whole genome sequence (S, M and L segments) and phylogenetic analyses indicate that the positive samples shared up to 99.88% nucleotide identity with and clustered around the Nigerian DUGV prototype strain IbAr 1792. Hence, DUGV with high similarity to the previously characterised strain has been detected in Nigeria. To our knowledge, this is the first report of DUGV in North-Central Nigeria and the most recent information after its last surveillance in 1974.

Gastro-intestinal tracts were examined from thirteen Gudali zebu cattle, ten goats and ten sheep from the Adamawa highland in Northern Cameroon. A total of 28,325 adult helminths were recovered from the abomasa, small and large intestines. Five trichostrongylid genera were identified by their morphology: Haemonchus, Trichostrongylus and Oesophagostomum were predominant in both cattle and small ruminants, whilst Cooperia was only found in cattle both in the abomasum and small intestines. The molecular species identification and the inference of their phylogenetic relationships was based on the analysis of the hypervariable region I of the small subunit 18S rDNA (SSU) and the Second Internal Transcribed Spacer (ITS-2) of 408 adult trichostrongylid worms, which were PCR-amplified, sequenced, and compared with available database entries. Consistent with earlier findings, the SSU was invariable within the Haemonchus and Trichostrongylus genera, confirming the prior classification based on the morphology of the worms, but the ITS-2 was highly inter- and intraspecifically variable and thus allowed to distinguish individual species and to study the haplotype diversity within the different species. In cattle, we report for the first time in Cameroon co-infection with two species of Haemonchus (H. placei and H. similis), together with two species of Cooperia (C. punctata and C. pectinata) and one species of Trichostrongylus (T. axei). In goats and sheep, we found one highly polymorphic clade of Haemonchus contortus and two Trichostrongylus species (T. axei and T. colubriformis). When compared with other Trichostrongylidae from different regions of the world and wildlife, the analysis of haplotypes did not indicate any host and geographical isolation, but a very high haplotype diversity among H. contortus. These findings illustrate the complexity of trichostrongylid populations in domestic ruminants and suggest grazing overlap between domestic and wildlife hosts.

Rift Valley fever (RVF) is a major viral zoonosis transmitted by mosquitoes. The virus is endemic in most parts of sub-Saharan Africa and can affect humans, livestock, and wild ungulates. Knowledge of the biology of vectors of Rift Valley fever virus (RVFV) is essential for the establishment of effective control measures of the disease. The objective of this study was to determine the species diversity and relative abundance of potential RVFV vectors in the North Region of Cameroon. Adult mosquitoes were trapped during the wet and dry seasons from December 2017 to January 2019 with “EVS Light” traps with CO2 baits placed at selected sites. The captured mosquitoes were identified using dichotomous keys according to standard procedures. The abundance was calculated with regard to site, zone, and collection season. A total of 27,851 mosquitoes belonging to four genera (Aedes, Anopheles, Mansonia, and Culex) and comprising 31 species were caught (including 22 secondary vectors (98.05%) and nine primary vectors (1.94%). The total number of mosquitoes varied significantly depending on the locality (p-value < 0.001). The average number of mosquitoes collected per trap night was significantly higher in irrigated areas (p-value < 0.001), compared to urban and non-irrigated areas. The study revealed the presence of potential primary and secondary vectors of RVFV with varying abundance and diversity according to locality and ecological site in the North Region of Cameroon. The results showed that the genus Mansonia with the species Ma. uniformis and Ma. africana formed the dominant taxon (52.33%), followed by the genera Culex (45.04%) and Anopheles (2.61%). The need for molecular analysis (PCR) tests for RVFV RNA research and viral isolation methods on these vectors to determine their role in the epidemiology and control of RVF cannot be overemphasized.

Abstract Background African indigenous taurine cattle display unique adaptive traits shaped by husbandry management, regional climate and exposure to endemic pathogens. They are less productive with respect to milk and meat production which has been associated with amongst others, small size, traditional beliefs, husbandry practices, limited feed resources, disease burden and lack of sustained breeding for trait improvement. This resulted in the severe dwindling of their population size rendering them vulnerable to extinction. The Namchi taurine cattle breed is referred to as [Namchi (Doayo)] and shows resistance traits against trypanosome infection and exposure to tick infestation. Nonetheless, the historically later introduced Zebu cattle are the main cattle breeds in Africa today, even though they suffer more from locally prevailing pathogens. By using a whole genome sequencing approach, we sequenced with high depth for the first time the genomes of five cattle breeds from Cameroon in order to provide a valuable genetic resource for future African cattle breeding: the Namchi, an endangered trypano-tolerant taurine breed, the Kapsiki, an indigenous trypano-susceptible taurine breed, and three Zebu (Bos indicus indicus) breeds: Ngaoundere Gudali, White Fulani and Red Fulani. Results Approximately 167 Gigabases of raw sequencing data were generated for each breed and mapped to the cattle reference genomes ARS-UCD1.2 and UMD3.1.The coverage was 103 to 140-fold when aligning the reads to ARS-UCD1.2 with an average mapping rate of ~ 99%, and 22 to 30-fold when aligning the reads to UMD3.1 with an average mapping rate of ~ 64%. The single nucleotide polymorphisms (SNPs) obtained from analysis using the genome ARS-UCD1.2 were compared with reference genomes of European Bos taurus Holstein, the Asian Bos indicus Brahman, and the African trypanotolerant N’Dama breeds. A total of ~ 100 million (M) SNPs were identified and 7.7 M of those were breed-specific. An approximately 11.1 M constituted of small insertions and deletions. By using only breed-specific non-synonymous variants we identified genes as genetic signatures and associated Gene Ontology (GO) terms that could explain certain cattle-breed specific phenotypes such as increased tolerance against trypanosome parasites in the Namchi breed and heat tolerance in the Kapsiki breed. Phylogenetic analysis grouped, except for Namchi, the Bos taurus breeds Kapsiki, N’Dama and Holstein together while the B. indicus breeds White and Red Fulani, Gudali and Brahman clustered separately. The deviating result for Namchi indicates a hybrid status of the selected animal with a recent introgression of Zebu genes into its genome. Conclusions The findings provide the first comprehensive set of genome-wide variant data of the most important Cameroonian cattle breeds. The genomic data shall constitute a foundation for breed amelioration whilst exploiting the heritable traits and support conservation efforts for the endangered local cattle breeds.

Crimean-Congo haemorrhagic fever is a viral tick-borne zoonotic disease caused by a Nairovirus, Crimean-Congo haemorrhagic fever virus (CCHFV). The present survey aimed to determine the exposure of one-humped camels (Camelus dromedarius) from southern Tunisia to CCHFV. A total of 273 sera from extensively reared camels were collected from Tataouine district, Tunisia, and tested by CCHFV-specific enzyme linked immunosorbent assays. By combining the results of three serological tests, the overall seroprevalence of CCHFV was estimated as 89.7% (245/273). No viral RNA was detected from camel sera using quantitative real-time PCR (RT-qPCR). A total of 165 ticks were collected from camels and tested with RT-qPCR, and only one Hyalomma impeltatum tick was positive for virus RNA.

Background African indigenous taurine cattle display unique adaptive traits shaped by husbandry management, regional climate and exposure to endemic pathogens. They are less productive with respect to milk and meat production which has been associated with amongst others, small size, traditional beliefs, husbandry practices, limited feed resources, disease burden and lack of sustained breeding for trait improvement. This resulted in the severe dwindling of their population size rendering them vulnerable to extinction. The Namchi taurine cattle breed is referred to as [Namchi (Doayo)] and shows resistance traits against trypanosome infection and exposure to tick infestation. Nonetheless, the historically later introduced Zebu cattle are the main cattle breeds in Africa today, even though they suffer more from locally prevailing pathogens. By using a whole genome sequencing approach, we sequenced with high depth for the first time the genomes of five cattle breeds from Cameroon in order to provide a valuable genetic resource for future African cattle breeding: the Namchi, an endangered trypano-tolerant taurine breed, the Kapsiki, an indigenous trypano-susceptible taurine breed, and three Zebu (Bos indicus indicus) breeds: Ngaoundere Gudali, White Fulani and Red Fulani. Results Approximately 167 Gigabases of raw sequencing data were generated for each breed and mapped to the cattle reference genomes ARS-UCD1.2 and UMD3.1.The coverage was 103 to 140-fold when aligning the reads to ARS-UCD1.2 with an average mapping rate of similar to 99%, and 22 to 30-fold when aligning the reads to UMD3.1 with an average mapping rate of similar to 64%. The single nucleotide polymorphisms (SNPs) obtained from analysis using the genome ARS-UCD1.2 were compared with reference genomes of EuropeanBos taurusHolstein, the AsianBos indicusBrahman, and the African trypanotolerant N'Dama breeds. A total of similar to 100 million (M) SNPs were identified and 7.7 M of those were breed-specific. An approximately 11.1 M constituted of small insertions and deletions. By using only breed-specific non-synonymous variants we identified genes as genetic signatures and associated Gene Ontology (GO) terms that could explain certain cattle-breed specific phenotypes such as increased tolerance against trypanosome parasites in the Namchi breed and heat tolerance in the Kapsiki breed. Phylogenetic analysis grouped, except for Namchi, theBos taurusbreeds Kapsiki, N'Dama and Holstein together while theB. indicusbreeds White and Red Fulani, Gudali and Brahman clustered separately. The deviating result for Namchi indicates a hybrid status of the selected animal with a recent introgression of Zebu genes into its genome. Conclusions The findings provide the first comprehensive set of genome-wide variant data of the most important Cameroonian cattle breeds. The genomic data shall constitute a foundation for breed amelioration whilst exploiting the heritable traits and support conservation efforts for the endangered local cattle breeds.

The species identification of tick vectors of Crimean-Congo hemorrhagic fever virus (CCHFV), especially Hyalomma (H.) species, is a prerequisite to understand the eco-epidemiology of this disease and to reveal vector and virus reservoir species. However, the morphologic species discrimination can be difficult for damaged or blood-fed ticks and in case of species intercrosses. Therefore, we used matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and restriction fragment length polymorphism (RFLP) analysis to distinguish the most common Hyalomma species from sub-Saharan Africa (H. truncatum, H. rufipes and H. dromedarii). Within the last years, MALDI-TOF MS analysis based on tick leg proteins has been shown to be a reliable method to distinguish several tick species. For this purpose, a reference spectral library of several European, American and African tick species was established. In this study, six different Hyalomma species were tested, all of which were all clearly distinguishable by mass spectrometric analyses. Moreover, MALDI TOF- MS was able to confirm morphologic findings where sequencing provided ambiguous results. In addition, a polymerase chain reaction (PCR) based on the CO1 gene amplification of ticks has been developed for the unequivocal species identification by amplicon sequencing and specific restriction endonuclease cleavage pattern analysis. RFLP proved to be a feasible auxiliary discrimination tool for selected Hyalomma species when access to sequencing methods is not available, as for instance during field studies.

Rift Valley fever (RVF) is a zoonotic vector borne infectious disease of major medical and veterinary importance particularly in sub-Saharan Africa. However, there is dearth of epidemiological knowledge of the disease in Cameroon. We conducted a cross-sectional study (January 2016–January 2017) to investigate the seroprevalence and potential risk factors of Rift Valley fever virus (RVFV) in sheep and goats in the North region of Cameroon. Stratified sampling approach was used to select herds where sera were collected from 680 randomly selected small ruminants (355 goats and 325 sheep) in eight localities (Kismatari, Lagdo, Pitoa, Garoua, Bocklé, Dembo, Poli and Touboro) within three administrative divisions (Bénoué, Mayo-Rey and Faro) in the North region. Anti-RVFV antibodies were detected using a competitive Enzyme-Linked Immunosorbent Assay (ELISA), while a capture ELISA was used for the detection of specific RVFV-Immunoglobulin M (Ig-M) antibodies. We evaluated the associated potential risk factors of RVF in small ruminants based on observations of animal-related intrinsic and extrinsic factors in combination with serological results. The results revealed that 3.4% (95% confidence interval (CI): 2.2–5.1%) of sampled animals and 24.6% (95% CI: 15.1–37.1%) of 65 sampled herds were seropositive for anti-RVFV antibodies and no difference in seropositivity between sheep and goats at individual animal as well as at herd levels was observed. Localities along hydrographic or large water banks such as Kismatari (OR: 14.333, (95% CI: 1.436–145.088)) and Pitoa (OR = 11.467 (95% CI: 1.249–50.306)) were significantly associated to RVFV antibody seroprevalence in a simple logistic regression. In addition, the multiple regression analysis showed that age and access to water points significantly influenced RVFV antibody seroprevalence in small ruminants. This study revealed that anti-RVFV antibodies are present in sheep and goats in the North region of Cameroon. It highlights the likely endemic circulation of RVFV in the considered localities despite the absence of clinical cases reported in animals or humans. Under these conditions, it is necessary to set up an early warning, surveillance and control strategy based on epizootic risk.

BACKGROUND:Public interest for tick-borne pathogens in cattle livestock is rising due to their veterinary and zoonotic importance. Consequently, correct identification of these potential pathogens is crucial to estimate the level of exposition, the risk and the detrimental impact on livestock and the human population.RESULTS:Conventional PCR with generic primers was used to identify groups of tick-borne pathogens in cattle breeds from northern Cameroon. The overall prevalence in 1260 blood samples was 89.1%, with 993 (78.8%) positive for Theileria/Babesia spp., 959 (76.1%) for Anaplasma/Ehrlichia spp., 225 (17.9%) for Borrelia spp., and 180 (14.3%) for Rickettsia spp. Sanger sequencing of a subset of positively-tested samples revealed the presence of Theileria mutans (92.2%, 130/141), T. velifera (16.3%, 23/141), Anaplasma centrale (10.9%, 15/137), A. marginale (30.7%, 42/137), A. platys (51.1%, 70/137), Anaplasma sp. 'Hadesa' (10.9%, 15/137), Ehrlichia ruminantium (0.7%, 1/137), E. canis (0.7%, 1/137), Borrelia theileri (91.3%, 42/46), Rickettsia africae (59.4%, 19/32) and R. felis (12.5%, 4/32). A high level of both intra- and inter-generic co-infections (76.0%) was observed. To the best of our knowledge, B. theileri, T. mutans, T. velifera, A. platys, Anaplasma sp. 'Hadesa', R. felis and E. canis are reported for the first time in cattle from Cameroon, and for R. felis it is the first discovery in the cattle host. Babesia spp. were not detected by sequencing. The highest number of still identifiable species co-infections was up to four pathogens per genus group. Multifactorial analyses revealed a significant association of infection with Borrelia theileri and anemia. Whereas animals of older age had a higher risk of infection, the Gudali cattle had a lower risk compared to the other local breeds.CONCLUSION:Co-infections of tick-borne pathogens with an overall high prevalence were found in all five study sites, and were more likely to occur than single infections. Fulani, Namchi and Kapsiki were the most infected breed in general; however, with regions as significant risk factor. A better-adapted approach for tick-borne pathogen identification in co-infected samples is a requirement for epidemiological investigations and tailored control measures.

Background: African animal trypanosomosis remains the major constraint of livestock production and livelihood of pastoral communities in Cameroon. Despite several decades of vector and parasite control efforts, it has not been eradicated. Alternative and sustainable control strategies require a sound knowledge of the local species, strains and vectors. In the Sudano-Sahelian and Guinea Savannah of Cameroon the prevalence and genetic diversity of trypanosomes infecting cattle was investigated by microscopy of cattle blood buffy coat and molecular methods using generic primers targeting parts of the internal transcribed spacer 1 (ITS-1) and encoded glycosomal glyceraldehyde 3-phosphate dehydrogenase-gene (gGAPDH). Results: A total of 1176 randomly chosen cattle from five divisions in the Sudano-Sahelian and Guinea Savannah of Cameroon were examined. The overall prevalence of trypanosomes by microscopy was 5.9% (56/953) in contrast to 53.2% (626/1176) when molecular tools were used. This indicated a limited sensitivity of microscopy in subclinical infections with frequently low parasitemia. Three trypanosome species were identified by light microscopy: T. vivax (2.3%), T. brucei (3.7%) and T. congolense (3.0%), whereas five were identified by PCR, namely T. grayi/T. theileri (30.8%), T. vivax (17.7%), T. brucei (14.5%) and T. congolense (5.1%). Unexpected cases of T. grayi (n = 4) and T. theileri (n = 26) were confirmed by sequencing. Phylogenetic analysis of the gGAPDH revealed the presence of T. vivax, clade A and T. vivax clade C, which were co-endemic in the Faro et Deo division. T. grayi/T. theileri were the predominant species infecting cattle in tsetse free areas. In contrast, T. vivax, T. brucei and T. congolense were more abundant in areas where the Glossina-vectors were present. Conclusions: The abundance of pathogenic trypanosomes in tsetse infested areas is alarming and even more, the occurrence of T. vivax, T. brucei, T. congolense, T. theileri and T. grayi in tsetse-free areas implies that tsetse control alone is not sufficient to control trypanosomosis in livestock. To implement control measures that reduce the risk of spread in tsetse free areas, close monitoring using molecular tools and a thorough search for alternative vectors of trypanosomes is recommended.