RESUMEN
BACKGROUND: Crimean-Congo hemorrhagic fever virus (CCHFV) belongs to the genus Orthonairovirus (Nairovididae) and is a (re)emerging tick-borne pathogen. It is endemic in most parts of Africa, Asia and 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 camels) in Mauritania in 2018. The tick species were determined morphologically and confirmed molecularly by using the cytochrome oxidase 1 gene marker. For the detection of CCHFV, ticks were tested individually by one-step multiplex real-time reverse-transcriptase quantitative polymerase chain reaction. The small segment of all positive samples was sequenced to determine the CCHFV genotype. RESULTS: In total, 39 of the 1523 ticks (2.56%) collected from 63 cattles and 28 camels tested positive for CCHFV. Three Hyalomma species were identified. Hyalomma rufipes had the largest proportion of positivity (5.67%; 16/282), followed by Hyalomma dromedarii (1.89%; 23/1214). No Hyalomma impeltatum tested positive (0%; 0/21). Positive ticks were found in only six out of 91 host animals. Viral sequence analysis revealed the presence of two different CCHFV lineages (Africa I and Africa III). CONCLUSIONS: In this study, 2.56% of Hyalomma ticks collected from camels and cattle in Mauritania tested positive for CCHFV. However, the true prevalence of CCHFV in unfed ticks may be lower, as a considerable number of ticks may have been passively infected during blood-feeding by co-feeding ticks or due to viremia of the host. The results indicate the need to track the actual area of circulation of this virus.
Asunto(s)
Sangre , Virus de la Fiebre Hemorrágica de Crimea-Congo/genética , Ganado/parasitología , Garrapatas/virología , Animales , Camelus/parasitología , Camelus/virología , Bovinos/parasitología , Bovinos/virología , Conducta Alimentaria , Femenino , Genotipo , Virus de la Fiebre Hemorrágica de Crimea-Congo/aislamiento & purificación , Fiebre Hemorrágica de Crimea/virología , Ganado/virología , Masculino , Mauritania , Filogenia , ARN Viral/genética , Garrapatas/genética , Garrapatas/fisiologíaRESUMEN
The influence of hay making on in situ N degradability of forages was assessed by comparing the degradability of nine hays with that of standing forages at the time of harvest. Three ryegrass, two cocksfoot, and three alfalfa forages were used. The N degradability of hays was related closely to that of the corresponding standing forages (R = .91) and was, on average, lower (-2.5 points). This decrease in degradability after hay making was not constant; it increased when the degradability of the standing forage was high and when harvesting conditions were poor.
