Laboratory capacity assessments in 25 African countries at high risk of yellow fever, August-December 2018.

INTRODUCTION: accurate and timely laboratory diagnosis of yellow fever (YF) is critical to the Eliminate Yellow Fever Epidemics (EYE) strategy. Gavi, the Vaccine Alliance recognized the need to support and build capacity in the national and regional laboratories in the Global YF Laboratory Network (GYFLN) as part of this strategy. METHODS: to better understand current capacity, gaps and needs of the GYFLN laboratories in Africa, assessments were carried out in national and regional reference laboratories in the 25 African countries at high risk for YF outbreaks that were eligible for new financial support from Gavi. RESULTS: the assessments found that the GYFLN in Africa has high capacity but 21% of specimens were not tested due to lack of testing kits or reagents and approximately 50% of presumptive YF cases were not confirmed at the regional reference laboratory due to problems with shipping. CONCLUSION: the laboratory assessments helped to document the baseline capacities of these laboratories prior to Gavi funding to support strengthening YF laboratories.

Geographical Distribution of Ticks Ixodidae in Côte d'Ivoire: Potential Reservoir of the Crimean-Congo Hemorrhagic Fever Virus.

Background: Ticks and tick-borne diseases are a major issue. These recent years, tick-borne diseases have attracted much attention because of their increasing incidence and the significant damage that they cause to livestock and human health. The objective was to identify the different species of ticks found in cattle and to determine the prevalence of Crimean-Congo hemorrhagic fever virus (CCHFV) in these different areas. Methods: The study was conducted in five regions of Côte d'Ivoire belonging to different geographic areas. The ticks were collected from cattle. The identification of ticks was done with a binocular microscope using the identification keys. The detection of CCHFV was done by RT-PCR using specific primers and probes. Findings: Of the ticks sampled, 4088 (96.9%) were adults. Of the genera Amblyomma, Hyalomma, and Rhipicephalus. The genus Rhipicephalus had the highest number with 54.3% of the collected ticks embodied in five species. It is followed by the genus Amblyomma with 43.7% and represented by only one species. The genus Hyalomma represented by seven species was obtained in a low proportion of 2.1%. The predominant species identified was Rhipicephalus (Boophilus) microplus with (48.7%), followed by the species Amblyomma variegatum (43.7%), and the other species <2%. In this study, CCHFV was detected in ticks belonging to the three genera identified. All-inclusive, 16 ticks (0.37%) out of 4219 collected from cattle tested positive for CCHFV. The species tested positive for CCHFV are A. variegatum, Hyalomma impressum, Rhipicephalus (Boophilus) geigyi, R. (B.) microplus, and Rhipicephalus sanguineus. All 16 ticks positive for CCHFV are adults and were obtained from the Korogho (11 ticks) and Bouaflé (5 ticks) regions. Conclusion: Three genera of ticks, Amblyomma, Hyalomma, and Rhipicephalus and 13 species infesting cattle were identified during this study. Eleven ticks were positive for CCHFV in Korhogo and five in Bouaflé. The genus mainly infested was A. Variegatum.

Evolutionary history and dynamics of dog rabies virus in western and central Africa.

The burden of rabies in Africa is estimated at 24,000 human deaths year(-1), almost all of which result from infection with dog rabies viruses (RABV). To investigate the evolutionary dynamics of RABV in western and central Africa, 92 isolates sampled from 27 African countries over 29 years were collected and sequenced. This revealed that RABV currently circulating in dogs in this region fell into a single lineage designated 'Africa 2'. A detailed analysis of the phylogeographical structure of this Africa 2 lineage revealed strong population subdivision at the country level, with only limited movement of virus among localities, including a possible east-to-west spread across Africa. In addition, Bayesian coalescent analysis suggested that the Africa 2 lineage was introduced into this region of Africa only recently (probably <200 years ago), in accordance with the timescale of expanding European colonial influence and urbanization, and then spread relatively slowly, perhaps occupying the entire region in a 100 year period.