Genomic Epidemiology of 2015-2016 Zika Virus Outbreak in Cape Verde.

During 2015-2016, Cape Verde, an island nation off the coast of West Africa, experienced a Zika virus (ZIKV) outbreak involving 7,580 suspected Zika cases and 18 microcephaly cases. Analysis of the complete genomes of 3 ZIKV isolates from the outbreak indicated the strain was of the Asian (not African) lineage. The Cape Verde ZIKV sequences formed a distinct monophylogenetic group and possessed 1-2 (T659A, I756V) unique amino acid changes in the envelope protein. Phylogeographic and serologic evidence support earlier introduction of this lineage into Cape Verde, possibly from northeast Brazil, between June 2014 and August 2015, suggesting cryptic circulation of the virus before the initial wave of cases were detected in October 2015. These findings underscore the utility of genomic-scale epidemiology for outbreak investigations.

Epidemiology of the Zika Virus Outbreak in the Cabo Verde Islands, West Africa.

INTRODUCTION: The Zika virus (ZIKV) outbreak in the island nation of Cabo Verde was of unprecedented magnitude in Africa and the first to be associated with microcephaly in the continent. METHODS: Using a simple mathematical framework we present a first epidemiological assessment of attack and observation rates from 7,580 ZIKV notified cases and 18 microcephaly reports between July 2015 and May 2016. RESULTS: In line with observations from the Americas and elsewhere, the single-wave Cabo Verdean ZIKV epidemic was characterized by a basic reproductive number of 1.85 (95% CI, 1.5 - 2.2), with overall the attack rate of 51.1% (range 42.1 - 61.1) and observation rate of 2.7% (range 2.29 - 3.33). CONCLUSION: Current herd-immunity may not be sufficient to prevent future small-to-medium epidemics in Cabo Verde. Together with a small observation rate, these results highlight the need for rapid and integrated epidemiological, molecular and genomic surveillance to tackle forthcoming outbreaks of ZIKV and other arboviruses.

Blindness and low vision in Cape Verde Islands: results of a national eye survey.

AIMS: Prior to establishing a national prevention of blindness program a population based survey was conducted in Cape Verde Islands in1998. The objectives of the survey were to estimate the overall and age-specific prevalence of blindness and low vision, to identify the main disorders causing blindness and low vision, and to estimate the population need for basic eye care services. METHODS: A two-level cluster random sampling procedure was used, selecting 30 clusters from the nine inhabited islands and 3,803 persons of all ages were included in the sample. RESULTS: 3,374 persons were examined (coverage 88.7%). The prevalence of bilateral blindness (visual acuity in the better eye less than 3/60) was 0.8% (95% confidence interval [CI] 0.5-1.1), of bilateral low vision (6/18 to 3/60 in the better eye) 1.7% (95% CI: 1.3-2.2) and of monocular blindness 1.5% (95% CI: 1.2-2.0). The major causes of blindness were age related cataract and glaucoma (57.7% and 15.4%, respectively, of blind people recruited). The major causes of bilateral low vision were cataract, refractive errors, and macular disorders (46.2%, 26.8%, and 8.9%, respectively, of persons with low vision). Nontrachomatous corneal opacities accounted for 7.7% of bilateral and for 11.5% of monocular blindness. Vascular retinopathy was responsible for 7.7% of bilateral and for 9.6% of monocular blindness. Trachoma is not a public health problem as only 2.3% of children less than 10 years of age were suffering from active trachoma. Palpebral or limbal vernal conjunctivitis were encountered in 4.5% of persons under 25. CONCLUSION: More than half of the visual impairments are treatable by provision of cataract surgery and cataract has been indicated as a priority target in the recently designed National Blindness Program of the Cape Verde Republic. Pathologic conditions such as diabetes are emerging as serious burden for ageing populations and account for most of the retinal vascular disease.