Eurosurveillance
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Enterovirus D68 (EV-D68) continued to circulate in a seasonal pattern in the Netherlands, after the outbreak in 2010. Outpatient EV-D68 cases, mainly in the under 20 and 50–59 years age groups, presented with relatively mild respiratory disease. Hospital-based enterovirus surveillance identified more severe cases, mainly in children under 10 years of age. Dutch partial VP1 genomic region sequences from 2012 through 2014 were distributed over three sublineages similar to EV-D68 from the outbreak in the US in 2014.
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A countrywide survey in Oman revealed Middle Eastrespiratory syndrome coronavirus (MERS-CoV) nucleicacid in five of 76 dromedary camels. Camel-derivedMERS-CoV sequences (3,754 nucleotides assembled from partial sequences of the open reading frame (ORF)1a, spike, and ORF4b genes) from Oman and Qatar were slightly different from each other, but closely related to human MERS-CoV sequences from the same geographical areas, suggesting local zoonotic transmission. High viral loads in nasal and conjunctival swabs suggest possible transmission by the respiratory route.
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Avian influenza A(H7N9) virus re-emerged in China in December 2013, after a decrease in the number of new cases during the preceding six months. Reassortment between influenza A(H7N9) and local H9N2 strains has spread from China's south-east coast to other regions. Three new reassortments of A(H7N9) virus were identified by phylogenetic analysis: between A(H7N9) and Zhejiang-derived strains, Guangdong/Hong Kong-derived strains or Hunan-derived A(H9N2) strains. Our findings suggest there is a possible risk that a pandemic could develop.
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A novel avian influenza A(H7N9) virus causing human infection emerged in February 2013 in China. To elucidate the mechanism of interspecies transmission, we compared the signature amino acids of avian influenza A(H7N9) viruses from human and non-human hosts and analysed the reassortants of 146 influenza A(H7N9) viruses with full genome sequences. We propose a genetic tuning procedure with continuous amino acid substitutions and reassorting that mediates host adaptation and interspecies transmission. ⋯ The continual reassortation between H7N9 and H9N2 viruses resulted in multiple genotypes for further host adaptation. When we analysed a potential association of mutations and reassortants with clinical outcome, only the PB2 E627K mutation slightly increased the case fatality rate. Genetic tuning may create opportunities for further adaptation of influenza A(H7N9) and its potential to cause a pandemic.
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Ebolavirus disease (EVD) outbreaks have been occurring sporadically in Central Africa since 1976. In 2014, the first outbreak in West Africa was reported in Guinea. Subsequent outbreaks then appeared in Liberia, Sierra Leone and Nigeria. ⋯ Our results suggest lower temperature and higher absolute humidity are associated with EVD outbreak onset in the previous EVD outbreaks in Africa during 1976 to 2014. Potential mechanisms through which climate may have an influence on ebolavirus infection in the natural host, intermediate hosts and humans are discussed. Current and future surveillance efforts should be supported to further understand ebolavirus transmission events between and within species.