ABSTRACT
Yellow fever(YF) is a natural focal disease transmitted by infected mosquitoes,which had caused epidemic in some areas of Europe and America port city in the history,bringing great disaster to human society.Since 40s of last century,a series of derivative strain of 17D vaccines,providing lifelong protection,had been vaccinated a large population who are trave ling to or living in areas at risk for YF,which avoid the outbreak of the disease,appearing quiet state.Since the beginning of 1990s,the disease had outbreak successively in Africa,tropical American areas and its nations.The mortality was even more higher than Ebola happened in 3 countries in West Africa between 2014 and 2015.In 2016-2017the large outbreak in Angola,Congo and Brazil,has claimed thousands of lives.Yellow fever has never occurred in Asia until the introduction of 11 cases by jet travel from Angola to China,which attracted the attention of Chinese government.Yellow fever elimination initiative strategic plan for 2017 2026 was launched by WHO,mainly based on that 17D vaccine which is safe and effective to control the spread of this disease.The measures of controlling mosquitoes and vaccination programs,in particular putting great expectations for the latter,are the main measures for prevention the disease and achievement the goal of WHO elimination strategic plan.But strong guarantees of related countries and abiding by the provisions of the global quarantine regulations are also important.Therefore,this article reviews the historical and the recent epidemic outbreaks of yellow fever,vaccination and other prevention measures,hoping that the WHO elimination of the yellow fever epidemic strategy will achieve successfully in 2026.
ABSTRACT
To analyze the epidemiology,genetic variation and genetic evolution of coxsackievirus A4 (CVA4) in patients with hand,foot and mouth disease in Fujian,the virus isolates were molecular typed and amplified the whole VP1 region by RT-PCR,then the genetic variation and evolution were studied.The results showed that 33 CVA4 cases (8.1％) were confirmed from the 407 non-EV71 non-CVA16 HFMD cases in Fujian Province during 2011 and 2014,accounting for 31 cases in 2012 and 2 cases in 2014.Compared with common characteristics of the HFMD epidemic,no specificity in the distribution of CVA4 cases was found between gender and age groups.Sequence analysis of VP1 nucleotide sequences of Fujian CVA4 isolates showed that the nucleotide and amino acid sequences similarity were 92.6 ％-100 ％ and 95.7 ％-100 ％ respectively,low similarity with the prototype (83.7％-85.4％,96.1％-99.0％) and abroad isolates (82.1％-89.1％,90.4％-99.6％) both in nucleotide and amino acid sequences,high similarity with domestic isolates both in nucleotide and amino acid sequences,with the similarity of 87.9％ 99.2 ％ and 96.1％-100 ％.The results from phylogenetic tree showed that the genetic distance between Fujian CVA4 isolates and the prototype and abroad strains was far,and the genetic distance was close to domestic isolates in China.The distribution of the phylogenetic trees of Fujian CVA4 strains showed multiple branches.Therefore,CVA4 is the major HFMD associated-pathogen other than EV71,CVA 16,CVA6,and CVA10 in Fujian Province from 2011 to 2014.CVA4 strains from Fujian Province is co-circulating and co-evolving with other domestic isolates.There is existence of multiple closely related CVA4 transmission chains in various regions of Fujian.
ABSTRACT
To analyze the epidemiology,genetic variation and genetic evolution of coxsackievirus A4 (CVA4) in patients with hand,foot and mouth disease in Fujian,the virus isolates were molecular typed and amplified the whole VP1 region by RT-PCR,then the genetic variation and evolution were studied.The results showed that 33 CVA4 cases (8.1％) were confirmed from the 407 non-EV71 non-CVA16 HFMD cases in Fujian Province during 2011 and 2014,accounting for 31 cases in 2012 and 2 cases in 2014.Compared with common characteristics of the HFMD epidemic,no specificity in the distribution of CVA4 cases was found between gender and age groups.Sequence analysis of VP1 nucleotide sequences of Fujian CVA4 isolates showed that the nucleotide and amino acid sequences similarity were 92.6 ％-100 ％ and 95.7 ％-100 ％ respectively,low similarity with the prototype (83.7％-85.4％,96.1％-99.0％) and abroad isolates (82.1％-89.1％,90.4％-99.6％) both in nucleotide and amino acid sequences,high similarity with domestic isolates both in nucleotide and amino acid sequences,with the similarity of 87.9％ 99.2 ％ and 96.1％-100 ％.The results from phylogenetic tree showed that the genetic distance between Fujian CVA4 isolates and the prototype and abroad strains was far,and the genetic distance was close to domestic isolates in China.The distribution of the phylogenetic trees of Fujian CVA4 strains showed multiple branches.Therefore,CVA4 is the major HFMD associated-pathogen other than EV71,CVA 16,CVA6,and CVA10 in Fujian Province from 2011 to 2014.CVA4 strains from Fujian Province is co-circulating and co-evolving with other domestic isolates.There is existence of multiple closely related CVA4 transmission chains in various regions of Fujian.