Molecular characterisation of a coxsackievirus A24 that caused an outbreak of acute haemorrhagic conjunctivitis, Tunisia 2003

Abstract

A B S T R A C TThis study reports the genetic characteristics of coxsackievirus A24 isolates from Tunisia, including a coxsackievirus A24 variant (CVA24v) that caused an outbreak of acute haemorrhagic conjunctivitis (AHC) between September and November 2003. The virus genome was detected by PCR from conjunctival swabs obtained from patients with AHC. Four virus isolates were obtained from PCRpositive samples and were serotyped by sequence analysis of the VP1 and VP4 genomic region and by seroneutralisation. Phylogenetic analysis of the VP1, VP4 and 3C genomic regions was performed. Other Tunisian CVA24 isolates from paralytic cases and healthy individuals were also amplified, sequenced and included in the phylogenetic analysis. The epidemic strain belonged to the CVA24 serotype. Phylogenetic analysis of the 3C region of the genome revealed a strong relationship between the Tunisian epidemic strain and strains that caused outbreaks in Korea (2002) and Guadeloupe and French Guiana (2003). Phylogenetic analysis of the VP1 and VP4 regions showed a clear distinction between serotype CVA24 isolates from conjunctivitis and non-conjunctivitis cases. This is the first study to report an outbreak of AHC caused by CVA24v in the North African region.

Molecular characterization of a coxsackievirus A24 variant that caused an outbreak of acute haemorrhagic conjunctivitis in Spain, 2004

“…Although other studies of recent outbreaks 10,11,[13][14][15] have used the 3C genomic region for molecular analysis, the VP1 region is demonstrably more informative for molecular epidemiological studies than the 3C region for two reasons: due to the high recombination rates among enterovirus, which could distort the analysis; and due to the serological pressure on the capsid region, which may therefore evolve faster than the region encoding non-structural proteins. Indeed, the 3 -end VP1 fragment analysis has been enough to differentiate between HEV serotypes and for their epidemiological studies, not only in this case but also in others.…”

“…Therefore, phylogenetic analysis of this region of the sequences from the Spanish and other CV-A24 strains isolated from recent outbreaks of AHC in Korea (2002Korea ( , 2003Korea ( and 2006, China (2002), Tunisia (2003), French Guiana and West Indies (2003), and Singapore (2005), [10][11][12]15 shows all CV-A24 strains from AHC to be phylogenetically close (Fig. 1b).…”

“…8 In recent years, several published reports with molecular studies of outbreaks caused by CV-A24v occurred in Korea (2002) [10][11][12][13][14][15] The phylogenetic analyses published revealed that all these strains were closely related and formed a separate cluster within genotype III.…”

Phylogenetic analysis of complete VP1 sequences of echoviruses 11 and 6: high genetic diversity and circulation of genotypes with a wide geographical and temporal range

“…In some cases, like that of poliovirus, the different genotypes cluster geographically and, even if long-range importations do occur, a genotype remains specific to a given geographical region (Kew et al, 1995). In contrast, other enteroviruses, such as coxsackieviruses A24 and E30, have temporal genotypes, each having circulated during a given period of time, and seem to have become extinct in favour of newly emerging genotypes (Lin et al, 2001;Oberste et al, 2003;Triki et al, 2007). The present work shows that, for both E6 and E11, genotypes containing isolates with wide geographical and temporal ranges can be found, meaning that some genotypes can persist over a long period of time and have a wide geographical range of circulation.…”

Sialic Acid Is a Cellular Receptor for Coxsackievirus A24 Variant, an Emerging Virus with Pandemic Potential

“…It continued with an outbreak in Malaysia the same year (18). In 2003, outbreaks of AHC were reported from South Korea (46), India (19), Nepal (25), Tunisia (60), and Congo (29), and in the western hemisphere from Nicaragua, Honduras, Guatemala, El Salvador, and Caribbean countries (45), French Guiana and the West Indies (15), Puerto Rico (2), and Brazil (38). In 2004, more outbreaks hit both the western (58) and eastern (29) hemispheres.…”