Outbreak of acute hemorrhagic conjunctivitis in Maharashtra and Gujarat states of India, caused by Coxsackie virus A-24 variant

Abstract

Acute hemorrhagic conjunctivitis is associated with enteroviruses. Among these, Coxsackie A-24 variant (CA-24) and Enterovirus-70 (EV-70) are known to cause epidemics and pandemics. An outbreak of acute hemorrhagic conjunctivitis occurred in August-September 2003 in Maharashtra and Gujarat states of India. The present investigation was carried out to determine the viral etiological agent associated with the epidemic. Virus isolates were obtained from 11 eye swabs of conjunctivitis patients using HeLa/ Hep-2 cell lines. The isolates were characterized by serological and mouse pathogenecity tests, RT-PCR using enterovirus common primers (VP4-VP2), CA-24 specific primers (3C-proteinase region), EV-70 primers (VP-3) followed by sequencing, and phylogenetic analysis. The virus was characterized as a Coxsackie A-24 variant (CA-24v) and none of the isolates were found to be positive for EV-70. Sequencing of the PCR products derived from all the 11 isolates revealed 98.4% (SE 0.20) nucleotide identity within the Indian strains and 98.6% (0.50) and 94.4% (0.30) nucleotide identity respectively with the West Indies and Asian strains reported worldwide. The findings suggest that the outbreak of acute hemorrhagic conjunctivitis that occurred in Maharashtra and Gujarat states of India during August-September 2003 was caused by the Coxsackie A-24 variant (CA-24v).