Neurological manifestations of acute haemorrhagic conjunctivitis

Identification of coxsackievirus A-24 GIV C5 strain as the cause of acute hemorrhagic conjunctivitis outbreak in Hyderabad, India in 2022

Viral infection is frequently the cause for acute hemorrhagic conjunctivitis (AHC) epidemics. AHC can result from adenoviruses, with enterovirus 70 and coxsackievirus A24 being the primary agents. AHC was initially identified in Ghana in 1969, caused by enterovirus 70 and leading to a global pandemic. Since 2000, outbreaks of AHC linked to coxsackievirus A24 variant have been documented in Spain, Pakistan, Singapore, India, Korea, and China. A sudden surge of conjunctivitis cases reported in October 2022 in and out of the Hyderabad region. This infection presented with usual symptoms of redness of the eyes, discharge, pain in the eyes and crusting. Occular swab samples from 110 patients were collected in order to identify and characterize the virus that was causing the epidemic. We examined adenovirus, enterovirus, COVID-19 and Herpes Simplex Virus by using commercially kits available at the hospital. Conserved regions in the enteroviral 5'-UTR and VP2 gene were analyzed further for characterization of serotype at the National apex laboratory. None of them was found positive except Enterovirus in 16.36 % (18/110) of the patients. From enterovirus-positive samples, the coxsackievirus A24 was observed in all 18 positive samples. These clinical isolates constitute a new lineage cluster associated with genotype IV-C5, according to additional sequencing of the full-length VP2 genes and subsequent phylogenetic analysis. In conclusion, the current outbreak of acute haemorrhagic conjunctivitis in Hyderabad, India was traced to the coxsackievirus A24 strain GIV C5.

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

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).

Towards an in vitro model for acute hemorrhagic conjunctivitis: cytokine-mediated vascular endothelial cell activation triggered by enterovirus type 70 infection

BACKGROUND

Little is known of the pathogenetic mechanisms of enterovirus type 70 (EV70), a causative agent of acute hemorrhagic conjunctivitis. However, virus- or cytokine-induced perturbation of vascular endothelial cells are potential triggering events.

OBJECTIVE

To determine whether EV70 infection of human umbilical vascular endothelial cells (HUVECs) and human corneal epithelial cells (HCEs) causes the release of vasoactive cytokines, capable of triggering vascular endothelial cell activation.

STUDY DESIGN

Susceptibility of cultured HUVECs and HCEs to EV70 was tested by observing the appearance of cytopathic effect or immunoprecipitation of viral protein in infected cells. The culture fluids from the virus-infected cells were tested for their ability to stimulate the expression of intercellular adhesion molecule-1 (ICAM-1) on uninfected HUVECs. Anti-cytokine antibodies were used to identify ICAM-1-activating cytokine(s).

RESULTS

Both HUVECs and HCEs were susceptible to EV70 infection. Culture fluids from EV70-infected HUVECs and HCEs stimulated ICAM-l expression on uninfected HUVECs, which was completely blocked by anti-interleukin-1alpha (IL-1alpha) antibody but not by interleukin-1beta (IL-1beta) or anti-tumor necrosis factor alpha (TNFalpha) antibodies.

CONCLUSION

This study provides the first evidence of EV70 infection of both HCEs and HUVECs, and furthermore, identifies IL-1alpha as the predominant endothelial cell-activating factor produced by EV70-infected cells. Since endothelial cell activation is often an initiating step towards vascular permeability and/or inflammation, the perturbation of endothelial cell function through EV70 induced IL-1alpha is thus a potential contributory factor in the pathogenesis of EV70-associated hemorrhagic conjunctivitis.

Enterovírus-70 na região metropolitana de São Paulo, Brasil, de 1984 a 1987: aspectos da infecção em períodos epidêmico e endêmico

São apresentados os resultados de estudos sobre o comportamento do Enterovírus-70 (EV-70) na região metropolitana de São Paulo desde sua provável introdução no verão de 1984, determinando extensa epidemia de conjuntivite hemorrágica aguda (C.H.A.), até o final de 1987 abrangendo período em que este agravo foi pouco notado. Na fase epidêmica ocorrida no primeiro trimestre de 1984 foram estudados 291 indivíduos divididos em três grupos denominados A, B e C, o primeiro formado por pessoas atingidas pela C.H.A. e os outros dois por indivíduos não atingidos por este agravo mas que, respectivamente, referiam contato domiciliar com casos de C.H.A. e os que não referiam o citado contato. A demonstração de anticorpos se fez pela técnica de imunofluorescência indireta (IFI) para detectar IgM específico para EV-70 e pela prova de neutralização em cultura de células BHK-21. Verificou-se que 56,7%, 33,3% e 20,6% dos indivíduos pertencentes, respectivamente, aos grupos A, B e C apresentavam anticorpos específicos da classe IgM. No grupo A a faixa etária mais atingida foi a de 10 a 29 anos. No período que vai do fim da primeira e única epidemia até o final de 1987, identificaram-se três casos esporádicos de C.H.A. e 10 pacientes com afecção neurológica aguda associada à infecção recente pelo EV-70. Nove, destes 10 casos, apresentaram paralisia de nervos cranianos, todos evoluindo sem seqüelas clinicamente discerníveis. As formas assintomáticas e os casos esporádicos de C.H.A. e de afecções neurológicas mantiveram a circulação do EV-70 no período não epidêmico.

Neurological complications of acute haemorrhagic conjunctivitis

Forty four cases of the neurological complications of acute haemorrhagic conjunctivitis (AHC) seen in India during 1981 epidemic are reported. The disease predominantly affected adult males. The preceding attack of AHC, a latent period, prodromal symptoms of fever, myalgia and root pains followed by acute onset of lower motor neurone paralysis of limbs and/or cranial nerves formed the classical picture of neurological involvement. The recovery was poor and nearly half of the patients remained severely handicapped. Electrophysiological studies showed early appearance of widespread fibrillations and fasciculations, large polyphasic potentials of increased amplitude and reduced interference pattern. Nerve conduction studies were normal in most of the cases. Cerebrospinal fluid (CSF) examination revealed lymphocytic pleocytosis and rise in protein content. Significant antibody titres against enterovirus type 70 (EV 70) were demonstrated in the serum and the CSF. HLA studies showed low occurrence of A2 and B15 HLA antigens. Muscle biopsies revealed neurogenic atrophy and sural nerve biopsies were histologically unremarkable. The similarities of this disease with poliomyelitis and its pathogenesis are discussed.

A study of the neurological disorder associated with acute haemorrhagic conjunctivitis due to enterovirus 70

Ninety cases of the neurological manifestations associated with acute haemorrhagic conjunctivitis caused by Enterovirus 70 (EV 70) are reported. The patients were seen during the widespread epidemics in 1971 and 1981. Male adults were predominantly affected by a "polio-like" paralysis of the limbs and/or cranial nerves. Root pains were often complained of early in the disease. In the absence of a necropsy, clinical and neurophysiological examinations helped to localise the lesions. Significant antibody titres against EV 70 were demonstrated in the serum and more relevantly in the CSF. Though other viruses can cause sporadic and epidemic conjunctivitis and similar paralysis independently, the combination of a haemorrhagic conjunctivitis and a neurological disease mostly simulating poliomyelitis is caused by EV 70 alone. It is therefore suggested that this combination be called "Enterovirus 70 disease". Because of its neurovirulence, it is important to identify this virus at the very beginning of an epidemic of conjunctivitis, so as to limit its spread by strict public health measures.

Adult polio-like syndrome following Enterovirus 70 conjunctivitis (natural history of the disease)

During the Indian EV 70 conjunctivitis epidemic in 1981, 79 patients with neurological complications were evaluated by clinical, electrophysiological, histopathological and virological studies. The disease was heralded by an attack of conjunctivitis and was followed, after a variable latent period, by a pre-paralytic, paralytic, and post-paralytic stage of slow recovery. The above events occurred in an orderly sequence. The paralysis affected the cranial nerves, limbs or both. The clinical course closely simulated poliomyelitis, without any evidence of radiculopathy or myelopathy. Cranial nerve palsies were seen in approximately half of the patients. The electrophysiological and histologicl studies pointed towards the affection of anterior horn cells. The raised neutralizing antibody titres to Enterovirus 70, confirmed the aetiology of the disease. On the available data, we believe that this nosological entity should be considered under the general title of "polio-like syndrome" following EV 70 conjunctivitis. On account of two epidemics in 1971 and 1981 with unfavourable prognosis and high resultant disability, and because of lack of specific therapy, it has become imperative to develop, as a top priority, a vaccine for immunization.