The isolation of enteroviruses from cases of acute conjunctivitis

Management and prevention of ocular viral and chlamydial infections

A majority of cases of preventable and/or curable ocular morbidity and blindness are caused by ocular infections. They may account for 70 to 90% of all ocular morbidity seen by family doctors, general practitioners, health centers, and local ophthalmologists in both developed and developing countries. Unfortunately, most health authorities and doctors, including ophthalmologists, consider these diseases to be of little or no importance because they are not fully aware of the high prevalence of these infections and the blinding sequelae which may occur following incorrect diagnosis and treatment. Also, they are not aware of the social and economic impact of these infections in the absence of proper management and implementation of preventive measures. In this review, we examine present knowledge of chlamydial and common viral ocular infections. We discuss the problems of diagnosis, management, and prevention and propose solutions relevant to developed and developing countries.

Virus-specific, early appearing neutralizing activity and interferon in tears of patients with acute hemorrhagic conjunctivitis

Virus-specific, early appearing neutralizing activities (ENA) and interferon (IFN) were detected in tears collected from patients during epidemics of acute hemorrhagic conjunctivitis (AHC). In one study, ENA that neutralized enterovirus type 70 (EV70) was detected in tears collected from 114 of 130 AHC patients in Florida. In another study, ENA against coxsackievirus type A24 (CA24) was detected in tears collected from 39 of 57 patients in Singapore with AHC caused by CA24. No tear samples contained ENAs to both EV70 and CA24. Tear samples from uninfected eyes did not contain ENA to EV70 or CA24. ENA to EV70 was detected in 6 of 11 patients 1-6h before the onset of AHC. In addition, tears of 68% of patients seen on the day of onset produced tears that contained ENA to EV70. Thus, ENA to EV70 may be detected less than 24h after infection (based on 24h incubation period). IFN beta was detected in 30% of tear samples collected from patients on the day of onset of AHC caused by EV70. This finding suggested that ENA and IFN could act together to inhibit primary infections of AHC. It was found that the combination of ENA and IFN inhibited virus replication synergistically (greater than or equal to 300 fold reduction) in preinfected cells. Our findings suggest that ENA represents a previously unreported early defense mechanism of the eye, that endogenous ENA and endogenous IFN could inhibit viruses synergistically in vivo, and that ENA in tears could be useful in identifying the agent causing AHC.

An outbreak of adenovirus keratoconjunctivitis in bristol

Nineteen cases of keratoconjunctivitis caused by an adenovirus serologically related to types 10 and 19 are described. Seventeen of the patients presented over a period of 7 weeks and included 4 who were involved in a minor outbreak at a factory. The presentation and clinical features closely resembled those caused by adenoviruses types 8 and 19. Mild to severe follicular conjunctivitis, superficial punctate keratitis, discrete subepithelial opacities, membrane formation, and conjunctival scarring were all observed.

A comparative study of viruses associated with acute haemorrhagic conjunctivitis

Seven representative isolates from six outbreaks of acute haemorrhagic conjunctivitis were shown to have the characteristics of enteroviruses. Two viruses differed from the remaining five isolates in producing paralysis in suckling mice and being resistant to 2-hydroxybenzyl-benzimidazole. These two viruses were also closely related antigenically and distinct from the other five viruses which were serologically similar to each other. Neither group of viruses was inhibited by antisera to the known enteroviruses and they probably represent two new enterovirus types one related to the Coxsackie A viruses and the other to the echoviruses.

Enterovirus type 70: the etiologic agent of pandemic acute haemorrhagic conjunctivitis

A new enterovirus, now classified as enterovirus type 70, was isolated from the conjunctiva of patients with acute haemorrhagic conjunctivitis during the 1971 epidemics that occurred in Japan, Singapore, and Morocco. These epidemics were parts of a pandemic involving Africa (Algeria, Ghana, Morocco, Nigeria, and Tunisia), Asia (Cambodia, China (Province of Taiwan), Hong Kong, India, Indonesia, Japan, Malaysia, the Philippines, Singapore, and Thailand), and England during 1969-71. A representative strain from each of the three epidemic areas was studied cooperatively. The strains exhibited the physicochemical characteristics of enteroviruses. Cross-neutralization tests showed that these viruses were distinct from all known human enterovirus immunotypes, but that they were antigenically closely related. The human origin of the viruses was demonstrated by the appearance of homologous neutralizing antibodies during convalescence in patients with acute haemorrhagic conjunctivitis.