Abstract
Purpose::
Adenovirus (AdV) readily infect the conjunctiva, causing contagious conjunctivitis associated with social community and nosocomial infection. Recently, nosocomial adenoviral conjunctivitis has often been observed in ophthalmology wards and has become a social problem in Japan. Therefore, the early detection and prevention of outbreaks of adenoviral conjunctivitis are required. Currently, the detail mechanism on conjunctiva after AdV infection is still unknown. We evaluated the transmission efficiency of conjunctivitis and clinical course after AdV infection of the conjunctiva.
Methods::
One inpatient was diagnosed with adenoviral conjunctivitis by severe conjunctival symptoms and rapid adenoviral antigen diagnostic kit in the ophthalmology ward. To detect patients with adenoviral conjunctivitis earlier and prevent outbreaks, we attempted to detect AdV antigen and DNA from the other 18 inpatients without obvious symptoms of adenoviral conjunctivitis by rapid antigen diagnostic kit and nested polymerase chain reaction (PCR), respectively. AdV DNAs of positive samples were quantified by real time PCR. After sampling, we carefully observed the clinical courses of all 18 cases.
Results::
AdV antigen and DNA were detected from 1 and 8 of 18 cases, respectively. All AdV positive samples were determined as AdV type 37 by phylogenetic analysis of the partial hexon gene. The AdV DNA copy number in 4 of the 8 samples were below the detection limit of the real-time PCR. However, in some cases, a high DNA copy number was detected. In one case, AdV antigen and more than 107 copies/ml DNA were detect, moreover, infectious virus was isolated by culture. After obsevation for one month, no symptoms of typical adenoviral conjunctivitis were observed in all 18 cases. But, some cases showed mild conjunctival injection and discharge for post eye operation.
Conclusions::
Ocular AdV infection shows various clinical courses from inapparent infection to severe conjunctivitis. These observations indicate that cases of inapparent infection or mild conjunctivitis are more common than previously thought. These cases might shed the infective virus and lead to the outbreak of adenoviral conjunctivitis.
Keywords: adenovirus • conjunctivitis • clinical (human) or epidemiologic studies: prevalence/incidence