Molecular epidemiology of adenoviral keratoconjunctivitis in Saudi Arabia.

PURPOSE: Adenoviral keratoconjunctivitis is a major cause of ocular morbidity and may lead to visual loss. Adenovirus types 8, 19, and 37 may cause epidemic keratoconjunctivitis. The main objective of this study was to determine the types of adenoviruses causing keratoconjunctivitis in Saudi Arabia. METHODS: We conducted a non-interventional observational clinical study. Seventy three eyes from 65 patients who presented to The Eye Center in Riyadh, Saudi Arabia with clinical features of acute adenoviral keratoconjunctivitis were included. Each patient underwent complete clinical examination and features such as membranous reaction, conjunctival hemorrhage, subepithelial corneal infiltrates, and preauricular lymph node enlargement were recorded. Conjunctival swabs were obtained from patients with presumed acute viral conjunctivitis. Immunochromatography (IC) and restriction fragment length polymorphism polymerase chain reaction (PCR-RFLP) were performed on the conjunctival swabs obtained from each eye. Serotype identification was performed using direct sequencing technique. RESULTS: Forty-nine (67.1%) were adenovirus type 8, 8 (11.0%) were adenovirus type 3, 6 (8.2%) type 37, 5 (6.8%) were adenovirus type 4, and 2 (2.3%) type 19. The remaining 5 were types 14, 19, and 22. The prevalence of membranous conjunctivitis was highest (83%) among eyes with adenovirus type 37 while subepithelial corneal opacities were most commonly seen among eyes with adenovirus type 8 (47%). Immunochromatography tests were positive for adenovirus in 48 (65.7%) out of 73 eyes. CONCLUSIONS: This study determined the types of adenoviruses causing keratoconjunctivitis at one center in Saudi Arabia. Direct sequencing techniques is an efficient, accurate, and rapid means of diagnosing adenoviral keratoconjunctivitis. The most common causes of adenoviral keratoconjunctivitis in Saudi Arabia were adenovirus types 8, 3, and 37. Membranous conjunctivitis and subepithelial opacities had the highest frequency of adenovirus types 37 and 8, respectively. Lymph nodes enlargement was least likely in adenovirus type 4.

[Evaluation of disinfectant against adenovirus by real-time polymerase chain reaction].

PURPOSE: To evaluate the effect of disinfectant against human adenovirus (HAdV) using a real-time polymerase chain reaction method. METHODS: Ethanol, povidone-iodine, and sodium hypochlorite were mixed with HAdV-3, -4, -8, -19, and -37. A diluted mixed solution was infected with A549 cells for six days and then the number of HAdV DNA copies was counted. A reduction in the number of HAdV DNA copyies by 4 log was considered as virucidal activity. RESULTS: Ethanol at 80% concentration was effective against all serotypes after ten minutes, but 70% and 40% concentrations of ethanol were ineffective against all serotypes. Povidone-iodine at 0.2% concentration was effective against HAdV-3, -4, -19, and -37 after one minute, and against HAdV-8 after three minutes. Sodium hypochlorite (0.1% concentration) was effective against all serotypes after 15 seconds. CONCLUSION: While all disinfectants were effective against HAdV, the effective concentration percentages and the times required were different, which indicates the importance of deliberating on the concentration, application time and location to apply the disinfectant, and what equipment to use for application.

Molecular epidemiology of adenoviral conjunctivitis in Hanoi, Vietnam.

PURPOSE: To investigate the serotypes of adenovirus causing conjunctivitis in Hanoi, Vietnam. DESIGN: Clinical diagnosis of adenoviral conjunctivitis and laboratory-based experimental study. METHODS: We collected 21 conjunctival swabs from 21 different patients with a clinical presentation compatible with adenoviral conjunctivitis, in Hanoi, Vietnam. Immunochromatography and real-time polymerase chain reaction (PCR) were performed to detect human adenovirus (HAdV). The sequence of PCR products was analyzed to determine the serotype of HAdV. RESULTS: Of 21 samples, HAdV DNA was detected in 14 samples (66.7%) by real-time PCR. The serotype analysis showed HAdV-8 in 11 samples (78.6%), HAdV-3 in two samples (14.3%), and HAdV-37 in one sample (7.1%). Of 11 HAdV-8 samples, one sample (9.1%) was prototype, and the other 10 samples (90.9%) had identical nucleotide sequence and were identified as a variant of HAdV-8. CONCLUSIONS: HAdV-8 was found to be the predominant serotype in Hanoi, Vietnam. Most of the HAdV-8 samples were a variant of HAdV-8.