SUMMARY: Adenoviruses are responsible for approximately 5-10z of acute respiratory infections globally. However, there are a limited number of reports on the types of circulating respiratory human adenoviruses (HAdV) in India. We detected HAdV in the post-mortem specimens of a young child who died as a result of an acute febrile illness. To retrospectively investigate the circulating adenovirus types in the Alappuzha region, samples (n ＝ 235) collected from patients with influenza-like illnesses who participated in the influenza surveillance program were screened for HAdV. Fourteen samples were identified as positive for adenovirus by PCR analysis. Adenovirus was isolated from 3 of the 14 PCRpositive samples cultured using HEK-293 cell lines. The viral strains isolated in the study were from children between 6 and 10 years of age. The isolates were identified as adenovirus species C and E. Sequencing analysis of the fiber gene and a BLAST search revealed that 2 of the isolates were type HAdV-C2, and the third isolate was a HAdV-E4. A fiber gene sequence-based phylogenetic tree showed that the HAdV-E4 isolate was similar to the Japanese HAdV-E4 strain, whereas the HAdV-C2 isolates formed a distinct cluster. Respiratory infections due to HAdV-E4 are generally observed in adults; this study is the first to demonstrate the involvement of the HAdV-E4 strain in respiratory illnesses in children.

Objective: Chikungunya virus (CHIKV) is a rapidly emerging arbovirus causing millions of infections in more than 40 countries. CHIKV is typically a biosafety level 3 pathogen in many countries and handling of CHIKV requires a high standard of laboratory safety settings. Many studies require the whole virus to be handled in a biosafety level 2 setting. A potential solution for managing this problem is pathogen inactivation without affecting its antigenicity. In the present study, we attempted to inactivate CHIKV by ultraviolet (UV) irradiation. Methods: Different UV doses were used to inactivate CHIKV. The replication status of the inactivated virus was verified in cell lines. Western blot, electron microscopy, and immune fluorescence assay were used, respectively, to view the antigenicity, structural integrity, and entry of the virus into cell lines. Results: The inactivation was complete when a UV dose of 0.09 J/cm² for 3 × 30 s was used and no change in antigenicity and integrity was observed. Conclusions: The study concludes that the UV-inactivated virus is antigenically stable and could be used in biosafety level 2 settings for different experiments.