|Year : 2020 | Volume
| Issue : 5 | Page : 736-737
Commentary: Adenoviral keratoconjunctivitis—Seasonal trends and influence of environmental factors
Center for Excellence in Cornea and Ocular Surface Disorders, Excel Eye Care, Ahmedabad, India
|Date of Web Publication||20-Apr-2020|
Dr. Jayesh Vazirani
Center for Excellence in Cornea and Ocular Surface Disorders, Excel Eye Care, 103, Shivalik High Street, Judges Bungalow Road, Ahmedabad, Gujarat - 380 015
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Vazirani J. Commentary: Adenoviral keratoconjunctivitis—Seasonal trends and influence of environmental factors. Indian J Ophthalmol 2020;68:736-7
|How to cite this URL:|
Vazirani J. Commentary: Adenoviral keratoconjunctivitis—Seasonal trends and influence of environmental factors. Indian J Ophthalmol [serial online] 2020 [cited 2020 May 28];68:736-7. Available from: http://www.ijo.in/text.asp?2020/68/5/736/282904
Most ophthalmologists deal with cases of acute conjunctivitis on a very frequent basis. Adenovirus is believed to be the commonest cause of infectious conjunctivitis. Epidemiological information related to adenoviral conjunctivitis is mostly derived from the reporting of outbreaks of epidemic keratoconjunctivitis (EKC), pharyngoconjunctival fever (PCF), or acute hemorrhagic conjunctivitis (AHC). However, many ocular adenoviruses are endemic, and ongoing infections in the absence of an outbreak usually go unreported. This is because very few countries have surveillance systems in place for adenoviral infections.
This issue of the journal carries a hospital-based study that describes the prevalence of presumed adenoviral EKC and attempts to correlate temporal patterns with local environmental factors. The study provides valuable information on the prevalence of EKC, filling a gap created by the absence of routine surveillance. A remarkable strength of the study is the large sample size. This highlights the utility of electronic medical records (EMR) systems in health research. Modern EMR systems allow for standardized data entry, accurate coding of diagnoses and easy retrieval of data based on selected parameters. This makes it possible to analyze large amounts of data with ease, and the so-called "big data" analysis helps in discerning trends and patterns with precision. Early adopters of EMR systems are now reaping the benefits of having the ability to harvest and process humongous amounts of data that would have taken ages to analyze in the pre-EMR, manual health records era.
The study found a mean monthly prevalence of 0.89% with a peak in the month of April (1.09%). This is consistent with an analysis of global outbreaks of EKC, PCF, and AHC over a 60-year period, which concluded that EKC and AHC were circulating predominantly in Asia during the early winter and spring. Data from Japan, which has a nationwide adenoviral surveillance project, also point to seasonal outbreaks in summer. However, a broader pattern emerging from the current study suggests that the prevalence of EKC is pretty much stable throughout the year in India, with small variations at times.
The second part of the study used a smaller dataset to perform correlation analysis with local environmental factors. The authors deduce that the prevalence of EKC is unaffected by variations in atmospheric temperature, but may be affected by a complex interplay of factors such as humidity, rainfall, and wind speed. The results of the study seem to debunk the myth that higher temperatures may arrest the spread of viral epidemics such as EKC.
A retrospective study such as this has some inherent limitations. For instance, it would be difficult to reliably distinguish cases of presumed adenoviral EKC from cases of microsporidial superficial keratoconjunctivitis—a condition with a similar clinical presentation. One way of reliably ascribing an adenoviral etiology to the presumed case of EKC would be to use molecular diagnostic methods. In the absence of funding for a surveillance project, routine use of such diagnostic tools may not be feasible.
In conclusion, this study provides robust data on the prevalence of presumed adenoviral EKC in India. Contrary to popular belief, the environmental temperature does not seem to impact the prevalence of EKC. The study serves as an excellent template for harnessing the power of EMR systems for relevant health research, which should be emulated by institutes all over the country. Evidence generated from such studies would prove invaluable for the purposes of advocacy and petitioning for the allocation of resources as well as from the perspective of framing public health policies.
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