Social distancing and other control measures have resulted in a lower incidence of conjunctivitis. Click image to enlarge.

Online surveillance has been conducted to pinpoint Google search trends in early detection of conjunctivitis outbreaks, but the restrictions implemented at the beginning of the COVID-19 pandemic may have altered the dynamics of conjunctivitis. In a recent study, researchers evaluated whether internet search interest and emergency department visits for conjunctivitis were associated with public health interventions adopted during the pandemic.

Data showed the difference in actual behavior compared with expected trends based on data from previous years and included analysis of noninfectious eye conditions for comparison. The study showed that shortly after COVID-19 pandemic-associated infection control measures were put in place in March 2020, online searches for conjunctivitis decreased by approximately 34% and emergency department visits for infectious conjunctivitis decreased by 37%.

The decrease in internet search interest didn’t occur until two to three weeks after COVID-19 restrictions began. “This time lag may suggest that the decrease in the incidence of conjunctivitis cases in this study were from viral causes, adenovirus in particular,” the authors noted. “The two- to three-week delay in decreased search interest would coincide with the end of an incubation period for a patient infected just prior to the wide adaptation of COVID-19 mitigation measures. Additionally, this period would correlate with the timing in which we would expect to observe the potential impact of public health measures on the outbreak rate of conjunctivitis.”

The authors concluded that COVID-19 public health initiatives may have contributed to a decline in the number of new infections because there was a relative decrease in emergency department encounters for conjunctivitis during the same period. “Search metrics in conjunction with mobility data may provide quantifiable metrics of social distancing implementation in the future and a method of surveillance of infectious conjunctivitis,” they explained.

Lavista Ferres JM, Meirick T, Lomazow W, et al. Association of public health measures during the COVID-19 pandemic with the incidence of infectious conjunctivitis. JAMA Ophthalmol. November 18, 2021. [Epub ahead of print].