Monthly normalized relative search volume data (0‐100) were extracted as CSV files from Google Trends in September 2024 for the search term “الرمد” (Arabic for “conjunctivitis”), with the location set to Saudi Arabia and the period from January 2011 to October 2024, without a category selection. Statistical analyses were conducted in R (version 4.4.2; R Foundation) with the Forecast, seatest, and season packages.

Poisson cosinor analysis was performed to assess seasonality during the pre–COVID-19 period (2011‐2019), avoiding pattern distortions due to COVID-19–related search behavior, with the significance level set at .025, consistent with previous studies [3]. To estimate the impact of COVID-19 restrictions, a log-transformed autoregressive integrated moving average (ARIMA) model (1,0,0) was fitted on data from 2011 to 2023, including binary variables for the intervention period (March 2020 to March 2022), monthly dummy variables, lag-12, and linear and quadratic trends (significance at P<.05). Residual diagnostics indicated approximate normality and passed the Ljung-Box test and passed the Ljung-Box test (χ²=16.19; P=.06) which indicates white noise in the residuals. Seasonality disruption was assessed using the Friedman test across the years before and during COVID-19.

The data are public source, so no institutional review board approval was needed.

This study shows that there is significant seasonality in the search volume for conjunctivitis. Moreover, there was a significant reduction in and disruption of seasonality during the pandemic, providing a line of evidence to complement traditional methods; the finding suggests that the preventive strategies taken to lower the risk of COVID-19 transmission may have also reduced the incidence of conjunctivitis or at least online search interest.

Previous studies from the United States have explored the seasonality of searches for conjunctivitis and obtained similar findings, that is, that search increases from fall to spring [2]. Several factors lead to an increased risk of conjunctivitis during winter, including indoor crowdedness and an increased risk of contact with infected people, especially in schools. Additionally, conjunctivitis cases increase with other infections, like the flu, that exhibit seasonal variation.

Adenoviral conjunctivitis has a similar transmission mechanism as coronaviruses [4], with transmission rates of 30% in nursing homes and 76% in schools [5,6]. Recently, Deiner et al [7] showed that there was a sustained reduction in searches for communicable diseases, including conjunctivitis, during the pandemic in the United States. In a study from Spain, there was a decrease in the incidence of conjunctivitis by 48.5% during the pandemic in 2020 [8]. Additionally, Lavista Ferres et al [9] published evidence of a decrease in nonallergic conjunctivitis cases in the emergency department of 37.3%.

These findings are based on Google Trends search volume, which may be influenced by other factors, such as the media, not only by the actual incidence of conjunctivitis. Therefore, further studies to elaborate on the seasonality and impact of COVID-19 restrictions are needed.

These findings highlight the potential seasonality of conjunctivitis. Understanding disease patterns and the role of public health measures against COVID-19 in reducing conjunctivitis spread has public health implications for the reduction of conjunctivitis prevalence.