COVID-19 altered MK presentation, corneal microbe profile

The coronavirus disease 2019 (COVID-19) pandemic has decreased presentation rates for microbial keratitis (MK) and altered the spectrum of isolated cultures, but had no clear impact on outcomes, a recent study has found.

Researchers retrospectively reviewed medical records of suspected MK patients requiring corneal scrapes who presented between 23 March and 30 June 2020. Outcomes, isolates, medications, and concurrent conditions were compared with patients who presented in the equivalent time windows pre-COVID-19, in 2017, 2018, and 2019.

Overall, 63, 50, and 68 patients presented for MK during 2017, 2018, and 2019, respectively. Only 49 did so during the pandemic, suggesting a slight decline in presentation rates. Similarly, total attendances to the clinic dropped from 12,128 and 12,239 in 2018 and 2019, respectively, to 5,759 in 2020. In turn, the proportion of MK presentations increased significantly from 0.5 percent pre-COVID-19 to 0.9 percent during the pandemic (p=0.001).

The rate of culture positivity was comparable between the pre-COVID-19 and pandemic eras (p=0.520), but the distribution of culture isolates differed. Poly-microbial infections occurred significantly more frequently before the pandemic (31.3 percent vs 8.3 percent; p=0.022), while gram-negative mono-infections tended to be more predominant in year 2020 (33.3 percent vs 18.2 percent; p=0.160).

Moreover, despite comparable rates of disease severity, rate of admission was significantly reduced during the pandemic (p<0.001).

“Increased handwashing practices, as well as changes in environmental factors, such as reduced contact lens wear, may have contributed” to the findings, particularly the changes in microbial spectra, the researchers said. “However, these findings must be validated on a larger scale.”