Risk Factors of Microbial Keratitis in Uganda: A Case Control Study

ABSTRACT

Purpose: Microbial keratitis (MK), is a frequent cause of sight loss worldwide, particularly in low and middle-income countries. This study aimed to investigate the risk factors of MK in Uganda.

Methods: Using a nested case control, we recruited healthy community controls for patients presenting with MK at the two main eye units in Southern Uganda between December 2016 and March 2018. Controls were individually matched for age, gender and village of the cases on a 1:1 ratio. We collected information on demographics, occupation, HIV and Diabetes Mellitus status. In STATA version 14.1, multivariable conditional logistic regression was used to generate odds ratios for risk factors of MK and a likelihood ratio test used to assess statistical significance of associations.

Results: Two hundred and fifteen case-control pairs were enrolled. The HIV positive patients among the cases was 9% versus 1% among the controls, p = .0003. Diabetes 7% among the cases versus 1.4% among the controls, p = .012. Eye trauma was 29% versus 0% among the cases and controls. In the multivariable model adjusted for age, sex and village, HIV (OR 83.5, 95%CI 2.01–3456, p = .020), Diabetes (OR 9.38, 95% CI 1.48–59.3, p = .017) and a farming occupation (OR 2.60, 95%CI 1.21–5.57, p = .014) were associated with MK. Compared to a low socio-economic status, a middle status was less likely to be associated with MK (OR 0.29, 95%CI 0.09–0.89, p < .0001).

Conclusion: MK was associated with HIV, Diabetes, being poor and farming as the main occupation. More studies are needed to explore how these factors predispose to MK.

KEYWORDS:

• Microbial keratitis
• keratitis
• diabetes mellitus
• HIV
• blindness
• Uganda

Acknowledgments

The authors would like to appreciate Mr Gilbert Arinda, Ms. Pauline Boonabaana, Mr Martin Bukenya, Mr Bernard Beinomugisha, Mr Martin Bukenya and Ms. Allen Asiimwe for helping in data collection.

Conflict of interest

None of the authors have any proprietary interests or conflicts of interest related to this submission.

Submission statement

This submission has not been published anywhere previously and that it is not simultaneously being considered for any other publication.

Additional information

Funding

SA is supported by a Research Fellowship from the Commonwealth Eye Health Consortium, funded by The Queen Elizabeth Diamond Jubilee Trust. MJB is supported by the Wellcome Trust (098481/Z/12/Z and 207472/Z/17/Z). The funding organizations were not involved in the design, collection, analysis and review of this manuscript;Wellcome Trust [098481/Z/12/Z,207472/Z/17/Z];